diff options
Diffstat (limited to 'arch/x86/kernel/signal_32.c')
-rw-r--r-- | arch/x86/kernel/signal_32.c | 303 |
1 files changed, 154 insertions, 149 deletions
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c index 0157a6f0f41..f1b11793083 100644 --- a/arch/x86/kernel/signal_32.c +++ b/arch/x86/kernel/signal_32.c @@ -4,32 +4,44 @@ * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes */ +#include <linux/list.h> -#include <linux/sched.h> -#include <linux/mm.h> -#include <linux/smp.h> +#include <linux/personality.h> +#include <linux/binfmts.h> +#include <linux/suspend.h> #include <linux/kernel.h> +#include <linux/ptrace.h> #include <linux/signal.h> +#include <linux/stddef.h> +#include <linux/unistd.h> #include <linux/errno.h> +#include <linux/sched.h> #include <linux/wait.h> -#include <linux/unistd.h> -#include <linux/stddef.h> -#include <linux/personality.h> -#include <linux/suspend.h> -#include <linux/ptrace.h> #include <linux/elf.h> -#include <linux/binfmts.h> +#include <linux/smp.h> +#include <linux/mm.h> + #include <asm/processor.h> #include <asm/ucontext.h> #include <asm/uaccess.h> #include <asm/i387.h> #include <asm/vdso.h> -#include "sigframe_32.h" -#define DEBUG_SIG 0 +#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 + /* * Atomically swap in the new signal mask, and wait for a signal. */ @@ -46,10 +58,11 @@ sys_sigsuspend(int history0, int history1, old_sigset_t mask) current->state = TASK_INTERRUPTIBLE; schedule(); set_thread_flag(TIF_RESTORE_SIGMASK); + return -ERESTARTNOHAND; } -asmlinkage int +asmlinkage int sys_sigaction(int sig, const struct old_sigaction __user *act, struct old_sigaction __user *oact) { @@ -58,10 +71,12 @@ sys_sigaction(int sig, const struct old_sigaction __user *act, 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); @@ -74,6 +89,7 @@ sys_sigaction(int sig, const struct old_sigaction __user *act, __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); } @@ -81,10 +97,12 @@ sys_sigaction(int sig, const struct old_sigaction __user *act, return ret; } -asmlinkage int -sys_sigaltstack(unsigned long bx) +asmlinkage int sys_sigaltstack(unsigned long bx) { - /* This is needed to make gcc realize it doesn't own the "struct pt_regs" */ + /* + * 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; @@ -96,9 +114,9 @@ sys_sigaltstack(unsigned long bx) /* * Do a signal return; undo the signal stack. */ - static int -restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax) +restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, + unsigned long *pax) { unsigned int err = 0; @@ -120,37 +138,29 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax #define GET_SEG(seg) \ { unsigned short tmp; \ err |= __get_user(tmp, &sc->seg); \ - loadsegment(seg,tmp); } - -#define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_RF | \ - X86_EFLAGS_OF | X86_EFLAGS_DF | \ - X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \ - X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF) + loadsegment(seg, tmp); } GET_SEG(gs); COPY_SEG(fs); COPY_SEG(es); COPY_SEG(ds); - COPY(di); - COPY(si); - COPY(bp); - COPY(sp); - COPY(bx); - COPY(dx); - COPY(cx); - COPY(ip); + COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); + COPY(dx); COPY(cx); COPY(ip); COPY_SEG_STRICT(cs); COPY_SEG_STRICT(ss); - + { unsigned int tmpflags; + err |= __get_user(tmpflags, &sc->flags); - regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); + regs->flags = (regs->flags & ~FIX_EFLAGS) | + (tmpflags & FIX_EFLAGS); regs->orig_ax = -1; /* disable syscall checks */ } { - struct _fpstate __user * buf; + struct _fpstate __user *buf; + err |= __get_user(buf, &sc->fpstate); if (buf) { if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) @@ -158,6 +168,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax err |= restore_i387(buf); } else { struct task_struct *me = current; + if (used_math()) { clear_fpu(me); clear_used_math(); @@ -165,24 +176,26 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax } } - err |= __get_user(*peax, &sc->ax); + err |= __get_user(*pax, &sc->ax); return err; badframe: return 1; } -asmlinkage int sys_sigreturn(unsigned long __unused) +asmlinkage unsigned long sys_sigreturn(unsigned long __unused) { - struct pt_regs *regs = (struct pt_regs *) &__unused; - struct sigframe __user *frame = (struct sigframe __user *)(regs->sp - 8); + struct sigframe __user *frame; + struct pt_regs *regs; + unsigned long ax; sigset_t set; - int ax; + + 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 + 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; @@ -192,33 +205,35 @@ asmlinkage int sys_sigreturn(unsigned long __unused) 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", + printk(KERN_INFO "%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("\n"); + printk(KERN_CONT "\n"); } force_sig(SIGSEGV, current); + return 0; -} +} asmlinkage int sys_rt_sigreturn(unsigned long __unused) { - struct pt_regs *regs = (struct pt_regs *) &__unused; - struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->sp - 4); + struct pt_regs *regs = (struct pt_regs *)&__unused; + struct rt_sigframe __user *frame; + unsigned long ax; sigset_t set; - int ax; + 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))) @@ -229,7 +244,7 @@ asmlinkage int sys_rt_sigreturn(unsigned long __unused) current->blocked = set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - + if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) goto badframe; @@ -241,12 +256,11 @@ asmlinkage int sys_rt_sigreturn(unsigned long __unused) badframe: force_sig(SIGSEGV, current); return 0; -} +} /* * Set up a signal frame. */ - static int setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, struct pt_regs *regs, unsigned long mask) @@ -277,9 +291,9 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, tmp = save_i387(fpstate); if (tmp < 0) - err = 1; + err = 1; else - err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); + err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); /* non-iBCS2 extensions.. */ err |= __put_user(mask, &sc->oldmask); @@ -292,7 +306,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, * Determine which stack to use.. */ static inline void __user * -get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) +get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) { unsigned long sp; @@ -310,32 +324,30 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) if (ka->sa.sa_flags & SA_ONSTACK) { if (sas_ss_flags(sp) == 0) sp = 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) { - sp = (unsigned long) ka->sa.sa_restorer; + } 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; } sp -= frame_size; - /* Align the stack pointer according to the i386 ABI, - * i.e. so that on function entry ((sp + 4) & 15) == 0. */ + /* + * 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; } -/* These symbols are defined with the addresses in the vsyscall page. - See vsyscall-sigreturn.S. */ -extern void __user __kernel_sigreturn; -extern void __user __kernel_rt_sigreturn; - -static int setup_frame(int sig, struct k_sigaction *ka, - sigset_t *set, struct pt_regs * regs) +static int +setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, + struct pt_regs *regs) { - void __user *restorer; struct sigframe __user *frame; + void __user *restorer; int err = 0; int usig; @@ -365,7 +377,7 @@ static int setup_frame(int sig, struct k_sigaction *ka, goto give_sigsegv; } - if (current->binfmt->hasvdso) + if (current->mm->context.vdso) restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); else restorer = &frame->retcode; @@ -374,9 +386,9 @@ static int setup_frame(int sig, struct k_sigaction *ka, /* Set up to return from userspace. */ err |= __put_user(restorer, &frame->pretcode); - + /* - * This is popl %eax ; movl $,%eax ; int $0x80 + * 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 @@ -390,11 +402,11 @@ static int setup_frame(int sig, struct k_sigaction *ka, goto give_sigsegv; /* 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) 0; - regs->cx = (unsigned long) 0; + 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; @@ -407,15 +419,10 @@ static int setup_frame(int sig, struct k_sigaction *ka, * The tracer may want to single-step inside the * handler too. */ - regs->flags &= ~(TF_MASK | X86_EFLAGS_DF); + regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF); if (test_thread_flag(TIF_SINGLESTEP)) ptrace_notify(SIGTRAP); -#if DEBUG_SIG - printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", - current->comm, current->pid, frame, regs->ip, frame->pretcode); -#endif - return 0; give_sigsegv: @@ -424,10 +431,10 @@ give_sigsegv: } static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, - sigset_t *set, struct pt_regs * regs) + sigset_t *set, struct pt_regs *regs) { - void __user *restorer; struct rt_sigframe __user *frame; + void __user *restorer; int err = 0; int usig; @@ -457,7 +464,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, &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, &frame->fpstate, - regs, set->sig[0]); + regs, set->sig[0]); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); if (err) goto give_sigsegv; @@ -467,9 +474,9 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, if (ka->sa.sa_flags & SA_RESTORER) restorer = ka->sa.sa_restorer; err |= __put_user(restorer, &frame->pretcode); - + /* - * This is movl $,%ax ; int $0x80 + * 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 @@ -483,11 +490,11 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, goto give_sigsegv; /* Set up registers for signal handler */ - regs->sp = (unsigned long) frame; - regs->ip = (unsigned long) ka->sa.sa_handler; - regs->ax = (unsigned long) usig; - regs->dx = (unsigned long) &frame->info; - regs->cx = (unsigned long) &frame->uc; + regs->sp = (unsigned long)frame; + regs->ip = (unsigned long)ka->sa.sa_handler; + regs->ax = (unsigned long)usig; + regs->dx = (unsigned long)&frame->info; + regs->cx = (unsigned long)&frame->uc; regs->ds = __USER_DS; regs->es = __USER_DS; @@ -500,15 +507,10 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, * The tracer may want to single-step inside the * handler too. */ - regs->flags &= ~(TF_MASK | X86_EFLAGS_DF); + regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF); if (test_thread_flag(TIF_SINGLESTEP)) ptrace_notify(SIGTRAP); -#if DEBUG_SIG - printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", - current->comm, current->pid, frame, regs->ip, frame->pretcode); -#endif - return 0; give_sigsegv: @@ -517,33 +519,33 @@ give_sigsegv: } /* - * OK, we're invoking a handler - */ - + * OK, we're invoking a handler: + */ static int handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, - sigset_t *oldset, struct pt_regs * regs) + sigset_t *oldset, struct pt_regs *regs) { int ret; /* Are we from a system call? */ - if (regs->orig_ax >= 0) { + if ((long)regs->orig_ax >= 0) { /* If so, check system call restarting.. */ switch (regs->ax) { - case -ERESTART_RESTARTBLOCK: - case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + case -ERESTARTNOHAND: + regs->ax = -EINTR; + break; + + case -ERESTARTSYS: + if (!(ka->sa.sa_flags & SA_RESTART)) { 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; + } + /* fallthrough */ + case -ERESTARTNOINTR: + regs->ax = regs->orig_ax; + regs->ip -= 2; + break; } } @@ -561,16 +563,17 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, else ret = setup_frame(sig, ka, oldset, regs); - if (ret == 0) { - 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); - } + if (ret) + return ret; - return ret; + 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); + + return 0; } /* @@ -580,18 +583,17 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, */ static void do_signal(struct pt_regs *regs) { + struct k_sigaction ka; siginfo_t info; int signr; - struct k_sigaction ka; 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. vm86 regs switched out by assembly code - * before reaching here, so testing against kernel - * CS suffices. + * 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; @@ -603,29 +605,31 @@ static void do_signal(struct pt_regs *regs) signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { - /* Re-enable any watchpoints before delivering the + /* + * 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 (unlikely(current->thread.debugreg7)) + if (current->thread.debugreg7) set_debugreg(current->thread.debugreg7, 7); - /* Whee! Actually deliver the signal. */ + /* Whee! Actually deliver the signal. */ if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { - /* a signal was successfully delivered; the saved + /* + * 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 TIF_RESTORE_SIGMASK flag */ + * clear the TIF_RESTORE_SIGMASK flag + */ if (test_thread_flag(TIF_RESTORE_SIGMASK)) clear_thread_flag(TIF_RESTORE_SIGMASK); } - return; } /* Did we come from a system call? */ - if (regs->orig_ax >= 0) { + if ((long)regs->orig_ax >= 0) { /* Restart the system call - no handlers present */ switch (regs->ax) { case -ERESTARTNOHAND: @@ -642,8 +646,10 @@ static void do_signal(struct pt_regs *regs) } } - /* if there's no signal to deliver, we just put the saved sigmask - * back */ + /* + * If there's no signal to deliver, we just put the saved sigmask + * back. + */ if (test_thread_flag(TIF_RESTORE_SIGMASK)) { clear_thread_flag(TIF_RESTORE_SIGMASK); sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); @@ -654,13 +660,12 @@ static void do_signal(struct pt_regs *regs) * notification of userspace execution resumption * - triggered by the TIF_WORK_MASK flags */ -__attribute__((regparm(3))) -void do_notify_resume(struct pt_regs *regs, void *_unused, - __u32 thread_info_flags) +void +do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) { /* Pending single-step? */ if (thread_info_flags & _TIF_SINGLESTEP) { - regs->flags |= TF_MASK; + regs->flags |= X86_EFLAGS_TF; clear_thread_flag(TIF_SINGLESTEP); } @@ -670,6 +675,6 @@ void do_notify_resume(struct pt_regs *regs, void *_unused, if (thread_info_flags & _TIF_HRTICK_RESCHED) hrtick_resched(); - + clear_thread_flag(TIF_IRET); } |