MFC r326282: (by fsu)

Remap ENOATTR to ENODATA in the linuxulator.
In the linux ENOADATA is frequently #defined as ENOATTR. The change is
required for an xattrs support implementation.

MFC r297597 (by bapt@):

Add kern.features flags for linux and linux64 modules

kern.features.linux: 1 meaning linux 32 bits binaries are supported
kern.features.linux64: 1 meaning linux 64 bits binaries are supported

The goal here is to help 3rd party applications (including ports) to determine
if the host do support linux emulation

Relnotes: yes

MFC 313564:
Drop the "created from" line from files generated by makesyscalls.sh.

This information is less useful when the generated files are included in
source control along with the source. If needed it can be reconstructed
from the $FreeBSD$ tag in the generated file. Removing this information
from the generated output permits committing the generated files along
with the change to the system call master list without having inconsistent
metadata in the generated files.

Regenerate the affected files along with the MFC.

MFC r303464 (by brooks@):

Don't create pointless backups of generated files in "make sysent".

Any sensible workflow will include a revision control system from which
to restore the old files if required. In normal usage, developers just
have to clean up the mess.

MFC 302900,302902,302921,303461,304009:
Add a mask of optional ptrace() events.

302900:
Add a test for user signal delivery.

This test verifies we get the correct ptrace event details when a signal
is posted to a traced process from userland.

302902:
Add a mask of optional ptrace() events.

ptrace() now stores a mask of optional events in p_ptevents. Currently
this mask is a single integer, but it can be expanded into an array of
integers in the future.

Two new ptrace requests can be used to manipulate the event mask:
PT_GET_EVENT_MASK fetches the current event mask and PT_SET_EVENT_MASK
sets the current event mask.

The current set of events include:
- PTRACE_EXEC: trace calls to execve().
- PTRACE_SCE: trace system call entries.
- PTRACE_SCX: trace syscam call exits.
- PTRACE_FORK: trace forks and auto-attach to new child processes.
- PTRACE_LWP: trace LWP events.

The S_PT_SCX and S_PT_SCE events in the procfs p_stops flags have
been replaced by PTRACE_SCE and PTRACE_SCX. PTRACE_FORK replaces
P_FOLLOW_FORK and PTRACE_LWP replaces P2_LWP_EVENTS.

The PT_FOLLOW_FORK and PT_LWP_EVENTS ptrace requests remain for
compatibility but now simply toggle corresponding flags in the
event mask.

While here, document that PT_SYSCALL, PT_TO_SCE, and PT_TO_SCX both
modify the event mask and continue the traced process.

302921:
Rename PTRACE_SYSCALL to LINUX_PTRACE_SYSCALL.

303461:
Note that not all optional ptrace events use SIGTRAP.

New child processes attached due to PTRACE_FORK use SIGSTOP instead of
SIGTRAP. All other ptrace events use SIGTRAP.

304009:
Remove description of P_FOLLOWFORK as this flag was removed.

MFC r302517:

Fix a copy/paste bug introduced during X86_64 Linuxulator work.
FreeBSD support NX bit on X86_64 processors out of the box, for i386 emulation
use READ_IMPLIES_EXEC flag, introduced in r302515.

While here move common part of mmap() and mprotect() code to the files in compat/linux
to reduce code dupcliation between Linuxulator's.

MFC r302518, r302626:

Add linux_mmap.c to the appropriate conf/files.

Regen for r302962 (Linux personality), record mergeinfo for r320516.

MFC r302515:

Implement Linux personality() system call mainly due to READ_IMPLIES_EXEC flag.
In Linux if this flag is set, PROT_READ implies PROT_EXEC for mmap().
Linux/i386 set this flag automatically if the binary requires executable stack.

READ_IMPLIES_EXEC flag will be used in the next Linux mmap() commit.

MFC r300359, r300360:

Correct an argument param of linux_sched_* system calls as a struct l_sched_param
does not defined due to it's nature.

MFC r298482:
Cleanup redundant parenthesis from existing howmany()/roundup() macro uses.

Requested by: dchagin

MFC r297062:

Regen for r297061 (fstatfs64 Linux syscall).

MFC r297061;

Implement fstatfs64 system call.

PR: 181012
Submitted by: John Wehle

MFC r294900:

Implement AT_SECURE properly.

AT_SECURE auxv entry has been added to the Linux 2.5 kernel to pass a
boolean flag indicating whether secure mode should be enabled. 1 means
that the program has changes its credentials during the execution.
Being exported AT_SECURE used by glibc issetugid() call.

Submitted by: imp, dchagin
Security: FreeBSD-SA-16:10.linux
Security: CVE-2016-1883

MFC r293613:

Implement vsyscall hack. Prior to 2.13 glibc uses vsyscall
instead of vdso. An upcoming linux_base-c6 needs it.

o Fix SCTP ICMPv6 error message vulnerability. [SA-16:01.sctp]
o Fix Linux compatibility layer incorrect futex handling. [SA-16:03.linux]
o Fix Linux compatibility layer setgroups(2) system call. [SA-16:04.linux]
o Fix TCP MD5 signature denial of service. [SA-16:05.tcp]
o Fix insecure default bsnmpd.conf permissions. [SA-16:06.bsnmpd]

Security: FreeBSD-SA-16:01.sctp, CVE-2016-1879
Security: FreeBSD-SA-16:03.linux, CVE-2016-1880
Security: FreeBSD-SA-16:04.linux, CVE-2016-1881
Security: FreeBSD-SA-16:05.tcp, CVE-2016-1882
Security: FreeBSD-SA-16:06.bsnmpd, CVE-2015-5677

MFC r289055 (by mjg@):

linux: fix handling of out-of-bounds syscall attempts

Due to an off by one the code would read an entry past the table, as
opposed to the last entry which contains the nosys handler.

This fixes my fault.

MFC r289058 (by cem@):

Fix missing semi-colon from r289055.

MFC r289768 (by jhb@):

Merge r289055 to amd64/linux32:

linux: fix handling of out-of-bounds syscall attempts

Due to an off by one the code would read an entry past the table, as
opposed to the last entry which contains the nosys handler.

MFC r283544:

When I merged the lemul branch I missied kib@'s r282708 commit.
This is not the final fix as I need properly cleanup thread resources
before other threads suicide.

Regen for r293592.

MFC r283492:

Implement Linux specific syncfs() system call.

Regen for r293588.

MFC r283488:

Implement recvmmsg() and sendmmsg() system calls.

MFC r283487:

Reduce duplication between MD Linux code by moving msg related
struct definitions out into the compat/linux/linux_socket.h

Regen for r293585.

MFC r283484:

Implement epoll_pwait() system call.

Regen for r293582.

MFC r283480:

Add utimensat() system call.

MFC r283474:

Rework signal code to allow using it by other modules, like linprocfs:

1. Linux sigset always 64 bit on all platforms. In order to move Linux
sigset code to the linux_common module define it as 64 bit int. Move
Linux sigset manipulation routines to the MI path.

2. Move Linux signal number definitions to the MI path. In general, they
are the same on all platforms except for a few signals.

3. Map Linux RT signals to the FreeBSD RT signals and hide signal conversion
tables to avoid conversion errors.

4. Emulate Linux SIGPWR signal via FreeBSD SIGRTMIN signal which is outside
of allowed on Linux signal numbers.

PR: 197216

MFC r283471:

According to Linux man sigaltstack(3) shall return EINVAL if the ss
argument is not a null pointer, and the ss_flags member pointed to by ss
contains flags other than SS_DISABLE. However, in fact, Linux also
allows SS_ONSTACK flag which is simply ignored.

For buggy apps (at least mono) ignore other than SS_DISABLE
flags as a Linux do.

While here move MI part of sigaltstack code to the appropriate place.

Regen for r293569.

MFC r283467:

Call nosys in case when the incorrect syscall number is specified.

Its my fault, fixed by mjg@ at r289055.

Regen for r293567.

MFC r283465:

Add preliminary fallocate system call implementation
to emulate posix_fallocate() function.

Regen for r293555.

MFC r283451:

Implement ppoll() system call.

Regen for r293549.

MFC r283444:

Implement eventfd system call.

MFC r283443:

Put the correct value for the abi_nfdbits parameter of kern_select() for
all supported Linuxulators.

Regen for r293546.

MFC r283441:

Implement epoll family system calls. This is a tiny wrapper
around kqueue() to implement epoll subset of functionality.
The kqueue user data are 32bit on i386 which is not enough for
epoll user data, so we keep user data in the proc emuldata.

Initial patch developed by rdivacky@ in 2007, then extended
by Yuri Victorovich @ r255672 and finished by me
in collaboration with mjg@ and jillies@.

MFC r283437:

To avoid code duplication move open/fcntl definitions to the MI
header file.

MFC r283436:

Use the BSD_TO_LINUX_SIGNAL() wherever there is no need
to check the ABI as it is known.

MFC r283432:

Being exported through vdso the note.Linux section used by glibc
to determine the kernel version (this saves one uname call).
Temporarily disable the export of a note.Linux section until I figured
out how to change the kernel version in the note.Linux on the fly.

MFC r283431:

Add AT_RANDOM and AT_EXECFN auxiliary vector entries which are used by
glibc. At list since glibc version 2.16 using AT_RANDOM is mandatory.

Regen for r293533.

MFC r283428:

Change linux faccessat syscall definition to match actual linux one.

The AT_EACCESS and AT_SYMLINK_NOFOLLOW flags are actually implemented
within the glibc wrapper function for faccessat(). If either of these
flags are specified, then the wrapper function employs fstatat() to
determine access permissions.

MFC r283421:

Introduce a new module linux_common.ko which is intended for the
following primary purposes:

1. Remove the dependency of linsysfs and linprocfs modules from linux.ko,
which will be architecture specific on amd64.

2. Incorporate into linux_common.ko general code for platforms on which
we'll support two Linuxulator modules (for both instruction set - 32 & 64 bit).

3. Move malloc(9) declaration to linux_common.ko, to enable getting memory
usage statistics properly.

Currently linux_common.ko incorporates a code from linux_mib.c and linux_util.c
and linprocfs, linsysfs and linux kernel modules depend on linux_common.ko.

Temporarily remove dtrace garbage from linux_mib.c and linux_util.c

MFC r283416:

x86_64 Linux do not use multiplexing on ipc system calls.
Move struct ipc_perm definition to the MD path as it differs for 64 and
32 bit platform.

MFC r283411:

Remove stale comment about a signal trampoline which
is moved to the shared page at r219609.

MFC r283410:

Put linux_platform into the vdso to avoid copying it onto the stack at
every exec.

MFC r283408:

Eliminate a now unused global declaration of elf_linux_sysvec.

MFC r283407:

Implement vdso - virtual dynamic shared object. Through vdso Linux
exposes functions from kernel with proper DWARF CFI information so that
it becomes easier to unwind through them.
Using vdso is a mandatory for a thread cancelation && cleanup
on a modern glibc.

Regen for r293511.

MFC r283403:

Implement pselect6() system call.

Regen for r293510.

MFC r283401:

Implement prlimit64() system call.

Regen for r293508.

MFC r283399:

Implement dup3() system call.

Regen for r293505.

MFC r283396:

Implement rt_sigqueueinfo() system call.

Regen for r293503.

MFC r283394:

Implement waitid() system call.

Regen for r293501.

MFC r283392:

struct l_rusage does not defined for i386 Linuxulator due to it's nature.

MFC r283391:

To reduce code duplication introduce linux_copyout_rusage() method.
Use it in linux_wait4() system call and move linux_wait4() to the MI path.
While here add a prototype for the static bsd_to_linux_rusage().

MFC r283385:

Some style(9) && whitespaces fixes. No functional changes.

MFC r283383:

Switch linuxulator to use the native 1:1 threads.

The reasons:
1. Get rid of the stubs/quirks with process dethreading,
process reparent when the process group leader exits and close
to this problems on wait(), waitpid(), etc.
2. Reuse our kernel code instead of writing excessive thread
managment routines in Linuxulator.

Implementation details:

1. The thread is created via kern_thr_new() in the clone() call with
the CLONE_THREAD parameter. Thus, everything else is a process.
2. The test that the process has a threads is done via P_HADTHREADS
bit p_flag of struct proc.
3. Per thread emulator state data structure is now located in the
struct thread and freed in the thread_dtor() hook.
Mandatory holdig of the p_mtx required when referencing emuldata
from the other threads.
4. PID mangling has changed. Now Linux pid is the native tid
and Linux tgid is the native pid, with the exception of the first
thread in the process where tid and pid are one and the same.

Ugliness:

In case when the Linux thread is the initial thread in the thread
group thread id is equal to the process id. Glibc depends on this
magic (assert in pthread_getattr_np.c). So for system calls that
take thread id as a parameter we should use the special method
to reference struct thread.

Regen fro r293487.

MFC r283379:

Implement a Linux version of sched_getparam() && sched_setparam().
Temporarily use the first thread in proc.

Regen for r293483.

MFC r283375:

In preparation for switching linuxulator to the use the native 1:1
threads use MI linux_sched_rr_get_interval() in i386.

Regen for r293478.

MFC r283370:

In preparation for switching linuxulator to the use the native 1:1
threads introduce linux_exit() stub instead of sys_exit() call
(which terminates process).
In the new linuxulator exit() system call terminates the calling
thread (not a whole process).

MFC r283369:

In preparation for switching linuxulator to the use the native 1:1
threads print the thread id in addition to the pid in debug messages.

MFC r282708:
On exec, single-threading must be enforced before arguments space is
allocated from exec_map.

Merge r263233 from HEAD to stable/10:

Update kernel inclusions of capability.h to use capsicum.h instead; some
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.

Sponsored by: Google, Inc.

Regen for r276810.

MFC r276508, r276509:
Correct an argument status of wait4 syscall for Linuxulator.

MFC 273988,273989,273995,274057:
MFamd64: Add support for extended FPU states on i386. This includes
support for AVX on i386.

MFC 273991:
MFamd64: Move extern declaration of _ucodesel and _udatasel to
<machine/md_var.h>

This is a direct commit rather than an MFC of r271744.

Re-gen after r272020 (r271743 in head) implementing most of
timer_{create,settime,gettime,getoverrun,delete}.

Approved by: re (gjb)
Sponsored by: DARPA/AFRL

MFC r271743:

Implement most of timer_{create,settime,gettime,getoverrun,delete}
for amd64/linux32. Fix the entirely bogus (untested) version from
r161310 for i386/linux using the same shared code in compat/linux.

It is unclear to me if we could support more clock mappings but
the current set allows me to successfully run commercial
32bit linux software under linuxolator on amd64.

Reviewed by: jhb
Differential Revision: D784
Sponsored by: DARPA, AFRL
Approved by: re (gjb)

Revert MFC r266925 because it can lead to instant panic at fexecve():

To allow to run interpreter itself add a new ELF branding type.

Pointed out by: kib, mjg

MFC r266925:

To allow to run the interpreter itself add a new ELF branding type.
Allow Linux ABI to run ELF interpreter.

MFC r258135: x86: Allow users to change PSL_RF via ptrace(PT_SETREGS...)

Debuggers may need to change PSL_RF. Note that tf_eflags is already stored
in the signal context during signal handling and PSL_RF previously could
be modified via sigreturn, so this change should not provide any new
ability to userspace.

For background see the thread at:
http://lists.freebsd.org/pipermail/freebsd-i386/2007-September/005910.html

Reviewed by: jhb, kib

Sponsored by: DARPA, AFRL
Approved by: re (gjb)

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Regen.

Approved by: re (delphij)

Revert r255672, it has some serious flaws, leaking file references etc.

Approved by: re (delphij)

Regen.

Approved by: re (delphij)

Implement epoll support in Linuxulator. This is a tiny wrapper around kqueue
to implement epoll subset of functionality. The kqueue user data are 32bit
on i386 which is not enough for epoll user data so this patch overrides
kqueue fileops to maintain enough space in struct file.

Initial patch developed by me in 2007 and then extended and finished
by Yuri Victorovich.

Approved by: re (delphij)
Sponsored by: Google Summer of Code
Submitted by: Yuri Victorovich <yuri at rawbw dot com>
Tested by: Yuri Victorovich <yuri at rawbw dot com>

Add a mmap flag (MAP_32BIT) on 64-bit platforms to request that a mapping use
an address in the first 2GB of the process's address space. This flag should
have the same semantics as the same flag on Linux.

To facilitate this, add a new parameter to vm_map_find() that specifies an
optional maximum virtual address. While here, fix several callers of
vm_map_find() to use a VMFS_* constant for the findspace argument instead of
TRUE and FALSE.

Reviewed by: alc
Approved by: re (kib)

Change the cap_rights_t type from uint64_t to a structure that we can extend
in the future in a backward compatible (API and ABI) way.

The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.

The structure definition looks like this:

struct cap_rights {
uint64_t cr_rights[CAP_RIGHTS_VERSION + 2];
};

The initial CAP_RIGHTS_VERSION is 0.

The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.

The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.

To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.

#define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL)

We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:

#define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL)
#define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL)

#define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP)

There is new API to manage the new cap_rights_t structure:

cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
void cap_rights_set(cap_rights_t *rights, ...);
void cap_rights_clear(cap_rights_t *rights, ...);
bool cap_rights_is_set(const cap_rights_t *rights, ...);

bool cap_rights_is_valid(const cap_rights_t *rights);
void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);

Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:

cap_rights_t rights;

cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);

There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:

#define cap_rights_set(rights, ...) \
__cap_rights_set((rights), __VA_ARGS__, 0ULL)
void __cap_rights_set(cap_rights_t *rights, ...);

Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:

cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);

Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.

This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.

Sponsored by: The FreeBSD Foundation

Reduce duplication between i386/linux/linux.h and amd64/linux32/linux.h
by moving bits that are MI out into headers in compat/linux.

Reviewed by: Chagin Dmitry dmitry | gmail
MFC after: 2 weeks

Don't assume that all Linux TCP-level socket options are identical to
FreeBSD TCP-level socket options (only the first two are). Instead,
using a mapping function and fail unsupported options as we do for other
socket option levels.

MFC after: 2 weeks

Revert previous commit...

Pointyhat to: kevlo (myself)

Prefer NULL over 0 for pointers

Regen.

The linux_lstat() system call accepts a pointer to a 'struct l_stat', not a
'struct ostat'.

- >500 static DTrace probes for the linuxulator
- DTrace scripts to check for errors, performance, ...
they serve mostly as examples of what you can do with the static probe;s
with moderate load the scripts may be overwhelmed, excessive lock-tracing
may influence program behavior (see the last design decission)

Design decissions:
- use "linuxulator" as the provider for the native bitsize; add the
bitsize for the non-native emulation (e.g. "linuxuator32" on amd64)
- Add probes only for locks which are acquired in one function and released
in another function. Locks which are aquired and released in the same
function should be easy to pair in the code, inter-function
locking is more easy to verify in DTrace.
- Probes for locks should be fired after locking and before releasing to
prevent races (to provide data/function stability in DTrace, see the
man-page of "dtrace -v ..." and the corresponding DTrace docs).

Regen for r234359.

Correct an argument type of iopl syscall for Linuxulator. This also fixes
a warning from Clang, i. e., "args->level < 0 is always false".

Regen for r234357.

Correct arguments of stat64, fstat64 and lstat64 syscalls for Linuxulator.

Regen for r234352.

- Implement pipe2 syscall for Linuxulator. This syscall appeared in 2.6.27
but GNU libc used it without checking its kernel version, e. g., Fedora 10.
- Move pipe(2) implementation for Linuxulator from MD files to MI file,
sys/compat/linux/linux_file.c. There is no MD code for this syscall at all.
- Correct an argument type for pipe() from l_ulong * to l_int *. Probably
this was the source of MI/MD confusion.

Reviewed by: emulation

regen

- add comments to syscalls.master and linux(32)_dummy about which linux
kernel version introduced the sysctl (based upon a linux man-page)
- add comments to sscalls.master regarding some names of sysctls which are
different than the linux-names (based upon the linux unistd.h)
- add some dummy sysctls
- name an unimplemented sysctl

MFC after: 1 month

Do not write to the user address directly, use suword().

Reported by: Bengt Ahlgren <bengta sics se>
MFC after: 1 week

Fix misuse of the kernel map in miscellaneous image activators.
Vnode-backed mappings cannot be put into the kernel map, since it is a
system map.

Use exec_map for transient mappings, and remove the mappings with
kmem_free_wakeup() to notify the waiters on available map space.

Do not map the whole executable into KVA at all to copy it out into
usermode. Directly use vn_rdwr() for the case of not page aligned
binary.

There is one place left where the potentially unbounded amount of data
is mapped into exec_map, namely, in the COFF image activator
enumeration of the needed shared libraries.

Reviewed by: alc
MFC after: 2 weeks

Convert files to UTF-8

Regen.

Implement linux_fadvise64() and linux_fadvise64_64() using
kern_posix_fadvise().

Reviewed by: silence on emulation@
MFC after: 2 weeks

- Add the ffclock_getcounter(), ffclock_getestimate() and ffclock_setestimate()
system calls to provide feed-forward clock management capabilities to
userspace processes. ffclock_getcounter() returns the current value of the
kernel's feed-forward clock counter. ffclock_getestimate() returns the current
feed-forward clock parameter estimates and ffclock_setestimate() updates the
feed-forward clock parameter estimates.

- Document the syscalls in the ffclock.2 man page.

- Regenerate the script-derived syscall related files.

Committed on behalf of Julien Ridoux and Darryl Veitch from the University of
Melbourne, Australia, as part of the FreeBSD Foundation funded "Feed-Forward
Clock Synchronization Algorithms" project.

For more information, see http://www.synclab.org/radclock/

Submitted by: Julien Ridoux (jridoux at unimelb edu au)

Regenerate system call tables.

Make the Linux *at() calls a bit more complete.

Properly support:

- AT_EACCESS for faccessat(),
- AT_SYMLINK_FOLLOW for linkat().

Regenerate system call tables.

Improve *access*() parameter name consistency.

The current code mixes the use of `flags' and `mode'. This is a bit
confusing, since the faccessat() function as a `flag' parameter to store
the AT_ flag.

Make this less confusing by using the same name as used in the POSIX
specification -- `amode'.

Correct the types of the arguments to return probes of the syscall
provider. Previously we were erroneously supplying the argument types of
the corresponding entry probe.

Reviewed by: rpaulo
MFC after: 1 week

Auto-generated code from sys_ prefixing makesyscalls.sh change

Approved by: re(bz)

In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by: rwatson
Approved by: re (bz)

Second-to-last commit implementing Capsicum capabilities in the FreeBSD
kernel for FreeBSD 9.0:

Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.

Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.

In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.

Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.

Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc

Add accounting for most of the memory-related resources.

Sponsored by: The FreeBSD Foundation
Reviewed by: kib (earlier version)

Revert r220032:linux compat: add SO_PASSCRED option with basic handling

I have not properly thought through the commit. After r220031 (linux
compat: improve and fix sendmsg/recvmsg compatibility) the basic
handling for SO_PASSCRED is not sufficient as it breaks recvmsg
functionality for SCM_CREDS messages because now we would need to handle
sockcred data in addition to cmsgcred. And that is not implemented yet.

Pointyhat to: avg

linux compat: add SO_PASSCRED option with basic handling

This seems to have been a part of a bigger patch by dchagin that either
haven't been committed or committed partially.

Submitted by: dchagin, nox
MFC after: 2 weeks

linux compat: add non-dummy capget and capset system calls, regenerate

And drop dummy definitions for those system calls.
This may transiently break the build.

PR: kern/149168
Submitted by: John Wehle <john@feith.com>
Reviewed by: netchild
MFC after: 2 weeks

linux compat: add non-dummy capget and capset system calls

PR: kern/149168
Submitted by: John Wehle <john@feith.com>
Reviewed by: netchild
MFC after: 2 weeks

Export the correct AT_PLATFORM value.
Since signal trampolines are copied to the shared page do not need to
leave place on the stack for it. Forgotten in the previous commit.

MFC after: 1 Week

Enable shared page use for amd64/linux32 and i386/linux binaries.
Move signal trampoline code from the top of the stack to the shared page.

MFC after: 2 Weeks

add DTrace systrace support for linux32 and freebsd32 on amd64 syscalls

Regenerate system call and systrace support files.

PR: kern/152822
Submitted by: Artem Belevich <fbsdlist@src.cx>
Reviewed by: jhb (earlier version)
MFC after: 3 weeks

add DTrace systrace support for linux32 and freebsd32 on amd64 syscalls

This commits makes necessary changes in syscall/sysent generation
infrastructure.

PR: kern/152822
Submitted by: Artem Belevich <fbsdlist@src.cx>
Reviewed by: jhb (ealier version)
MFC after: 3 weeks

Extend struct sysvec with new method sv_schedtail, which is used for an
explicit process at fork trampoline path instead of eventhadler(schedtail)
invocation for each child process.

Remove eventhandler(schedtail) code and change linux ABI to use newly added
sysvec method.

While here replace explicit comparing of module sysentvec structure with the
newly created process sysentvec to detect the linux ABI.

Discussed with: kib

MFC after: 2 Week

For realtime signals fill the sigval value.

Sort include files in the alphabetical order.

Move linux_clone(), linux_fork(), linux_vfork() to a MI path.

In preparation for moving linux_clone() to a MI path
introduce linux_set_upcall_kse().

In preparation for moving linux_clone () to a MI path
move the TLS code in a separate function.

Use function parameter instead of direct using register.

Regen for r218610.

The fourth argument of linux_clone is a pointer to the TLS. Change clone syscall definition to match actual linux one.

Setting VV_TEXT here is redundant. It is already set by do_execve().

Reviewed by: kib

Regen for r218101.

MFC after: 1 Month.

Change linux futex syscall definition to match actual linux one.

MFC after: 1 Month.

The kern_wait() code already removes the SIGCHLD signal for the waited
process. Removing other SIGCHLD signals is not needed and may cause
problems.

Pointed out by: jilles

MFC after: 1 Month.

Implement a variation of the linux_common_wait() which should
be used by linuxolator itself.

Move linux_wait4() to MD path as it requires native struct
rusage translation to struct l_rusage on linux32/amd64.

MFC after: 1 Month.

Add macro to test the sv_flags of any process. Change some places to test
the flags instead of explicit comparing with address of known sysentvec
structures.

MFC after: 1 month

Add macro DECLARE_MODULE_TIED to denote a module as requiring the
kernel of exactly the same __FreeBSD_version as the headers module was
compiled against.

Mark our in-tree ABI emulators with DECLARE_MODULE_TIED. The modules
use kernel interfaces that the Release Engineering Team feel are not
stable enough to guarantee they will not change during the life cycle
of a STABLE branch. In particular, the layout of struct sysentvec is
declared to be not part of the STABLE KBI.

Discussed with: bz, rwatson
Approved by: re (bz, kensmith)
MFC after: 2 weeks

The interpreter name should no longer be treated as a buffer that can be
overwritten. (This change should have been included in r210545.)

Submitted by: kib

Regenerate

Do not require pos parameter to be zero in MAP_ANONYMOUS mmap requests
in Linux emulation layer. Linux seems to only require that pos is
page-aligned, but otherwise ignores it. Default FreeBSD mmap parameter
checking is too strict to allow some Linux binaries to run. tsMuxeR is
one example of such a binary.

Discussed with: jhb
MFC after: 1 week

Introduce the x86 kernel interfaces to allow kernel code to use
FPU/SSE hardware. Caller should provide a save area that is chained
into the stack of the areas; pcb save_area for usermode FPU state is
on top. The pcb now contains a pointer to the current FPU saved area,
used during FPUDNA handling and context switches. There is also a
facility to allow the kernel thread to use pcb save_area.

Change the dreaded warnings "npxdna in kernel mode!" into the panics
when FPU usage is not registered.

KPI discussed with: fabient
Tested by: pho, fabient
Hardware provided by: Sentex Communications
MFC after: 1 month

Reorganize syscall entry and leave handling.

Extend struct sysvec with three new elements:
sv_fetch_syscall_args - the method to fetch syscall arguments from
usermode into struct syscall_args. The structure is machine-depended
(this might be reconsidered after all architectures are converted).
sv_set_syscall_retval - the method to set a return value for usermode
from the syscall. It is a generalization of
cpu_set_syscall_retval(9) to allow ABIs to override the way to set a
return value.
sv_syscallnames - the table of syscall names.

Use sv_set_syscall_retval in kern_sigsuspend() instead of hardcoding
the call to cpu_set_syscall_retval().

The new functions syscallenter(9) and syscallret(9) are provided that
use sv_*syscall* pointers and contain the common repeated code from
the syscall() implementations for the architecture-specific syscall
trap handlers.

Syscallenter() fetches arguments, calls syscall implementation from
ABI sysent table, and set up return frame. The end of syscall
bookkeeping is done by syscallret().

Take advantage of single place for MI syscall handling code and
implement ptrace_lwpinfo pl_flags PL_FLAG_SCE, PL_FLAG_SCX and
PL_FLAG_EXEC. The SCE and SCX flags notify the debugger that the
thread is stopped at syscall entry or return point respectively. The
EXEC flag augments SCX and notifies debugger that the process address
space was changed by one of exec(2)-family syscalls.

The i386, amd64, sparc64, sun4v, powerpc and ia64 syscall()s are
changed to use syscallenter()/syscallret(). MIPS and arm are not
converted and use the mostly unchanged syscall() implementation.

Reviewed by: jhb, marcel, marius, nwhitehorn, stas
Tested by: marcel (ia64), marius (sparc64), nwhitehorn (powerpc),
stas (mips)
MFC after: 1 month

Rename st_*timespec fields to st_*tim for POSIX 2008 compliance.

A nice thing about POSIX 2008 is that it finally standardizes a way to
obtain file access/modification/change times in sub-second precision,
namely using struct timespec, which we already have for a very long
time. Unfortunately POSIX uses different names.

This commit adds compatibility macros, so existing code should still
build properly. Also change all source code in the kernel to work
without any of the compatibility macros. This makes it all a less
ambiguous.

I am also renaming st_birthtime to st_birthtim, even though it was a
local extension anyway. It seems Cygwin also has a st_birthtim.

Change the arguments of exec_setregs() so that it receives a pointer
to the image_params struct instead of several members of that struct
individually. This makes it easier to expand its arguments in the future
without touching all platforms.

Reviewed by: jhb

Fix some problems with effective mmap() offsets > 32 bits. This was
partially fixed on amd64 earlier. Rather than forcing linux_mmap_common()
to use a 32-bit offset, have it accept a 64-bit file offset. This offset
is then passed to the real mmap() call. Rather than inventing a structure
to hold the normal linux_mmap args that has a 64-bit offset, just pass
each of the arguments individually to linux_mmap_common() since that more
closes matches the existing style of various kern_foo() functions.

Submitted by: Christian Zander @ Nvidia
MFC after: 1 week

In r197963, a race with thread being selected for signal delivery
while in kernel mode, and later changing signal mask to block the
signal, was fixed for sigprocmask(2) and ptread_exit(3). The same race
exists for sigreturn(2), setcontext(2) and swapcontext(2) syscalls.

Use kern_sigprocmask() instead of direct manipulation of td_sigmask to
reschedule newly blocked signals, closing the race.

Reviewed by: davidxu
Tested by: pho
MFC after: 1 month

As jhb@ pointed out to me, r197057 was incorrect, not least because these
are generated files.

Fix handling of .note.ABI-tag section for GNU systems [1].
Handle GNU/Linux according to LSB Core Specification 4.0,
Chapter 11. Object Format, 11.8. ABI note tag.

Also check the first word of desc, not only name, according to
glibc abi-tags specification to distinguish between Linux and
kFreeBSD.

Add explicit handling for Debian GNU/kFreeBSD, which runs
on our kernels as well [2].

In {amd64,i386}/trap.c, when checking osrel of the current process,
also check the ABI to not change the signal behaviour for Linux
binary processes, now that we save an osrel version for all three
from the lists above in struct proc [2].

These changes make it possible to run FreeBSD, Debian GNU/kFreeBSD
and Linux binaries on the same machine again for at least i386 and
amd64, and no longer break kFreeBSD which was detected as GNU(/Linux).

PR: kern/135468
Submitted by: dchagin [1] (initial patch)
Suggested by: kib [2]
Tested by: Petr Salinger (Petr.Salinger seznam.cz) for kFreeBSD
Reviewed by: kib
MFC after: 3 days

Return ENOSYS instead of EINVAL for invalid function codes to match the
behavior of Linux.

Reported by: Alexander Best alexbestms of math.uni-muenster.de
Approved by: re (kib)

Implement accept4 syscall.

Approved by: kib (mentor)
MFC after: 1 month

Regenerate generated syscall files following changes to struct sysent in
r193234.

Somewhere between 2.6.23 and 2.6.27, Linux added SOCK_CLOEXEC and
SOCK_NONBLOCK flags, that allow to save fcntl() calls.

Implement a variation of the socket() syscall which takes a flags
in addition to the type argument.

Approved by: kib (mentor)
MFC after: 1 month

Do not export AT_CLKTCK when emulating Linux kernel prior
to 2.4.0, as it has appeared in the 2.4.0-rc7 first time.
Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
glibc falls back to the hard-coded CLK_TCK value when aux entry
is not present.

Glibc versions prior to 2.2.1 always use hard-coded CLK_TCK value.

For older applications/libc's which depends on hard-coded CLK_TCK
value user should set compat.linux.osrelease less than 2.4.0.

Approved by: kib (mentor)

Rework r189362, r191883.
The frequency of the statistics clock is given by stathz.
Use stathz if it is available, otherwise use hz.

Pointed out by: bde

Approved by: kib (mentor)

Move the per-prison Linux MIB from a private one-off pointer to the new
OSD-based jail extensions. This allows the Linux MIB to accessed via
jail_set and jail_get, and serves as a demonstration of adding jail support
to a module.

Reviewed by: dchagin, kib
Approved by: bz (mentor)

To avoid excessive code duplication move MI definitions to the MI
header file. As it is defined in Linux.

Approved by: kib (mentor)
MFC after: 1 month

Move extern variable definitions to the header file.

Approved by: kib (mentor)
MFC after: 1 month

Reimplement futexes.
Old implemention used Giant to protect the kernel data structures,
but at the same time called malloc(M_WAITOK), that could cause the
calling thread to sleep and lost Giant protection. User-visible
result was the missed wakeup.

New implementation uses one sx lock per futex. The sx protects
the futex structures and allows to sleep while copyin or copyout
are performed.

Unlike linux, we return EINVAL when FUTEX_CMP_REQUEUE operation
is requested and either caller specified futexes are equial or
second futex already exists. This is acceptable since the situation
can only occur from the application error, and glibc falls back to
old FUTEX_WAKE operation when FUTEX_CMP_REQUEUE returns an error.

Approved by: kib (mentor)
MFC after: 1 month

Fix KBI breakage by r190520 which affects older linux.ko binaries:

1) Move the new field (brand_note) to the end of the Brandinfo structure.
2) Add a new flag BI_BRAND_NOTE that indicates that the brand_note pointer
is valid.
3) Use the brand_note field if the flag BI_BRAND_NOTE is set and as old
modules won't have the flag set, so the new field brand_note would be
ignored.

Suggested by: jhb
Reviewed by: jhb
Approved by: kib (mentor)
MFC after: 6 days

Implement new way of branding ELF binaries by looking to a
".note.ABI-tag" section.

The search order of a brand is changed, now first of all the
".note.ABI-tag" is looked through.

Move code which fetch osreldate for ELF binary to check_note() handler.

PR: 118473
Approved by: kib (mentor)

A better fix for handling different FPU initial control words for different
ABIs:
- Store the FPU initial control word in the pcb for each thread.
- When first using the FPU, load the initial control word after restoring
the clean state if it is not the standard control word.
- Provide a correct control word for Linux/i386 binaries under
FreeBSD/amd64.
- Adjust the control word returned for fpugetregs()/npxgetregs() when a
thread hasn't used the FPU yet to reflect the real initial control
word for the current ABI.
- The Linux/i386 ABI for FreeBSD/i386 now properly sets the right control
word instead of trashing whatever the current state of the FPU is.

Reviewed by: bde

Add AT_PLATFORM, AT_HWCAP and AT_CLKTCK auxiliary vector entries which
are used by glibc. This silents the message "2.4+ kernel w/o ELF notes?"
from some programs at start, among them are top and pkill.

Do the assignment of the vector entries in elf_linux_fixup()
as it is done in glibc.

Fix some minor style issues.

Submitted by: Marcin Cieslak <saper at SYSTEM PL>
Approved by: kib (mentor)
MFC after: 1 week

Adapt linux emulation to use cv for vfork wait.

Submitted by: Takahiro Kurosawa <takahiro.kurosawa gmail com>
PR: kern/131506

Change some movl's to mov's. Newer GAS no longer accept 'movl' instructions
for moving between a segment register and a 32-bit memory location.

Looked at by: jhb

Remove obsolete AT_DEBUG stuff. It never should have been committed
in the first place, let alone migrated to linux emulation.

Reviewed by: peter, rdivacky

Make linux_sendmsg() and linux_recvmsg() work on linux32/amd64.
Change types used in the linux' struct msghdr and struct cmsghdr
definitions to the properly-sized architecture-specific types.
Move ancillary data handler from linux_sendit() to linux_sendmsg().

Submitted by: dchagin

Add sv_flags field to struct sysentvec with intention to provide description
of the ABI of the currently executing image. Change some places to test
the flags instead of explicit comparing with address of known sysentvec
structures to determine ABI features.

Discussed with: dchagin, imp, jhb, peter

In the robust futexes list head, futex_offset shall be signed,
and glibc actually supplies negative offsets. Change l_ulong to l_long.

Submitted by: dchagin

Several cleanups related to pipe(2).

- Use `fildes[2]' instead of `*fildes' to make more clear that pipe(2)
fills an array with two descriptors.

- Remove EFAULT from the manual page. Because of the current calling
convention, pipe(2) raises a segmentation fault when an invalid
address is passed.

- Introduce kern_pipe() to make it easier for binary emulations to
implement pipe(2).

- Make Linux binary emulation use kern_pipe(), which means we don't have
to recover td_retval after calling the FreeBSD system call.

Approved by: rdivacky
Discussed on: arch

Regenerate system call tables for r184789.

Mark uname(), getdomainname() and setdomainname() with COMPAT_FREEBSD4.

Looking at our source code history, it seems the uname(),
getdomainname() and setdomainname() system calls got deprecated
somewhere after FreeBSD 1.1, but they have never been phased out
properly. Because we don't have a COMPAT_FREEBSD1, just use
COMPAT_FREEBSD4.

Also fix the Linuxolator to build without the setdomainname() routine by
just making it call userland_sysctl on kern.domainname. Also replace the
setdomainname()'s implementation to use this approach, because we're
duplicating code with sysctl_domainname().

I wasn't able to keep these three routines working in our
COMPAT_FREEBSD32, because that would require yet another keyword for
syscalls.master (COMPAT4+NOPROTO). Because this routine is probably
unused already, this won't be a problem in practice. If it turns out to
be a problem, we'll just restore this functionality.

Reviewed by: rdivacky, kib

Correctly fill siginfo for the signals delivered by linux tkill/tgkill.
It is required for async cancellation to work.

Fix PROC_LOCK leak in linux_tgkill when signal delivery attempt is made
to not linux process.

Do not call em_find(p, ...) with p unlocked.

Move common code for linux_tkill() and linux_tgkill() into
linux_do_tkill().

Change linux siginfo_t definition to match actual linux one. Extend
uid fields to 4 bytes from 2. The extension does not change structure
layout and is binary compatible with previous definition, because i386
is little endian, and each uid field has 2 byte padding after it.

Reported by: Nicolas Joly <njoly pasteur fr>
Submitted by: dchangin
MFC after: 1 month

Make robust futexes work on linux32/amd64. Use PTRIN to read
user-mode pointers. Change types used in the structures definitions to
properly-sized architecture-specific types.

Submitted by: dchagin
MFC after: 1 week

Change the static struct sysentvec and struct Elf_Brandinfo initializers
to the C99 style. At least, it is easier to read sysent definitions
that way, and search for the actual instances of sigcode etc.

Explicitely initialize sysentvec.sv_maxssiz that was missed in most
sysvecs.

No objection from: jhb
MFC after: 1 month

Segment registers are stored in the uc_mcontext member of the struct
l_ucontext. To restore the registers content, trampoline needs to
dereference uc_mcontext instead of taking some undefined values from
l_ucontext.

Submitted by: Dmitry Chagin <dchagin@>
MFC after: 1 week

Regen.

Approved by: kib (mentor)

Implement robust futexes. Most of the code is modelled after
what Linux does. This is because robust futexes are mostly
userspace thing which we cannot alter. Two syscalls maintain
pointer to userspace list and when process exits a routine
walks this list waking up processes sleeping on futexes
from that list.

Reviewed by: kib (mentor)
MFC after: 1 month

Implement linux_truncate64() syscall.

Tested by: Aline de Freitas <aline@riseup.net>
Approved by: kib (mentor)

Regenerate.

Add stubs for syscalls introduced in Linux 2.6.17 kernel.
Some GNU libc version started using them before 2.6.17 was officially out.

MFC after: 3 days

Regenerate

Implement the linux syscalls
openat, mkdirat, mknodat, fchownat, futimesat, fstatat, unlinkat,
renameat, linkat, symlinkat, readlinkat, fchmodat, faccessat.

Submitted by: rdivacky
Sponsored by: Google Summer of Code 2007
Tested by: pho

Add the support for the AT_FDCWD and fd-relative name lookups to the
namei(9).

Based on the submission by rdivacky,
sponsored by Google Summer of Code 2007
Reviewed by: rwatson, rdivacky
Tested by: pho

Regen.

Implement sched_setaffinity and get_setaffinity using
real cpu affinity setting primitives.

Reviewed by: jeff
Approved by: kib (mentor)

Since version 4.3, gcc changed its behaviour concerning the i386/amd64
ABI and the direction flag, that is it now assumes that the direction
flag is cleared at the entry of a function and it doesn't clear once
more if needed. This new behaviour conforms to the i386/amd64 ABI.

Modify the signal handler frame setup code to clear the DF {e,r}flags
bit on the amd64/i386 for the signal handlers.

jhb@ noted that it might break old apps if they assumed DF == 1 would be
preserved in the signal handlers, but that such apps should be rare and
that older versions of gcc would not generate such apps.

Submitted by: Aurelien Jarno <aurelien aurel32 net>
PR: 121422
Reviewed by: jhb
MFC after: 2 weeks

Remove kernel support for M:N threading.

While the KSE project was quite successful in bringing threading to
FreeBSD, the M:N approach taken by the kse library was never developed
to its full potential. Backwards compatibility will be provided via
libmap.conf for dynamically linked binaries and static binaries will
be broken.

Fix Linux mmap with MAP_GROWSDOWN flag.

Reported by: Andriy Gapon (avg at icyb dot net dot ua)
Tested by: Andriy Gapon (avg at icyb dot net dot ua)
Pointyhat: me
MFC after: 3 days

VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.

KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.

Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>

vn_lock() is currently only used with the 'curthread' passed as argument.
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.

Manpage and FreeBSD_version will be updated through further commits.

As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.

Tested by: Diego Sardina <siarodx at gmail dot com>,
Andrea Di Pasquale <whyx dot it at gmail dot com>

Implement read_default_ldt in linux_modify_ldt(). It copies out zeroed
descriptor, like real Linux does.

Tested by: Yuriy Tsibizov <yuriy.tsibizov at gmail com>
Submitted by: rdivacky
MFC after: 1 week

Fix for the panic("vm_thread_new: kstack allocation failed") and
silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.

As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.

The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).

In collaboration with: Peter Holm
Reviewed by: jhb

Fill in cr2 in the signal context from ksi->ksi_addr.
Together with the sys/i386/i386/trap.c rev. 1.306 it fixes the PR.

Submitted by: rdivacky
Suggested by: jhb
Sponsored by: Google Summer of Code 2007
PR: kern/77710
Approved by: re (kensmith)

regen.

Approved by: re (kensmith)

The kernel version of Linux statfs64 is actually supposed to take
3 arguments, but we had forgotten the second argument. Also make the
Linux statfs64 struct depend on the architecture because it has an
extra 4 bytes padding on amd64 compared to i386.

The three argument fix is from David Taylor, the struct statfs64
stuff is my fault. With this patch I can install i386 Linux matlab
on an amd64 machine.

Submitted by: David Taylor <davidt_at_yadt.co.uk>
Approved by: re (kensmith)

- Move all of the PS_ flags into either p_flag or td_flags.
- p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or
previously the sched_lock. These bugs have existed for some time.
- Allow swapout to try each thread in a process individually and then
swapin the whole process if any of these fail. This allows us to move
most scheduler related swap flags into td_flags.
- Keep ki_sflag for backwards compat but change all in source tools to
use the new and more correct location of P_INMEM.

Reported by: pho
Reviewed by: attilio, kib
Approved by: re (kensmith)

Regenerate.

Approved by: re (kensmith)

Implement fake linux sched_getaffinity() syscall to enable java to work
with Linux 2.6 emulation. This shall be reimplemented once FreeBSD gets
native scheduler affinity syscalls.

Submitted by: rdivacky
Reviewed by: jkim
Sponsored by: Google Summer of Code 2007
Approved by: re (kensmith)

i386_set_ioperm, i386_get_ldt and i386_set_ldt are now MPSAFE
(Giant/sched_lock free) so remove unuseful Giant cruft.

Approved by: jeff
Approved by: re
Sponsorized by: NGX Italy (http://www.ngx.it)

Don't add the 'pad' argument to the mmap/truncate/etc syscalls.

Submitted by: kensmith
Approved by: re (kensmith)

Commit 14/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.

Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)

Move futex support code from <arch>/support.s into linux compat directory.
Implement all futex atomic operations in assembler to not depend on the
fuword() that does not allow to distinguish between -1 and failure return.
Correctly return 0 from atomic operations on success.

In collaboration with: rdivacky
Tested by: Scot Hetzel <swhetzel gmail com>, Milos Vyletel <mvyletel mzm cz>
Sponsored by: Google SoC 2007

Do not dereference linux_to_bsd_signal[-1] if userland has
passed zero as exit signal.

GCC 4.2 changes the kernel data segment layout not to have 0
in that memory location. This code ran by luck before and now
the luck has run out.

MFP4: Turn emul_lock into a mutex.

Submitted by: rdivacky

Implement the openat() linux syscall
Submitted by: Roman Divacky (rdivacky@)
MFC after: 2 weeks

MFP4: 115220, 115222

- Fix style(9) and reduce diff between amd64 and i386.
- Prefix Linuxulator macros with LINUX_ to prevent future collision.

MFP4: 115094

Linux does not check file descriptor when MAP_ANONYMOUS is set.
This should fix recent LTP test regressions.

Reported by: Scot Hetzel (swhetzel at gmail dot com)
netchild

Partial MFp4 of 114977:
Whitespace commit: Fix grammar, spelling and punctuation.

Submitted by: "Scot Hetzel" <swhetzel@gmail.com>

MFp4 (114193 (i386 part), 114194, 114195, 114200):
- Dont "return" in linux_clone() after we forked the new process in a case
of problems.
- Move the copyout of p2->p_pid outside the emul_lock coverage in
linux_clone().
- Cache the em->pdeath_signal in a local variable and move the copyout
out of the emul_lock coverage.
- Move the free() out of the emul_shared_lock coverage in a preparation
to switch emul_lock to non-sleepable lock (mutex).

Submitted by: rdivacky

Regen.

MFP4: 113025, 113146, 113177, 113203, 113500, 113546, 113570

- PROT_READ, PROT_WRITE, or PROT_EXEC implies PROT_READ and PROT_EXEC.
Linux/ia64's i386 emulation layer does this and it complies with Linux
header files. This fixes mmap05 LTP test case on amd64.
- Do not adjust stack size when failure has occurred.
- Synchronize i386 mmap/mprotect with amd64.

Introduce some more SO_ option equivalents from Linux to FreeBSD.

The msg variable in linux_recvmsg() was not initialized.
Copy it from userspace.

Submitted by: rdivacky

Fix LOR that occurs because proctree_lock was acquired while holding
emuldata lock by moving the code upwards outside the emul_lock coverage.

Submitted by: rdivacky

- Remove setrunqueue and replace it with direct calls to sched_add().
setrunqueue() was mostly empty. The few asserts and thread state
setting were moved to the individual schedulers. sched_add() was
chosen to displace it for naming consistency reasons.
- Remove adjustrunqueue, it was 4 lines of code that was ifdef'd to be
different on all three schedulers where it was only called in one place
each.
- Remove the long ifdef'd out remrunqueue code.
- Remove the now redundant ts_state. Inspect the thread state directly.
- Don't set TSF_* flags from kern_switch.c, we were only doing this to
support a feature in one scheduler.
- Change sched_choose() to return a thread rather than a td_sched. Also,
rely on the schedulers to return the idlethread. This simplifies the
logic in choosethread(). Aside from the run queue links kern_switch.c
mostly does not care about the contents of td_sched.

Discussed with: julian

- Move the idle thread loop into the per scheduler area. ULE wants to
do something different from the other schedulers.

Suggested by: jhb

Tested on: x86/amd64 sched_{4BSD, ULE, CORE}.

MFp4 (113077, 113083, 113103, 113124, 113097):

Dont expose em->shared to the outside world before its properly
initialized. Might not affect anything but its at least a better
coding style.

Dont expose em via p->p_emuldata until its properly initialized.
This also enables us to get rid of some locking and simplify the
code because we are workin on a local copy.

In linux_fork and linux_vfork create the process in stopped state
to be sure that the new process runs with fully initialized emuldata
structure [1]. Also fix the vfork (both in linux_clone and linux_vfork)
race that could result in never woken up process [2].

Reported by: Scot Hetzel [1]
Suggested by: jhb [2]
Reviewed by: jhb (at least some important parts)
Submitted by: rdivacky
Tested by: Scot Hetzel (on amd64)

Change 2 comments (in the new code) to comply to style(9).

Suggested by: jhb

MFp4 (112893):
Make linux_vfork() actually work. This enables make to work again with 2.6.
It also fixes the LTP vfork tests.

Submitted by: rdivacky

MFp4 (112498):
Rename the locking flags to EMUL_DOLOCK and EMUL_DONTLOCK to prevent confusion.

Submitted by: rdivacky

regen after addition of linux_utimes and linux_rt_sigtimedwait

MFp4 (111746, 108671, 108945, 112352):
- add linux utimes syscall [1]
- add linux rt_sigtimedwait syscall [2]

Submitted by: "Scot Hetzel" <swhetzel@gmail.com> [1]
Submitted by: Bruce Becker <hostmaster@whois.gts.net> [2]
PR: 93199 [2]

Regen (just to fix 'generated from' line from the previous commit).

Add linux_nanosleep() and regen.

MFP4: 109655

- Move linux_nanosleep() from src/sys/amd64/linux32/linux32_machdep.c to
src/sys/compat/linux/linux_time.c.
- Validate timespec ranges before use as Linux kernel does.
- Fix l_timespec structure.
- Clean up style(9) nits.

Merge posix4/* into normal kernel hierarchy.

Reviewed by: glanced at by jhb
Approved by: silence on -arch@ and -standards@

Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges. These may
require some future tweaking.

Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>

regen after linux_io_* backout

Backout the linux aio stuff. Several problems where identified and the
dynamic nature (if no native aio code is available, the linux part
returns ENOSYS because of missing requisites) should be solved differently
than it is.

All this will be done in P4.

Not included in this commit is a backout of the changes to the native aio
code (removing static in some places). Those changes (and some more) will
also be needed when the reworked linux aio stuff will reenter the tree.

Requested by: rwatson
Discussed with: rwatson

regen (prctl addition)

MFP4:
Implement prctl().

Submitted by: rdivacky
Tested with: LTP

Fix a recent regression regarding valid signals.

Submitted by: rdivacky

regen (linux AIO stuff)

MFP4 (with some minor changes):

Implement the linux_io_* syscalls (AIO). They are only enabled if the native
AIO code is available (either compiled in to the kernel or as a module) at
the time the functions are used. If the AIO stuff is not available there
will be a ENOSYS.

From the submitter:
---snip---
DESIGN NOTES:

1. Linux permits a process to own multiple AIO queues (distinguished by
"context"), but FreeBSD creates only one single AIO queue per process.
My code maintains a request queue (STAILQ of queue(3)) per "context",
and throws all AIO requests of all contexts owned by a process into
the single FreeBSD per-process AIO queue.

When the process calls io_destroy(2), io_getevents(2), io_submit(2) and
io_cancel(2), my code can pick out requests owned by the specified context
from the single FreeBSD per-process AIO queue according to the per-context
request queues maintained by my code.

2. The request queue maintained by my code stores contrast information between
Linux IO control blocks (struct linux_iocb) and FreeBSD IO control blocks
(struct aiocb). FreeBSD IO control block actually exists in userland memory
space, required by FreeBSD native aio_XXXXXX(2).

3. It is quite troubling that the function io_getevents() of libaio-0.3.105
needs to use Linux-specific "struct aio_ring", which is a partial mirror
of context in user space. I would rather take the address of context in
kernel as the context ID, but the io_getevents() of libaio forces me to
take the address of the "ring" in user space as the context ID.

To my surprise, one comment line in the file "io_getevents.c" of
libaio-0.3.105 reads:

Ben will hate me for this

REFERENCE:

1. Linux kernel source code: http://www.kernel.org/pub/linux/kernel/v2.6/
(include/linux/aio_abi.h, fs/aio.c)

2. Linux manual pages: http://www.kernel.org/pub/linux/docs/manpages/
(io_setup(2), io_destroy(2), io_getevents(2), io_submit(2), io_cancel(2))

3. Linux Scalability Effort: http://lse.sourceforge.net/io/aio.html
The design notes: http://lse.sourceforge.net/io/aionotes.txt

4. The package libaio, both source and binary:
http://rpmfind.net/linux/rpm2html/search.php?query=libaio
Simple transparent interface to Linux AIO system calls.

5. Libaio-oracle: http://oss.oracle.com/projects/libaio-oracle/
POSIX AIO implementation based on Linux AIO system calls (depending on
libaio).
---snip---

Submitted by: Li, Xiao <intron@intron.ac>

MFP4 (106538 + 106541):
Implement CLONE_VFORK. This fixes the clone05 LTP test.

Submitted by: rdivacky

Revert my previous commit, I mismerged this to the wrong place.

Pointy hat to: netchild

MFP4 (106541): Fix the clone05 test in the LTP.

Submitted by: rdivacky

MFP4 (107144[1]): Implement CLONE_FS on i386[1] and amd64.

Submitted by: rdivacky [1]

MFP4 (107868 - 107870):
Use a macro to test for a valid signal instead of doing it my hand everywhere.

Submitted by: rdivacky

Regenerate.

Use AUE_CREAT instead of AUE_O_CREAT for linux_creat().

Obtained from: TrustedBSD Project

Regenerate.

Use AUE_GETDIRENTRIES instead of AUE_O_GETDENTS and AUE_NULL for a number
of directory reading system calls.

Respell a mis-spelled event name.

Clean up white space/line wraps in a couple of places.

Assign event numbers to some new system call entries that have turned
up in the list since audit support was added.

Obtained from: TrustedBSD Project

style(9)

While I'm here add a MFC reminder, I forgot it in the previous commit.

Noticed by: ssouhlal
MFC after: 1 week

Bring the i386 linux mmap code more into line with how linux (2.4.x)
behaves. This fixes a lot of test which failed before. For amd64 there
are still some problems, but without any testers which apply patches
and run some predefines tests we can't do more ATM.

Submitted by: Marcin Cieslak <saper@SYSTEM.PL> (minor fixups by myself)
Tested with: LTP

Change futex lock from mutex to sx. Make futex_get atomic (protected by the
futex lock).

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Suggested by: jhb

Fix video playing and network connections in realplayer (and most likely
other stuff) in the osrelease=2.6.16 case:
- implement CLONE_PARENT semantic
- fix TLS loading in clone CLONE_SETTLS
- lock proc in the currently disabled part of CLONE_THREAD

I suggest to not unload the linux module after testing this, there are
some "<defunct>" processes hanging around after exiting (they aren't
with osrelease=2.4.2) and they may panic your kernel when unloading the
linux module. They are in state Z and some of them consume CPU according
to ps. But I don't trust the CPU part, the idle threads gets too much CPU
that this may be possible (accumulating idle, X and 2 defunct processes
results in 104.7%, this looks to much to be a rounding error).

Noticed by: Intron <mag@intron.ac>
Submitted by: rdivacky (in collaboration with Intron)
Tested by: Intron, netchild
Reviewed by: jhb (previous version)

regen

Add the linux statfs64 call. This allows Tivoli backup to proceed a little
but further on -current (still not successful, but a step into the right
direction).

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Tested by: Paul Mather <paul@gromit.dlib.vt.edu>

Emulate what vfork does instead of using it in linux_vfork. This way
we can do the stuff we need to do with linux processes at fork and
don't panic the kernel at exit of the child.

Submitted by: rdivacky
Tested with: tst-vfork* (glibc regression tests)
Tested by: netchild

Get rid of some nested includes.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Noticed by: jhb

Move some stuff into headers where they belong.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Noticed by: jhb, ssouhlal

Style fixes to comments.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Noticed by: jhb, ssouhlal

Regen to propogate <prefix>_AUE_<mumble> changes as well as the earlier
systrace changes.

- Remove unused sysvec variables from various syscalls.conf.
- Send the systrace_args files for all the compat ABIs to /dev/null for
now. Right now makesyscalls.sh generates a file with a hardcoded
function name, so it wouldn't work for any of the ABIs anyway. Probably
the function name should be configurable via a 'systracename' variable
and the functions should be stored in a function pointer in the sysvec
structure.

add autogenerated systrace_args stuff for dtrace

Add the linux 2.6.x stuff (not used by default!):
- TLS - complete
- pid/tid mangling - complete
- thread area - complete
- futexes - complete with issues
- clone() extension - complete with some possible minor issues
- mq*/timer*/clock* stuff - complete but untested and the mq* stuff is
disabled when not build as part of the kernel with native FreeBSD mq*
support (module support for this will come later)

Tested with:
- linux-firefox - works, tested
- linux-opera - works, tested
- linux-realplay - doesnt work, issue with futexes
- linux-skype - doesnt work, issue with futexes
- linux-rt2-demo - works, tested
- linux-acroread - doesnt work, unknown reason (coredump) and sometimes
issue with futexes
- various unix utilities in linux-base-gentoo3 and linux-base-fc4:
everything tried worked

On amd64 not everything is supported like on i386, the catchup is planned for
later when the remaining bugs in the new functions are fixed.

To test this new stuff, you have to run
sysctl compat.linux.osrelease=2.6.16
to switch back use
sysctl compat.linux.osrelease=2.4.2

Don't switch while running a linux program, strange things may or may not
happen.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Some suggestions/help by: jhb, kib, manu@NetBSD.org, netchild

regen

Add new syscalls in the linuxolator (only used when the sysctl
compat.linux.osrelease is changed to "2.6.16" or similar).

On amd64 not everything is supported like on i386, the catchup is planned for
later when the remaining bugs in the new functions are fixed.

Sponsored by: Google SoC 2006
Submitted by: rdivacky

Add some more errno mappings (bsd -> linux) and a comment about the status..

Submitted by: "Intron" <mag@intron.ac>

Regen for MPSAFE flag removal.

Now that all system calls are MPSAFE, retire the SYF_MPSAFE flag used to
mark system calls as being MPSAFE:
- Stop conditionally acquiring Giant around system call invocations.
- Remove all of the 'M' prefixes from the master system call files.
- Remove support for the 'M' prefix from the script that generates the
syscall-related files from the master system call files.
- Don't explicitly set SYF_MPSAFE when registering nfssvc.

Various fixes to comments in the syscall master files including removing
cruft from the audit import and adding mention of COMPAT4 to freebsd32.

Regen.

- Pass the MPSAFE flag to namei() in linux_uselib() and handle conditional
Giant VFS locking in that function.
- Remove bogus code to handle the case where namei() returns success but a
NULL vnode pointer.
- Note that this code duplicates exec_check_permissions() and annotate
where it differs.
- Hold the vnode lock longer to protect the write to set VV_TEXT in
v_vflag.
- Mark linux_uselib() MPSAFE.

Reviewed by: rwatson

Regen.

- Add conditional VFS Giant locking to getdents_common() (linux ABIs),
ibcs2_getdents(), ibcs2_read(), ogetdirentries(), svr4_sys_getdents(),
and svr4_sys_getdents64() similar to that in getdirentries().
- Mark ibcs2_getdents(), ibcs2_read(), linux_getdents(), linux_getdents64(),
linux_readdir(), ogetdirentries(), svr4_sys_getdents(), and
svr4_sys_getdents64() MPSAFE.

Regen.

- Protect the list of linux ioctl handlers with an sx lock.
- Hold Giant while calling linux ioctl handlers for now as they aren't all
known to be MPSAFE yet.
- Mark linux_ioctl() MPSAFE.

Regen.

- Add a kern_semctl() helper function for __semctl(). It accepts a pointer
to a copied-in copy of the 'union semun' and a uioseg to indicate which
memory space the 'buf' pointer of the union points to. This is then used
in linux_semctl() and svr4_sys_semctl() to eliminate use of the stackgap.
- Mark linux_ipc() and svr4_sys_semsys() MPSAFE.

Regen.

- Expand the scope of Giant some in mount(2) to protect the vfsp structure
from going away. mount(2) is now MPSAFE.
- Expand the scope of Giant some in unmount(2) to protect the mp structure
(or rather, to handle concurrent unmount races) from going away.
umount(2) is now MPSAFE, as well as linux_umount() and linux_oldumount().
- nmount(2) and linux_mount() were already MPSAFE.

Regen.

linux_brk() is MPSAFE.

regen after change to syscalls.master

Switch to using the DUMMY infrastructure instead of UNIMPL for the new
syscalls. This way there will be a log message printed to the console
(this time for real).

Note: UNIMPL should be used for syscalls we do not implement ever, e.g.
syscalls to load linux kernel modules.

Submitted by: rdivacky
Sponsored by: Goole SoC 2006
P4 IDs: 99600, 99602

regen after MFP4 (soc2006/rdivacky_linuxolator) of syscalls.master

P4-Changes: similar to 98673 and 98675 but regenerated locally
Sponsored by: Google SoC 2006
Submitted by: rdivacky

MFP4 (soc2006/rdivacky_linuxolator)

Update of syscall.master:
o Adding of several new dummy syscalls (268-310)
o Synchronization of amd64 syscall.master with i386 one
o Auditing added to amd64 syscall.master
o Change auditing type for lstat syscall (bugfix). [1]

P4-Changes: 98672, 98674
Noticed by: rwatson [1]
Sponsored by: Google SoC 2006
Submitted by: rdivacky

regen (linux rt_sigpending)

Implement rt_sigpending in the linuxolator.

PR: 92671
Submitted by: Markus Niemist"o <markus.niemisto@gmx.net>

Enhance the Linux emulation layer to make MegaRAID SAS managements tool happy.
Add back in a scheme to emulate old type major/minor numbers via hooks into
stat, linprocfs to return major/minors that Linux app's expect. Currently
only /dev/null is always registered. Drivers can register via the Linux
type shim similar to the ioctl shim but by using
linux_device_register_handler/linux_device_unregister_handler functions.
The structure is:

struct linux_device_handler {
char *bsd_driver_name;
char *linux_driver_name;
char *bsd_device_name;
char *linux_device_name;
int linux_major;
int linux_minor;
int linux_char_device;
};

Linprocfs uses this to display the major number of the driver. The
soon to be available linsysfs will use it to fill in the driver name.
Linux_stat uses it to translate the major/minor into Linux type values.

Note major numbers are dynamically assigned via passing in a -1 for
the major number so we don't need to keep track of them.

This is somewhat needed due to us switching to our devfs. MegaCli
will not run until I add in the linsysfs and mfi Linux compat changes.

Sponsored by: IronPort Systems

regen

Fixup some problems in my previous commit (COMPAT_43).

Pointyhat to: netchild

regen after COMPAT_43 removal

Get rid of the need of COMPAT_43 in the linuxolator.

Submitted by: Divacky Roman <xdivac02@stud.fit.vutbr.cz>
Obtained from: DragonFly (some parts)

Close some races between procfs/ptrace and exit(2):
- Reorder the events in exit(2) slightly so that we trigger the S_EXIT
stop event earlier. After we have signalled that, we set P_WEXIT and
then wait for any processes with a hold on the vmspace via PHOLD to
release it. PHOLD now KASSERT()'s that P_WEXIT is clear when it is
invoked, and PRELE now does a wakeup if P_WEXIT is set and p_lock drops
to zero.
- Change proc_rwmem() to require that the processing read from has its
vmspace held via PHOLD by the caller and get rid of all the junk to
screw around with the vmspace reference count as we no longer need it.
- In ptrace() and pseudofs(), treat a process with P_WEXIT set as if it
doesn't exist.
- Only do one PHOLD in kern_ptrace() now, and do it earlier so it covers
FIX_SSTEP() (since on alpha at least this can end up calling proc_rwmem()
to clear an earlier single-step simualted via a breakpoint). We only
do one to avoid races. Also, by making the EINVAL error for unknown
requests be part of the default: case in the switch, the various
switch cases can now just break out to return which removes a _lot_ of
duplicated PRELE and proc unlocks, etc. Also, it fixes at least one bug
where a LWP ptrace command could return EINVAL with the proc lock still
held.
- Changed the locking for ptrace_single_step(), ptrace_set_pc(), and
ptrace_clear_single_step() to always be called with the proc lock
held (it was a mixed bag previously). Alpha and arm have to drop
the lock while the mess around with breakpoints, but other archs
avoid extra lock release/acquires in ptrace(). I did have to fix a
couple of other consumers in kern_kse and a few other places to
hold the proc lock and PHOLD.

Tested by: ps (1 mostly, but some bits of 2-4 as well)
MFC after: 1 week

- Always call exec_free_args() in kern_execve() instead of doing it in all
the callers if the exec either succeeds or fails early.
- Move the code to call exit1() if the exec fails after the vmspace is
gone to the bottom of kern_execve() to cut down on some code duplication.

Regenerate.

Assign audit event identifiers to Linux i386 system calls.

Obtained from: TrustedBSD Project

Remove kern.elf32.can_exec_dyn sysctl. Instead extend Brandinfo structure
with flags bitfield and set BI_CAN_EXEC_DYN flag for all brands that usually
allow executing elf dynamic binaries (aka shared libraries). When it is
requested to execute ET_DYN elf image check if this flag is on after we
know the elf brand allowing execution if so.

PR: kern/87615
Submitted by: Marcin Koziej <creep@desk.pl>

Remove linux_mib_destroy() (which I actually added in between 5.0 and 5.1)
which existed to cleanup the linux_osname mutex. Now that MTX_SYSINIT()
has grown a SYSUNINIT to destroy mutexes on unload, the extra destroy here
was redundant and resulted in panics in debug kernels.

MFC after: 1 week
Reported by: Goran Gajic ggajic at afrodita dot rcub dot bg dot ac dot yu

The signal code is now an int rather than a long, so update debug printfs.

1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.

2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.

3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.

4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.

5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.

6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.

Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64

Propagate error code of kern_execve() to the caller properly.

PR: 81670
Submitted by: Andrew Bliznak <andriko.b@gmail.com>
Pointy hat to: sobomax

Move MODULE_DEPEND() statements for SYSVIPC dependencies to linux_ipc.c
so that they aren't duplicated 3 times and are also in the same file as
the code that depends on the SYSVIPC modules.

Regen.

Make a pass through all the compat ABIs sychronizing the MP safe flags
with the master syscall table as well as marking several ABI wrapper
functions safe.

MFC after: 1 week

Remove the CPU_ENABLE_SSE option from the i386 and pc98 architectures,
as they are already default for I686_CPU for almost 3 years, and
CPU_DISABLE_SSE always disables it. On the other hand, CPU_ENABLE_SSE
does not work for I486_CPU and I586_CPU.

This commit has:
- Removed the option from conf/options.*
- Removed the option and comments from MD NOTES files
- Simplified the CPU_ENABLE_SSE ifdef's so they don't
deal with CPU_ENABLE_SSE from kernel configuration. (*)

For most users, this commit should be largely no-op. If you used to
place CPU_ENABLE_SSE into your kernel configuration for some reason,
it is time to remove it.

(*) The ifdef's of CPU_ENABLE_SSE are not removed at this point, since
we need to change it to !defined(CPU_DISABLE_SSE) && defined(I686_CPU),
not just !defined(CPU_DISABLE_SSE), if we really want to do so.

Discussed on: -arch
Approved by: re (scottl)

Regen after addition of linux_getpriority wrapper.

PR: kern/81951
Submitted by: Andriy Gapon <avg@icyb.net.ua>
MFC after: 1 week

Properly convert FreeBSD priority values into Linux values in the
getpriority(2) syscall.

PR: kern/81951
Submitted by: Andriy Gapon <avg@icyb.net.ua>

Rebuild generated system call definition files following the addition of
the audit event field to the syscalls.master file format.

Submitted by: wsalamon
Obtained from: TrustedBSD Project

Introduce a new field in the syscalls.master file format to hold the
audit event identifier associated with each system call, which will
be stored by makesyscalls.sh in the sy_auevent field of struct sysent.
For now, default the audit identifier on all system calls to AUE_NULL,
but in the near future, other BSM event identifiers will be used. The
mapping of system calls to event identifiers is many:one due to
multiple system calls that map to the same end functionality across
compatibility wrappers, ABI wrappers, etc.

Submitted by: wsalamon
Obtained from: TrustedBSD Project

Add support for O_NOFOLLOW and O_DIRECT to Linux fcntl() F_GETFL/F_SETFL.

- Change the vm_mmap() function to accept an objtype_t parameter specifying
the type of object represented by the handle argument.
- Allow vm_mmap() to map device memory via cdev objects in addition to
vnodes and anonymous memory. Note that mmaping a cdev directly does not
currently perform any MAC checks like mapping a vnode does.
- Unbreak the DRM getbufs ioctl by having it call vm_mmap() directly on the
cdev the ioctl is acting on rather than trying to find a suitable vnode
to map from.

Reviewed by: alc, arch@

Regen after addition of linux_nosys handler.

Handle unimplemented syscall by instantly returning ENOSYS instead of sending
signal first and only then returning ENOSYS to match what real linux does.

PR: kern/74302
Submitted by: Travis Poppe <tlp@LiquidX.org>

In linux emulation layer try to detect attempt to use linux_clone() to
create kernel threads and call rfork(2) with RFTHREAD flag set in this case,
which puts parent and child into the same threading group. As a result
all threads that belong to the same program end up in the same threading
group.

This is similar to what linuxthreads port does, though in this case we don't
have a luxury of having access to the source code and there is no definite
way to differentiate linux_clone() called for threading purposes from other
uses, so that we have to resort to heuristics.

Allow SIGTHR to be delivered between all processes in the same threading
group previously it has been blocked for s[ug]id processes.

This also should improve locking of the same file descriptor from different
threads in programs running under linux compat layer.

PR: kern/72922
Reported by: Andriy Gapon <avg@icyb.net.ua>
Idea suggested by: rwatson

Use linux_emul_convpath() rather than linux_emul_find() as
linux_emul_find() is going away.

Use the LCONVPATHEXIST() macro rather than it's exact expansion to be
consistent.

When running Linux binaries, set up the initial FPU state as Linux
would.

PR: 28966

o Split out kernel part of execve(2) syscall into two parts: one that
copies arguments into the kernel space and one that operates
completely in the kernel space;

o use kernel-only version of execve(2) to kill another stackgap in
linuxlator/i386.

Obtained from: DragonFlyBSD (partially)
MFC after: 2 weeks

o Move copyin()/copyout() out of i386_{get,set}_ldt() and
i386_{get,set}_ioperm() and make those APIs visible in the kernel namespace;

o use i386_{get,set}_ldt() and i386_{get,set}_ioperm() instead of sysarch()
in the linuxlator, which allows to kill another two stackgaps.

MFC after: 2 weeks

/* -> /*- for copyright notices, minor format tweaks as necessary

Axe the semblance of support for PECOFF and Linux a.out core dumps.

Maintain the broken state of backwards compatibilty for a.out (and
PECOFF!) core dumps. None of the old versions of gdb I tried were
able to read a.out core dumps before or after this change.

Reviewed by: arch@

Fix the following race:

1. Process p1 is currently being swapped in.
2. Process p2 calls linux_ptrace(PTRACE_GETFPXREGS, p1_pid, ...)
3. After acquiring a reference to FIRST_THREAD_IN_PROC(p1),
p2 blocks in faultin() while p1 finishes being swapped in.
This means p2 won't get back the lock on p1 until after p1's
threads are runnable.
4. After p1 is swapped in, the first thread in p1 exits.
5. p2 now uses its dangling reference to p1's first thread.

Regen.

Add a few stub syscalls to get TransGaming's winex a bit closer to
working.

Give setrunqueue() and sched_add() more of a clue as to
where they are coming from and what is expected from them.

MFC after: 2 days

Correct the arguments to kern_sigaltstack() as they were reversed.

PR: kern/68079
Submitted by: Georg-W. Koltermann gwk at rahn-koltermann dot de

Regenerate after fcntl() wrappers were marked MP safe.

Fix the ABI wrappers to use kern_fcntl() rather than calling fcntl()
directly. This removes a few more users of the stackgap and also marks
the syscalls using these wrappers MP safe where appropriate.

Tested on: i386 with linux acroread5
Compiled on: i386, alpha LINT

Add a new type, l_uintptr_t, which is an unsigned integer type with the
same width as a pointer under Linux. Add two new macros, PTRIN and PTROUT,
which convert between l_uintptr_t and native pointers.

Do a pass over all modules in the kernel and make them return EOPNOTSUPP
for unknown events.

A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".

Consistently use __inline instead of __inline__ as the former is an empty macro
in <sys/cdefs.h> for compilers without support for inline.

Add casts so all these quantities are a constant type.

Change the types of vn_rdwr_inchunks()'s len and aresid arguments to
size_t and size_t *, respectively. Update callers for the new interface.
This is a better fix for overflows that occurred when dumping segments
larger than 2GB to core files.

Use the BSD madvise() syscall implementation for Linux binary emulation,
instead of treating it as an unimplemented syscall. This appears to make
StarOffice 7.0 Linux binaries work according to submitter; also tested
with nvidia driver by submitter.

Submitted by: Matthias Schuendehuette

Regenerate.

- Mark ABI syscalls that call wait4() MP safe as recent changes to
the kernel wait4() made these all panic() implementations otherwise.
- The i386 linux_ptrace() syscall is MP safe. Alpha was already marked
MP safe.

Regen.

The following compat syscalls are now mpsafe: linux_getrlimit(),
linux_setrlimit(), linux_old_getrlimit(), osf1_getrlimit(),
osf1_setrlimit(), svr4_sys_ulimit(), svr4_sys_setrlimit(),
svr4_sys_getrlimit(), svr4_sys_setrlimit64(), svr4_sys_getrlimit64(),
ibcs2_sysconf(), and ibcs2_ulimit().

Locking for the per-process resource limits structure.
- struct plimit includes a mutex to protect a reference count. The plimit
structure is treated similarly to struct ucred in that is is always copy
on write, so having a reference to a structure is sufficient to read from
it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
limits from a process to keep the limit structure from changing out from
under you while reading from it.
- Various global limits that are ints are not protected by a lock since
int writes are atomic on all the archs we support and thus a lock
wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
either an rlimit, or the current or max individual limit of the specified
resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
(it didn't used the stackgap when it should have) but uses lim_rlimit()
and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits. It
also no longer uses the stackgap for accessing sysctl's for the
ibcs2_sysconf() syscall but uses kernel_sysctl() instead. As a result,
ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.

Submitted by: mtm (mostly, I only did a few cleanups and catchups)
Tested on: i386
Compiled on: alpha, amd64

Make sigaltstack as per-threaded, because per-process sigaltstack state
is useless for threaded programs, multiple threads can not share same
stack.
The alternative signal stack is private for thread, no lock is needed,
the orignal P_ALTSTACK is now moved into td_pflags and renamed to
TDP_ALTSTACK.
For single thread or Linux clone() based threaded program, there is no
semantic changed, because those programs only have one kernel thread
in every process.

Make sigaltstack as per-threaded, because per-process sigaltstack state
is useless for threaded programs, multiple threads can not share same
stack.
The alternative signal stack is private for thread, no lock is needed,
the orignal P_ALTSTACK is now moved into td_pflags and renamed to
TDP_ALTSTACK.
For single thread or Linux clone() based threaded program, there is no
semantic changed, because those programs only have one kernel thread
in every process.

Reviewed by: deischen, dfr

Sorted includes. Removed duplicates exposed by this.

GC unused 'syshide' override to /dev/null. This was here to disable
the output of the namespc column. Its functionality was removed some time
ago, but the overrides and the namespc column remained.

Regen (should be a NOP except for rcsid changes)

GC unused third namespace column.

Add an additional field to the elf brandinfo structure to support
quicker exec-time replacement of the elf interpreter on an emulation
environment where an entire /compat/* tree isn't really warranted.

Pull latest changes from OpenBSD:

- improve sysinfo(2) syscall;
- add dummy fadvise64(2) syscall;
- add dummy *xattr(2) family of syscalls;
- add protos for the syscalls 222-225, 238-249 and 253-267;
- add exit_group(2) syscall, which is currently just wired to exit(2).

Obtained from: OpenBSD
MFC after: 2 weeks

Regen.

Sync up MP safe flags with global syscalls.master for the first time. This
includes read(), write(), close(), linux_setuid16(), linux_getuid16(),
linux_pause(), linux_nice(), linux_kill(), dup(), linux_pipe(),
linux_setgid16(), linux_getgid16(), linux_signal(), linux_geteuid16(),
linux_getegid16(), acct(), setpgid(), umask(), dup2(), getppid(),
getpgrp(), setsid(), linux_sigaction(), linux_sgetmask(), linux_ssetmask(),
linux_setreuid16(), linux_setregid16(), linux_sigsuspend(), getrusage(),
gettimeofday(), linux_getgroups16(), linux_setgroups16(), getpriority(),
setpriority(), linux_sigreturn(), linux_clone(), linux_sigprocmask(),
linux_getsid(), mlock(), munlock(), mlockall(), munlockall(),
sched_setparam(), sched_getparam(), linux_sched_setscheduler(),
linux_sched_getscheduler(), linux_sched_get_priority_max(),
linux_sched_get_priority_min(), sched_rr_get_interval(),
linux_setresuid16(), linux_getresuid16(), linux_setresgid16(),
linux_getresgid16(), linux_rt_sigaction(), linux_rt_sigprocmask(),
linux_rt_sigsuspend(), geteuid(), getegid(), setreuid(), setregid(),
linux_getgroups(), linux_setgroups(), setresuid(), getresuid(),
setresgid(), getresgid(), setuid(), and setgid().

Add sysentvec->sv_fixlimits() hook so that we can catch cases on 64 bit
systems where the data/stack/etc limits are too big for a 32 bit process.

Move the 5 or so identical instances of ELF_RTLD_ADDR() into imgact_elf.c.

Supply an ia32_fixlimits function. Export the clip/default values to
sysctl under the compat.ia32 heirarchy.

Have mmap(0, ...) respect the current p->p_limits[RLIMIT_DATA].rlim_max
value rather than the sysctl tweakable variable. This allows mmap to
place mappings at sensible locations when limits have been reduced.

Have the imgact_elf.c ld-elf.so.1 placement algorithm use the same
method as mmap(0, ...) now does.

Note that we cannot remove all references to the sysctl tweakable
maxdsiz etc variables because /etc/login.conf specifies a datasize
of 'unlimited'. And that causes exec etc to fail since it can no
longer find space to mmap things.

Restored non-egregious casts so that this file compiles on i386's with
64-bit longs again.

Rename P_THREADED to P_SA. P_SA means a process is using scheduler
activations.

Use __FBSDID().

- Merge struct procsig with struct sigacts.
- Move struct sigacts out of the u-area and malloc() it using the
M_SUBPROC malloc bucket.
- Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(),
sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared().
- Remove the p_sigignore, p_sigacts, and p_sigcatch macros.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Add sigacts locking.
- Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now
that sigacts is locked.
- Several in-kernel functions such as psignal(), tdsignal(), trapsignal(),
and thread_stopped() are now MP safe.

Reviewed by: arch@
Approved by: re (rwatson)

Provide exec_linux_setregs() to override exec_setregs().
Linux initializes %gs to 0. Mimic this behavior.

Submitted by: Christian Zander <zander@minion.de>
Reviewed by: jake
Approved by: re

Prefer the proc lock to sched_lock when testing PS_INMEM now that it is
safe to do so.

Synchronize the two linux_clone() implementations which includes a few
minor cleanups in both.

Don't drop the proc lock just to reacquire it after a few simple assignment
statements. Just hold the lock the entire time.

Sync up with changes to ptrace() and use P_SHOULDSTOP instead of
a duplicate P_TRACED check.

Submitted by: marcel

- Move p->p_sigmask to td->td_sigmask. Signal masks will be per thread with
a follow on commit to kern_sig.c
- signotify() now operates on a thread since unmasked pending signals are
stored in the thread.
- PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.

- Change trapsignal() to accept a thread and not a proc.
- Change all consumers to pass in a thread.

Right now this does not cause any functional changes but it will be important
later when signals can be delivered to specific threads.

Add missing includes from previous commit.

Reported by: des

Add a cleanup function to destroy the osname_lock and call it on module
unload.

Submitted by: gallatin
Reported by: Martin Karlsson <mk-freebsd@bredband.net>

Print the return value from mmap() in the DEBUG case.

Sync up linux and svr compat elf fixup functions for exec(). These
functions are now all basically identical except that alpha linux uses
Elf64 arguments and svr4 and i386 linux use Elf32. The fixups include
changing the first argument to be a register_t ** to match the prototype
for fixup functions, asserting that the process in the image_params struct
is always curproc and removing unnecessary locking to read credentials as a
result, and a few style fixes.

Including <sys/stdint.h> is (almost?) universally only to be able to use
%j in printfs, so put a newsted include in <sys/systm.h> where the printf
prototype lives and save everybody else the trouble.

Clean up whitespace and remove register keyword.

More caddr_t removal, in conjunction with copy{in,out}(9) this time.
Also clean up some egregious casts and incorrect use of sizeof.

Correctly map SIGSYS signal to/from Linux.

Submitted by: "Georg-W. Koltermann" <g.w.k@web.de>

Regen from syscalls.master 1.50.

Mark linux_getpid(), linux_getuid() and linux_getgid() as MPSAFE.

Back out M_* changes, per decision of the TRB.

Approved by: trb

Mark linux_sigpending() as MPSAFE.

Regen from syscalls.master 1.49.

Add IPv6 support for Linuxlator.

Reviewed by: dwmalone
MFC after: 10 days

Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.

bzero() the sigframe before we fill it. This was not done at all in
linux_rt_sendsig() and only done for the fpstate in linux_sendsig().

Style(9). Make some function declarations consistent with the rest,
and remove some nearby extraneous {}'s.

Fixed syntax errors and printf format errors.

- Add support for IPC_64 extensions into shmctl(2), semctl(2) and msgctl(2);
- add wrappers for mmap2(2) and ftruncate64(2) system calls;
- don't spam console with printf's when VFAT_READDIR_BOTH ioctl(2) is invoked;
- add support for SOUND_MIXER_READ_STEREODEVS ioctl(2);
- make msgctl(IPC_STAT) and IPC_SET actually working by converting from
BSD msqid_ds to Linux and vice versa;
- properly return EINVAL if semget(2) is called with nsems being negative.

Reviewed by: marcel
Approved by: marcel
Tested with: LSB runtime test

Some kernel threads try to do significant work, and the default KSTACK_PAGES
doesn't give them enough stack to do much before blowing away the pcb.
This adds MI and MD code to allow the allocation of an alternate kstack
who's size can be speficied when calling kthread_create. Passing the
value 0 prevents the alternate kstack from being created. Note that the
ia64 MD code is missing for now, and PowerPC was only partially written
due to the pmap.c being incomplete there.
Though this patch does not modify anything to make use of the alternate
kstack, acpi and usb are good candidates.

Reviewed by: jake, peter, jhb

Back out last commit. Linux uses the old 4.3BSD sockaddr format.

Don't use compatability syscall wrappers in emulation code.
This is needed for the COMPAT_FREEBSD3 option split.

Reviewed by: alfred, jake

Use the fields in the sysentvec and in the vm map header in place of the
constants VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS, USRSTACK and PS_STRINGS.
This is mainly so that they can be variable even for the native abi, based
on different machine types. Get stack protections from the sysentvec too.
This makes it trivial to map the stack non-executable for certain abis, on
machines that support it.

Removed unused includes. Sorted includes. This is part of removing
includes of <sys/user.h> for its pollution only. <sys/user.h> wasn't
even used for its pollution here.

Completely redo thread states.

Reviewed by: davidxu@freebsd.org

Tidy up some loose ends that bde pointed out. caddr_t bad, ok?
Move fill_kinfo_proc to before we copy the results instead of after
the copy and too late.

There is still more to do here.

The true value of how the kernel was configured for KSTACK_PAGES was not
available at module compile time. Do not #include the bogus
opt_kstack_pages.h at this point and instead refer to the variables that
are also exported via sysctl.

Diff reduction in comments for filling the siginfo structure - refer to
filling in the POSIX parts, when doing the same thing in every port of
FreeBSD.

Include <machine/pcb.h> instead of depending on namespace pollution in
<sys/user.h>.

Automatically enable CPU_ENABLE_SSE (detect and enable SSE instructions)
if compiling with I686_CPU as a target. CPU_DISABLE_SSE will prevent
this from happening and will guarantee the code is not compiled in.

I am still not happy with this, but gcc is now generating code that uses
these instructions if you set CPUTYPE to p3/p4 or athlon-4/mp/xp or higher.

Supposedly linux has added a 6th syscall arg register (%ebp). I am not
100% sure if this is enough, but it will not harm anything.

Give this a self contained a.out coredump routine.
XXX freebsd-aout coredumps for a linux-aout binary is a bit pointless.

Include <sys/systm.h> for the definition of offsetof() instead of depending
on the definition being misplaced in <sys/types.h>. The definition probably
belongs in <sys/stddef.h>.

Split up ptrace() into a wrapper that does the copying to and from
user space and a kern_ptrace() implementation. Use the kern_*()
version in the Linux emulation code to remove more stack gap uses.

Approved by: des

Use the new kern_* functions to avoid the need to store arguments
in the stack gap. This converts most VFS and signal related system
calls, as well as select().

Discussed on: -arch
Approved by: marcel

Added fields for VM_MIN_ADDRESS, PS_STRINGS and stack protections to
sysentvec. Initialized all fields of all sysentvecs, which will allow
them to be used instead of constants in more places. Provided stack
fixup routines for emulations that previously used the default.

- Hold the vnode lock throughout execve.
- Set VV_TEXT in the top level execve code.
- Fixup the image activators to deal with the newly locked vnode.

- Replace v_flag with v_iflag and v_vflag
- v_vflag is protected by the vnode lock and is used when synchronization
with VOP calls is needed.
- v_iflag is protected by interlock and is used for dealing with vnode
management issues. These flags include X/O LOCK, FREE, DOOMED, etc.
- All accesses to v_iflag and v_vflag have either been locked or marked with
mp_fixme's.
- Many ASSERT_VOP_LOCKED calls have been added where the locking was not
clear.
- Many functions in vfs_subr.c were restructured to provide for stronger
locking.

Idea stolen from: BSD/OS

Infrastructure tweaks to allow having both an Elf32 and an Elf64 executable
handler in the kernel at the same time. Also, allow for the
exec_new_vmspace() code to build a different sized vmspace depending on
the executable environment. This is a big help for execing i386 binaries
on ia64. The ELF exec code grows the ability to map partial pages when
there is a page size difference, eg: emulating 4K pages on 8K or 16K
hardware pages.

Flesh out the i386 emulation support for ia64. At this point, the only
binary that I know of that fails is cvsup, because the cvsup runtime
tries to execute code in pages not marked executable.

Obtained from: dfr (mostly, many tweaks from me).

Enable emulation of the F_GETLK64, F_SETLK64, and F_SETLKW64
lock commands arguments to linux_fcntl64().

Part 1 of KSE-III

The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)

Reviewed by: Almost everyone who counts
(at various times, peter, jhb, matt, alfred, mini, bernd,
and a cast of thousands)

NOTE: this is still Beta code, and contains lots of debugging stuff.
expect slight instability in signals..

Fix typo in the BSD copyright: s/withough/without/

Spotted and suggested by: des
MFC after: 3 weeks

o Fix race condition caused by doing ptrace() for permission
checking, followed by a lookup of the process. Do not call
ptrace() for permission checking, but do it inline.
Spotted by: rwatson

o While here, copy-in arguments before we lock. This fixes
a possible permanent lock.

Reviewed by: rwatson

Hook up the new linux_ptrace implementation.

PR: 33299
Submitted by: Alexander N. Kabaev <ak03@gte.com>

Regen (linux_ptrace)

PR: 33299

Sparkling new implementation of linux_ptrace. Slight tweaking by
yours truly.

PR: 33299
Submitted by: Alexander N. Kabaev <ak03@gte.com>

Spell "separate" correctly.

Moved signal handling and rescheduling from userret() to ast() so that
they aren't in the usual path of execution for syscalls and traps.
The main complication for this is that we have to set flags to control
ast() everywhere that changes the signal mask.

Avoid locking in userret() in most of the remaining cases.

Submitted by: luoqi (first part only, long ago, reorganized by me)
Reminded by: dillon

Change the suser() API to take advantage of td_ucred as well as do a
general cleanup of the API. The entire API now consists of two functions
similar to the pre-KSE API. The suser() function takes a thread pointer
as its only argument. The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0. The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.

Discussed on: smp@

Fixed some style bugs in the removal of __P(()). Continuation lines
were not outdented to preserve non-KNF lining up of code with parentheses.
Switch to KNF formatting.

Remove __P.

Eliminate unnecessary calls to grow_stack() and useracc() from linux_sendsig()
and linux_rt_sendsig(). (See i386/i386/machdep.c revisions 1.503 and 1.504.)

Fix format warning.

Submitted by: LINT, -Werror

Simple p_ucred -> td_ucred changes to start using the per-thread ucred
reference.

Pre-KSE/M3 commit.
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.

Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,

Clear the single-step flag for signal handlers. This fixes bogus trace
traps on the first instruction of signal handlers.

In trap.c:syscall(), fake a trace trap if the single-step flag was set
on entry to the kernel, not if it will be set on exit from the kernel.
This fixes bogus trace traps after the last instruction of signal handlers.

gdb-4.18 (the version in FreeBSD) still has problems with the program in
the PR. These seem to be due to bugs in gdb and not in FreeBSD, and are
fixed in gdb-5.1 (the distribution version).

PR: 33262
Tested by: k Macy <kip_macy@yahoo.com>
MFC after: 1 day

Convert BSD trap codes to i386.

Submitted by: F. Gouget <fgouget@free.fr>

Eliminate the prefix parameter to linux_emul_find(), which was always
linux_emul_path anyway. Linux_emul_find() has interesting bugs in its
prefix handling (which luckily are not currently exploitable); this
commit is preliminary to an attempt at cleaning it up.

Approved by: marcel

Implement linux_chown and linux_lchown. The fchown syscall maps
directly to the native syscall, because no filename handling
needs to be done.

Tested by: Martin Blapp <mb@imp.ch>