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authorAl Viro <viro@zeniv.linux.org.uk>2012-05-02 21:02:03 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-05-21 14:39:11 -0400
commit6b5c8045ecc7e726cdaa2a9d9c8e5008050e1252 (patch)
tree2bf168797818da579310adcd192765fcbe34ae87 /arch/arm
parent21c1176a72bd019d513b26e05d491a31b50b18d2 (diff)
downloadop-kernel-dev-6b5c8045ecc7e726cdaa2a9d9c8e5008050e1252.zip
op-kernel-dev-6b5c8045ecc7e726cdaa2a9d9c8e5008050e1252.tar.gz
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 <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/thread_info.h5
-rw-r--r--arch/arm/kernel/ptrace.c3
-rw-r--r--arch/arm/kernel/signal.c33
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 2d0cfc2..680c623 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 9650c14..d407ebf 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -24,6 +24,7 @@
#include <linux/hw_breakpoint.h>
#include <linux/regset.h>
#include <linux/audit.h>
+#include <linux/unistd.h>
#include <asm/pgtable.h>
#include <asm/traps.h>
@@ -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 6b37d4d..75c70d1 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
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