From 8efc0ab50edbac5c65191b8a58dfdab3741b7901 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 6 Jan 2006 00:11:44 -0800 Subject: [PATCH] [PATCH] frv: fix signal handling The attached patch makes FRV signal handling work properly: (1) After do_notify_resume() has been called, the work flags must be checked again (there may be another signal to deliver or the process might require rescheduling for instance). (2) After the signal frame is set up on the userspace stack, ptrace() should be given an opportunity to single-step into the signal handler. (3) The error state from setting up a signal frame should be passed back up the call chain. (4) The segfault handler shouldn't be preemptively reset in the arch if we fail to deliver a SEGV signal: force_sig() will take care of that. Signed-off-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/frv/kernel/entry.S | 2 +- arch/frv/kernel/signal.c | 73 +++++++++++++++++++++++++--------------- 2 files changed, 46 insertions(+), 29 deletions(-) diff --git a/arch/frv/kernel/entry.S b/arch/frv/kernel/entry.S index ad10ea5954..5f6548388b 100644 --- a/arch/frv/kernel/entry.S +++ b/arch/frv/kernel/entry.S @@ -1076,7 +1076,7 @@ __entry_work_notifysig: LEDS 0x6410 ori.p gr4,#0,gr8 call do_notify_resume - bra __entry_return_direct + bra __entry_resume_userspace # perform syscall entry tracing __syscall_trace_entry: diff --git a/arch/frv/kernel/signal.c b/arch/frv/kernel/signal.c index d4ccc0728d..89a1cf5c07 100644 --- a/arch/frv/kernel/signal.c +++ b/arch/frv/kernel/signal.c @@ -297,7 +297,8 @@ static inline void __user *get_sigframe(struct k_sigaction *ka, /* * */ -static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs) +static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, + struct pt_regs *regs) { struct sigframe __user *frame; int rsig; @@ -362,26 +363,30 @@ static void setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct p set_fs(USER_DS); + /* the tracer may want to single-step inside the handler */ + if (test_thread_flag(TIF_SINGLESTEP)) + ptrace_notify(SIGTRAP); + #if DEBUG_SIG printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", - sig, current->comm, current->pid, frame, regs->pc, frame->pretcode); + sig, current->comm, current->pid, frame, regs->pc, + frame->pretcode); #endif - return; + return 1; give_sigsegv: - if (sig == SIGSEGV) - ka->sa.sa_handler = SIG_DFL; - force_sig(SIGSEGV, current); + return 0; + } /* end setup_frame() */ /*****************************************************************************/ /* * */ -static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, - sigset_t *set, struct pt_regs * regs) +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; int rsig; @@ -457,17 +462,21 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, set_fs(USER_DS); + /* the tracer may want to single-step inside the handler */ + if (test_thread_flag(TIF_SINGLESTEP)) + ptrace_notify(SIGTRAP); + #if DEBUG_SIG printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", - sig, current->comm, current->pid, frame, regs->pc, frame->pretcode); + sig, current->comm, current->pid, frame, regs->pc, + frame->pretcode); #endif - return; + return 1; give_sigsegv: - if (sig == SIGSEGV) - ka->sa.sa_handler = SIG_DFL; force_sig(SIGSEGV, current); + return 0; } /* end setup_rt_frame() */ @@ -475,10 +484,12 @@ give_sigsegv: /* * OK, we're invoking a handler */ -static void handle_signal(unsigned long sig, siginfo_t *info, - struct k_sigaction *ka, sigset_t *oldset, - struct pt_regs *regs) +static int handle_signal(unsigned long sig, siginfo_t *info, + struct k_sigaction *ka, sigset_t *oldset, + struct pt_regs *regs) { + int ret; + /* Are we from a system call? */ if (in_syscall(regs)) { /* If so, check system call restarting.. */ @@ -493,6 +504,7 @@ static void handle_signal(unsigned long sig, siginfo_t *info, regs->gr8 = -EINTR; break; } + /* fallthrough */ case -ERESTARTNOINTR: regs->gr8 = regs->orig_gr8; @@ -502,16 +514,22 @@ static void handle_signal(unsigned long sig, siginfo_t *info, /* 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_frame(sig, ka, oldset, regs); + ret = setup_frame(sig, ka, oldset, regs); + + if (ret) { + spin_lock_irq(¤t->sighand->siglock); + sigorsets(¤t->blocked, ¤t->blocked, + &ka->sa.sa_mask); + if (!(ka->sa.sa_flags & SA_NODEFER)) + sigaddset(¤t->blocked, sig); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + } + + return ret; - spin_lock_irq(¤t->sighand->siglock); - sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); - if (!(ka->sa.sa_flags & SA_NODEFER)) - sigaddset(¤t->blocked, sig); - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); } /* end handle_signal() */ /*****************************************************************************/ @@ -542,12 +560,10 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset) oldset = ¤t->blocked; signr = get_signal_to_deliver(&info, &ka, regs, NULL); - if (signr > 0) { - handle_signal(signr, &info, &ka, oldset, regs); - return 1; - } + if (signr > 0) + return handle_signal(signr, &info, &ka, oldset, regs); - no_signal: +no_signal: /* Did we come from a system call? */ if (regs->syscallno >= 0) { /* Restart the system call - no handlers present */ @@ -565,6 +581,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset) } return 0; + } /* end do_signal() */ /*****************************************************************************/ -- 2.39.5