ARM: 7470/1: Revert "7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK""

This reverts commit 433e2f307b.

Conflicts:

	arch/arm/kernel/ptrace.c

Reintroduce the new syscall restart handling in preparation for further
patches from Al Viro.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Will Deacon 2012-07-19 17:46:44 +01:00 committed by Russell King
parent ad72254114
commit ad82cc08f7
3 changed files with 17 additions and 29 deletions

View File

@ -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_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)
#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SYSCALL_RESTARTSYS)
/*
* Change these and you break ASM code in entry-common.S

View File

@ -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>
@ -940,7 +941,12 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno,
asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)
{
int ret = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER);
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);
audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0, regs->ARM_r1,
regs->ARM_r2, regs->ARM_r3);
return ret;

View File

@ -605,12 +605,10 @@ 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;
}
}
@ -626,12 +624,14 @@ 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);
}
handle_signal(signr, &ka, &info, regs);
@ -645,29 +645,8 @@ 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);
}
restore_saved_sigmask();