Messages in this thread Patch in this message | | | Subject | [PATCH -tip ] [BUGFIX] kprobes: Move hash_64() into .text.kprobe section | From | Masami Hiramatsu <> | Date | Mon, 11 Mar 2013 23:22:33 +0900 |
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Beacuse 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 adds __kprobes tag on the hash_64() and moves all those instances into .text.kprobe section so that kprobes can refuse probing on the instances.
I've ensured that all hash_64 instances moves to the address between __kprobes_text_start and __kprobes_text_end with this patch as below.
ffffffff8138bea0 T __kprobes_text_start ffffffff8138bec0 t hash_64.constprop.8 ffffffff8138ef98 t hash_64.constprop.26 ffffffff8138efae t hash_64 ffffffff8138f066 t hash_64.constprop.43 ffffffff8138f649 t hash_64.constprop.25 ffffffff8139103a t hash_64.constprop.77 ffffffff81391050 t hash_64.constprop.24 ffffffff81391066 t hash_64.constprop.40 ffffffff8139107c t hash_64.constprop.15 ffffffff81391092 T __kprobes_text_end
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> --- 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..d83f62f 100644 --- a/include/linux/hash.h +++ b/include/linux/hash.h @@ -15,6 +15,7 @@ */ #include <asm/types.h> +#include <linux/kprobes.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 __kprobes inline u64 hash_64(u64 val, unsigned int bits) { u64 hash = val;
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