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Diffstat (limited to 'arch/arm/kernel/signal.c')
-rw-r--r--arch/arm/kernel/signal.c137
1 files changed, 65 insertions, 72 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index f6bc5d44278..e7714f367eb 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -1,7 +1,7 @@
/*
* linux/arch/arm/kernel/signal.c
*
- * Copyright (C) 1995-2002 Russell King
+ * Copyright (C) 1995-2009 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -12,6 +12,7 @@
#include <linux/personality.h>
#include <linux/freezer.h>
#include <linux/uaccess.h>
+#include <linux/tracehook.h>
#include <asm/elf.h>
#include <asm/cacheflush.h>
@@ -28,6 +29,7 @@
*/
#define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE))
#define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE))
+#define SWI_SYS_RESTART (0xef000000|__NR_restart_syscall|__NR_OABI_SYSCALL_BASE)
/*
* With EABI, the syscall number has to be loaded into r7.
@@ -47,57 +49,34 @@ const unsigned long sigreturn_codes[7] = {
MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
};
-static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);
+/*
+ * Either we support OABI only, or we have EABI with the OABI
+ * compat layer enabled. In the later case we don't know if
+ * user space is EABI or not, and if not we must not clobber r7.
+ * Always using the OABI syscall solves that issue and works for
+ * all those cases.
+ */
+const unsigned long syscall_restart_code[2] = {
+ SWI_SYS_RESTART, /* swi __NR_restart_syscall */
+ 0xe49df004, /* ldr pc, [sp], #4 */
+};
/*
* atomically swap in the new signal mask, and wait for a signal.
*/
-asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
+asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
{
- sigset_t saveset;
-
mask &= _BLOCKABLE;
spin_lock_irq(&current->sighand->siglock);
- saveset = current->blocked;
+ current->saved_sigmask = current->blocked;
siginitset(&current->blocked, mask);
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
- regs->ARM_r0 = -EINTR;
-
- while (1) {
- current->state = TASK_INTERRUPTIBLE;
- schedule();
- if (do_signal(&saveset, regs, 0))
- return regs->ARM_r0;
- }
-}
-
-asmlinkage int
-sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
-{
- sigset_t saveset, newset;
-
- /* XXX: Don't preclude handling different sized sigset_t's. */
- if (sigsetsize != sizeof(sigset_t))
- return -EINVAL;
-
- if (copy_from_user(&newset, unewset, sizeof(newset)))
- return -EFAULT;
- sigdelsetmask(&newset, ~_BLOCKABLE);
-
- spin_lock_irq(&current->sighand->siglock);
- saveset = current->blocked;
- current->blocked = newset;
- recalc_sigpending();
- spin_unlock_irq(&current->sighand->siglock);
- regs->ARM_r0 = -EINTR;
- while (1) {
- current->state = TASK_INTERRUPTIBLE;
- schedule();
- if (do_signal(&saveset, regs, 0))
- return regs->ARM_r0;
- }
+ current->state = TASK_INTERRUPTIBLE;
+ schedule();
+ set_restore_sigmask();
+ return -ERESTARTNOHAND;
}
asmlinkage int
@@ -545,7 +524,7 @@ static inline void setup_syscall_restart(struct pt_regs *regs)
/*
* OK, we're invoking a handler
*/
-static void
+static int
handle_signal(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset,
struct pt_regs * regs, int syscall)
@@ -596,7 +575,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
if (ret != 0) {
force_sigsegv(sig, tsk);
- return;
+ return ret;
}
/*
@@ -610,6 +589,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
recalc_sigpending();
spin_unlock_irq(&tsk->sighand->siglock);
+ return 0;
}
/*
@@ -621,7 +601,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
-static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
+static void do_signal(struct pt_regs *regs, int syscall)
{
struct k_sigaction ka;
siginfo_t info;
@@ -634,7 +614,7 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
* if so.
*/
if (!user_mode(regs))
- return 0;
+ return;
if (try_to_freeze())
goto no_signal;
@@ -643,9 +623,24 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
- handle_signal(signr, &ka, &info, oldset, regs, syscall);
+ sigset_t *oldset;
+
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ oldset = &current->saved_sigmask;
+ else
+ oldset = &current->blocked;
+ if (handle_signal(signr, &ka, &info, oldset, regs, syscall) == 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 TIF_RESTORE_SIGMASK flag.
+ */
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+ }
single_step_set(current);
- return 1;
+ return;
}
no_signal:
@@ -663,32 +658,16 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
regs->ARM_pc -= 4;
#else
u32 __user *usp;
- u32 swival = __NR_restart_syscall;
- regs->ARM_sp -= 12;
+ regs->ARM_sp -= 4;
usp = (u32 __user *)regs->ARM_sp;
- /*
- * Either we supports OABI only, or we have
- * EABI with the OABI compat layer enabled.
- * In the later case we don't know if user
- * space is EABI or not, and if not we must
- * not clobber r7. Always using the OABI
- * syscall solves that issue and works for
- * all those cases.
- */
- swival = swival - __NR_SYSCALL_BASE + __NR_OABI_SYSCALL_BASE;
-
- put_user(regs->ARM_pc, &usp[0]);
- /* swi __NR_restart_syscall */
- put_user(0xef000000 | swival, &usp[1]);
- /* ldr pc, [sp], #12 */
- put_user(0xe49df00c, &usp[2]);
-
- flush_icache_range((unsigned long)usp,
- (unsigned long)(usp + 3));
-
- regs->ARM_pc = regs->ARM_sp + 4;
+ if (put_user(regs->ARM_pc, usp) == 0) {
+ regs->ARM_pc = KERN_RESTART_CODE;
+ } else {
+ regs->ARM_sp += 4;
+ force_sigsegv(0, current);
+ }
#endif
}
}
@@ -697,14 +676,28 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
regs->ARM_r0 == -ERESTARTNOINTR) {
setup_syscall_restart(regs);
}
+
+ /* 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, &current->saved_sigmask, NULL);
+ }
}
single_step_set(current);
- return 0;
}
asmlinkage void
do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
{
if (thread_flags & _TIF_SIGPENDING)
- do_signal(&current->blocked, regs, syscall);
+ do_signal(regs, syscall);
+
+ if (thread_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ if (current->replacement_session_keyring)
+ key_replace_session_keyring();
+ }
}
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