jump_label: Warn on failed jump_label patching attempt
authorJosh Poimboeuf <jpoimboe@redhat.com>
Tue, 20 Feb 2018 17:37:52 +0000 (11:37 -0600)
committerIngo Molnar <mingo@kernel.org>
Wed, 21 Feb 2018 15:54:06 +0000 (16:54 +0100)
commitdc1dd184c2f0016bec35c0d7a48c057e0ad763d3
tree43323dde05f7db864de96e8dfbaafc1397142268
parent33352244706369ea6736781ae41fe41692eb69bb
jump_label: Warn on failed jump_label patching attempt

Currently when the jump label code encounters an address which isn't
recognized by kernel_text_address(), it just silently fails.

This can be dangerous because jump labels are used in a variety of
places, and are generally expected to work.  Convert the silent failure
to a warning.

This won't warn about attempted writes to tracepoints in __init code
after initmem has been freed, as those are already guarded by the
entry->code check.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/de3a271c93807adb7ed48f4e946b4f9156617680.1519051220.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/jump_label.c