linux-stable/arch/x86
Jason Wessel 5352ae638e perf, hw_breakpoint, kgdb: Do not take mutex for kernel debugger
This patch fixes the regression in functionality where the
kernel debugger and the perf API do not nicely share hw
breakpoint reservations.

The kernel debugger cannot use any mutex_lock() calls because it
can start the kernel running from an invalid context.

A mutex free version of the reservation API needed to get
created for the kernel debugger to safely update hw breakpoint
reservations.

The possibility for a breakpoint reservation to be concurrently
processed at the time that kgdb interrupts the system is
improbable. Should this corner case occur the end user is
warned, and the kernel debugger will prohibit updating the
hardware breakpoint reservations.

Any time the kernel debugger reserves a hardware breakpoint it
will be a system wide reservation.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: torvalds@linux-foundation.org
LKML-Reference: <1264719883-7285-3-git-send-email-jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-30 08:42:21 +01:00
..
boot x86: add support for LZO-compressed kernels 2010-01-11 09:34:05 -08:00
configs tracing: Rename FTRACE_SYSCALLS for tracepoints 2009-08-26 00:17:35 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2009-12-01 15:16:22 +08:00
ia32 Unify sys_mmap* 2009-12-11 06:44:29 -05:00
include/asm perf: x86: Add support for the ANY bit 2010-01-21 13:40:41 +01:00
kernel perf, hw_breakpoint, kgdb: Do not take mutex for kernel debugger 2010-01-30 08:42:21 +01:00
kvm KVM: x86: Fix leak of free lapic date in kvm_arch_vcpu_init() 2010-01-25 12:26:40 -02:00
lguest lguest: move panic notifier registration to its expected place. 2009-09-23 22:26:44 +09:30
lib Merge branch 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent 2009-12-28 09:23:13 +01:00
math-emu
mm hw-breakpoints, perf: Fix broken mmiotrace due to dr6 by reference change 2010-01-17 08:01:44 +01:00
oprofile perf events, x86/stacktrace: Make stack walking optional 2009-12-17 09:56:19 +01:00
pci Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip 2010-01-08 13:55:52 -08:00
power hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events 2009-11-08 15:34:42 +01:00
tools Merge branch 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent 2009-12-28 09:23:13 +01:00
vdso sysctl x86: Remove dead binary sysctl support 2009-11-12 02:05:04 -08:00
video
xen x86: xen: 64-bit kernel RPL should be 0 2010-01-13 11:23:54 +01:00
Kbuild
Kconfig core, x86: make LIST_POISON less deadly 2010-01-11 09:45:37 -08:00
Kconfig.cpu Revert "x86: Side-step lguest problem by only building cmpxchg8b_emu for pre-Pentium" 2010-01-05 16:01:35 -08:00
Kconfig.debug Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-11 20:47:30 -08:00
Makefile Merge branch 'perf/core' into perf/probes 2009-11-17 10:17:47 +01:00
Makefile_32.cpu Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-08 13:38:11 -08:00