The patch titled
x86_64: fix die_lock nesting
has been removed from the -mm tree. Its filename is
x86_64-fix-die_lock-nesting.patch
This patch was probably dropped from -mm because
it has now been merged into a subsystem tree or
into Linus's tree, or because it was folded into
its parent patch in the -mm tree.
From: Corey Minyard <minyard@xxxxxxx>
I noticed this when poking around in this area.
The oops_begin() function in x86_64 would only conditionally claim the
die_lock if the call is nested, but oops_end() would always release the
spinlock. This patch adds a nest count for the die lock so that the release
of the lock is only done on the final oops_end().
Signed-off-by: Corey Minyard <minyard@xxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/x86_64/kernel/traps.c | 10 +++++++++-
1 files changed, 9 insertions(+), 1 deletion(-)
diff -puN arch/x86_64/kernel/traps.c~x86_64-fix-die_lock-nesting arch/x86_64/kernel/traps.c
--- devel/arch/x86_64/kernel/traps.c~x86_64-fix-die_lock-nesting 2006-05-10 21:18:08.000000000 -0700
+++ devel-akpm/arch/x86_64/kernel/traps.c 2006-05-10 21:18:08.000000000 -0700
@@ -385,6 +385,7 @@ void out_of_line_bug(void)
static DEFINE_SPINLOCK(die_lock);
static int die_owner = -1;
+static unsigned int die_nest_count;
unsigned __kprobes long oops_begin(void)
{
@@ -399,6 +400,7 @@ unsigned __kprobes long oops_begin(void)
else
spin_lock(&die_lock);
}
+ die_nest_count++;
die_owner = cpu;
console_verbose();
bust_spinlocks(1);
@@ -409,7 +411,13 @@ void __kprobes oops_end(unsigned long fl
{
die_owner = -1;
bust_spinlocks(0);
- spin_unlock_irqrestore(&die_lock, flags);
+ die_nest_count--;
+ if (die_nest_count)
+ /* We still own the lock */
+ local_irq_restore(flags);
+ else
+ /* Nest count reaches zero, release the lock. */
+ spin_unlock_irqrestore(&die_lock, flags);
if (panic_on_oops)
panic("Oops");
}
_
Patches currently in -mm which might be from minyard@xxxxxxx are
origin.patch
strstrip-api.patch
ipmi-strstrip-conversion.patch
drivers-char-ipmi-ipmi_msghandlerc-make-proc_ipmi_root-static.patch
-
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