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kdb: core for kgdb back end (2 of 2)

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This patch contains the hooks and instrumentation into kernel which
live outside the kernel/debug directory, which the kdb core
will call to run commands like lsmod, dmesg, bt etc...

CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>
This commit is contained in:
Jason Wessel
2010-05-20 21:04:21 -05:00
parent 5d5314d679
commit 67fc4e0cb9
9 changed files with 92 additions and 3 deletions
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40
kernel/signal.c
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@@ -2735,3 +2735,43 @@ void __init signals_init(void)
{
sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC);
}
#ifdef CONFIG_KGDB_KDB
#include <linux/kdb.h>
/*
* kdb_send_sig_info - Allows kdb to send signals without exposing
* signal internals. This function checks if the required locks are
* available before calling the main signal code, to avoid kdb
* deadlocks.
*/
void
kdb_send_sig_info(struct task_struct *t, struct siginfo *info)
{
static struct task_struct *kdb_prev_t;
int sig, new_t;
if (!spin_trylock(&t->sighand->siglock)) {
kdb_printf("Can't do kill command now.\n"
"The sigmask lock is held somewhere else in "
"kernel, try again later\n");
return;
}
spin_unlock(&t->sighand->siglock);
new_t = kdb_prev_t != t;
kdb_prev_t = t;
if (t->state != TASK_RUNNING && new_t) {
kdb_printf("Process is not RUNNING, sending a signal from "
"kdb risks deadlock\n"
"on the run queue locks. "
"The signal has _not_ been sent.\n"
"Reissue the kill command if you want to risk "
"the deadlock.\n");
return;
}
sig = info->si_signo;
if (send_sig_info(sig, info, t))
kdb_printf("Fail to deliver Signal %d to process %d.\n",
sig, t->pid);
else
kdb_printf("Signal %d is sent to process %d.\n", sig, t->pid);
}
#endif /* CONFIG_KGDB_KDB */