kprobes: disable preempt for module_text_address() and kernel_text_address()
commita189d0350f387786b1fb5a5d19e3a5ab0bc0cceb
authorMasami Hiramatsu <mhiramat@redhat.com>
Wed, 12 Nov 2008 21:26:51 +0000 (12 13:26 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 13 Nov 2008 01:17:16 +0000 (12 17:17 -0800)
treed6133d035e0d23a8271f12204e53338f8f343351
parent3b1b3f6e57064aa8f91c290fe51cda4c74642902
kprobes: disable preempt for module_text_address() and kernel_text_address()

__register_kprobe() can be preempted after checking probing address but
before module_text_address() or try_module_get(), and in this interval
the module can be unloaded.  In that case, try_module_get(probed_mod)
will access to invalid address, or kprobe will probe invalid address.

This patch uses preempt_disable() to protect it and uses
__module_text_address() and __kernel_text_address().

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/kprobes.c