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Commit 00df111e authored by Al Viro's avatar Al Viro
Browse files

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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 8ca8230b

arch/parisc/hpux/gate.S

+1 −1
Original line number Diff line number Diff line
@@ -71,7 +71,7 @@ ENTRY(hpux_gateway_page) 
	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 */

arch/parisc/kernel/signal.c

+8 −8
Original line number Diff line number Diff line
@@ -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:

arch/parisc/kernel/syscall.S

+1 −1
Original line number Diff line number Diff line
@@ -156,7 +156,7 @@ linux_gateway_entry: 
	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 */