| /* |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs |
| * |
| * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson |
| * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes |
| * 2000-2002 x86-64 support by Andi Kleen |
| */ |
| #include <linux/perf_counter.h> |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/smp.h> |
| #include <linux/kernel.h> |
| #include <linux/signal.h> |
| #include <linux/errno.h> |
| #include <linux/wait.h> |
| #include <linux/ptrace.h> |
| #include <linux/tracehook.h> |
| #include <linux/unistd.h> |
| #include <linux/stddef.h> |
| #include <linux/personality.h> |
| #include <linux/uaccess.h> |
| |
| #include <asm/processor.h> |
| #include <asm/ucontext.h> |
| #include <asm/i387.h> |
| #include <asm/vdso.h> |
| |
| #ifdef CONFIG_X86_64 |
| #include <asm/proto.h> |
| #include <asm/ia32_unistd.h> |
| #include <asm/mce.h> |
| #endif /* CONFIG_X86_64 */ |
| |
| #include <asm/syscall.h> |
| #include <asm/syscalls.h> |
| |
| #include "sigframe.h" |
| |
| #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| |
| #define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \ |
| X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \ |
| X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \ |
| X86_EFLAGS_CF) |
| |
| #ifdef CONFIG_X86_32 |
| # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF) |
| #else |
| # define FIX_EFLAGS __FIX_EFLAGS |
| #endif |
| |
| #define COPY(x) { \ |
| err |= __get_user(regs->x, &sc->x); \ |
| } |
| |
| #define COPY_SEG(seg) { \ |
| unsigned short tmp; \ |
| err |= __get_user(tmp, &sc->seg); \ |
| regs->seg = tmp; \ |
| } |
| |
| #define COPY_SEG_CPL3(seg) { \ |
| unsigned short tmp; \ |
| err |= __get_user(tmp, &sc->seg); \ |
| regs->seg = tmp | 3; \ |
| } |
| |
| #define GET_SEG(seg) { \ |
| unsigned short tmp; \ |
| err |= __get_user(tmp, &sc->seg); \ |
| loadsegment(seg, tmp); \ |
| } |
| |
| static int |
| restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, |
| unsigned long *pax) |
| { |
| void __user *buf; |
| unsigned int tmpflags; |
| unsigned int err = 0; |
| |
| /* Always make any pending restarted system calls return -EINTR */ |
| current_thread_info()->restart_block.fn = do_no_restart_syscall; |
| |
| #ifdef CONFIG_X86_32 |
| GET_SEG(gs); |
| COPY_SEG(fs); |
| COPY_SEG(es); |
| COPY_SEG(ds); |
| #endif /* CONFIG_X86_32 */ |
| |
| COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
| COPY(dx); COPY(cx); COPY(ip); |
| |
| #ifdef CONFIG_X86_64 |
| COPY(r8); |
| COPY(r9); |
| COPY(r10); |
| COPY(r11); |
| COPY(r12); |
| COPY(r13); |
| COPY(r14); |
| COPY(r15); |
| #endif /* CONFIG_X86_64 */ |
| |
| #ifdef CONFIG_X86_32 |
| COPY_SEG_CPL3(cs); |
| COPY_SEG_CPL3(ss); |
| #else /* !CONFIG_X86_32 */ |
| /* Kernel saves and restores only the CS segment register on signals, |
| * which is the bare minimum needed to allow mixed 32/64-bit code. |
| * App's signal handler can save/restore other segments if needed. */ |
| COPY_SEG_CPL3(cs); |
| #endif /* CONFIG_X86_32 */ |
| |
| err |= __get_user(tmpflags, &sc->flags); |
| regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); |
| regs->orig_ax = -1; /* disable syscall checks */ |
| |
| err |= __get_user(buf, &sc->fpstate); |
| err |= restore_i387_xstate(buf); |
| |
| err |= __get_user(*pax, &sc->ax); |
| return err; |
| } |
| |
| static int |
| setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, |
| struct pt_regs *regs, unsigned long mask) |
| { |
| int err = 0; |
| |
| #ifdef CONFIG_X86_32 |
| { |
| unsigned int tmp; |
| |
| savesegment(gs, tmp); |
| err |= __put_user(tmp, (unsigned int __user *)&sc->gs); |
| } |
| err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs); |
| err |= __put_user(regs->es, (unsigned int __user *)&sc->es); |
| err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds); |
| #endif /* CONFIG_X86_32 */ |
| |
| err |= __put_user(regs->di, &sc->di); |
| err |= __put_user(regs->si, &sc->si); |
| err |= __put_user(regs->bp, &sc->bp); |
| err |= __put_user(regs->sp, &sc->sp); |
| err |= __put_user(regs->bx, &sc->bx); |
| err |= __put_user(regs->dx, &sc->dx); |
| err |= __put_user(regs->cx, &sc->cx); |
| err |= __put_user(regs->ax, &sc->ax); |
| #ifdef CONFIG_X86_64 |
| err |= __put_user(regs->r8, &sc->r8); |
| err |= __put_user(regs->r9, &sc->r9); |
| err |= __put_user(regs->r10, &sc->r10); |
| err |= __put_user(regs->r11, &sc->r11); |
| err |= __put_user(regs->r12, &sc->r12); |
| err |= __put_user(regs->r13, &sc->r13); |
| err |= __put_user(regs->r14, &sc->r14); |
| err |= __put_user(regs->r15, &sc->r15); |
| #endif /* CONFIG_X86_64 */ |
| |
| err |= __put_user(current->thread.trap_no, &sc->trapno); |
| err |= __put_user(current->thread.error_code, &sc->err); |
| err |= __put_user(regs->ip, &sc->ip); |
| #ifdef CONFIG_X86_32 |
| err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs); |
| err |= __put_user(regs->flags, &sc->flags); |
| err |= __put_user(regs->sp, &sc->sp_at_signal); |
| err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss); |
| #else /* !CONFIG_X86_32 */ |
| err |= __put_user(regs->flags, &sc->flags); |
| err |= __put_user(regs->cs, &sc->cs); |
| err |= __put_user(0, &sc->gs); |
| err |= __put_user(0, &sc->fs); |
| #endif /* CONFIG_X86_32 */ |
| |
| err |= __put_user(fpstate, &sc->fpstate); |
| |
| /* non-iBCS2 extensions.. */ |
| err |= __put_user(mask, &sc->oldmask); |
| err |= __put_user(current->thread.cr2, &sc->cr2); |
| |
| return err; |
| } |
| |
| /* |
| * Set up a signal frame. |
| */ |
| #ifdef CONFIG_X86_32 |
| static const struct { |
| u16 poplmovl; |
| u32 val; |
| u16 int80; |
| } __attribute__((packed)) retcode = { |
| 0xb858, /* popl %eax; movl $..., %eax */ |
| __NR_sigreturn, |
| 0x80cd, /* int $0x80 */ |
| }; |
| |
| static const struct { |
| u8 movl; |
| u32 val; |
| u16 int80; |
| u8 pad; |
| } __attribute__((packed)) rt_retcode = { |
| 0xb8, /* movl $..., %eax */ |
| __NR_rt_sigreturn, |
| 0x80cd, /* int $0x80 */ |
| 0 |
| }; |
| |
| /* |
| * Determine which stack to use.. |
| */ |
| static inline void __user * |
| get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, |
| void **fpstate) |
| { |
| unsigned long sp; |
| |
| /* Default to using normal stack */ |
| sp = regs->sp; |
| |
| /* |
| * If we are on the alternate signal stack and would overflow it, don't. |
| * Return an always-bogus address instead so we will die with SIGSEGV. |
| */ |
| if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) |
| return (void __user *) -1L; |
| |
| /* This is the X/Open sanctioned signal stack switching. */ |
| if (ka->sa.sa_flags & SA_ONSTACK) { |
| if (sas_ss_flags(sp) == 0) |
| sp = current->sas_ss_sp + current->sas_ss_size; |
| } else { |
| /* This is the legacy signal stack switching. */ |
| if ((regs->ss & 0xffff) != __USER_DS && |
| !(ka->sa.sa_flags & SA_RESTORER) && |
| ka->sa.sa_restorer) |
| sp = (unsigned long) ka->sa.sa_restorer; |
| } |
| |
| if (used_math()) { |
| sp = sp - sig_xstate_size; |
| *fpstate = (struct _fpstate *) sp; |
| if (save_i387_xstate(*fpstate) < 0) |
| return (void __user *)-1L; |
| } |
| |
| sp -= frame_size; |
| /* |
| * Align the stack pointer according to the i386 ABI, |
| * i.e. so that on function entry ((sp + 4) & 15) == 0. |
| */ |
| sp = ((sp + 4) & -16ul) - 4; |
| |
| return (void __user *) sp; |
| } |
| |
| static int |
| __setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, |
| struct pt_regs *regs) |
| { |
| struct sigframe __user *frame; |
| void __user *restorer; |
| int err = 0; |
| void __user *fpstate = NULL; |
| |
| frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| return -EFAULT; |
| |
| if (__put_user(sig, &frame->sig)) |
| return -EFAULT; |
| |
| if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) |
| return -EFAULT; |
| |
| if (_NSIG_WORDS > 1) { |
| if (__copy_to_user(&frame->extramask, &set->sig[1], |
| sizeof(frame->extramask))) |
| return -EFAULT; |
| } |
| |
| if (current->mm->context.vdso) |
| restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); |
| else |
| restorer = &frame->retcode; |
| if (ka->sa.sa_flags & SA_RESTORER) |
| restorer = ka->sa.sa_restorer; |
| |
| /* Set up to return from userspace. */ |
| err |= __put_user(restorer, &frame->pretcode); |
| |
| /* |
| * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
| * |
| * WE DO NOT USE IT ANY MORE! It's only left here for historical |
| * reasons and because gdb uses it as a signature to notice |
| * signal handler stack frames. |
| */ |
| err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode); |
| |
| if (err) |
| return -EFAULT; |
| |
| /* Set up registers for signal handler */ |
| regs->sp = (unsigned long)frame; |
| regs->ip = (unsigned long)ka->sa.sa_handler; |
| regs->ax = (unsigned long)sig; |
| regs->dx = 0; |
| regs->cx = 0; |
| |
| regs->ds = __USER_DS; |
| regs->es = __USER_DS; |
| regs->ss = __USER_DS; |
| regs->cs = __USER_CS; |
| |
| return 0; |
| } |
| |
| static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
| sigset_t *set, struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame; |
| void __user *restorer; |
| int err = 0; |
| void __user *fpstate = NULL; |
| |
| frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| return -EFAULT; |
| |
| err |= __put_user(sig, &frame->sig); |
| err |= __put_user(&frame->info, &frame->pinfo); |
| err |= __put_user(&frame->uc, &frame->puc); |
| err |= copy_siginfo_to_user(&frame->info, info); |
| if (err) |
| return -EFAULT; |
| |
| /* Create the ucontext. */ |
| if (cpu_has_xsave) |
| err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags); |
| else |
| 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->sp), |
| &frame->uc.uc_stack.ss_flags); |
| err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); |
| err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
| regs, set->sig[0]); |
| err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
| if (err) |
| return -EFAULT; |
| |
| /* Set up to return from userspace. */ |
| restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn); |
| if (ka->sa.sa_flags & SA_RESTORER) |
| restorer = ka->sa.sa_restorer; |
| err |= __put_user(restorer, &frame->pretcode); |
| |
| /* |
| * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 |
| * |
| * WE DO NOT USE IT ANY MORE! It's only left here for historical |
| * reasons and because gdb uses it as a signature to notice |
| * signal handler stack frames. |
| */ |
| err |= __put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode); |
| |
| if (err) |
| return -EFAULT; |
| |
| /* Set up registers for signal handler */ |
| regs->sp = (unsigned long)frame; |
| regs->ip = (unsigned long)ka->sa.sa_handler; |
| regs->ax = (unsigned long)sig; |
| regs->dx = (unsigned long)&frame->info; |
| regs->cx = (unsigned long)&frame->uc; |
| |
| regs->ds = __USER_DS; |
| regs->es = __USER_DS; |
| regs->ss = __USER_DS; |
| regs->cs = __USER_CS; |
| |
| return 0; |
| } |
| #else /* !CONFIG_X86_32 */ |
| /* |
| * Determine which stack to use.. |
| */ |
| static void __user * |
| get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size) |
| { |
| /* Default to using normal stack - redzone*/ |
| sp -= 128; |
| |
| /* This is the X/Open sanctioned signal stack switching. */ |
| if (ka->sa.sa_flags & SA_ONSTACK) { |
| if (sas_ss_flags(sp) == 0) |
| sp = current->sas_ss_sp + current->sas_ss_size; |
| } |
| |
| return (void __user *)round_down(sp - size, 64); |
| } |
| |
| static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
| sigset_t *set, struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame; |
| void __user *fp = NULL; |
| int err = 0; |
| struct task_struct *me = current; |
| |
| if (used_math()) { |
| fp = get_stack(ka, regs->sp, sig_xstate_size); |
| frame = (void __user *)round_down( |
| (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8; |
| |
| if (save_i387_xstate(fp) < 0) |
| return -EFAULT; |
| } else |
| frame = get_stack(ka, regs->sp, sizeof(struct rt_sigframe)) - 8; |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| return -EFAULT; |
| |
| if (ka->sa.sa_flags & SA_SIGINFO) { |
| if (copy_siginfo_to_user(&frame->info, info)) |
| return -EFAULT; |
| } |
| |
| /* Create the ucontext. */ |
| if (cpu_has_xsave) |
| err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags); |
| else |
| err |= __put_user(0, &frame->uc.uc_flags); |
| err |= __put_user(0, &frame->uc.uc_link); |
| err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp); |
| err |= __put_user(sas_ss_flags(regs->sp), |
| &frame->uc.uc_stack.ss_flags); |
| err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size); |
| err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]); |
| err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
| |
| /* Set up to return from userspace. If provided, use a stub |
| already in userspace. */ |
| /* x86-64 should always use SA_RESTORER. */ |
| if (ka->sa.sa_flags & SA_RESTORER) { |
| err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); |
| } else { |
| /* could use a vstub here */ |
| return -EFAULT; |
| } |
| |
| if (err) |
| return -EFAULT; |
| |
| /* Set up registers for signal handler */ |
| regs->di = sig; |
| /* In case the signal handler was declared without prototypes */ |
| regs->ax = 0; |
| |
| /* This also works for non SA_SIGINFO handlers because they expect the |
| next argument after the signal number on the stack. */ |
| regs->si = (unsigned long)&frame->info; |
| regs->dx = (unsigned long)&frame->uc; |
| regs->ip = (unsigned long) ka->sa.sa_handler; |
| |
| regs->sp = (unsigned long)frame; |
| |
| /* Set up the CS register to run signal handlers in 64-bit mode, |
| even if the handler happens to be interrupting 32-bit code. */ |
| regs->cs = __USER_CS; |
| |
| return 0; |
| } |
| #endif /* CONFIG_X86_32 */ |
| |
| #ifdef CONFIG_X86_32 |
| /* |
| * Atomically swap in the new signal mask, and wait for a signal. |
| */ |
| asmlinkage int |
| sys_sigsuspend(int history0, int history1, old_sigset_t mask) |
| { |
| mask &= _BLOCKABLE; |
| spin_lock_irq(¤t->sighand->siglock); |
| current->saved_sigmask = current->blocked; |
| siginitset(¤t->blocked, mask); |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| current->state = TASK_INTERRUPTIBLE; |
| schedule(); |
| set_restore_sigmask(); |
| |
| return -ERESTARTNOHAND; |
| } |
| |
| asmlinkage int |
| sys_sigaction(int sig, const struct old_sigaction __user *act, |
| struct old_sigaction __user *oact) |
| { |
| struct k_sigaction new_ka, old_ka; |
| int ret; |
| |
| if (act) { |
| old_sigset_t mask; |
| |
| if (!access_ok(VERIFY_READ, act, sizeof(*act)) || |
| __get_user(new_ka.sa.sa_handler, &act->sa_handler) || |
| __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) |
| return -EFAULT; |
| |
| __get_user(new_ka.sa.sa_flags, &act->sa_flags); |
| __get_user(mask, &act->sa_mask); |
| siginitset(&new_ka.sa.sa_mask, mask); |
| } |
| |
| ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); |
| |
| if (!ret && oact) { |
| if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || |
| __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || |
| __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) |
| return -EFAULT; |
| |
| __put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
| __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); |
| } |
| |
| return ret; |
| } |
| #endif /* CONFIG_X86_32 */ |
| |
| #ifdef CONFIG_X86_32 |
| asmlinkage int sys_sigaltstack(unsigned long bx) |
| { |
| /* |
| * This is needed to make gcc realize it doesn't own the |
| * "struct pt_regs" |
| */ |
| struct pt_regs *regs = (struct pt_regs *)&bx; |
| const stack_t __user *uss = (const stack_t __user *)bx; |
| stack_t __user *uoss = (stack_t __user *)regs->cx; |
| |
| return do_sigaltstack(uss, uoss, regs->sp); |
| } |
| #else /* !CONFIG_X86_32 */ |
| asmlinkage long |
| sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, |
| struct pt_regs *regs) |
| { |
| return do_sigaltstack(uss, uoss, regs->sp); |
| } |
| #endif /* CONFIG_X86_32 */ |
| |
| /* |
| * Do a signal return; undo the signal stack. |
| */ |
| #ifdef CONFIG_X86_32 |
| asmlinkage unsigned long sys_sigreturn(unsigned long __unused) |
| { |
| struct sigframe __user *frame; |
| struct pt_regs *regs; |
| unsigned long ax; |
| sigset_t set; |
| |
| regs = (struct pt_regs *) &__unused; |
| frame = (struct sigframe __user *)(regs->sp - 8); |
| |
| if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| goto badframe; |
| if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 |
| && __copy_from_user(&set.sig[1], &frame->extramask, |
| sizeof(frame->extramask)))) |
| goto badframe; |
| |
| sigdelsetmask(&set, ~_BLOCKABLE); |
| spin_lock_irq(¤t->sighand->siglock); |
| current->blocked = set; |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| if (restore_sigcontext(regs, &frame->sc, &ax)) |
| goto badframe; |
| return ax; |
| |
| badframe: |
| if (show_unhandled_signals && printk_ratelimit()) { |
| printk("%s%s[%d] bad frame in sigreturn frame:" |
| "%p ip:%lx sp:%lx oeax:%lx", |
| task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
| current->comm, task_pid_nr(current), frame, regs->ip, |
| regs->sp, regs->orig_ax); |
| print_vma_addr(" in ", regs->ip); |
| printk(KERN_CONT "\n"); |
| } |
| |
| force_sig(SIGSEGV, current); |
| |
| return 0; |
| } |
| #endif /* CONFIG_X86_32 */ |
| |
| static long do_rt_sigreturn(struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame; |
| unsigned long ax; |
| sigset_t set; |
| |
| frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); |
| if (!access_ok(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->sighand->siglock); |
| current->blocked = set; |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) |
| goto badframe; |
| |
| if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) |
| goto badframe; |
| |
| return ax; |
| |
| badframe: |
| signal_fault(regs, frame, "rt_sigreturn"); |
| return 0; |
| } |
| |
| #ifdef CONFIG_X86_32 |
| asmlinkage int sys_rt_sigreturn(struct pt_regs regs) |
| { |
| return do_rt_sigreturn(®s); |
| } |
| #else /* !CONFIG_X86_32 */ |
| asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) |
| { |
| return do_rt_sigreturn(regs); |
| } |
| #endif /* CONFIG_X86_32 */ |
| |
| /* |
| * OK, we're invoking a handler: |
| */ |
| static int signr_convert(int sig) |
| { |
| #ifdef CONFIG_X86_32 |
| struct thread_info *info = current_thread_info(); |
| |
| if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32) |
| return info->exec_domain->signal_invmap[sig]; |
| #endif /* CONFIG_X86_32 */ |
| return sig; |
| } |
| |
| #ifdef CONFIG_X86_32 |
| |
| #define is_ia32 1 |
| #define ia32_setup_frame __setup_frame |
| #define ia32_setup_rt_frame __setup_rt_frame |
| |
| #else /* !CONFIG_X86_32 */ |
| |
| #ifdef CONFIG_IA32_EMULATION |
| #define is_ia32 test_thread_flag(TIF_IA32) |
| #else /* !CONFIG_IA32_EMULATION */ |
| #define is_ia32 0 |
| #endif /* CONFIG_IA32_EMULATION */ |
| |
| #endif /* CONFIG_X86_32 */ |
| |
| static int |
| setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
| sigset_t *set, struct pt_regs *regs) |
| { |
| int usig = signr_convert(sig); |
| int ret; |
| |
| /* Set up the stack frame */ |
| if (is_ia32) { |
| if (ka->sa.sa_flags & SA_SIGINFO) |
| ret = ia32_setup_rt_frame(usig, ka, info, set, regs); |
| else |
| ret = ia32_setup_frame(usig, ka, set, regs); |
| } else |
| ret = __setup_rt_frame(sig, ka, info, set, regs); |
| |
| if (ret) { |
| force_sigsegv(sig, current); |
| return -EFAULT; |
| } |
| |
| return ret; |
| } |
| |
| static int |
| handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, |
| sigset_t *oldset, struct pt_regs *regs) |
| { |
| int ret; |
| |
| /* Are we from a system call? */ |
| if (syscall_get_nr(current, regs) >= 0) { |
| /* If so, check system call restarting.. */ |
| switch (syscall_get_error(current, regs)) { |
| case -ERESTART_RESTARTBLOCK: |
| case -ERESTARTNOHAND: |
| regs->ax = -EINTR; |
| break; |
| |
| case -ERESTARTSYS: |
| if (!(ka->sa.sa_flags & SA_RESTART)) { |
| regs->ax = -EINTR; |
| break; |
| } |
| /* fallthrough */ |
| case -ERESTARTNOINTR: |
| regs->ax = regs->orig_ax; |
| regs->ip -= 2; |
| break; |
| } |
| } |
| |
| /* |
| * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF |
| * flag so that register information in the sigcontext is correct. |
| */ |
| if (unlikely(regs->flags & X86_EFLAGS_TF) && |
| likely(test_and_clear_thread_flag(TIF_FORCED_TF))) |
| regs->flags &= ~X86_EFLAGS_TF; |
| |
| ret = setup_rt_frame(sig, ka, info, oldset, regs); |
| |
| if (ret) |
| return ret; |
| |
| #ifdef CONFIG_X86_64 |
| /* |
| * This has nothing to do with segment registers, |
| * despite the name. This magic affects uaccess.h |
| * macros' behavior. Reset it to the normal setting. |
| */ |
| set_fs(USER_DS); |
| #endif |
| |
| /* |
| * Clear the direction flag as per the ABI for function entry. |
| */ |
| regs->flags &= ~X86_EFLAGS_DF; |
| |
| /* |
| * Clear TF when entering the signal handler, but |
| * notify any tracer that was single-stepping it. |
| * The tracer may want to single-step inside the |
| * handler too. |
| */ |
| regs->flags &= ~X86_EFLAGS_TF; |
| |
| spin_lock_irq(¤t->sighand->siglock); |
| sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); |
| if (!(ka->sa.sa_flags & SA_NODEFER)) |
| sigaddset(¤t->blocked, sig); |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| tracehook_signal_handler(sig, info, ka, regs, |
| test_thread_flag(TIF_SINGLESTEP)); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_X86_32 |
| #define NR_restart_syscall __NR_restart_syscall |
| #else /* !CONFIG_X86_32 */ |
| #define NR_restart_syscall \ |
| test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall |
| #endif /* CONFIG_X86_32 */ |
| |
| /* |
| * Note that 'init' is a special process: it doesn't get signals it doesn't |
| * want to handle. Thus you cannot kill init even with a SIGKILL even by |
| * mistake. |
| */ |
| static void do_signal(struct pt_regs *regs) |
| { |
| struct k_sigaction ka; |
| siginfo_t info; |
| int signr; |
| sigset_t *oldset; |
| |
| /* |
| * We want the common case to go fast, which is why we may in certain |
| * cases get here from kernel mode. Just return without doing anything |
| * if so. |
| * X86_32: vm86 regs switched out by assembly code before reaching |
| * here, so testing against kernel CS suffices. |
| */ |
| if (!user_mode(regs)) |
| return; |
| |
| if (current_thread_info()->status & TS_RESTORE_SIGMASK) |
| oldset = ¤t->saved_sigmask; |
| else |
| oldset = ¤t->blocked; |
| |
| signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| if (signr > 0) { |
| /* |
| * Re-enable any watchpoints before delivering the |
| * signal to user space. The processor register will |
| * have been cleared if the watchpoint triggered |
| * inside the kernel. |
| */ |
| if (current->thread.debugreg7) |
| set_debugreg(current->thread.debugreg7, 7); |
| |
| /* Whee! Actually deliver the signal. */ |
| if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { |
| /* |
| * A signal was successfully delivered; the saved |
| * sigmask will have been stored in the signal frame, |
| * and will be restored by sigreturn, so we can simply |
| * clear the TS_RESTORE_SIGMASK flag. |
| */ |
| current_thread_info()->status &= ~TS_RESTORE_SIGMASK; |
| } |
| return; |
| } |
| |
| /* Did we come from a system call? */ |
| if (syscall_get_nr(current, regs) >= 0) { |
| /* Restart the system call - no handlers present */ |
| switch (syscall_get_error(current, regs)) { |
| case -ERESTARTNOHAND: |
| case -ERESTARTSYS: |
| case -ERESTARTNOINTR: |
| regs->ax = regs->orig_ax; |
| regs->ip -= 2; |
| break; |
| |
| case -ERESTART_RESTARTBLOCK: |
| regs->ax = NR_restart_syscall; |
| regs->ip -= 2; |
| break; |
| } |
| } |
| |
| /* |
| * If there's no signal to deliver, we just put the saved sigmask |
| * back. |
| */ |
| if (current_thread_info()->status & TS_RESTORE_SIGMASK) { |
| current_thread_info()->status &= ~TS_RESTORE_SIGMASK; |
| sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
| } |
| } |
| |
| /* |
| * notification of userspace execution resumption |
| * - triggered by the TIF_WORK_MASK flags |
| */ |
| void |
| do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) |
| { |
| #if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE) |
| /* notify userspace of pending MCEs */ |
| if (thread_info_flags & _TIF_MCE_NOTIFY) |
| mce_notify_user(); |
| #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */ |
| |
| /* deal with pending signal delivery */ |
| if (thread_info_flags & _TIF_SIGPENDING) |
| do_signal(regs); |
| |
| if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
| clear_thread_flag(TIF_NOTIFY_RESUME); |
| tracehook_notify_resume(regs); |
| } |
| |
| if (thread_info_flags & _TIF_PERF_COUNTERS) { |
| clear_thread_flag(TIF_PERF_COUNTERS); |
| perf_counter_notify(regs); |
| } |
| |
| #ifdef CONFIG_X86_32 |
| clear_thread_flag(TIF_IRET); |
| #endif /* CONFIG_X86_32 */ |
| } |
| |
| void signal_fault(struct pt_regs *regs, void __user *frame, char *where) |
| { |
| struct task_struct *me = current; |
| |
| if (show_unhandled_signals && printk_ratelimit()) { |
| printk(KERN_INFO |
| "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", |
| me->comm, me->pid, where, frame, |
| regs->ip, regs->sp, regs->orig_ax); |
| print_vma_addr(" in ", regs->ip); |
| printk(KERN_CONT "\n"); |
| } |
| |
| force_sig(SIGSEGV, me); |
| } |