ia32_signal.c
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- /*
- * linux/arch/x86_64/ia32/ia32_signal.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- *
- * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
- * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
- * 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen
- *
- * $Id: ia32_signal.c,v 1.22 2002/07/29 10:34:03 ak Exp $
- */
- #include <linux/sched.h>
- #include <linux/mm.h>
- #include <linux/smp.h>
- #include <linux/smp_lock.h>
- #include <linux/kernel.h>
- #include <linux/signal.h>
- #include <linux/errno.h>
- #include <linux/wait.h>
- #include <linux/ptrace.h>
- #include <linux/unistd.h>
- #include <linux/stddef.h>
- #include <linux/personality.h>
- #include <asm/ucontext.h>
- #include <asm/uaccess.h>
- #include <asm/i387.h>
- #include <asm/ia32.h>
- #include <asm/ptrace.h>
- #include <asm/ia32_unistd.h>
- #include <asm/user32.h>
- #include <asm/sigcontext32.h>
- #include <asm/fpu32.h>
- #define ptr_to_u32(x) ((u32)(u64)(x)) /* avoid gcc warning */
- #define DEBUG_SIG 0
- #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
- asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
- void signal_fault(struct pt_regs *regs, void *frame, char *where);
- static int ia32_copy_siginfo_to_user(siginfo_t32 *to, siginfo_t *from)
- {
- if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t)))
- return -EFAULT;
- if (from->si_code < 0)
- return __copy_to_user(to, from, sizeof(siginfo_t));
- else {
- int err;
- /* If you change siginfo_t structure, please be sure
- this code is fixed accordingly.
- It should never copy any pad contained in the structure
- to avoid security leaks, but must copy the generic
- 3 ints plus the relevant union member. */
- err = __put_user(from->si_signo, &to->si_signo);
- err |= __put_user(from->si_errno, &to->si_errno);
- err |= __put_user((short)from->si_code, &to->si_code);
- /* First 32bits of unions are always present. */
- err |= __put_user(from->si_pid, &to->si_pid);
- switch (from->si_code >> 16) {
- case __SI_FAULT >> 16:
- break;
- case __SI_CHLD >> 16:
- err |= __put_user(from->si_utime, &to->si_utime);
- err |= __put_user(from->si_stime, &to->si_stime);
- err |= __put_user(from->si_status, &to->si_status);
- default:
- err |= __put_user(from->si_uid, &to->si_uid);
- break;
- /* case __SI_RT: This is not generated by the kernel as of now. */
- }
- return err;
- }
- }
- asmlinkage int
- sys32_sigsuspend(int history0, int history1, old_sigset_t mask, struct pt_regs regs)
- {
- sigset_t saveset;
- mask &= _BLOCKABLE;
- spin_lock_irq(¤t->sigmask_lock);
- saveset = current->blocked;
- siginitset(¤t->blocked, mask);
- recalc_sigpending(current);
- spin_unlock_irq(¤t->sigmask_lock);
- regs.rax = -EINTR;
- while (1) {
- current->state = TASK_INTERRUPTIBLE;
- schedule();
- if (do_signal(®s, &saveset))
- return -EINTR;
- }
- }
- asmlinkage int
- sys32_sigaltstack(const stack_ia32_t *uss_ptr, stack_ia32_t *uoss_ptr,
- struct pt_regs regs)
- {
- stack_t uss,uoss;
- int ret;
- mm_segment_t seg;
- if (!access_ok(VERIFY_READ,uss_ptr,sizeof(stack_ia32_t)) ||
- __get_user(ptr_to_u32(uss.ss_sp), &uss_ptr->ss_sp) ||
- __get_user((u32)uss.ss_flags, &uss_ptr->ss_flags) ||
- __get_user((u32)uss.ss_size, &uss_ptr->ss_size))
- return -EFAULT;
- seg = get_fs();
- set_fs(KERNEL_DS);
- ret = do_sigaltstack(&uss, &uoss, regs.rsp);
- set_fs(seg);
- if (ret >= 0 && uoss_ptr) {
- if (!access_ok(VERIFY_WRITE,uss_ptr,sizeof(stack_ia32_t)) ||
- __put_user(ptr_to_u32(uss.ss_sp), &uss_ptr->ss_sp) ||
- __put_user((u32)uss.ss_flags, &uss_ptr->ss_flags) ||
- __put_user((u32)uss.ss_size, &uss_ptr->ss_size))
- ret = -EFAULT;
- }
- return ret;
- }
- /*
- * Do a signal return; undo the signal stack.
- */
- struct sigframe
- {
- u32 pretcode;
- int sig;
- struct sigcontext_ia32 sc;
- struct _fpstate_ia32 fpstate;
- unsigned int extramask[_IA32_NSIG_WORDS-1];
- char retcode[8];
- };
- struct rt_sigframe
- {
- u32 pretcode;
- int sig;
- u32 pinfo;
- u32 puc;
- struct siginfo32 info;
- struct ucontext_ia32 uc;
- struct _fpstate_ia32 fpstate;
- char retcode[8];
- };
- static int
- ia32_restore_sigcontext(struct pt_regs *regs, struct sigcontext_ia32 *sc, unsigned int *peax)
- {
- unsigned int err = 0;
-
- #if DEBUG_SIG
- printk("SIG restore_sigcontext: sc=%p err(%x) eip(%x) cs(%x) flg(%x)n",
- sc, sc->err, sc->eip, sc->cs, sc->eflags);
- #endif
- #define COPY(x) {
- unsigned int reg;
- err |= __get_user(reg, &sc->e ##x);
- regs->r ## x = reg;
- }
- #define RELOAD_SEG(seg,mask)
- { unsigned int cur;
- unsigned short pre;
- err |= __get_user(pre, &sc->seg);
- asm volatile("movl %%" #seg ",%0" : "=r" (cur));
- pre |= mask;
- if (pre != cur) loadsegment(seg,pre); }
- /* Reload fs and gs if they have changed in the signal handler.
- This does not handle long fs/gs base changes in the handler, but
- does not clobber them at least in the normal case. */
-
- {
- unsigned short gs;
- err |= __get_user(gs, &sc->gs);
- load_gs_index(gs);
- }
- RELOAD_SEG(fs,0);
- RELOAD_SEG(ds,0);
- RELOAD_SEG(es,0);
- COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
- COPY(dx); COPY(cx); COPY(ip);
- /* Don't touch extended registers */
- #if 1 /* not ready for this yet */
- err |= __get_user(regs->cs, &sc->cs);
- regs->cs |= 2;
- err |= __get_user(regs->ss, &sc->ss);
- regs->ss |= 2;
- #else
- regs->cs = __USER32_CS;
- regs->ss = __USER32_DS;
- #endif
-
- {
- unsigned int tmpflags;
- err |= __get_user(tmpflags, &sc->eflags);
- regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
- regs->orig_rax = -1; /* disable syscall checks */
- }
- {
- u32 tmp;
- struct _fpstate_ia32 * buf;
- err |= __get_user(tmp, &sc->fpstate);
- buf = (struct _fpstate_ia32 *) (u64)tmp;
- if (buf) {
- if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
- goto badframe;
- err |= restore_i387_ia32(current, buf, 0);
- }
- }
- {
- u32 tmp;
- err |= __get_user(tmp, &sc->eax);
- *peax = tmp;
- }
- return err;
- badframe:
- return 1;
- }
- asmlinkage int sys32_sigreturn(struct pt_regs regs)
- {
- struct sigframe *frame = (struct sigframe *)(regs.rsp - 8);
- sigset_t set;
- unsigned int eax;
- if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
- goto badframe;
- if (__get_user(set.sig[0], &frame->sc.oldmask)
- || (_IA32_NSIG_WORDS > 1
- && __copy_from_user((((char *) &set.sig) + 4), &frame->extramask,
- sizeof(frame->extramask))))
- goto badframe;
- sigdelsetmask(&set, ~_BLOCKABLE);
- spin_lock_irq(¤t->sigmask_lock);
- current->blocked = set;
- recalc_sigpending(current);
- spin_unlock_irq(¤t->sigmask_lock);
-
- if (ia32_restore_sigcontext(®s, &frame->sc, &eax))
- goto badframe;
- return eax;
- badframe:
- signal_fault(®s,frame,"32bit sigreturn");
- return 0;
- }
- asmlinkage int sys32_rt_sigreturn(struct pt_regs regs)
- {
- struct rt_sigframe *frame = (struct rt_sigframe *)(regs.rsp - 4);
- sigset_t set;
- stack_t st;
- unsigned int eax;
- if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
- goto badframe;
- if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
- goto badframe;
- sigdelsetmask(&set, ~_BLOCKABLE);
- spin_lock_irq(¤t->sigmask_lock);
- current->blocked = set;
- recalc_sigpending(current);
- spin_unlock_irq(¤t->sigmask_lock);
-
- if (ia32_restore_sigcontext(®s, &frame->uc.uc_mcontext, &eax))
- goto badframe;
- if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
- goto badframe;
- /* It is more difficult to avoid calling this function than to
- call it and ignore errors. */
- {
- mm_segment_t oldds = get_fs();
- set_fs(KERNEL_DS);
- do_sigaltstack(&st, NULL, regs.rsp);
- set_fs(oldds);
- }
- return eax;
- badframe:
- signal_fault(®s,frame,"32bit rt sigreturn");
- return 0;
- }
- /*
- * Set up a signal frame.
- */
- static int
- ia32_setup_sigcontext(struct sigcontext_ia32 *sc, struct _fpstate_ia32 *fpstate,
- struct pt_regs *regs, unsigned int mask)
- {
- int tmp, err = 0;
- tmp = 0;
- __asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp));
- err |= __put_user(tmp, (unsigned int *)&sc->gs);
- __asm__("movl %%fs,%0" : "=r"(tmp): "0"(tmp));
- err |= __put_user(tmp, (unsigned int *)&sc->fs);
- __asm__("movl %%ds,%0" : "=r"(tmp): "0"(tmp));
- err |= __put_user(tmp, (unsigned int *)&sc->ds);
- __asm__("movl %%es,%0" : "=r"(tmp): "0"(tmp));
- err |= __put_user(tmp, (unsigned int *)&sc->es);
- err |= __put_user((u32)regs->rdi, &sc->edi);
- err |= __put_user((u32)regs->rsi, &sc->esi);
- err |= __put_user((u32)regs->rbp, &sc->ebp);
- err |= __put_user((u32)regs->rsp, &sc->esp);
- err |= __put_user((u32)regs->rbx, &sc->ebx);
- err |= __put_user((u32)regs->rdx, &sc->edx);
- err |= __put_user((u32)regs->rcx, &sc->ecx);
- err |= __put_user((u32)regs->rax, &sc->eax);
- err |= __put_user((u32)regs->cs, &sc->cs);
- err |= __put_user((u32)regs->ss, &sc->ss);
- err |= __put_user(current->thread.trap_no, &sc->trapno);
- err |= __put_user(current->thread.error_code, &sc->err);
- err |= __put_user((u32)regs->rip, &sc->eip);
- err |= __put_user((u32)regs->eflags, &sc->eflags);
- err |= __put_user((u32)regs->rsp, &sc->esp_at_signal);
- tmp = save_i387_ia32(current, fpstate, regs, 0);
- if (tmp < 0)
- err = -EFAULT;
- else
- err |= __put_user((u32)(u64)(tmp ? fpstate : NULL), &sc->fpstate);
- /* non-iBCS2 extensions.. */
- err |= __put_user(mask, &sc->oldmask);
- err |= __put_user(current->thread.cr2, &sc->cr2);
- return err;
- }
- /*
- * Determine which stack to use..
- */
- static inline void *
- get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
- {
- unsigned long rsp;
- /* Default to using normal stack */
- rsp = regs->rsp;
- /* This is the X/Open sanctioned signal stack switching. */
- if (ka->sa.sa_flags & SA_ONSTACK) {
- if (! on_sig_stack(rsp))
- rsp = current->sas_ss_sp + current->sas_ss_size;
- }
- /* This is the legacy signal stack switching. */
- else if ((regs->ss & 0xffff) != __USER_DS &&
- !(ka->sa.sa_flags & SA_RESTORER) &&
- ka->sa.sa_restorer) {
- rsp = (unsigned long) ka->sa.sa_restorer;
- }
- return (void *)((rsp - frame_size) & -8UL);
- }
- void ia32_setup_frame(int sig, struct k_sigaction *ka,
- sigset32_t *set, struct pt_regs * regs)
- {
- struct sigframe *frame;
- int err = 0;
- frame = get_sigframe(ka, regs, sizeof(*frame));
- if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
- goto give_sigsegv;
- err |= __put_user((current->exec_domain
- && current->exec_domain->signal_invmap
- && sig < 32
- ? current->exec_domain->signal_invmap[sig]
- : sig),
- &frame->sig);
- if (err)
- goto give_sigsegv;
- err |= ia32_setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]);
- if (err)
- goto give_sigsegv;
- if (_IA32_NSIG_WORDS > 1) {
- err |= __copy_to_user(frame->extramask, &set->sig[1],
- sizeof(frame->extramask));
- }
- if (err)
- goto give_sigsegv;
- /* Set up to return from userspace. If provided, use a stub
- already in userspace. */
- if (ka->sa.sa_flags & SA_RESTORER) {
- err |= __put_user((u32)(u64)ka->sa.sa_restorer, &frame->pretcode);
- } else {
- err |= __put_user((u32)(u64)frame->retcode, &frame->pretcode);
- /* This is popl %eax ; movl $,%eax ; int $0x80 */
- err |= __put_user((u16)0xb858, (short *)(frame->retcode+0));
- err |= __put_user((u32)__NR_ia32_sigreturn, (int *)(frame->retcode+2));
- err |= __put_user((u16)0x80cd, (short *)(frame->retcode+6));
- }
- if (err)
- goto give_sigsegv;
- /* Set up registers for signal handler */
- regs->rsp = (unsigned long) frame;
- regs->rip = (unsigned long) ka->sa.sa_handler;
- asm volatile("movl %0,%%ds" :: "r" (__USER32_DS));
- asm volatile("movl %0,%%es" :: "r" (__USER32_DS));
- regs->cs = __USER32_CS;
- regs->ss = __USER32_DS;
- set_fs(USER_DS);
- regs->eflags &= ~TF_MASK;
- #if DEBUG_SIG
- printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%pn",
- current->comm, current->pid, frame, regs->rip, frame->pretcode);
- #endif
- return;
- give_sigsegv:
- if (sig == SIGSEGV)
- ka->sa.sa_handler = SIG_DFL;
- signal_fault(regs,frame,"32bit signal deliver");
- }
- void ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
- sigset32_t *set, struct pt_regs * regs)
- {
- struct rt_sigframe *frame;
- int err = 0;
- frame = get_sigframe(ka, regs, sizeof(*frame));
- if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
- goto give_sigsegv;
- err |= __put_user((current->exec_domain
- && current->exec_domain->signal_invmap
- && sig < 32
- ? current->exec_domain->signal_invmap[sig]
- : sig),
- &frame->sig);
- err |= __put_user((u32)(u64)&frame->info, &frame->pinfo);
- err |= __put_user((u32)(u64)&frame->uc, &frame->puc);
- err |= ia32_copy_siginfo_to_user(&frame->info, info);
- if (err)
- goto give_sigsegv;
- /* Create the ucontext. */
- err |= __put_user(0, &frame->uc.uc_flags);
- err |= __put_user(0, &frame->uc.uc_link);
- err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
- err |= __put_user(sas_ss_flags(regs->rsp),
- &frame->uc.uc_stack.ss_flags);
- err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
- err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
- regs, set->sig[0]);
- err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
- if (err)
- goto give_sigsegv;
- /* Set up to return from userspace. If provided, use a stub
- already in userspace. */
- if (ka->sa.sa_flags & SA_RESTORER) {
- err |= __put_user((u32)(u64)ka->sa.sa_restorer, &frame->pretcode);
- } else {
- err |= __put_user(ptr_to_u32(frame->retcode), &frame->pretcode);
- /* This is movl $,%eax ; int $0x80 */
- err |= __put_user(0xb8, (char *)(frame->retcode+0));
- err |= __put_user((u32)__NR_ia32_rt_sigreturn, (int *)(frame->retcode+1));
- err |= __put_user(0x80cd, (short *)(frame->retcode+5));
- }
- if (err)
- goto give_sigsegv;
- /* Set up registers for signal handler */
- regs->rsp = (unsigned long) frame;
- regs->rip = (unsigned long) ka->sa.sa_handler;
- asm volatile("movl %0,%%ds" :: "r" (__USER32_DS));
- asm volatile("movl %0,%%es" :: "r" (__USER32_DS));
- regs->cs = __USER32_CS;
- regs->ss = __USER32_DS;
- set_fs(USER_DS);
- regs->eflags &= ~TF_MASK;
- #if DEBUG_SIG
- printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%pn",
- current->comm, current->pid, frame, regs->rip, frame->pretcode);
- #endif
- return;
- give_sigsegv:
- if (sig == SIGSEGV)
- ka->sa.sa_handler = SIG_DFL;
- signal_fault(regs,frame,"32bit rt signal deliver");
- }