The patch titled
add print_fatal_signals support
has been added to the -mm tree. Its filename is
add-print_fatal_signals-support.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: add print_fatal_signals support
From: Ingo Molnar <mingo@xxxxxxx>
Add the print-fatal-signals=1 boot option and the
/proc/sys/kernel/print-fatal-signals runtime switch.
This feature prints some minimal information about userspace segfaults to
the kernel console. This is useful to find early bootup bugs where
userspace debugging is very hard.
Defaults to off.
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
Documentation/kernel-parameters.txt | 6 ++++
include/linux/sysctl.h | 1
kernel/signal.c | 38 ++++++++++++++++++++++++++
kernel/sysctl.c | 9 ++++++
4 files changed, 54 insertions(+)
diff -puN Documentation/kernel-parameters.txt~add-print_fatal_signals-support Documentation/kernel-parameters.txt
--- devel/Documentation/kernel-parameters.txt~add-print_fatal_signals-support 2006-05-21 05:55:05.000000000 -0700
+++ devel-akpm/Documentation/kernel-parameters.txt 2006-05-21 05:55:05.000000000 -0700
@@ -1273,6 +1273,12 @@ running once the system is up.
autoconfiguration.
Ranges are in pairs (memory base and size).
+ print-fatal-signals=
+ [KNL] debug: print fatal signals
+ print-fatal-signals=1: print segfault info to
+ the kernel console.
+ default: off.
+
profile= [KNL] Enable kernel profiling via /proc/profile
Format: [schedule,]<number>
Param: "schedule" - profile schedule points.
diff -puN include/linux/sysctl.h~add-print_fatal_signals-support include/linux/sysctl.h
--- devel/include/linux/sysctl.h~add-print_fatal_signals-support 2006-05-21 05:55:05.000000000 -0700
+++ devel-akpm/include/linux/sysctl.h 2006-05-21 05:55:05.000000000 -0700
@@ -93,6 +93,7 @@ enum
KERN_CAP_BSET=14, /* int: capability bounding set */
KERN_PANIC=15, /* int: panic timeout */
KERN_REALROOTDEV=16, /* real root device to mount after initrd */
+ KERN_PRINT_FATAL=17, /* int: print fatal signals (0/1) */
KERN_SPARC_REBOOT=21, /* reboot command on Sparc */
KERN_CTLALTDEL=22, /* int: allow ctl-alt-del to reboot */
diff -puN kernel/signal.c~add-print_fatal_signals-support kernel/signal.c
--- devel/kernel/signal.c~add-print_fatal_signals-support 2006-05-21 05:55:05.000000000 -0700
+++ devel-akpm/kernel/signal.c 2006-05-21 05:55:05.000000000 -0700
@@ -763,6 +763,37 @@ out_set:
#define LEGACY_QUEUE(sigptr, sig) \
(((sig) < SIGRTMIN) && sigismember(&(sigptr)->signal, (sig)))
+int print_fatal_signals = 0;
+
+static void print_fatal_signal(struct pt_regs *regs, int signr)
+{
+ printk("%s/%d: potentially unexpected fatal signal %d.\n",
+ current->comm, current->pid, signr);
+
+#ifdef __i386__
+ printk("code at %08lx: ", regs->eip);
+ {
+ int i;
+ for (i = 0; i < 16; i++) {
+ unsigned char insn;
+
+ __get_user(insn, (unsigned char *)(regs->eip + i));
+ printk("%02x ", insn);
+ }
+ }
+#endif
+ printk("\n");
+ show_regs(regs);
+}
+
+static int __init setup_print_fatal_signals(char *str)
+{
+ get_option (&str, &print_fatal_signals);
+
+ return 1;
+}
+
+__setup("print-fatal-signals=", setup_print_fatal_signals);
static int
specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
@@ -1773,6 +1804,11 @@ relock:
if (!signr)
break; /* will return 0 */
+ if ((signr == SIGSEGV) && print_fatal_signals) {
+ spin_unlock_irq(¤t->sighand->siglock);
+ print_fatal_signal(regs, signr);
+ spin_lock_irq(¤t->sighand->siglock);
+ }
if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
ptrace_signal_deliver(regs, cookie);
@@ -1868,6 +1904,8 @@ relock:
* Anything else is fatal, maybe with a core dump.
*/
current->flags |= PF_SIGNALED;
+ if ((signr != SIGKILL) && print_fatal_signals)
+ print_fatal_signal(regs, signr);
if (sig_kernel_coredump(signr)) {
/*
* If it was able to dump core, this kills all
diff -puN kernel/sysctl.c~add-print_fatal_signals-support kernel/sysctl.c
--- devel/kernel/sysctl.c~add-print_fatal_signals-support 2006-05-21 05:55:05.000000000 -0700
+++ devel-akpm/kernel/sysctl.c 2006-05-21 05:55:05.000000000 -0700
@@ -75,6 +75,7 @@ extern int pid_max_min, pid_max_max;
extern int sysctl_drop_caches;
extern int percpu_pagelist_fraction;
extern int compat_log;
+extern int print_fatal_signals;
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
int unknown_nmi_panic;
@@ -334,6 +335,14 @@ static ctl_table kern_table[] = {
.proc_handler = &proc_dointvec,
},
#endif
+ {
+ .ctl_name = KERN_PRINT_FATAL,
+ .procname = "print-fatal-signals",
+ .data = &print_fatal_signals,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
#ifdef __sparc__
{
.ctl_name = KERN_SPARC_REBOOT,
_
Patches currently in -mm which might be from mingo@xxxxxxx are
git-acpi.patch
fix-drivers-mfd-ucb1x00-corec-irq-probing-bug.patch
git-dvb.patch
git-netdev-all.patch
fix-for-serial-uart-lockup.patch
qla2xxx-lock-ordering-fix.patch
qla2xxx-lock-ordering-fix-warning-fix.patch
swapless-pm-add-r-w-migration-entries-fix.patch
i386-break-out-of-recursion-in-stackframe-walk.patch
work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs.patch
kernel-kernel-cpuc-to-mutexes.patch
cond-resched-might-sleep-fix.patch
define-__raw_get_cpu_var-and-use-it.patch
ide-cd-end-of-media-error-fix.patch
time-clocksource-infrastructure.patch
sched-comment-bitmap-size-accounting.patch
sched-fix-interactive-ceiling-code.patch
sched-implement-smpnice.patch
sched-protect-calculation-of-max_pull-from-integer-wrap.patch
sched-store-weighted-load-on-up.patch
sched-add-discrete-weighted-cpu-load-function.patch
sched-prevent-high-load-weight-tasks-suppressing-balancing.patch
sched-improve-stability-of-smpnice-load-balancing.patch
sched-improve-smpnice-load-balancing-when-load-per-task.patch
smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing.patch
smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing-fix.patch
sched-modify-move_tasks-to-improve-load-balancing-outcomes.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks-fix-2.patch
sched_domain-handle-kmalloc-failure.patch
sched_domain-handle-kmalloc-failure-fix.patch
sched_domain-dont-use-gfp_atomic.patch
sched_domain-use-kmalloc_node.patch
sched_domain-allocate-sched_group-structures-dynamically.patch
sched-add-above-background-load-function.patch
mm-implement-swap-prefetching-fix.patch
pi-futex-futex-code-cleanups.patch
pi-futex-futex-code-cleanups-fix.patch
pi-futex-introduce-debug_check_no_locks_freed.patch
pi-futex-add-plist-implementation.patch
pi-futex-scheduler-support-for-pi.patch
pi-futex-rt-mutex-core.patch
pi-futex-rt-mutex-core-fix-timeout-race.patch
pi-futex-rt-mutex-docs.patch
pi-futex-rt-mutex-debug.patch
pi-futex-rt-mutex-tester.patch
pi-futex-rt-mutex-futex-api.patch
pi-futex-futex_lock_pi-futex_unlock_pi-support.patch
pi-futex-v2.patch
pi-futex-v3.patch
pi-futex-patchset-v4.patch
pi-futex-patchset-v4-update.patch
pi-futex-patchset-v4-fix.patch
rtmutex-remove-buggy-bug_on-in-pi-boosting-code.patch
futex-pi-enforce-waiter-bit-when-owner-died-is-detected.patch
rtmutex-debug-printk-correct-task-information.patch
futex-pi-make-use-of-restart_block-when-interrupted.patch
document-futex-pi-design.patch
futex_requeue-optimization.patch
reiser4.patch
detect-atomic-counter-underflows.patch
debug-shared-irqs.patch
make-frame_pointer-default=y.patch
mutex-subsystem-synchro-test-module.patch
add-print_fatal_signals-support.patch
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