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authorGeorge Anzinger <george@mvista.com>2005-09-03 15:56:48 -0700
committerLinus Torvalds <torvalds@evo.osdl.org>2005-09-05 00:06:13 -0700
commit748f2edb52712aa3d926470a888608dc500d17e8 (patch)
tree9fb37795934642e11bad0d747d1271df393a993d
parentf2f30ebca6c0c95e987cb9a1fd1495770a75432e (diff)
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[PATCH] x86 NMI: better support for debuggers
This patch adds a notify to the die_nmi notify that the system is about to be taken down. If the notify is handled with a NOTIFY_STOP return, the system is given a new lease on life. We also change the nmi watchdog to carry on if die_nmi returns. This give debug code a chance to a) catch watchdog timeouts and b) possibly allow the system to continue, realizing that the time out may be due to debugger activities such as single stepping which is usually done with "other" cpus held. Signed-off-by: George Anzinger<george@mvista.com> Cc: Keith Owens <kaos@ocs.com.au> Signed-off-by: George Anzinger <george@mvista.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/i386/kernel/nmi.c5
-rw-r--r--arch/i386/kernel/traps.c4
-rw-r--r--include/asm-i386/kdebug.h11
3 files changed, 17 insertions, 3 deletions
diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index 8c242bb1ef45..8bbdbda07a2d 100644
--- a/arch/i386/kernel/nmi.c
+++ b/arch/i386/kernel/nmi.c
@@ -501,8 +501,11 @@ void nmi_watchdog_tick (struct pt_regs * regs)
*/
alert_counter[cpu]++;
if (alert_counter[cpu] == 5*nmi_hz)
+ /*
+ * die_nmi will return ONLY if NOTIFY_STOP happens..
+ */
die_nmi(regs, "NMI Watchdog detected LOCKUP");
- } else {
+
last_irq_sums[cpu] = sum;
alert_counter[cpu] = 0;
}
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index b2b4bb890bb7..54629bb5893a 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -565,6 +565,10 @@ static DEFINE_SPINLOCK(nmi_print_lock);
void die_nmi (struct pt_regs *regs, const char *msg)
{
+ if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 0, SIGINT) ==
+ NOTIFY_STOP)
+ return;
+
spin_lock(&nmi_print_lock);
/*
* We are in trouble anyway, lets at least try
diff --git a/include/asm-i386/kdebug.h b/include/asm-i386/kdebug.h
index b3f8d5f59d5d..316138e89910 100644
--- a/include/asm-i386/kdebug.h
+++ b/include/asm-i386/kdebug.h
@@ -41,9 +41,16 @@ enum die_val {
DIE_PAGE_FAULT,
};
-static inline int notify_die(enum die_val val,char *str,struct pt_regs *regs,long err,int trap, int sig)
+static inline int notify_die(enum die_val val, const char *str,
+ struct pt_regs *regs, long err, int trap, int sig)
{
- struct die_args args = { .regs=regs, .str=str, .err=err, .trapnr=trap,.signr=sig };
+ struct die_args args = {
+ .regs = regs,
+ .str = str,
+ .err = err,
+ .trapnr = trap,
+ .signr = sig
+ };
return notifier_call_chain(&i386die_chain, val, &args);
}