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>
This commit is contained in:
Al Viro
2012-05-02 21:02:03 -04:00
parent 21c1176a72
commit 6b5c8045ec
3 changed files with 13 additions and 28 deletions

View File

@@ -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