Steven Rostedt 732f3ca7d4 ftrace: use only 5 byte nops for x86 ... Mathieu Desnoyers revealed a bug in the original code. The nop that is used to relpace the mcount caller can be a two part nop. This runs the risk where a process can be preempted after executing the first nop, but before the second part of the nop. The ftrace code calls kstop_machine to keep multiple CPUs from executing code that is being modified, but it does not protect against a task preempting in the middle of a two part nop. If the above preemption happens and the tracer is enabled, after the kstop_machine runs, all those nops will be calls to the trace function. If the preempted process that was preempted between the two nops is executed again, it will execute half of the call to the trace function, and this might crash the system. This patch instead uses what both the latest Intel and AMD spec suggests. That is the P6_NOP5 sequence of "0x0f 0x1f 0x44 0x00 0x00". Note, some older CPUs and QEMU might fault on this nop, so this nop is executed with fault handling first. If it detects a fault, it will then use the code "0x66 0x66 0x66 0x66 0x90". If that faults, it will then default to a simple "jmp 1f; .byte 0x00 0x00 0x00; 1:". The jmp is not optimal but will do if the first two can not be executed. TODO: Examine the cpuid to determine the nop to use. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2008-10-14 10:35:01 +02:00
..
acpi	Merge branch 'linus' into x86/quirks	2008-10-12 12:43:21 +02:00
cpu	ftrace: mark lapic_wd_event() notrace	2008-10-14 10:34:36 +02:00
.gitignore	arch/x86/kernel/.gitignore: Added vmlinux.lds to .gitignore file because it shouldn't be tracked.	2008-07-10 10:13:51 -07:00
Makefile	traps: x86: finalize unification of traps.c	2008-10-13 10:33:29 +02:00
alternative.c	x86: improve UP kernel when CPU-hotplug and SMP is enabled	2008-10-13 10:33:46 +02:00
amd_iommu.c	Merge branches 'core/iommu', 'x86/amd-iommu' and 'x86/iommu' into x86-v28-for-linus-phase3-B	2008-10-10 19:47:12 +02:00
amd_iommu_init.c	x86, amd-iommu: propagate PCI device enabling error	2008-10-12 15:24:53 +02:00
aperture_64.c	x86, debug printouts: IOMMU setup failures should not be KERN_ERR	2008-09-30 10:25:28 +02:00
apic_32.c	Merge branch 'linus' into oprofile-v2	2008-10-13 11:05:51 +02:00
apic_64.c	Merge branch 'linus' into oprofile-v2	2008-10-13 11:05:51 +02:00
apm_32.c	Merge branches 'x86/alternatives', 'x86/cleanups', 'x86/commandline', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/doc', 'x86/exports', 'x86/fpu', 'x86/gart', 'x86/idle', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/oprofile', 'x86/paravirt', 'x86/reboot', 'x86/sparse-fixes', 'x86/tsc', 'x86/urgent' and 'x86/vmalloc' into x86-v28-for-linus-phase1	2008-10-06 18:17:07 +02:00
asm-offsets.c	…
asm-offsets_32.c	x86/paravirt: split sysret and sysexit	2008-07-08 13:13:15 +02:00
asm-offsets_64.c	x86: consolidate header guards	2008-07-22 21:53:53 +02:00
audit_64.c	…
bios_uv.c	x86: coding style fixes to arch/x86/kernel/bios_uv.c	2008-08-15 16:53:24 +02:00
bootflag.c	x86: coding style cleanup for kernel/bootflag.c	2008-01-30 13:32:31 +01:00
cpuid.c	Merge branch 'x86/urgent' into x86/cleanups	2008-08-25 22:45:37 -07:00
crash.c	x86: allow machine_crash_shutdown to be replaced	2008-04-27 12:00:29 +03:00
crash_dump_32.c	…
crash_dump_64.c	Merge branches 'x86/alternatives', 'x86/cleanups', 'x86/commandline', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/doc', 'x86/exports', 'x86/fpu', 'x86/gart', 'x86/idle', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/oprofile', 'x86/paravirt', 'x86/reboot', 'x86/sparse-fixes', 'x86/tsc', 'x86/urgent' and 'x86/vmalloc' into x86-v28-for-linus-phase1	2008-10-06 18:17:07 +02:00
doublefault_32.c	x86: fix virt_addr_valid() with CONFIG_DEBUG_VIRTUAL=y, v2	2008-10-13 10:33:15 +02:00
ds.c	x86: ds.c ptrace.c integer as NULL pointer sparse fixes	2008-09-24 09:57:47 +02:00
dumpstack_32.c	dumpstack: x86: various small unification steps	2008-10-13 10:33:45 +02:00
dumpstack_64.c	dumpstack: x86: various small unification steps, fix	2008-10-13 10:33:49 +02:00
e820.c	Merge commit 'v2.6.27-rc6' into x86/unify-cpu-detect	2008-09-10 14:00:45 +02:00
early-quirks.c	Merge branch 'linus' into x86/quirks	2008-10-12 12:43:21 +02:00
early_printk.c	warnings: fix arch/x86/kernel/early_printk.c	2008-10-12 15:19:36 +02:00
efi.c	x86: trivial printk fix in efi.c	2008-10-03 10:18:30 +02:00
efi_32.c	x86: fix i486 suspend to disk CR4 oops	2008-08-18 08:50:19 +02:00
efi_64.c	x86: add flags parameter to reserve_bootmem_generic()	2008-07-08 11:49:49 +02:00
efi_stub_32.S	…
efi_stub_64.S	x86: EFI runtime service support	2008-01-30 13:31:19 +01:00
entry_32.S	ftrace: x86 mcount stub	2008-10-14 10:34:58 +02:00
entry_64.S	ftrace: x86 mcount stub	2008-10-14 10:34:58 +02:00
es7000_32.c	x86: check dsdt before find oem table for es7000, v2	2008-10-13 10:21:07 +02:00
ftrace.c	ftrace: use only 5 byte nops for x86	2008-10-14 10:35:01 +02:00
genapic_64.c	GRU Driver: export is_uv_system(), zap_page_range() & follow_page()	2008-07-30 09:41:48 -07:00
genapic_flat_64.c	Merge branch 'linus' into x86/x2apic	2008-07-25 13:08:16 +02:00
genx2apic_cluster.c	Merge branch 'x86/x2apic' into x86/core	2008-09-05 09:21:21 +02:00
genx2apic_phys.c	Merge branch 'x86/x2apic' into x86/core	2008-09-05 09:21:21 +02:00
genx2apic_uv_x.c	x86, UV: new UV genapic functions for x2apic	2008-10-13 10:22:53 +02:00
geode_32.c	x86, geode: add a VSA2 ID for General Software	2008-06-19 14:19:03 +02:00
head.c	x86: print out EBDA/lowmem address	2008-10-13 10:21:10 +02:00
head32.c	x86: extract common part of head32.c and head64.c into head.c	2008-06-05 15:10:02 +02:00
head64.c	x86_64: be less annoying on boot, v2	2008-09-29 10:04:53 +02:00
head_32.S	x86, cpa: rename PTE attribute macros for kernel direct mapping in early boot	2008-10-10 19:29:11 +02:00
head_64.S	x86, cpa: rename PTE attribute macros for kernel direct mapping in early boot	2008-10-10 19:29:11 +02:00
hpet.c	Merge commit 'v2.6.27-rc6' into timers/hpet	2008-09-14 18:24:00 +02:00
i386_ksyms_32.c	ftrace: store mcount address in rec->ip	2008-06-23 22:10:56 +02:00
i387.c	x86: xsave: set FP, SSE bits in the xsave header in the user sigcontext	2008-10-07 14:36:08 -07:00
i8237.c	…
i8253.c	x86: cleanup div_sc() usage	2008-04-26 17:35:47 +02:00
i8259.c	x64, x2apic/intr-remap: 8259 specific mask/unmask routines	2008-07-12 08:44:55 +02:00
init_task.c	[PATCH] take init_files to fs/file.c	2008-05-16 17:22:20 -04:00
io_apic_32.c	Merge branch 'x86/cpu' into x86/x2apic	2008-08-23 17:46:59 +02:00
io_apic_64.c	warnings: fix arch/x86/kernel/io_apic_64.c	2008-10-12 15:22:22 +02:00
io_delay.c	x86: add io delay quirk for Presario F700	2008-09-03 16:42:51 -07:00
ioport.c	x86: Introducing asm/syscalls.h	2008-07-22 14:35:57 +02:00
ipi.c	X86_SMP: ipi.c declare functions before they get used	2008-07-25 11:57:46 +05:30
irq_32.c	x86: capitalize function call interrupts consistently	2008-09-04 10:51:36 -07:00
irq_64.c	x86: capitalize function call interrupts consistently	2008-09-04 10:51:36 -07:00
irqinit_32.c	x86: apic interrupts - move assignments to irqinit_32.c, v2	2008-08-11 16:43:09 +02:00
irqinit_64.c	x86: cleanup, remove extra ifdef	2008-10-13 10:22:44 +02:00
k8.c	x86, gart: add detection of AMD family 0x11 northbridges	2008-09-05 19:11:44 +02:00
kdebugfs.c	arch/x86/kernel/kdebugfs.c: introduce missing kfree	2008-09-10 14:03:49 +02:00
kgdb.c	kgdb, x86: Avoid invoking kgdb_nmicallback twice per NMI	2008-10-06 13:50:59 -05:00
kprobes.c	kprobes: improve kretprobe scalability with hashed locking	2008-07-25 10:53:30 -07:00
kvm.c	x86, paravirt_ops: use unsigned long instead of u32 for alloc_p*() pfn args	2008-08-22 05:34:44 +02:00
kvmclock.c	x86: KVM guest: make kvm_smp_prepare_boot_cpu() static	2008-07-20 12:42:37 +03:00
ldt.c	Merge branch 'linus' into x86/xen	2008-10-12 12:37:32 +02:00
machine_kexec_32.c	kexec jump: fix for ftrace	2008-08-15 08:35:43 -07:00
machine_kexec_64.c	kexec jump	2008-07-26 12:00:04 -07:00
mca_32.c	x86: coding style fixes to arch/x86/kernel/mca_32.c	2008-04-17 17:40:49 +02:00
mfgpt_32.c	x86, geode-mfgpt: check IRQ before using MFGPT as clocksource	2008-08-15 17:12:32 +02:00
microcode_amd.c	x86, microcode_amd: cleanup, mark request_microcode_user() as unsupported	2008-09-24 10:32:37 +02:00
microcode_core.c	x86/microcode: fix sleeping function called from invalid context at kernel/mutex.c	2008-10-02 17:52:33 +02:00
microcode_intel.c	x86: moved microcode.c to microcode_intel.c	2008-09-23 12:21:42 +02:00
mmconf-fam10h_64.c	x86: mmconf: fix section mismatch warning	2008-08-18 07:49:06 +02:00
module_32.c	…
module_64.c	PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures	2008-07-24 10:47:21 -07:00
mpparse.c	Merge branch 'x86/apic' into x86-v28-for-linus-phase4-B	2008-10-11 20:17:36 +02:00
msr.c	x86: msr: correct return value on partial operations	2008-08-25 17:46:12 -07:00
nmi.c	x86, NMI watchdog: setup before enabling NMI watchdog	2008-09-22 19:48:19 +02:00
numaq_32.c	Merge branch 'x86/apic' into x86-v28-for-linus-phase4-B	2008-10-11 20:17:36 +02:00
olpc.c	x86, olpc: fix endian bug in openfirmware workaround	2008-09-24 10:29:04 +02:00
paravirt-spinlocks.c	x86: export pv_lock_ops non-GPL	2008-08-22 15:43:17 +02:00
paravirt.c	Merge branch 'linus' into x86/xen	2008-10-12 12:37:32 +02:00
paravirt_patch_32.c	x86: coding style fixes to arch/x86/kernel/paravirt_patch_32.c	2008-08-15 16:53:25 +02:00
paravirt_patch_64.c	x86/paravirt: add sysret/sysexit pvops for returning to 32-bit compatibility userspace	2008-07-08 13:15:52 +02:00
pci-calgary_64.c	iommu: export iommu_area_reserve helper function	2008-09-22 16:47:50 +02:00
pci-dma.c	Merge branches 'core/iommu', 'x86/amd-iommu' and 'x86/iommu' into x86-v28-for-linus-phase3-B	2008-10-10 19:47:12 +02:00
pci-gart_64.c	Merge branches 'core/iommu', 'x86/amd-iommu' and 'x86/iommu' into x86-v28-for-linus-phase3-B	2008-10-10 19:47:12 +02:00
pci-nommu.c	x86: export pci-nommu's alloc_coherent	2008-09-25 11:02:25 +02:00
pci-swiotlb_64.c	dma-mapping: add the device argument to dma_mapping_error()	2008-07-26 12:00:03 -07:00
pcspeaker.c	x86: use platform_device_register_simple()	2008-09-22 12:58:36 +02:00
pmtimer_64.c	x86: move pmtmr related declarations	2008-01-30 13:30:18 +01:00
probe_roms_32.c	x86: seperate probe_roms into another file	2008-07-08 12:50:05 +02:00
process.c	Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-D	2008-10-11 20:23:20 +02:00
process_32.c	x86: __show_registers() and __show_regs() API unification	2008-10-13 10:33:04 +02:00
process_64.c	x86: __show_registers() and __show_regs() API unification	2008-10-13 10:33:04 +02:00
ptrace.c	Merge branches 'x86/xen', 'x86/build', 'x86/microcode', 'x86/mm-debug-v2', 'x86/memory-corruption-check', 'x86/early-printk', 'x86/xsave', 'x86/ptrace-v2', 'x86/quirks', 'x86/setup', 'x86/spinlocks' and 'x86/signal' into x86/core-v2	2008-10-12 15:50:02 +02:00
pvclock.c	x86: Add structs and functions for paravirt clocksource	2008-06-24 21:02:31 +03:00
quirks.c	x86: hpet: modify IXP400 quirk to enable interrupts	2008-09-05 18:59:41 +02:00
reboot.c	x86: default to reboot via ACPI	2008-08-25 12:31:32 +02:00
reboot_fixups_32.c	x86: constify data in reboot.c	2008-05-25 08:58:30 +02:00
relocate_kernel_32.S	kexec jump: check code size in control page	2008-08-15 08:35:42 -07:00
relocate_kernel_64.S	x86: relocate_kernel - use predefined macroses for page attributes	2008-04-17 17:41:29 +02:00
rtc.c	provide rtc_cmos platform device	2008-06-12 18:05:42 -07:00
scx200_32.c	x86: fix sparse warning in kernel/scx200_32.c	2008-01-31 22:05:45 +01:00
setup.c	x86, uv: add early detection of UV system types	2008-10-13 10:21:51 +02:00
setup_percpu.c	Merge commit 'v2.6.27-rc7' into x86/debug	2008-09-22 13:08:57 +02:00
sigframe.h	Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-D	2008-10-11 20:23:20 +02:00
signal_32.c	Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-D	2008-10-11 20:23:20 +02:00
signal_64.c	Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-D	2008-10-11 20:23:20 +02:00
smp.c	x86: add cpu hotplug hooks into smp_ops	2008-08-25 10:59:18 +02:00
smpboot.c	x86: remove additional_cpus	2008-10-13 10:33:48 +02:00
smpcommon.c	x86: change init_gdt to update the gdt via write_gdt, rather than a direct write.	2008-08-15 19:16:05 +02:00
stacktrace.c	stacktrace: fix modular build, export print_stack_trace and save_stack_trace	2008-06-30 09:20:55 +02:00
step.c	x86 ptrace: user-sets-TF nits	2008-07-16 12:15:17 -07:00
summit_32.c	x86: mach_summit to summit	2008-07-26 16:31:35 +02:00
sys_i386_32.c	x86: Introducing asm/syscalls.h	2008-07-22 14:35:57 +02:00
sys_x86_64.c	Merge branches 'x86/alternatives', 'x86/cleanups', 'x86/commandline', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/doc', 'x86/exports', 'x86/fpu', 'x86/gart', 'x86/idle', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/oprofile', 'x86/paravirt', 'x86/reboot', 'x86/sparse-fixes', 'x86/tsc', 'x86/urgent' and 'x86/vmalloc' into x86-v28-for-linus-phase1	2008-10-06 18:17:07 +02:00
syscall_64.c	x86: consolidate header guards	2008-07-22 21:53:53 +02:00
syscall_table_32.S	flag parameters add-on: remove epoll_create size param	2008-07-24 10:47:29 -07:00
tce_64.c	…
test_nx.c	x86: Explicitly include required header files.	2008-04-17 17:41:15 +02:00
test_rodata.c	x86: include proper prototypes for rodata_test	2008-02-14 23:30:20 +01:00
time_32.c	x86: wrap MCA_bus test around an ifdef	2008-10-13 10:21:47 +02:00
time_64.c	x86: move vgetcpu mode probing to cpu detection	2008-10-13 10:21:49 +02:00
tlb_32.c	x86: build fix for !CONFIG_SMP	2008-09-05 17:44:08 +02:00
tlb_64.c	Merge branch 'generic-ipi' into generic-ipi-for-linus	2008-07-15 21:55:59 +02:00
tlb_uv.c	x86, SGI UV: hardcode the TLB flush interrupt system vector	2008-08-20 12:36:03 +02:00
tls.c	x86: Introducing asm/syscalls.h	2008-07-22 14:35:57 +02:00
tls.h	x86: x86 user_regset TLS	2008-01-30 13:31:52 +01:00
topology.c	x86: fix section mismatch warning in topology.c:arch_register_cpu	2008-02-19 16:18:30 +01:00
trampoline.c	x86: extend e820 ealy_res support 32bit	2008-05-25 10:55:11 +02:00
trampoline_32.S	x86: trampoline_32.S - switch to .cpuinit.data	2008-04-26 17:35:47 +02:00
trampoline_64.S	x86: move suspend wakeup code to C	2008-04-17 17:41:37 +02:00
traps.c	dumpstack: x86: move die_nmi to dumpstack_32.c	2008-10-13 10:33:39 +02:00
tsc.c	Merge branches 'x86/alternatives', 'x86/cleanups', 'x86/commandline', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/doc', 'x86/exports', 'x86/fpu', 'x86/gart', 'x86/idle', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/oprofile', 'x86/paravirt', 'x86/reboot', 'x86/sparse-fixes', 'x86/tsc', 'x86/urgent' and 'x86/vmalloc' into x86-v28-for-linus-phase1	2008-10-06 18:17:07 +02:00
tsc_sync.c	x86: use WARN() in arch/x86/kernel	2008-08-21 10:01:52 +02:00
verify_cpu_64.S	…
visws_quirks.c	Merge branch 'linus' into x86/cleanups	2008-08-20 11:52:15 +02:00
vm86_32.c	x86: Introducing asm/syscalls.h	2008-07-22 14:35:57 +02:00
vmi_32.c	Merge branch 'x86/apic' into x86-v28-for-linus-phase4-B	2008-10-11 20:17:36 +02:00
vmiclock_32.c	x86: rename paravirtualized TSC functions	2008-07-09 07:43:28 +02:00
vmlinux.lds.S	…
vmlinux_32.lds.S	Merge commit '63cc8c75156462d4b42cbdd76c293b7eee7ddbfe':	2008-09-05 09:24:30 +02:00
vmlinux_64.lds.S	x86: fix early panic on amd64 due to typo in supported CPU section	2008-10-12 11:19:27 +02:00
vsmp_64.c	x86: fix 27-rc crash on vsmp due to paravirt during module load	2008-09-23 10:31:26 +02:00
vsyscall_64.c	Merge branch 'generic-ipi' into generic-ipi-for-linus	2008-07-15 21:55:59 +02:00
x8664_ksyms_64.c	Merge branch 'auto-ftrace-next' into tracing/for-linus	2008-07-14 16:11:52 +02:00
xsave.c	x86, fpu: check __clear_user() return value	2008-10-12 15:17:39 +02:00