[PATCH -tip v2 1/2] [BUGFIX] kprobes: make hash_64() as always inlined

* [PATCH -tip v2 1/2] [BUGFIX] kprobes: make hash_64() as always inlined
@ 2013-03-14 11:52 Masami Hiramatsu
  2013-03-14 11:52 ` [PATCH -tip v2 2/2] [BUGFIX] kprobes/x86: Check Interrupt Flag modifier when registering probe Masami Hiramatsu
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Masami Hiramatsu @ 2013-03-14 11:52 UTC (permalink / raw)
  To: Ingo Molnar, Linus Torvalds, linux-kernel
  Cc: Timo Juhani Lindfors, Ananth N Mavinakayanahalli,
	Pavel Emelyanov, Jiri Kosina, Ingo Molnar, Nadia Yvette Chambers,
	yrl.pp-manager.tt, David S. Miller

Because hash_64() is called from the get_kprobe() inside
int3 handler, kernel causes int3 recursion and crashes if
kprobes user puts a probe on it.

Usually hash_64() is inlined into caller function, but in
some cases, it has instances by gcc's interprocedural
constant propagation.

This patch uses __always_inline instead of inline to
prevent gcc from doing such things.

Changes in v2:
 - Use __always_inline instead of using __kprobes

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Timo Juhani Lindfors <timo.lindfors@iki.fi>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Nadia Yvette Chambers <nyc@holomorphy.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---
 include/linux/hash.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/hash.h b/include/linux/hash.h
index 61c97ae..f09a0ae 100644
--- a/include/linux/hash.h
+++ b/include/linux/hash.h
@@ -15,6 +15,7 @@
  */
 
 #include <asm/types.h>
+#include <linux/compiler.h>
 
 /* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */
 #define GOLDEN_RATIO_PRIME_32 0x9e370001UL
@@ -31,7 +32,7 @@
 #error Wordsize not 32 or 64
 #endif
 
-static inline u64 hash_64(u64 val, unsigned int bits)
+static __always_inline u64 hash_64(u64 val, unsigned int bits)
 {
 	u64 hash = val;
 


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