parisc: fix double restarts
Don't bother restoring r28 on syscall restarts; it's clobbered by
syscall anyway. Reuse (now unused) ->orig_r28 as "no restarts allowed"
flag.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/parisc/hpux/gate.S b/arch/parisc/hpux/gate.S
index 38a1c1b..0114688 100644
--- a/arch/parisc/hpux/gate.S
+++ b/arch/parisc/hpux/gate.S
@@ -71,7 +71,7 @@
STREG %r26, TASK_PT_GR26(%r1) /* 1st argument */
STREG %r27, TASK_PT_GR27(%r1) /* user dp */
STREG %r28, TASK_PT_GR28(%r1) /* return value 0 */
- STREG %r28, TASK_PT_ORIG_R28(%r1) /* return value 0 (saved for signals) */
+ STREG %r0, TASK_PT_ORIG_R28(%r1) /* don't prohibit restarts */
STREG %r29, TASK_PT_GR29(%r1) /* 8th argument */
STREG %r31, TASK_PT_GR31(%r1) /* preserve syscall return ptr */
diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c
index 594459b..3790a32 100644
--- a/arch/parisc/kernel/signal.c
+++ b/arch/parisc/kernel/signal.c
@@ -113,6 +113,8 @@
(usp - sigframe_size);
DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
+ regs->orig_r28 = 1; /* no restarts for sigreturn */
+
#ifdef CONFIG_64BIT
compat_frame = (struct compat_rt_sigframe __user *)frame;
@@ -462,6 +464,9 @@
static inline void
syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
{
+ if (regs->orig_r28)
+ return;
+ regs->orig_r28 = 1; /* no more restarts */
/* Check the return code */
switch (regs->gr[28]) {
case -ERESTART_RESTARTBLOCK:
@@ -482,8 +487,6 @@
* we have to do is fiddle the return pointer.
*/
regs->gr[31] -= 8; /* delayed branching */
- /* Preserve original r28. */
- regs->gr[28] = regs->orig_r28;
break;
}
}
@@ -491,6 +494,9 @@
static inline void
insert_restart_trampoline(struct pt_regs *regs)
{
+ if (regs->orig_r28)
+ return;
+ regs->orig_r28 = 1; /* no more restarts */
switch(regs->gr[28]) {
case -ERESTART_RESTARTBLOCK: {
/* Restart the system call - no handlers present */
@@ -525,9 +531,6 @@
flush_user_icache_range(regs->gr[30], regs->gr[30] + 4);
regs->gr[31] = regs->gr[30] + 8;
- /* Preserve original r28. */
- regs->gr[28] = regs->orig_r28;
-
return;
}
case -ERESTARTNOHAND:
@@ -539,9 +542,6 @@
* slot of the branch external instruction.
*/
regs->gr[31] -= 8;
- /* Preserve original r28. */
- regs->gr[28] = regs->orig_r28;
-
return;
}
default:
diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index 82a52b2..54a9cbf 100644
--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -156,7 +156,7 @@
STREG %r26, TASK_PT_GR26(%r1) /* 1st argument */
STREG %r27, TASK_PT_GR27(%r1) /* user dp */
STREG %r28, TASK_PT_GR28(%r1) /* return value 0 */
- STREG %r28, TASK_PT_ORIG_R28(%r1) /* return value 0 (saved for signals) */
+ STREG %r0, TASK_PT_ORIG_R28(%r1) /* don't prohibit restarts */
STREG %r29, TASK_PT_GR29(%r1) /* return value 1 */
STREG %r31, TASK_PT_GR31(%r1) /* preserve syscall return ptr */
