5 files changed, 27 insertions, 73 deletions

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 7bd2d3cb8957..4afed88d250a 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -53,9 +53,13 @@ fast_work_pending:
 work_pending:
         tst     r1, #_TIF_NEED_RESCHED
         bne     work_resched
-        tst     r1, #_TIF_SIGPENDING|_TIF_NOTIFY_RESUME
-        beq     no_work_pending
+        /*
+         * TIF_SIGPENDING or TIF_NOTIFY_RESUME must've been set if we got here
+         */
+        ldr     r2, [sp, #S_PSR]
         mov     r0, sp                          @ 'regs'
+        tst     r2, #15                         @ are we returning to user mode?
+        bne     no_work_pending                 @ no?  just leave, then...
         mov     r2, why                         @ 'syscall'
         tst     r1, #_TIF_SIGPENDING            @ delivering a signal?
         movne   why, #0                         @ prevent further restarts
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 14e38261cd31..5700a7ae7f0b 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -25,6 +25,7 @@
 #include <linux/regset.h>
 #include <linux/audit.h>
 #include <linux/tracehook.h>
+#include <linux/unistd.h>
 
 #include <asm/pgtable.h>
 #include <asm/traps.h>
@@ -917,6 +918,8 @@ asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
                 audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0,
                                     regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);
 
+        if (why == 0 && test_and_clear_thread_flag(TIF_SYSCALL_RESTARTSYS))
+                scno = __NR_restart_syscall - __NR_SYSCALL_BASE;
         if (!test_thread_flag(TIF_SYSCALL_TRACE))
                 return scno;
 
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 4e5fdd9bd9e3..17fc36c41cff 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -29,7 +29,6 @@
  */
 #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.
@@ -50,18 +49,6 @@ 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)
@@ -82,10 +69,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *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))
+                    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
+                    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+                    __get_user(mask, &act->sa_mask))
                         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);
         }
 
@@ -94,10 +81,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
         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))
+                    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
+                    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+                    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
                         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;
@@ -602,15 +589,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
         int signr;
 
         /*
-         * 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.
-         */
-        if (!user_mode(regs))
-                return;
-
-        /*
          * If we were from a system call, check for system call restarting...
          */
         if (syscall) {
@@ -626,18 +604,13 @@ static void do_signal(struct pt_regs *regs, int syscall)
                 case -ERESTARTNOHAND:
                 case -ERESTARTSYS:
                 case -ERESTARTNOINTR:
+                case -ERESTART_RESTARTBLOCK:
                         regs->ARM_r0 = regs->ARM_ORIG_r0;
                         regs->ARM_pc = restart_addr;
                         break;
-                case -ERESTART_RESTARTBLOCK:
-                        regs->ARM_r0 = -EINTR;
-                        break;
                 }
         }
 
-        if (try_to_freeze())
-                goto no_signal;
-
         /*
          * Get the signal to deliver.  When running under ptrace, at this
          * point the debugger may change all our registers ...
@@ -652,12 +625,14 @@ static void do_signal(struct pt_regs *regs, int syscall)
                  * debugger has chosen to restart at a different PC.
                  */
                 if (regs->ARM_pc == restart_addr) {
-                        if (retval == -ERESTARTNOHAND
+                        if (retval == -ERESTARTNOHAND ||
+                            retval == -ERESTART_RESTARTBLOCK
                             || (retval == -ERESTARTSYS
                                 && !(ka.sa.sa_flags & SA_RESTART))) {
                                 regs->ARM_r0 = -EINTR;
                                 regs->ARM_pc = continue_addr;
                         }
+                        clear_thread_flag(TIF_SYSCALL_RESTARTSYS);
                 }
 
                 if (test_thread_flag(TIF_RESTORE_SIGMASK))
@@ -677,7 +652,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
                 return;
         }
 
- no_signal:
         if (syscall) {
                 /*
                  * Handle restarting a different system call.  As above,
@@ -685,38 +659,15 @@ static void do_signal(struct pt_regs *regs, int syscall)
                  * 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
-                        }
-                }
-
-                /* 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);
-                }
+                    && regs->ARM_pc == restart_addr)
+                        set_thread_flag(TIF_SYSCALL_RESTARTSYS);
         }
+
+        /* If there's no signal to deliver, we just put the saved sigmask
+         * back.
+         */
+        if (test_and_clear_thread_flag(TIF_RESTORE_SIGMASK))
+                set_current_blocked(&current->saved_sigmask);
 }
 
 asmlinkage void
diff --git a/arch/arm/kernel/signal.h b/arch/arm/kernel/signal.h
index 6fcfe8398aa4..5ff067b7c752 100644
--- a/arch/arm/kernel/signal.h
+++ b/arch/arm/kernel/signal.h
@@ -8,7 +8,5 @@
  * published by the Free Software Foundation.
  */
 #define KERN_SIGRETURN_CODE     (CONFIG_VECTORS_BASE + 0x00000500)
-#define KERN_RESTART_CODE       (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes))
 
 extern const unsigned long sigreturn_codes[7];
-extern const unsigned long syscall_restart_code[2];
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 3647170e9a16..4928d89758f4 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -820,8 +820,6 @@ void __init early_trap_init(void *vectors_base)
          */
         memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE),
                sigreturn_codes, sizeof(sigreturn_codes));
-        memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE),
-               syscall_restart_code, sizeof(syscall_restart_code));
 
         flush_icache_range(vectors, vectors + PAGE_SIZE);
         modify_domain(DOMAIN_USER, DOMAIN_CLIENT);