From 6b5c8045ecc7e726cdaa2a9d9c8e5008050e1252 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 2 May 2012 21:02:03 -0400 Subject: [PATCH] arm: new way of handling ERESTART_RESTARTBLOCK new "syscall start" flag; handled in syscall_trace() by switching syscall number to that of syscall_restart(2). Restarts of that kind (ERESTART_RESTARTBLOCK) are handled by setting that bit; syscall number is not modified until the actual call. Signed-off-by: Al Viro --- arch/arm/include/asm/thread_info.h | 5 ++++- arch/arm/kernel/ptrace.c | 3 +++ arch/arm/kernel/signal.c | 33 ++++++------------------------ 3 files changed, 13 insertions(+), 28 deletions(-) diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index 2d0cfc2ba23c..680c623a3d1f 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -148,6 +148,7 @@ 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 */ @@ -163,9 +164,11 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, #define _TIF_USING_IWMMXT (1 << TIF_USING_IWMMXT) #define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK) #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) +#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ + _TIF_SYSCALL_RESTARTSYS) /* * Change these and you break ASM code in entry-common.S diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index 9650c143afc1..d407ebf41801 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -916,6 +917,8 @@ 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; if (!(current->ptrace & PT_PTRACED)) diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 6b37d4ddf0b6..75c70d1850df 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -624,12 +624,10 @@ 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; } } @@ -647,12 +645,14 @@ 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)) @@ -679,29 +679,8 @@ 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 - } - } + && regs->ARM_pc == restart_addr) + set_thread_flag(TIF_SYSCALL_RESTARTSYS); } /* If there's no signal to deliver, we just put the saved sigmask -- 2.20.1