From 00df111e7eb505558c54f23861e9341e56dd5fb0 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 19 May 2012 00:29:22 -0400 Subject: 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 --- arch/parisc/kernel/signal.c | 16 ++++++++-------- arch/parisc/kernel/syscall.S | 2 +- 2 files changed, 9 insertions(+), 9 deletions(-) (limited to 'arch/parisc/kernel') 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 @@ 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: 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 @@ 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 */ -- cgit v1.1 From e3b880c6ee55e8858a75e3dcf6c3dda04d5e3605 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 19 May 2012 01:13:01 -0400 Subject: parisc: don't bother looping in do_signal() entry.S code had been looping until no pending signals are left since 2005 anyway; no need to bother with that in do_signal() itself. If the failure to set a sigframe up raises SIGSEGV, we'll just pick it up the next time around the loop(s) in entry.S anyway. Signed-off-by: Al Viro --- arch/parisc/kernel/signal.c | 29 +++++++---------------------- 1 file changed, 7 insertions(+), 22 deletions(-) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c index 3790a32..5379969 100644 --- a/arch/parisc/kernel/signal.c +++ b/arch/parisc/kernel/signal.c @@ -439,7 +439,7 @@ give_sigsegv: * OK, we're invoking a handler. */ -static long +static void handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, struct pt_regs *regs, int in_syscall) { @@ -449,7 +449,7 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, /* Set up the stack frame */ if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall)) - return 0; + return; signal_delivered(sig, info, ka, regs, test_thread_flag(TIF_SINGLESTEP) || @@ -457,8 +457,6 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n", regs->gr[28]); - - return 1; } static inline void @@ -570,30 +568,17 @@ do_signal(struct pt_regs *regs, long in_syscall) DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n", regs, regs->sr[7], in_syscall); - /* Everyone else checks to see if they are in kernel mode at - this point and exits if that's the case. I'm not sure why - we would be called in that case, but for some reason we - are. */ - - /* May need to force signal if handle_signal failed to deliver */ - while (1) { - signr = get_signal_to_deliver(&info, &ka, regs, NULL); - DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); - if (signr <= 0) - break; - + if (signr > 0) { /* Restart a system call if necessary. */ if (in_syscall) syscall_restart(regs, &ka); - /* Whee! Actually deliver the signal. If the - delivery failed, we need to continue to iterate in - this loop so we can deliver the SIGSEGV... */ - if (handle_signal(signr, &info, &ka, regs, in_syscall)) - return; + handle_signal(signr, &info, &ka, regs, in_syscall); + return; } - /* end of while(1) looping forever if we can't force a signal */ /* Did we come from a system call? */ if (in_syscall) -- cgit v1.1 From 64482bd8ef1700e98d96fb6e240c501d68c8371c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 20 May 2012 11:59:03 -0400 Subject: parisc: decide whether to go to slow path (tracesys) based on thread flags Signed-off-by: Al Viro --- arch/parisc/kernel/syscall.S | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index 54a9cbf..86742df 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -180,9 +180,10 @@ linux_gateway_entry: /* Are we being ptraced? */ mfctl %cr30, %r1 - LDREG TI_TASK(%r1),%r1 - ldw TASK_PTRACE(%r1), %r1 - bb,<,n %r1,31,.Ltracesys + LDREG TI_FLAGS(%r1),%r1 + ldi _TIF_SYSCALL_TRACE_MASK, %r19 + and,COND(=) %r1, %r19, %r0 + b,n .Ltracesys /* Note! We cannot use the syscall table that is mapped nearby since the gateway page is mapped execute-only. */ -- cgit v1.1