From 2b5faa4c553f90ee2dde1d976b220b1ca9741ef0 Mon Sep 17 00:00:00 2001 From: Jesper Derehag Date: Tue, 19 Mar 2013 20:50:05 +0000 Subject: connector: Added coredumping event to the process connector Process connector can now also detect coredumping events. Main aim of patch is get notified at start of coredumping, instead of having to wait for it to finish and then being notified through EXIT event. Could be used for instance by process-managers that want to get notified as soon as possible about process failures, and not necessarily beeing notified after coredump, which could be in the order of minutes depending on size of coredump, piping and so on. Signed-off-by: Jesper Derehag Signed-off-by: David S. Miller --- kernel/signal.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/signal.c') diff --git a/kernel/signal.c b/kernel/signal.c index dd72567767d9..497330ec2ae9 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -32,6 +32,7 @@ #include #include #include +#include #define CREATE_TRACE_POINTS #include @@ -2350,6 +2351,7 @@ relock: if (sig_kernel_coredump(signr)) { if (print_fatal_signals) print_fatal_signal(info->si_signo); + proc_coredump_connector(current); /* * If it was able to dump core, this kills all * other threads in the group and synchronizes with -- cgit v1.2.2 From b9e146d8eb3b9ecae5086d373b50fa0c1f3e7f0f Mon Sep 17 00:00:00 2001 From: Emese Revfy Date: Wed, 17 Apr 2013 15:58:36 -0700 Subject: kernel/signal.c: stop info leak via the tkill and the tgkill syscalls This fixes a kernel memory contents leak via the tkill and tgkill syscalls for compat processes. This is visible in the siginfo_t->_sifields._rt.si_sigval.sival_ptr field when handling signals delivered from tkill. The place of the infoleak: int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) { ... put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr); ... } Signed-off-by: Emese Revfy Reviewed-by: PaX Team Signed-off-by: Kees Cook Cc: Al Viro Cc: Oleg Nesterov Cc: "Eric W. Biederman" Cc: Serge Hallyn Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/signal.c') diff --git a/kernel/signal.c b/kernel/signal.c index dd72567767d9..598dc06be421 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2948,7 +2948,7 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) static int do_tkill(pid_t tgid, pid_t pid, int sig) { - struct siginfo info; + struct siginfo info = {}; info.si_signo = sig; info.si_errno = 0; -- cgit v1.2.2 From 681a90ffe829b8ee25d5266d7e69af256c090940 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Tue, 30 Apr 2013 15:27:19 -0700 Subject: arc, print-fatal-signals: reduce duplicated information After the recent generic debug info on dump_stack() and friends, arc is printing duplicate information on debug dumps. [ARCLinux]$ ./crash crash/50: potentially unexpected fatal signal 11. <-- [1] /sbin/crash, TGID 50 <-- [2] Pid: 50, comm: crash Not tainted 3.9.0-rc4+ #132 <-- [3] ... Remove them. [tj@kernel.org: updated patch desc] Signed-off-by: Vineet Gupta Signed-off-by: Tejun Heo Cc: Bjorn Helgaas Cc: David S. Miller Cc: Fengguang Wu Cc: Heiko Carstens Cc: Jesper Nilsson Cc: Martin Schwidefsky Cc: Mike Frysinger Cc: Sam Ravnborg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'kernel/signal.c') diff --git a/kernel/signal.c b/kernel/signal.c index 598dc06be421..27ece019bd0a 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1160,8 +1160,7 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, static void print_fatal_signal(int signr) { struct pt_regs *regs = signal_pt_regs(); - printk(KERN_INFO "%s/%d: potentially unexpected fatal signal %d.\n", - current->comm, task_pid_nr(current), signr); + printk(KERN_INFO "potentially unexpected fatal signal %d.\n", signr); #if defined(__i386__) && !defined(__arch_um__) printk(KERN_INFO "code at %08lx: ", regs->ip); -- cgit v1.2.2 From 403bad72b67d8b3f5a0240af5023adfa48132a65 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 30 Apr 2013 15:28:10 -0700 Subject: coredump: only SIGKILL should interrupt the coredumping task There are 2 well known and ancient problems with coredump/signals, and a lot of related bug reports: - do_coredump() clears TIF_SIGPENDING but of course this can't help if, say, SIGCHLD comes after that. In this case the coredump can fail unexpectedly. See for example wait_for_dump_helper()->signal_pending() check but there are other reasons. - At the same time, dumping a huge core on the slow media can take a lot of time/resources and there is no way to kill the coredumping task reliably. In particular this is not oom_kill-friendly. This patch tries to fix the 1st problem, and makes the preparation for the next changes. We add the new SIGNAL_GROUP_COREDUMP flag set by zap_threads() to indicate that this process dumps the core. prepare_signal() checks this flag and nacks any signal except SIGKILL. Note that this check tries to be conservative, in the long term we should probably treat the SIGNAL_GROUP_EXIT case equally but this needs more discussion. See marc.info/?l=linux-kernel&m=120508897917439 Notes: - recalc_sigpending() doesn't check SIGNAL_GROUP_COREDUMP. The patch assumes that dump_write/etc paths should never call it, but we can change it as well. - There is another source of TIF_SIGPENDING, freezer. This will be addressed separately. Signed-off-by: Oleg Nesterov Tested-by: Mandeep Singh Baines Cc: Ingo Molnar Cc: Neil Horman Cc: "Rafael J. Wysocki" Cc: Roland McGrath Cc: Tejun Heo Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'kernel/signal.c') diff --git a/kernel/signal.c b/kernel/signal.c index 27ece019bd0a..cede58910f9c 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -854,12 +854,14 @@ static void ptrace_trap_notify(struct task_struct *t) * Returns true if the signal should be actually delivered, otherwise * it should be dropped. */ -static int prepare_signal(int sig, struct task_struct *p, bool force) +static bool prepare_signal(int sig, struct task_struct *p, bool force) { struct signal_struct *signal = p->signal; struct task_struct *t; - if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) { + if (signal->flags & (SIGNAL_GROUP_EXIT | SIGNAL_GROUP_COREDUMP)) { + if (signal->flags & SIGNAL_GROUP_COREDUMP) + return sig == SIGKILL; /* * The process is in the middle of dying, nothing to do. */ -- cgit v1.2.2