Messages in this thread Patch in this message | | | Date | Tue, 27 Oct 2009 01:39:14 +0900 | From | Naohiro Ooiwa <> | Subject | Re: [PATCH] show message when exceeded rlimit of pending signals |
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Hi Ingo,
Now that you mention it, I think so, too. I update my patch.
How is the following patch. Could you please review it.
Thanks you. Naohiro Ooiwa
Signed-off-by: Naohiro Ooiwa <nooiwa@miraclelinux.com> --- Documentation/kernel-parameters.txt | 9 ++++++++- kernel/signal.c | 16 +++++++++++++--- 2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9107b38..01c2723 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2032,8 +2032,15 @@ and is between 256 and 4096 characters. It is defined in the file
print-fatal-signals= [KNL] debug: print fatal signals + If you would like to know what the cause of a coredump + by signal number, if your working system may have + too many POSIX.1 timers, and when during the system + test,you may as well to enable this parameter. print-fatal-signals=1: print segfault info to - the kernel console. + the kernel console, and print caution that reached the + limit of pending signals to the kernel console. + When printed the caution messages, you can try + "ulimit -i unlimited". default: off.
printk.time= Show timing data prefixed to each printk message line diff --git a/kernel/signal.c b/kernel/signal.c index 6705320..137112e 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -188,6 +188,14 @@ int next_signal(struct sigpending *pending, sigset_t *mask) return sig; }
+int print_fatal_signals; + +static void show_reach_rlimit_sigpending(void) +{ + if (printk_ratelimit()) + printk(KERN_WARNING "%s/%d: reached the limit of pending signals.\n", current->comm, current->pid); +} + /* * allocate a new signal queue record * - this may be called without locks if and only if t == current, otherwise an @@ -209,8 +217,12 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, atomic_inc(&user->sigpending); if (override_rlimit || atomic_read(&user->sigpending) <= - t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) + t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) { q = kmem_cache_alloc(sigqueue_cachep, flags); + } else { + if (print_fatal_signals) + show_reach_rlimit_sigpending(); + } if (unlikely(q == NULL)) { atomic_dec(&user->sigpending); free_uid(user); @@ -925,8 +937,6 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, return __send_signal(sig, info, t, group, from_ancestor_ns); }
-int print_fatal_signals; - static void print_fatal_signal(struct pt_regs *regs, int signr) { printk("%s/%d: potentially unexpected fatal signal %d.\n", -- 1.5.4.1
Ingo Molnar wrote: > * nooiwa <nooiwa@miraclelinux.com> wrote: > >> +++ b/kernel/sysctl.c >> @@ -67,6 +67,7 @@ static int deprecated_sysctl_warning(struct __sysctl_args *args); >> /* External variables not in a header file. */ >> extern int C_A_D; >> extern int print_fatal_signals; >> +extern int print_reach_rlimit_sigpending; > > Ooiwa-san, Roland, Andrew - what do you think about just making this > part of the existing print_fatal_signals flag, instead of adding a new > one? > > Signal queue overflows are a 'fatal', signal-related condition as well - > we lose a signal in essence. The patch would be smaller as well. > > Ingo
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