1
linux/arch/x86/kernel
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
..
acpi x86: Document linker script ASSERT() quirk 2009-10-16 07:18:46 +02:00
apic x86, UV: Fix information in __uv_hub_info structure 2009-10-16 08:18:34 +02:00
cpu x86/perf: Exclude the debug stack from the callchains 2009-12-06 08:27:21 +01:00
.gitignore
alternative.c Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-14 07:57:32 -07:00
amd_iommu_init.c Merge branches 'amd-iommu/fixes' and 'dma-debug/fixes' into iommu/fixes 2009-11-03 12:05:40 +01:00
amd_iommu.c Merge branches 'amd-iommu/fixes' and 'dma-debug/fixes' into iommu/fixes 2009-11-03 12:05:40 +01:00
aperture_64.c kmemleak: Ignore the aperture memory hole on x86_64 2009-09-01 11:12:32 +01:00
apm_32.c Merge commit 'origin/x86/urgent' into x86/asm 2009-08-25 15:40:29 -07:00
asm-offsets_32.c
asm-offsets_64.c tracing: Define NR_syscalls for x86_64 2009-08-26 21:29:58 +02:00
asm-offsets.c
audit_64.c
bios_uv.c
bootflag.c
check.c
cpuid.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
crash_dump_32.c x86: crash_dump: Fix non-pae kdump kernel memory accesses 2009-10-26 12:38:59 +01:00
crash_dump_64.c
crash.c
doublefault_32.c x86: Use get_desc_base() 2009-07-19 18:27:51 +02:00
ds_selftest.c
ds_selftest.h
ds.c
dumpstack_32.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
dumpstack_64.c x86: Fixup wrong irq frame link in stacktraces 2009-12-06 08:27:24 +01:00
dumpstack.c x86: Remove duplicated #include 2009-07-11 10:17:08 +02:00
dumpstack.h
e820.c pci: increase alignment to make more space for hidden code 2009-10-11 14:43:36 -07:00
early_printk.c x86: earlyprintk: Fix regression to handle serial,ttySn as 1 arg 2009-10-01 10:34:16 +02:00
early-quirks.c
efi_32.c
efi_64.c x86: Make 64-bit efi_ioremap use ioremap on MMIO regions 2009-08-03 13:34:25 -07:00
efi_stub_32.S
efi_stub_64.S
efi.c x86: Make EFI RTC function depend on 32bit again 2009-10-27 12:35:48 +01:00
entry_32.S Merge branch 'perf/core' into perf/probes 2009-10-23 08:23:20 +02:00
entry_64.S x86: Fixup wrong debug exception frame link in stacktraces 2009-12-06 08:27:22 +01:00
ftrace.c tracing: Move syscalls metadata handling from arch to core 2009-10-14 09:53:56 +02:00
geode_32.c
head32.c x86: Add Moorestown early detection 2009-08-31 11:09:40 +02:00
head64.c x86: Add early platform detection 2009-08-31 11:09:40 +02:00
head_32.S Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
head_64.S Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
head.c
hpet.c
hw_breakpoint.c hw-breakpoints: Use overflow handler instead of the event callback 2009-12-06 08:27:18 +01:00
i386_ksyms_32.c x86: Don't generate cmpxchg8b_emu if CONFIG_X86_CMPXCHG64=y 2009-10-01 08:42:24 +02:00
i387.c
i8237.c
i8253.c x86: Do not unregister PIT clocksource on PIT oneshot setup/shutdown 2009-08-21 21:13:37 +02:00
i8259.c
init_task.c Use new __init_task_data macro in arch init_task.c files. 2009-09-21 06:27:08 +02:00
io_delay.c
ioport.c
irq_32.c x86: Use printk_once() 2009-08-09 22:28:34 +02:00
irq_64.c
irq.c x86: Tighten conditionals on MCE related statistics 2009-11-23 19:40:06 +01:00
irqinit.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
k8.c
kdebugfs.c
kgdb.c
kprobes.c Merge branch 'tracing/hw-breakpoints' into perf/core 2009-11-21 14:07:23 +01:00
kvm.c KVM guest: do not batch pte updates from interrupt context 2009-09-10 18:10:50 +03:00
kvmclock.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
ldt.c cpumask: use mm_cpumask() wrapper: x86 2009-09-24 09:34:52 +09:30
machine_kexec_32.c
machine_kexec_64.c
Makefile Merge commit 'perf/core' into perf/hw-breakpoint 2009-10-18 01:12:33 +02:00
mca_32.c
mfgpt_32.c x86: geode: Mark mfgpt irq IRQF_TIMER to prevent resume failure 2009-07-24 08:42:52 +02:00
microcode_amd.c x86, amd-ucode: Check UCODE_MAGIC before loading the container file 2009-11-10 05:46:09 +01:00
microcode_core.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
microcode_intel.c
mmconf-fam10h_64.c
module.c
mpparse.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
mrst.c x86: Add Moorestown early detection 2009-08-31 11:09:40 +02:00
msr.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
olpc.c
paravirt_patch_32.c
paravirt_patch_64.c
paravirt-spinlocks.c
paravirt.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
pci-calgary_64.c
pci-dma.c x86/PCI: Adjust GFP mask handling for coherent allocations 2009-11-08 07:44:30 -08:00
pci-gart_64.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
pci-nommu.c dma-ops: Remove flush_write_buffers() in dma-mapping-common.h 2009-08-10 09:34:57 +02:00
pci-swiotlb.c Merge git://git.infradead.org/iommu-2.6 2009-09-23 10:06:10 -07:00
pcspeaker.c
pmtimer_64.c
probe_roms_32.c
process_32.c hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events 2009-11-08 15:34:42 +01:00
process_64.c Merge branch 'tracing/hw-breakpoints' into perf/core 2009-11-21 14:07:23 +01:00
process.c hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events 2009-11-08 15:34:42 +01:00
ptrace.c hw-breakpoints: Modify breakpoints without unregistering them 2009-12-09 09:48:20 +01:00
pvclock.c x86: Fix warning in pvclock.c 2009-07-14 16:25:05 +02:00
quirks.c x86/PCI: pci quirks, fix pci refcounting 2009-09-09 14:11:02 -07:00
reboot_fixups_32.c
reboot.c x86: Add reboot quirk for 3 series Mac mini 2009-11-02 15:46:17 +01:00
relocate_kernel_32.S
relocate_kernel_64.S
rtc.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
scx200_32.c
setup_percpu.c x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA 2009-08-14 15:00:52 +09:00
setup.c Merge branch 'perf/mce' into perf/core 2009-12-03 20:11:06 +01:00
sfi.c SFI: remove unneeded includes 2009-09-15 15:08:40 -04:00
signal.c Merge commit 'perf/core' into perf/hw-breakpoint 2009-10-18 01:12:33 +02:00
smp.c Revert "x86, timers: Check for pending timers after (device) interrupts" 2009-10-09 15:58:20 +02:00
smpboot.c hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events 2009-11-08 15:34:42 +01:00
stacktrace.c
step.c x86: Use get_desc_base() 2009-07-19 18:27:51 +02:00
sys_i386_32.c
sys_x86_64.c tracing: Convert x86_64 mmap and uname to use DEFINE_SYSCALL 2009-08-11 20:35:29 +02:00
syscall_64.c
syscall_table_32.S perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
tboot.c x86, intel_txt: clean up the impact on generic code, unbreak non-x86 2009-09-01 18:25:07 -07:00
tce_64.c
test_nx.c
test_rodata.c
time.c x86: fix kernel panic on 32 bits when profiling 2009-10-12 11:53:51 -07:00
tlb_uv.c x86, UV: Fix and clean up bau code to use uv_gpa_to_pnode() 2009-10-16 14:51:53 +02:00
tls.c
tls.h
topology.c
trampoline_32.S x86: cpuinit-annotate SMP boot trampolines properly 2009-09-20 20:23:37 +02:00
trampoline_64.S x86: Fix Suspend to RAM freeze on Acer Aspire 1511Lmi laptop 2009-10-12 18:06:48 +02:00
trampoline.c x86: Fix Suspend to RAM freeze on Acer Aspire 1511Lmi laptop 2009-10-12 18:06:48 +02:00
traps.c Merge commit 'perf/core' into perf/hw-breakpoint 2009-10-18 01:12:33 +02:00
tsc_sync.c x86: Reduce verbosity of "TSC is reliable" message 2009-09-24 11:35:19 +02:00
tsc.c Merge branch 'linus' into x86/urgent 2009-09-20 20:25:03 +02:00
uv_irq.c
uv_sysfs.c
uv_time.c
verify_cpu_64.S
visws_quirks.c x86: Add timer_init to x86_init_ops 2009-08-31 09:35:46 +02:00
vm86_32.c
vmi_32.c x86, vmi: Mark VMI deprecated and schedule it for removal 2009-10-08 22:27:55 +02:00
vmiclock_32.c x86: Move tsc_calibration to x86_init_ops 2009-08-31 09:35:47 +02:00
vmlinux.lds.S x86: Document linker script ASSERT() quirk 2009-10-16 07:18:46 +02:00
vsmp_64.c
vsyscall_64.c sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
x86_init.c x86: Move get/set_wallclock to x86_platform_ops 2009-09-16 14:34:50 +02:00
x8664_ksyms_64.c
xsave.c