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parisc: fix double restarts

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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>
This commit is contained in:
Al Viro
2012-05-19 00:29:22 -04:00
parent 8ca8230b71
commit 00df111e7e
3 changed files with 10 additions and 10 deletions
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16
arch/parisc/kernel/signal.c
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@@ -113,6 +113,8 @@ sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
(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 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
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 @@ syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
* 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 @@ syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
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 @@ insert_restart_trampoline(struct pt_regs *regs)
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 @@ insert_restart_trampoline(struct pt_regs *regs)
* slot of the branch external instruction.
*/
regs->gr[31] -= 8;
/* Preserve original r28. */
regs->gr[28] = regs->orig_r28;
return;
}
default: