[PATCH 14/41] microblaze: Fix signal masking

Matt Fleming
2011-08-11T14:03:53Z

From: Matt Fleming <matt.fleming@intel.com>

There are a couple of problems with the current signal code,

1. If we failed to setup the signal stack frame then we
should not be masking any signals.

2. ka->sa.sa_mask is only added to the current blocked signals list if
SA_NODEFER is set in ka->sa.sa_flags. If we successfully setup the
signal frame and are going to run the handler then we must honour
sa_mask.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
---
arch/microblaze/kernel/signal.c | 31 ++++++++++++++++++-------------
1 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c
index 9e749c0..f2c13d5 100644
--- a/arch/microblaze/kernel/signal.c
+++ b/arch/microblaze/kernel/signal.c
@@ -169,7 +169,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
return (void __user *)((sp - frame_size) & -8UL);
}

-static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
@@ -267,10 +267,11 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
current->comm, current->pid, frame, regs->pc);
#endif

- return;
+ return 0;

give_sigsegv:
force_sigsegv(sig, current);
+ return -EFAULT;
}

/* Handle restarting system calls */
@@ -314,21 +315,25 @@ static int
handle_signal(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
{
+ int ret;
+
/* Set up the stack frame */
if (ka->sa.sa_flags & SA_SIGINFO)
- setup_rt_frame(sig, ka, info, oldset, regs);
+ ret = setup_rt_frame(sig, ka, info, oldset, regs);
else
- setup_rt_frame(sig, ka, NULL, oldset, regs);
+ ret = setup_rt_frame(sig, ka, NULL, oldset, regs);
+
+ if (ret)
+ return ret;

- if (!(ka->sa.sa_flags & SA_NODEFER)) {
- spin_lock_irq(&current->sighand->siglock);
- sigorsets(&current->blocked,
- &current->blocked, &ka->sa.sa_mask);
+ spin_lock_irq(&current->sighand->siglock);
+ sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
+ if (!(ka->sa.sa_flags & SA_NODEFER))
sigaddset(&current->blocked, sig);
- recalc_sigpending();
- spin_unlock_irq(&current->sighand->siglock);
- }
- return 1;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ return 0;
}

/*
@@ -369,7 +374,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_syscall)
/* Whee! Actually deliver the signal. */
if (in_syscall)
handle_restart(regs, &ka, 1);
- if (handle_signal(signr, &ka, &info, oldset, regs)) {
+ if (!handle_signal(signr, &ka, &info, oldset, regs)) {
/*
* A signal was successfully delivered; the saved
* sigmask will have been stored in the signal frame,
--
1.7.4.4