linux/arch/arm64/kernel
Li Bin ee556d00cf arm64: ftrace: fix function_graph tracer panic
When function graph tracer is enabled, the following operation
will trigger panic:

mount -t debugfs nodev /sys/kernel
echo next_tgid > /sys/kernel/tracing/set_ftrace_filter
echo function_graph > /sys/kernel/tracing/current_tracer
ls /proc/

------------[ cut here ]------------
[  198.501417] Unable to handle kernel paging request at virtual address cb88537fdc8ba316
[  198.506126] pgd = ffffffc008f79000
[  198.509363] [cb88537fdc8ba316] *pgd=00000000488c6003, *pud=00000000488c6003, *pmd=0000000000000000
[  198.517726] Internal error: Oops: 94000005 [#1] SMP
[  198.518798] Modules linked in:
[  198.520582] CPU: 1 PID: 1388 Comm: ls Tainted: G
[  198.521800] Hardware name: linux,dummy-virt (DT)
[  198.522852] task: ffffffc0fa9e8000 ti: ffffffc0f9ab0000 task.ti: ffffffc0f9ab0000
[  198.524306] PC is at next_tgid+0x30/0x100
[  198.525205] LR is at return_to_handler+0x0/0x20
[  198.526090] pc : [<ffffffc0002a1070>] lr : [<ffffffc0000907c0>] pstate: 60000145
[  198.527392] sp : ffffffc0f9ab3d40
[  198.528084] x29: ffffffc0f9ab3d40 x28: ffffffc0f9ab0000
[  198.529406] x27: ffffffc000d6a000 x26: ffffffc000b786e8
[  198.530659] x25: ffffffc0002a1900 x24: ffffffc0faf16c00
[  198.531942] x23: ffffffc0f9ab3ea0 x22: 0000000000000002
[  198.533202] x21: ffffffc000d85050 x20: 0000000000000002
[  198.534446] x19: 0000000000000002 x18: 0000000000000000
[  198.535719] x17: 000000000049fa08 x16: ffffffc000242efc
[  198.537030] x15: 0000007fa472b54c x14: ffffffffff000000
[  198.538347] x13: ffffffc0fada84a0 x12: 0000000000000001
[  198.539634] x11: ffffffc0f9ab3d70 x10: ffffffc0f9ab3d70
[  198.540915] x9 : ffffffc0000907c0 x8 : ffffffc0f9ab3d40
[  198.542215] x7 : 0000002e330f08f0 x6 : 0000000000000015
[  198.543508] x5 : 0000000000000f08 x4 : ffffffc0f9835ec0
[  198.544792] x3 : cb88537fdc8ba316 x2 : cb88537fdc8ba306
[  198.546108] x1 : 0000000000000002 x0 : ffffffc000d85050
[  198.547432]
[  198.547920] Process ls (pid: 1388, stack limit = 0xffffffc0f9ab0020)
[  198.549170] Stack: (0xffffffc0f9ab3d40 to 0xffffffc0f9ab4000)
[  198.582568] Call trace:
[  198.583313] [<ffffffc0002a1070>] next_tgid+0x30/0x100
[  198.584359] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
[  198.585503] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
[  198.586574] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
[  198.587660] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
[  198.588896] Code: aa0003f5 2a0103f4 b4000102 91004043 (885f7c60)
[  198.591092] ---[ end trace 6a346f8f20949ac8 ]---

This is because when using function graph tracer, if the traced
function return value is in multi regs ([x0-x7]), return_to_handler
may corrupt them. So in return_to_handler, the parameter regs should
be protected properly.

Cc: <stable@vger.kernel.org> # 3.18+
Signed-off-by: Li Bin <huawei.libin@huawei.com>
Acked-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-02 11:12:56 +01:00
..
vdso arm64: vdso: work-around broken ELF toolchains in Makefile 2015-06-19 14:54:10 +01:00
.gitignore arm64: Build infrastructure 2012-09-17 13:42:21 +01:00
acpi.c arm64: psci: remove ACPI coupling 2015-05-27 13:22:24 +01:00
alternative.c arm64: alternatives: ensure secondary CPUs execute ISB after patching 2015-08-04 18:52:09 +01:00
arm64ksyms.c arm64: Add ftrace support 2014-05-29 09:08:08 +01:00
armv8_deprecated.c arm64: kernel: Add support for Privileged Access Never 2015-07-27 11:08:41 +01:00
asm-offsets.c arm64: KVM: remove remaining reference to vgic_sr_vectors 2015-08-12 11:28:23 +01:00
cacheinfo.c arm64: kernel: add support for cpu cache information 2015-01-15 11:55:07 +00:00
cpu_errata.c arm64: fix midr range for Cortex-A57 erratum 832075 2015-04-01 11:12:03 +01:00
cpu_ops.c arm64: force CONFIG_SMP=y and remove redundant #ifdefs 2015-07-27 11:08:40 +01:00
cpufeature.c arm64: lse: use generic cpufeature detection for LSE atomics 2015-07-27 16:37:14 +01:00
cpuidle.c arm64: cpuidle: add __init section marker to arm_cpuidle_init 2015-07-02 17:44:27 +01:00
cpuinfo.c arm64: Extract feature parsing code from cpu_errata.c 2015-03-30 11:03:43 +01:00
debug-monitors.c arm64: cpu hotplug: ensure we mask out CPU_TASKS_FROZEN in notifiers 2015-09-17 11:57:02 +01:00
efi-entry.S arm64 updates for 3.19 2014-12-09 13:12:47 -08:00
efi-stub.c arm64: efi: prefer AllocatePages() over efi_low_alloc() for vmlinux 2015-07-27 11:08:41 +01:00
efi.c arm64/efi: map the entire UEFI vendor string before reading it 2015-07-27 18:00:05 +01:00
entry32.S arm64: entry32: remove pointless register assignment 2015-07-10 16:47:13 +01:00
entry-fpsimd.S arm64: fpsimd: fix a typo in fpsimd_save_partial_state ENDPROC 2014-07-31 11:42:42 +01:00
entry-ftrace.S arm64: ftrace: fix function_graph tracer panic 2015-10-02 11:12:56 +01:00
entry.S arm64: entry: always restore x0 from the stack on syscall return 2015-08-21 15:11:43 +01:00
fpsimd.c arm64: flush FP/SIMD state correctly after execve() 2015-08-27 09:55:26 +01:00
ftrace.c arm64: ftrace: fix ftrace_modify_graph_caller for branch replace 2015-02-23 09:13:45 +00:00
head.S arm64: head.S: initialise mdcr_el2 in el2_setup 2015-09-15 15:50:01 +01:00
hw_breakpoint.c arm64: cpu hotplug: ensure we mask out CPU_TASKS_FROZEN in notifiers 2015-09-17 11:57:02 +01:00
hyp-stub.S irqchip: gic-v3: Initial support for GICv3 2014-07-08 22:11:47 +00:00
image.h arm64: Update the Image header 2014-07-10 12:36:40 +01:00
insn.c arm64: insn: use set_fixmap_offset to make it more clear 2015-07-27 11:08:41 +01:00
io.c arm64: optimize memcpy_{from,to}io() and memset_io() 2014-11-06 17:25:27 +00:00
irq.c arm64: force CONFIG_SMP=y and remove redundant #ifdefs 2015-07-27 11:08:40 +01:00
jump_label.c jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP} 2015-08-03 11:34:12 +02:00
kgdb.c arm64/debug: Simplify BRK insn opcode declarations 2015-07-27 11:08:42 +01:00
kuser32.S arm64: Add __NR_* definitions for compat syscalls 2014-07-10 11:02:40 +01:00
Makefile arm64: makefile: fix perf_callchain.o kconfig dependency 2015-08-24 13:44:08 +01:00
module.c arm64: errata: add module build workaround for erratum #843419 2015-09-17 11:57:03 +01:00
pci.c ARM64: PCI: do not enable resources on PROBE_ONLY systems 2015-07-30 20:17:07 +01:00
perf_callchain.c arm64: perf: factor out callchain code 2015-07-27 11:08:39 +01:00
perf_event.c arm64: perf: condense event number maps 2015-07-27 11:08:40 +01:00
perf_regs.c perf: Move task_pt_regs sampling into arch code 2015-01-09 11:12:28 +01:00
process.c arm64: kernel thread don't need to save fpsimd context. 2015-06-11 15:35:23 +01:00
psci-call.S arm64: psci: move psci firmware calls out of line 2015-02-26 18:23:53 +00:00
psci.c Merge branch 'aarch64/psci/drivers' into aarch64/for-next/core 2015-08-05 14:14:06 +01:00
ptrace.c arm64: Better native ptrace support for compat tasks 2015-07-27 11:08:39 +01:00
return_address.c arm64: LLVMLinux: Use global stack pointer in return_address() 2014-09-08 14:39:19 +01:00
setup.c arm64: support initrd outside kernel linear map 2015-09-08 15:35:28 -07:00
signal32.c arm64: compat: fix vfp save/restore across signal handlers in big-endian 2015-09-17 11:57:03 +01:00
signal.c arm64: Removed unused variable 2015-04-13 20:40:10 +02:00
sleep.S arm64: mm: ensure patched kernel text is fetched from PoU 2015-08-05 10:05:20 +01:00
smp_spin_table.c ARM64: kernel: make cpu_ops hooks DT agnostic 2015-05-19 16:09:29 +01:00
smp.c arm64: remove dead-code depending on CONFIG_UP_LATE_INIT 2015-07-29 18:32:09 +01:00
stacktrace.c arm64: LLVMLinux: Use current_stack_pointer in save_stack_trace_tsk 2014-09-08 14:39:19 +01:00
suspend.c arm64: kernel: rename __cpu_suspend to keep it aligned with arm 2015-06-19 14:46:39 +01:00
sys32.c arm64: fix implementation of mmap2 compat syscall 2015-03-19 10:43:51 +00:00
sys_compat.c arm64: compat: align cacheflush syscall with arch/arm 2014-12-01 13:31:12 +00:00
sys.c arm64: make sys_call_table const 2015-01-27 09:38:08 +00:00
time.c arm64: force CONFIG_SMP=y and remove redundant #ifdefs 2015-07-27 11:08:40 +01:00
topology.c arm64: kernel: remove non-legit DT warnings when booting using ACPI 2015-07-27 11:08:41 +01:00
trace-events-emulation.h arm64: Trace emulation of AArch32 legacy instructions 2014-11-20 16:35:02 +00:00
traps.c arm64/BUG: Show explicit backtrace for WARNs 2015-07-27 11:08:42 +01:00
vdso.c arm64: VDSO: fix coarse clock monotonicity regression 2015-08-10 15:37:45 +01:00
vmlinux.lds.S arm64: reduce ID map to a single page 2015-06-02 17:44:51 +01:00