leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
325cdacd03
linux/arch/parisc
History
Josh Poimboeuf 325cdacd03 debug: Fix WARN_ON_ONCE() for modules 
Mike Galbraith reported a situation where a WARN_ON_ONCE() call in DRM
code turned into an oops.  As it turns out, WARN_ON_ONCE() seems to be
completely broken when called from a module.

The bug was introduced with the following commit:

  19d436268d ("debug: Add _ONCE() logic to report_bug()")

That commit changed WARN_ON_ONCE() to move its 'once' logic into the bug
trap handler.  It requires a writable bug table so that the BUGFLAG_DONE
bit can be written to the flags to indicate the first warning has
occurred.

The bug table was made writable for vmlinux, which relies on
vmlinux.lds.S and vmlinux.lds.h for laying out the sections.  However,
it wasn't made writable for modules, which rely on the ELF section
header flags.

Reported-by: Mike Galbraith <efault@gmx.de>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 19d436268d ("debug: Add _ONCE() logic to report_bug()")
Link: http://lkml.kernel.org/r/a53b04235a65478dd9afc51f5b329fdc65c84364.1500095401.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-20 12:31:04 +02:00
..
configs arch: Rename CONFIG_DEBUG_RODATA and CONFIG_DEBUG_MODULE_RONX 2017-02-07 12:32:52 -08:00
include debug: Fix WARN_ON_ONCE() for modules 2017-07-20 12:31:04 +02:00
kernel Merge branch 'parisc-4.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2017-07-03 15:27:58 -07:00
lib parisc: Inline trivial exception code in lusercopy.S 2017-05-10 17:46:12 +02:00
math-emu sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
mm parisc: Report SIGSEGV instead of SIGBUS when running out of stack 2017-07-02 22:27:08 +02:00
oprofile
defpalo.conf parisc: switch to gzip-compressed vmlinuz kernel 2013-07-09 22:09:20 +02:00
install.sh parisc: make "make install" not depend on vmlinux 2013-11-07 22:28:06 +01:00
Kconfig HAVE_ARCH_HARDENED_USERCOPY is unconditional now 2017-04-26 12:11:06 -04:00
Kconfig.debug arch: Move CONFIG_DEBUG_RODATA and CONFIG_SET_MODULE_RONX to be common 2017-02-07 12:32:52 -08:00
Makefile parisc: Fix ftrace function tracer 2016-04-14 17:47:19 +02:00
nm