Messages in this thread Patch in this message | | | Date | Tue, 29 Nov 2005 21:18:00 GMT | From | David Howells <> | Subject | [PATCH 1/2] FRV: Fix FRV signal handling |
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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 <dhowells@redhat.com> --- warthog>diffstat -p1 frv-signal-2615rc2.diff arch/frv/kernel/entry.S | 2 - arch/frv/kernel/signal.c | 73 ++++++++++++++++++++++++++++------------------- 2 files changed, 46 insertions(+), 29 deletions(-)
diff -uNrp linux-2.6.15-rc2-frv-shmem/arch/frv/kernel/entry.S linux-2.6.15-rc2-frv-signal/arch/frv/kernel/entry.S --- linux-2.6.15-rc2-frv-shmem/arch/frv/kernel/entry.S 2005-03-02 12:07:44.000000000 +0000 +++ linux-2.6.15-rc2-frv-signal/arch/frv/kernel/entry.S 2005-11-29 16:01:40.000000000 +0000 @@ -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 -uNrp linux-2.6.15-rc2-frv-shmem/arch/frv/kernel/signal.c linux-2.6.15-rc2-frv-signal/arch/frv/kernel/signal.c --- linux-2.6.15-rc2-frv-shmem/arch/frv/kernel/signal.c 2005-11-01 13:18:57.000000000 +0000 +++ linux-2.6.15-rc2-frv-signal/arch/frv/kernel/signal.c 2005-11-29 16:41:11.000000000 +0000 @@ -297,7 +297,8 @@ static inline void __user *get_sigframe( /* * */ -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 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, stru 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 regs->gr8 = -EINTR; break; } + /* fallthrough */ case -ERESTARTNOINTR: regs->gr8 = regs->orig_gr8; @@ -502,16 +514,22 @@ static void handle_signal(unsigned long /* 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, sigs 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, sigs } return 0; + } /* end do_signal() */ /*****************************************************************************/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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