kernel_optimize_test/arch/x86/kernel
Jesper Juhl 2e5aa6824d x86-64: Don't use pointer to out-of-scope variable in dump_trace()
In arch/x86/kernel/dumpstack_64.c::dump_trace() we have this code:

...
  		if (!stack) {
  			unsigned long dummy;
  			stack = &dummy;
  			if (task && task != current)
  				stack = (unsigned long *)task->thread.sp;
  		}

  		bp = stack_frame(task, regs);
  		/*
  		 * Print function call entries in all stacks, starting at the
  		 * current stack address. If the stacks consist of nested
  		 * exceptions
  		 */
  		tinfo = task_thread_info(task);

  		for (;;) {
  			char *id;
  			unsigned long *estack_end;
  			estack_end = in_exception_stack(cpu, (unsigned long)stack,
  							&used, &id);
...

You'll notice that we assign to 'stack' the address of the variable
'dummy' which is only in-scope inside the 'if (!stack)'. So when we later
access stack (at the end of the above, and assuming we did not take the
'if (task && task != current)' branch) we'll be using the address of a
variable that is no longer in scope. I believe this patch is the proper
fix, but I freely admit that I'm not 100% certain.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
LKML-Reference: <alpine.LNX.2.00.1101242232590.10252@swampdragon.chaosbits.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-01-24 13:46:15 -08:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2011-01-13 20:15:35 -08:00
apic Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-11 11:11:46 -08:00
cpu x86, mcheck, therm_throt.c: Export symbol platform_thermal_notify to allow coretemp to handler intr 2011-01-21 14:11:12 +01:00
.gitignore
alternative.c Merge branches 'x86-alternatives-for-linus', 'x86-fpu-for-linus', 'x86-hwmon-for-linus', 'x86-paravirt-for-linus', 'core-locking-for-linus' and 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-06 11:11:50 -08:00
amd_iommu_init.c Merge branch 'x86-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 14:23:48 -07:00
amd_iommu.c tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
amd_nb.c x86: Use PCI method for enabling AMD extended config space before MSR method 2011-01-11 12:43:41 +01:00
apb_timer.c x86, mrst: Set correct APB timer IRQ affinity for secondary cpu 2011-01-14 11:53:44 -08:00
aperture_64.c x86: Use PCI method for enabling AMD extended config space before MSR method 2011-01-11 12:43:41 +01:00
apm_32.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
asm-offsets_32.c x86, asm: Fix CFI macro invocations to deal with shortcomings in gas 2010-10-19 14:28:02 -07:00
asm-offsets_64.c
asm-offsets.c
audit_64.c
bootflag.c
check.c x86: Use memblock to replace early_res 2010-08-27 11:12:29 -07:00
cpuid.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
crash_dump_32.c mm: stack based kmap_atomic() 2010-10-26 16:52:08 -07:00
crash_dump_64.c mm, x86: Saving vmcore with non-lazy freeing of vmas 2010-09-17 09:11:56 +02:00
crash.c
doublefault_32.c
dumpstack_32.c x86: Eliminate bp argument from the stack tracing routines 2010-11-18 14:37:34 +01:00
dumpstack_64.c x86-64: Don't use pointer to out-of-scope variable in dump_trace() 2011-01-24 13:46:15 -08:00
dumpstack.c Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2011-01-13 20:15:35 -08:00
e820.c PM / ACPI: Move NVS saving and restoring code to drivers/acpi 2011-01-07 00:36:55 -05:00
early_printk.c x86, earlyprintk: Move mrst early console to platform/ and fix a typo 2010-12-06 20:52:04 +01:00
early-quirks.c Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 13:18:06 -07:00
entry_32.S KVM: Handle async PF in a guest. 2011-01-12 11:23:16 +02:00
entry_64.S Merge branch 'kvm-updates/2.6.38' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2011-01-13 10:14:24 -08:00
ftrace.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
head32.c x86: Add CE4100 platform support 2010-11-12 00:45:41 +01:00
head64.c x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S 2010-10-14 09:06:49 +02:00
head_32.S Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-01-13 10:05:56 -08:00
head_64.S
head.c x86: Use memblock to replace early_res 2010-08-27 11:12:29 -07:00
hpet.c x86: HPET: Chose a paranoid safe value for the ETIME check 2010-12-13 13:42:44 +01:00
hw_breakpoint.c x86: Use this_cpu_ops to optimize code 2010-12-30 12:20:28 +01:00
i386_ksyms_32.c
i387.c KVM: Initialize fpu state in preemptible context 2011-01-12 12:02:26 +02:00
i8237.c
i8253.c
i8259.c x86: i8259: Convert to new irq_chip functions 2010-10-12 16:53:36 +02:00
init_task.c
io_delay.c
ioport.c
irq_32.c Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-18 14:29:21 -08:00
irq_64.c
irq_work.c irq_work: Add generic hardirq context callbacks 2010-10-18 19:58:50 +02:00
irq.c Merge branch 'x86-olpc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-13 10:15:12 -08:00
irqinit.c Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 14:11:46 -07:00
jump_label.c jump label: x86 support 2010-09-22 16:33:03 -04:00
kdebugfs.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
kgdb.c x86, NMI: Remove DIE_NMI_IPI 2011-01-07 15:08:53 +01:00
kprobes.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-01-07 17:02:58 -08:00
kvm.c KVM guest: Fix kvm clock initialization when it's configured out 2011-01-12 11:30:56 +02:00
kvmclock.c KVM paravirt: Move kvm_smp_prepare_boot_cpu() from kvmclock.c to kvm.c. 2011-01-12 11:23:10 +02:00
ldt.c
machine_kexec_32.c
machine_kexec_64.c x86, cleanups: Use clear_page/copy_page rather than memset/memcpy 2010-09-22 15:36:49 -07:00
Makefile Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-06 11:06:31 -08:00
mca_32.c
microcode_amd.c Merge branch 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-06 11:06:09 -08:00
microcode_core.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
microcode_intel.c x86/microcode: Fix double vfree() and remove redundant pointer checks before vfree() 2010-12-27 14:33:30 +01:00
mmconf-fam10h_64.c x86-64: Fix and clean up AMD Fam10 MMCONF enabling 2010-11-18 13:41:35 +01:00
module.c mm: unify module_alloc code for vmalloc 2011-01-13 17:32:34 -08:00
mpparse.c x86: Further simplify mp_irq info handling 2010-12-09 21:52:06 +01:00
msr.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
paravirt_patch_32.c
paravirt_patch_64.c
paravirt-spinlocks.c
paravirt.c thp: add pmd paravirt ops 2011-01-13 17:32:39 -08:00
pci-calgary_64.c x86, calgary: Make Calgary IOMMU use IOMMU_INIT_* macros. 2010-08-26 15:14:15 -07:00
pci-dma.c x86, iommu: Utilize the IOMMU_INIT macros functionality. 2010-08-26 15:14:52 -07:00
pci-gart_64.c x86, amd-nb: Cleanup AMD northbridge caching code 2010-11-18 15:53:05 +01:00
pci-iommu_table.c x86, iommu: Add proper dependency sort routine (and sanity check). 2010-08-26 15:13:19 -07:00
pci-nommu.c
pci-swiotlb.c x86, swiotlb: Make SWIOTLB use IOMMU_INIT_* macros. 2010-08-26 15:13:37 -07:00
pcspeaker.c
probe_roms_32.c
process_32.c cpuidle/x86/perf: fix power:cpu_idle double end events and throw cpu_idle events from the cpuidle layer 2011-01-12 18:05:16 -05:00
process_64.c cpuidle/x86/perf: fix power:cpu_idle double end events and throw cpu_idle events from the cpuidle layer 2011-01-12 18:05:16 -05:00
process.c x86, hotplug: Fix powersavings with offlined cores on AMD 2011-01-21 18:14:54 -08:00
ptrace.c ptrace: cleanup arch_ptrace() on x86 2010-10-27 18:03:10 -07:00
pvclock.c x86/pvclock: Zero last_value on resume 2010-11-28 09:33:20 +01:00
quirks.c x86: HPET force enable for CX700 / VIA Epia LT 2010-09-15 16:27:04 +02:00
reboot_fixups_32.c x86: Ce4100: Add reboot_fixup() for CE4100 2010-11-12 00:45:41 +01:00
reboot.c x86, NMI: Remove DIE_NMI_IPI 2011-01-07 15:08:53 +01:00
relocate_kernel_32.S
relocate_kernel_64.S
resource.c x86: avoid high BIOS area when allocating address space 2010-12-17 10:01:30 -08:00
rtc.c set_rtc_mmss: show warning message only once 2011-01-13 08:03:07 -08:00
setup_percpu.c Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 18:52:11 -07:00
setup.c Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-06 10:51:36 -08:00
signal.c
smp.c x86, kexec: Make sure to stop all CPUs before exiting the kernel 2010-10-21 13:30:44 -07:00
smpboot.c x86, hotplug: Fix powersavings with offlined cores on AMD 2011-01-21 18:14:54 -08:00
stacktrace.c x86: Eliminate bp argument from the stack tracing routines 2010-11-18 14:37:34 +01:00
step.c
sys_i386_32.c i386: Make kernel_execve() suitable for stack unwinding 2010-09-03 08:16:02 +02:00
sys_x86_64.c
syscall_64.c
syscall_table_32.S x86: fix up system call numbering nit 2010-08-10 15:35:10 -07:00
tboot.c thp: pte alloc trans splitting 2011-01-13 17:32:40 -08:00
tce_64.c
test_nx.c
test_rodata.c
time.c x86, nmi_watchdog: Remove all stub function calls from old nmi_watchdog 2010-11-18 09:08:23 +01:00
tls.c
tls.h
topology.c
trampoline_32.S
trampoline_64.S x86, cpu: Rename verify_cpu_64.S to verify_cpu.S 2010-11-10 15:42:42 -08:00
trampoline.c Merge branch 'x86-trampoline-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-22 20:37:50 -07:00
traps.c x86, NMI: Clean-up default_do_nmi() 2011-01-07 15:08:53 +01:00
tsc_sync.c
tsc.c Merge branches 'core-fixes-for-linus', 'x86-fixes-for-linus', 'timers-fixes-for-linus' and 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-01-15 12:45:00 -08:00
verify_cpu.S x86: Fix included-by file reference comments 2010-11-18 09:58:54 +01:00
vm86_32.c thp: split_huge_page_mm/vma 2011-01-13 17:32:41 -08:00
vmlinux.lds.S Revert "x86: Make relocatable kernel work with new binutils" 2011-01-19 10:09:42 +01:00
vsmp_64.c
vsyscall_64.c
x86_init.c x86: Introduce x86_msi_ops 2010-10-18 10:49:34 -04:00
x8664_ksyms_64.c
xsave.c x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem() 2010-12-13 16:13:11 -08:00