cloudabi32_sysvec.c revision 316576
1/*- 2 * Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/ 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26#include <sys/cdefs.h> 27__FBSDID("$FreeBSD: stable/11/sys/i386/cloudabi32/cloudabi32_sysvec.c 316576 2017-04-06 15:19:18Z kib $"); 28 29#include <sys/param.h> 30#include <sys/imgact.h> 31#include <sys/kernel.h> 32#include <sys/proc.h> 33#include <sys/sysent.h> 34 35#include <vm/vm.h> 36#include <vm/pmap.h> 37 38#include <machine/frame.h> 39#include <machine/pcb.h> 40#include <machine/vmparam.h> 41 42#include <compat/cloudabi/cloudabi_util.h> 43 44#include <compat/cloudabi32/cloudabi32_syscall.h> 45#include <compat/cloudabi32/cloudabi32_util.h> 46 47extern const char *cloudabi32_syscallnames[]; 48extern struct sysent cloudabi32_sysent[]; 49 50static int 51cloudabi32_fixup_tcb(register_t **stack_base, struct image_params *imgp) 52{ 53 int error; 54 uint32_t args[2]; 55 56 /* Place auxiliary vector and TCB on the stack. */ 57 error = cloudabi32_fixup(stack_base, imgp); 58 if (error != 0) 59 return (error); 60 61 /* 62 * On i386, the TCB is referred to by %gs:0. Reuse the empty 63 * space normally used by the return address (args[0]) to store 64 * a single element array, containing a pointer to the TCB. %gs 65 * base will point to this. 66 * 67 * Also let the first argument of the entry point (args[1]) 68 * refer to the auxiliary vector, which is stored right after 69 * the TCB. 70 */ 71 args[0] = (uintptr_t)*stack_base; 72 args[1] = (uintptr_t)*stack_base + 73 roundup(sizeof(cloudabi32_tcb_t), sizeof(register_t)); 74 *stack_base -= howmany(sizeof(args), sizeof(register_t)); 75 return (copyout(args, *stack_base, sizeof(args))); 76} 77 78static void 79cloudabi32_proc_setregs(struct thread *td, struct image_params *imgp, 80 unsigned long stack) 81{ 82 83 exec_setregs(td, imgp, stack); 84 (void)cpu_set_user_tls(td, (void *)stack); 85} 86 87static int 88cloudabi32_fetch_syscall_args(struct thread *td, struct syscall_args *sa) 89{ 90 struct trapframe *frame = td->td_frame; 91 int error; 92 93 /* Obtain system call number. */ 94 sa->code = frame->tf_eax; 95 if (sa->code >= CLOUDABI32_SYS_MAXSYSCALL) 96 return (ENOSYS); 97 sa->callp = &cloudabi32_sysent[sa->code]; 98 sa->narg = sa->callp->sy_narg; 99 100 /* Fetch system call arguments from the stack. */ 101 error = copyin((void *)(frame->tf_esp + 4), sa->args, 102 sa->narg * sizeof(sa->args[0])); 103 if (error != 0) 104 return (error); 105 106 /* Default system call return values. */ 107 td->td_retval[0] = 0; 108 td->td_retval[1] = frame->tf_edx; 109 return (0); 110} 111 112static void 113cloudabi32_set_syscall_retval(struct thread *td, int error) 114{ 115 struct trapframe *frame = td->td_frame; 116 117 switch (error) { 118 case 0: 119 /* System call succeeded. */ 120 frame->tf_eax = td->td_retval[0]; 121 frame->tf_edx = td->td_retval[1]; 122 frame->tf_eflags &= ~PSL_C; 123 break; 124 case ERESTART: 125 /* Restart system call. */ 126 frame->tf_eip -= frame->tf_err; 127 break; 128 case EJUSTRETURN: 129 break; 130 default: 131 /* System call returned an error. */ 132 frame->tf_eax = cloudabi_convert_errno(error); 133 frame->tf_eflags |= PSL_C; 134 break; 135 } 136} 137 138static void 139cloudabi32_schedtail(struct thread *td) 140{ 141 struct trapframe *frame = td->td_frame; 142 143 /* Initial register values for processes returning from fork. */ 144 frame->tf_eax = CLOUDABI_PROCESS_CHILD; 145 frame->tf_edx = td->td_tid; 146} 147 148int 149cloudabi32_thread_setregs(struct thread *td, 150 const cloudabi32_threadattr_t *attr, uint32_t tcb) 151{ 152 stack_t stack; 153 uint32_t args[3]; 154 void *frameptr; 155 int error; 156 157 /* Perform standard register initialization. */ 158 stack.ss_sp = TO_PTR(attr->stack); 159 stack.ss_size = attr->stack_len - sizeof(args); 160 cpu_set_upcall(td, TO_PTR(attr->entry_point), NULL, &stack); 161 162 /* 163 * Copy the arguments for the thread entry point onto the stack 164 * (args[1] and args[2]). Similar to process startup, use the 165 * otherwise unused return address (args[0]) for TLS. 166 */ 167 args[0] = tcb; 168 args[1] = td->td_tid; 169 args[2] = attr->argument; 170 frameptr = (void *)td->td_frame->tf_esp; 171 error = copyout(args, frameptr, sizeof(args)); 172 if (error != 0) 173 return (error); 174 175 return (cpu_set_user_tls(td, frameptr)); 176} 177 178static struct sysentvec cloudabi32_elf_sysvec = { 179 .sv_size = CLOUDABI32_SYS_MAXSYSCALL, 180 .sv_table = cloudabi32_sysent, 181 .sv_fixup = cloudabi32_fixup_tcb, 182 .sv_name = "CloudABI ELF32", 183 .sv_coredump = elf32_coredump, 184 .sv_pagesize = PAGE_SIZE, 185 .sv_minuser = VM_MIN_ADDRESS, 186 .sv_maxuser = VM_MAXUSER_ADDRESS, 187 .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE, 188 .sv_copyout_strings = cloudabi32_copyout_strings, 189 .sv_setregs = cloudabi32_proc_setregs, 190 .sv_flags = SV_ABI_CLOUDABI | SV_CAPSICUM | SV_IA32 | SV_ILP32, 191 .sv_set_syscall_retval = cloudabi32_set_syscall_retval, 192 .sv_fetch_syscall_args = cloudabi32_fetch_syscall_args, 193 .sv_syscallnames = cloudabi32_syscallnames, 194 .sv_schedtail = cloudabi32_schedtail, 195}; 196 197INIT_SYSENTVEC(elf_sysvec, &cloudabi32_elf_sysvec); 198 199Elf32_Brandinfo cloudabi32_brand = { 200 .brand = ELFOSABI_CLOUDABI, 201 .machine = EM_386, 202 .sysvec = &cloudabi32_elf_sysvec, 203 .flags = BI_BRAND_ONLY_STATIC, 204}; 205