aha/arch
Frederic Weisbecker 44234adcdc hw-breakpoints: Modify breakpoints without unregistering them
Currently, when ptrace needs to modify a breakpoint, like disabling
it, changing its address, type or len, it calls
modify_user_hw_breakpoint(). This latter will perform the heavy and
racy task of unregistering the old breakpoint and registering a new
one.

This is racy as someone else might steal the reserved breakpoint
slot under us, which is undesired as the breakpoint is only
supposed to be modified, sometimes in the middle of a debugging
workflow. We don't want our slot to be stolen in the middle.

So instead of unregistering/registering the breakpoint, just
disable it while we modify its breakpoint fields and re-enable it
after if necessary.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
LKML-Reference: <1260347148-5519-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 09:48:20 +01:00
..
alpha alpha: move THREAD_SIZE definition outside #ifndef ASSEMBLY 2009-11-12 07:25:56 -08:00
arm Merge branch 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6 2009-11-12 14:57:15 -08:00
avr32 at91: at91sam9g45 family: identify several chip versions 2009-11-03 18:42:31 +01:00
blackfin headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
cris const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
frv frv: fix check on unsigned in do_signal() 2009-10-29 07:39:32 -07:00
h8300 h8300: Cleanup linker script using new linker script macros. 2009-09-24 17:16:22 -07:00
ia64 Revert "[IA64] fix percpu warnings" 2009-11-02 09:23:08 -08:00
m32r m32r: fix arch/m32r/boot/compressed/Makefile 2009-11-09 09:00:50 +09:00
m68k tty: Mark generic_serial users as BROKEN 2009-10-30 14:43:12 -07:00
m68knommu m68knommu: fix rename of pt_regs offset defines breakage 2009-09-30 10:06:07 +10:00
microblaze microblaze: Clear sticky FSR register after saving it to func parametr 2009-10-05 11:37:47 +02:00
mips MIPS: O32: Fix ppoll 2009-11-02 12:00:08 +01:00
mn10300 mn10300: fix kernel build failures when using gcc-4.x 2009-10-01 16:11:12 -07:00
parisc parisc: Fix linker script breakage. 2009-09-28 00:25:07 -04:00
powerpc Merge branches 'perf/powerpc' and 'perf/bench' into perf/core 2009-11-15 09:51:24 +01:00
s390 Merge commit 'v2.6.32-rc6' into perf/core 2009-11-04 11:59:45 +01:00
score Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next 2009-09-23 15:37:02 -07:00
sh sh: Replace old style lock initializer 2009-11-09 10:47:40 +09:00
sparc sparc: Move of_set_property_mutex acquisition outside of devtree_lock grab. 2009-11-08 17:41:20 -08:00
um headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
x86 hw-breakpoints: Modify breakpoints without unregistering them 2009-12-09 09:48:20 +01:00
xtensa headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
.gitignore
Kconfig hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events 2009-11-08 15:34:42 +01:00