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-rw-r--r--arch/arm/kernel/signal.c115
1 files changed, 48 insertions, 67 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 536c5d6..56f72d2 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -10,7 +10,6 @@
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/personality.h>
-#include <linux/freezer.h>
#include <linux/uaccess.h>
#include <linux/tracehook.h>
@@ -27,7 +26,6 @@
*/
#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.
@@ -48,18 +46,6 @@ const unsigned long sigreturn_codes[7] = {
};
/*
- * 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)
@@ -582,12 +568,13 @@ 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 void do_signal(struct pt_regs *regs, int syscall)
+static int do_signal(struct pt_regs *regs, int syscall)
{
unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
struct k_sigaction ka;
siginfo_t info;
int signr;
+ int restart = 0;
/*
* If we were from a system call, check for system call restarting...
@@ -602,15 +589,15 @@ static void do_signal(struct pt_regs *regs, int syscall)
* debugger will see the already changed PSW.
*/
switch (retval) {
+ case -ERESTART_RESTARTBLOCK:
+ restart -= 2;
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
+ restart++;
regs->ARM_r0 = regs->ARM_ORIG_r0;
regs->ARM_pc = restart_addr;
break;
- case -ERESTART_RESTARTBLOCK:
- regs->ARM_r0 = -EINTR;
- break;
}
}
@@ -619,14 +606,17 @@ static void do_signal(struct pt_regs *regs, int syscall)
* point the debugger may change all our registers ...
*/
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+ /*
+ * Depending on the signal settings we may need to revert the
+ * decision to restart the system call. But skip this if a
+ * debugger has chosen to restart at a different PC.
+ */
+ if (regs->ARM_pc != restart_addr)
+ restart = 0;
if (signr > 0) {
- /*
- * Depending on the signal settings we may need to revert the
- * decision to restart the system call. But skip this if a
- * debugger has chosen to restart at a different PC.
- */
- if (regs->ARM_pc == restart_addr) {
- if (retval == -ERESTARTNOHAND
+ if (unlikely(restart)) {
+ if (retval == -ERESTARTNOHAND ||
+ retval == -ERESTART_RESTARTBLOCK
|| (retval == -ERESTARTSYS
&& !(ka.sa.sa_flags & SA_RESTART))) {
regs->ARM_r0 = -EINTR;
@@ -635,52 +625,43 @@ static void do_signal(struct pt_regs *regs, int syscall)
}
handle_signal(signr, &ka, &info, regs);
- return;
- }
-
- if (syscall) {
- /*
- * Handle restarting a different system call. As above,
- * if a debugger has chosen to restart at a different PC,
- * ignore the restart.
- */
- if (retval == -ERESTART_RESTARTBLOCK
- && regs->ARM_pc == continue_addr) {
- if (thumb_mode(regs)) {
- regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
- regs->ARM_pc -= 2;
- } else {
-#if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT)
- regs->ARM_r7 = __NR_restart_syscall;
- regs->ARM_pc -= 4;
-#else
- u32 __user *usp;
-
- regs->ARM_sp -= 4;
- usp = (u32 __user *)regs->ARM_sp;
-
- if (put_user(regs->ARM_pc, usp) == 0) {
- regs->ARM_pc = KERN_RESTART_CODE;
- } else {
- regs->ARM_sp += 4;
- force_sigsegv(0, current);
- }
-#endif
- }
- }
+ return 0;
}
restore_saved_sigmask();
+ if (unlikely(restart))
+ regs->ARM_pc = continue_addr;
+ return restart;
}
-asmlinkage void
-do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
+asmlinkage int
+do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
{
- if (thread_flags & _TIF_SIGPENDING)
- do_signal(regs, syscall);
-
- if (thread_flags & _TIF_NOTIFY_RESUME) {
- clear_thread_flag(TIF_NOTIFY_RESUME);
- tracehook_notify_resume(regs);
- }
+ do {
+ if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+ schedule();
+ } else {
+ if (unlikely(!user_mode(regs)))
+ return 0;
+ local_irq_enable();
+ if (thread_flags & _TIF_SIGPENDING) {
+ int restart = do_signal(regs, syscall);
+ if (unlikely(restart)) {
+ /*
+ * Restart without handlers.
+ * Deal with it without leaving
+ * the kernel space.
+ */
+ return restart;
+ }
+ syscall = 0;
+ } else {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
+ }
+ local_irq_disable();
+ thread_flags = current_thread_info()->flags;
+ } while (thread_flags & _TIF_WORK_MASK);
+ return 0;
}