Messages in this thread | | | Date | Tue, 16 Sep 2008 19:42:17 +0200 | From | Marcin Slusarz <> | Subject | Re: RFC: [patch] log fatal signals like SIGSEGV |
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On Tue, Sep 16, 2008 at 02:59:16PM +0200, Thomas Jarosch wrote: > Here's the new version: > ----------------------------------------------------------------- > From: Thomas Jarosch <thomas.jarosch@intra2net.com> > > Log the signals SIGSEGV, SIGILL, SIGABRT, SIGBUS, SIGKILL and SIGFPE > to aid debugging of obscure problems. Also logs the sender of the signal. > > The log message looks like this: > "kernel: signal 9 sent to freezed[2634] uid:100, > parent init[1] uid:0 by bash[3168] uid:0, parent sshd[3164] uid:0" > > The printing code is based on grsecurity's signal logger. > > Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com> > Signed-off-by: Gerd v. Egidy <gve@intra2net.com> > > diff -u -r -p linux-2.6.26.vanilla/kernel/signal.c linux-2.6.26/kernel/signal.c > --- linux-2.6.26.vanilla/kernel/signal.c Tue Sep 16 13:45:34 2008 > +++ linux-2.6.26/kernel/signal.c Tue Sep 16 14:02:54 2008 > @@ -801,6 +801,24 @@ static inline int legacy_queue(struct si > return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); > } > > +static void log_signal_and_sender(const int sig, const struct task_struct *t) > +{ > + if (!((sig == SIGSEGV) || (sig == SIGILL) || (sig == SIGABRT) > + || (sig == SIGBUS) || (sig == SIGKILL) || (sig == SIGFPE))) > + return; > + > + if (printk_ratelimit()) { > + /* Note: tasklist_lock is already locked by siglock */ > + printk(KERN_WARNING "signal %d sent to %.30s[%d] uid:%u, " > + "parent %.30s[%d] uid:%u by %.30s[%d] uid:%u, " > + "parent %.30s[%d] uid:%u\n", sig, t->comm, > + t->pid, t->uid, t->parent->comm, t->parent->pid, > + t->parent->uid, current->comm, current->pid, > + current->uid, current->parent->comm, > + current->parent->pid, current->parent->uid); > + } > +} > + > static int send_signal(int sig, struct siginfo *info, struct task_struct *t, > int group) > { > @@ -810,6 +828,8 @@ static int send_signal(int sig, struct s > assert_spin_locked(&t->sighand->siglock); > if (!prepare_signal(sig, t)) > return 0; > + > + log_signal_and_sender(sig, t); > > pending = group ? &t->signal->shared_pending : &t->pending; > /* >
It looks much better now. But I don't think it will go in as is. Maybe you can disable it by default and create a sysctl switch?
Marcin
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