The patch titled
x86_64 kprobes: debug_stack nesting fix
has been removed from the -mm tree. Its filename is
x86_64-kprobes-debug_stack-nesting-fix.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: "bibo,mao" <bibo.mao@xxxxxxxxx>
On x86_64, INT1 and INT3 trap stack is IST stack called DEBUG_STACK. When
an INT1/INT3 trap happens the system will switch to DEBUG_STACK in hardware.
Current DEBUG_STACK size is 4K, when int1/int3 trap happens, kernel will
decrement the current DEBUG_STACK IST value by 4k. But if the int3/int1
trap is nested, it will destroy onother vector's IST stack.
This patch modifies this, it sets the DEBUG_STACK size to 8K and allows two
level of nested int1/int3 trap.
Kprobe DEBUG_STACK may be nested, because a kprobe hanlder may be probed by
other kprobes.
Signed-off-by: bibo, mao <bibo.mao@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/asm-x86_64/page.h | 8 ++++++++
1 files changed, 8 insertions(+)
diff -puN include/asm-x86_64/page.h~x86_64-kprobes-debug_stack-nesting-fix include/asm-x86_64/page.h
--- devel/include/asm-x86_64/page.h~x86_64-kprobes-debug_stack-nesting-fix 2006-05-11 04:15:12.000000000 -0700
+++ devel-akpm/include/asm-x86_64/page.h 2006-05-11 04:16:07.000000000 -0700
@@ -20,7 +20,15 @@
#define EXCEPTION_STACK_ORDER 0
#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
+#ifdef CONFIG_KPROBES
+/*
+ * kprobes uses an 8k stack because int1/int3 exceptions can nest
+ */
+#define DEBUG_STACK_ORDER (EXCEPTION_STACK_ORDER + 1)
+#else
#define DEBUG_STACK_ORDER EXCEPTION_STACK_ORDER
+#endif
+
#define DEBUG_STKSZ (PAGE_SIZE << DEBUG_STACK_ORDER)
#define IRQSTACK_ORDER 2
_
Patches currently in -mm which might be from bibo.mao@xxxxxxxxx are
origin.patch
x86_64-kprobes-debug_stack-nesting-fix.patch
kprobemulti-kprobe-posthandler-for-booster.patch
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