diff options
author | Michael Ellerman <michael@ellerman.id.au> | 2007-07-19 04:48:11 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-19 13:04:44 -0400 |
commit | 3d7e33825d8799115dd2495c9944badd3272a623 (patch) | |
tree | 869eeefa9dd88c622db199f636cd1785c6099947 /arch/ia64/kernel/kprobes.c | |
parent | 9e367d859297b9377d65574f538cf52730e9eda8 (diff) |
jprobes: make jprobes a little safer for users
I realise jprobes are a razor-blades-included type of interface, but that
doesn't mean we can't try and make them safer to use. This guy I know once
wrote code like this:
struct jprobe jp = { .kp.symbol_name = "foo", .entry = "jprobe_foo" };
And then his kernel exploded. Oops.
This patch adds an arch hook, arch_deref_entry_point() (I don't like it
either) which takes the void * in a struct jprobe, and gives back the text
address that it represents.
We can then use that in register_jprobe() to check that the entry point we're
passed is actually in the kernel text, rather than just some random value.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/ia64/kernel/kprobes.c')
-rw-r--r-- | arch/ia64/kernel/kprobes.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 5bc46f151344..5dc98b5abcfb 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c | |||
@@ -936,10 +936,15 @@ static void ia64_get_bsp_cfm(struct unw_frame_info *info, void *arg) | |||
936 | return; | 936 | return; |
937 | } | 937 | } |
938 | 938 | ||
939 | unsigned long arch_deref_entry_point(void *entry) | ||
940 | { | ||
941 | return ((struct fnptr *)entry)->ip; | ||
942 | } | ||
943 | |||
939 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) | 944 | int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) |
940 | { | 945 | { |
941 | struct jprobe *jp = container_of(p, struct jprobe, kp); | 946 | struct jprobe *jp = container_of(p, struct jprobe, kp); |
942 | unsigned long addr = ((struct fnptr *)(jp->entry))->ip; | 947 | unsigned long addr = arch_deref_entry_point(jp->entry); |
943 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); | 948 | struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); |
944 | struct param_bsp_cfm pa; | 949 | struct param_bsp_cfm pa; |
945 | int bytes; | 950 | int bytes; |