linux/arch
Helge Deller 59b33f148c parisc: fix interruption handler to respect pagefault_disable()
Running an "echo t > /proc/sysrq-trigger" crashes the parisc kernel.  The
problem is, that in print_worker_info() we try to read the workqueue info via
the probe_kernel_read() functions which use pagefault_disable() to avoid
crashes like this:
    probe_kernel_read(&pwq, &worker->current_pwq, sizeof(pwq));
    probe_kernel_read(&wq, &pwq->wq, sizeof(wq));
    probe_kernel_read(name, wq->name, sizeof(name) - 1);

The problem here is, that the first probe_kernel_read(&pwq) might return zero
in pwq and as such the following probe_kernel_reads() try to access contents of
the page zero which is read protected and generate a kernel segfault.

With this patch we fix the interruption handler to call parisc_terminate()
directly only if pagefault_disable() was not called (in which case
preempt_count()==0).  Otherwise we hand over to the pagefault handler which
will try to look up the faulting address in the fixup tables.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v3.0+
Signed-off-by: John David Anglin  <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
2013-10-13 17:45:20 +02:00
..
alpha Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
arc ARC: Ignore ptrace SETREGSET request for synthetic register "stop_pc" 2013-10-12 12:00:36 +05:30
arm compiler/gcc4: Add quirk for 'asm goto' miscompilation bug 2013-10-11 07:39:14 +02:00
arm64 arm64: Remove duplicate DEBUG_STACK_USAGE config 2013-10-02 18:03:26 +01:00
avr32 avr32: cast syscall_return to silence compiler warning 2013-09-30 08:42:01 +02:00
blackfin Merge branch 'genirq' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2013-09-13 07:31:38 -07:00
c6x Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
cris Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
frv Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
h8300 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
hexagon Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
ia64 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
m32r Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
m68k Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
metag Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
microblaze Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
mips Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-10-12 11:06:18 -07:00
mn10300 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
openrisc openrisc: clean-up prom.h 2013-09-24 21:12:27 -05:00
parisc parisc: fix interruption handler to respect pagefault_disable() 2013-10-13 17:45:20 +02:00
powerpc compiler/gcc4: Add quirk for 'asm goto' miscompilation bug 2013-10-11 07:39:14 +02:00
s390 compiler/gcc4: Add quirk for 'asm goto' miscompilation bug 2013-10-11 07:39:14 +02:00
score Score: Modify the Makefile of Score, remove -mlong-calls for compiling 2013-09-26 03:46:03 +08:00
sh Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
sparc compiler/gcc4: Add quirk for 'asm goto' miscompilation bug 2013-10-11 07:39:14 +02:00
tile arch: tile: re-use kbasename() helper 2013-09-30 10:34:46 -04:00
um Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
unicore32 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
x86 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-10-12 11:06:18 -07:00
xtensa Xtensa patchset for v3.12 2013-09-13 10:57:48 -07:00
.gitignore
Kconfig mutex: replace CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX with simple ifdef 2013-09-28 12:46:21 +02:00