From 6628521784d1da3b7354c6b6e8499e19ab46a3d1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 19 Jul 2012 17:48:50 +0100 Subject: [PATCH] ARM: 7474/1: get rid of TIF_SYSCALL_RESTARTSYS just let do_work_pending() return 1 on normal local restarts and -1 on those that had been caused by ERESTART_RESTARTBLOCK (and 0 is still "all done, sod off to userland now"). And let the asm glue flip scno to restart_syscall(2) one if it got negative from us... [will: resolved conflicts with audit fixes] Signed-off-by: Al Viro Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/include/asm/thread_info.h | 5 +---- arch/arm/kernel/entry-common.S | 3 ++- arch/arm/kernel/ptrace.c | 7 +------ arch/arm/kernel/signal.c | 15 ++++++--------- 4 files changed, 10 insertions(+), 20 deletions(-) diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index b79f8e9..af7b0bd 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -148,7 +148,6 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, #define TIF_NOTIFY_RESUME 2 /* callback before returning to user */ #define TIF_SYSCALL_TRACE 8 #define TIF_SYSCALL_AUDIT 9 -#define TIF_SYSCALL_RESTARTSYS 10 #define TIF_POLLING_NRFLAG 16 #define TIF_USING_IWMMXT 17 #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ @@ -164,11 +163,9 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_USING_IWMMXT (1 << TIF_USING_IWMMXT) #define _TIF_SECCOMP (1 << TIF_SECCOMP) -#define _TIF_SYSCALL_RESTARTSYS (1 << TIF_SYSCALL_RESTARTSYS) /* Checks for any syscall work in entry-common.S */ -#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ - _TIF_SYSCALL_RESTARTSYS) +#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT) /* * Change these and you break ASM code in entry-common.S diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 8ae58c47..2909bbca 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -54,8 +54,9 @@ work_pending: mov r0, sp @ 'regs' mov r2, why @ 'syscall' bl do_work_pending - tst r0, #1 + cmp r0, #0 beq no_work_pending + movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE) ldmia sp, {r0 - r6} @ have to reload r0 - r6 b local_restart @ ... and off we go diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index efd25d6..3e0fc5f 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -941,12 +941,7 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno, asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) { - int ret; - - if (test_and_clear_thread_flag(TIF_SYSCALL_RESTARTSYS)) - scno = __NR_restart_syscall - __NR_SYSCALL_BASE; - - ret = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER); + int ret = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER); audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2, regs->ARM_r3); return ret; diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 99851cb..f27789e 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -591,7 +591,7 @@ static int do_signal(struct pt_regs *regs, int syscall) */ switch (retval) { case -ERESTART_RESTARTBLOCK: - restart++; + restart -= 2; case -ERESTARTNOHAND: case -ERESTARTSYS: case -ERESTARTNOINTR: @@ -629,13 +629,9 @@ static int do_signal(struct pt_regs *regs, int syscall) return 0; } - if (unlikely(restart)) { - if (restart > 1) - set_thread_flag(TIF_SYSCALL_RESTARTSYS); - regs->ARM_pc = continue_addr; - } - restore_saved_sigmask(); + if (unlikely(restart)) + regs->ARM_pc = continue_addr; return restart; } @@ -650,13 +646,14 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) return 0; local_irq_enable(); if (thread_flags & _TIF_SIGPENDING) { - if (unlikely(do_signal(regs, syscall))) { + int restart = do_signal(regs, syscall); + if (unlikely(restart)) { /* * Restart without handlers. * Deal with it without leaving * the kernel space. */ - return 1; + return restart; } syscall = 0; } else { -- 2.7.4