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author | Josh Poimboeuf <jpoimboe@redhat.com> | 2017-07-25 08:54:24 -0500 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2017-07-26 14:05:36 +0200 |
commit | 81d387190039c14edac8de2b3ec789beb899afd9 (patch) | |
tree | 73d1c44e4b1b212457e9cea254ee7d69ccc4ba75 /arch | |
parent | a34a766ff96d9e88572e35a45066279e40a85d84 (diff) | |
download | op-kernel-dev-81d387190039c14edac8de2b3ec789beb899afd9.zip op-kernel-dev-81d387190039c14edac8de2b3ec789beb899afd9.tar.gz |
x86/kconfig: Consolidate unwinders into multiple choice selection
There are three mutually exclusive unwinders. Make that more obvious by
combining them into a multiple-choice selection:
CONFIG_FRAME_POINTER_UNWINDER
CONFIG_ORC_UNWINDER
CONFIG_GUESS_UNWINDER (if CONFIG_EXPERT=y)
Frame pointers are still the default (for now).
The old CONFIG_FRAME_POINTER option is still used in some
arch-independent places, so keep it around, but make it
invisible to the user on x86 - it's now selected by
CONFIG_FRAME_POINTER_UNWINDER=y.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/20170725135424.zukjmgpz3plf5pmt@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/Kconfig | 3 | ||||
-rw-r--r-- | arch/x86/Kconfig.debug | 47 | ||||
-rw-r--r-- | arch/x86/configs/tiny.config | 2 | ||||
-rw-r--r-- | arch/x86/include/asm/unwind.h | 4 |
4 files changed, 45 insertions, 11 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7ccf26a..9b30212 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -73,7 +73,6 @@ config X86 select ARCH_USE_QUEUED_RWLOCKS select ARCH_USE_QUEUED_SPINLOCKS select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH - select ARCH_WANT_FRAME_POINTERS select ARCH_WANTS_DYNAMIC_TASK_STRUCT select ARCH_WANTS_THP_SWAP if X86_64 select BUILDTIME_EXTABLE_SORT @@ -168,7 +167,7 @@ config X86 select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_REGS_AND_STACK_ACCESS_API - select HAVE_RELIABLE_STACKTRACE if X86_64 && FRAME_POINTER && STACK_VALIDATION + select HAVE_RELIABLE_STACKTRACE if X86_64 && FRAME_POINTER_UNWINDER && STACK_VALIDATION select HAVE_STACK_VALIDATION if X86_64 select HAVE_SYSCALL_TRACEPOINTS select HAVE_UNSTABLE_SCHED_CLOCK diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 268a318..93bbb31 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -355,9 +355,32 @@ config PUNIT_ATOM_DEBUG The current power state can be read from /sys/kernel/debug/punit_atom/dev_power_state +choice + prompt "Choose kernel unwinder" + default FRAME_POINTER_UNWINDER + ---help--- + This determines which method will be used for unwinding kernel stack + traces for panics, oopses, bugs, warnings, perf, /proc/<pid>/stack, + livepatch, lockdep, and more. + +config FRAME_POINTER_UNWINDER + bool "Frame pointer unwinder" + select FRAME_POINTER + ---help--- + This option enables the frame pointer unwinder for unwinding kernel + stack traces. + + The unwinder itself is fast and it uses less RAM than the ORC + unwinder, but the kernel text size will grow by ~3% and the kernel's + overall performance will degrade by roughly 5-10%. + + This option is recommended if you want to use the livepatch + consistency model, as this is currently the only way to get a + reliable stack trace (CONFIG_HAVE_RELIABLE_STACKTRACE). + config ORC_UNWINDER bool "ORC unwinder" - depends on X86_64 && !FRAME_POINTER + depends on X86_64 select STACK_VALIDATION ---help--- This option enables the ORC (Oops Rewind Capability) unwinder for @@ -371,12 +394,22 @@ config ORC_UNWINDER Enabling this option will increase the kernel's runtime memory usage by roughly 2-4MB, depending on your kernel config. -config FRAME_POINTER_UNWINDER - def_bool y - depends on !ORC_UNWINDER && FRAME_POINTER - config GUESS_UNWINDER - def_bool y - depends on !ORC_UNWINDER && !FRAME_POINTER + bool "Guess unwinder" + depends on EXPERT + ---help--- + This option enables the "guess" unwinder for unwinding kernel stack + traces. It scans the stack and reports every kernel text address it + finds. Some of the addresses it reports may be incorrect. + + While this option often produces false positives, it can still be + useful in many cases. Unlike the other unwinders, it has no runtime + overhead. + +endchoice + +config FRAME_POINTER + depends on !ORC_UNWINDER && !GUESS_UNWINDER + bool endmenu diff --git a/arch/x86/configs/tiny.config b/arch/x86/configs/tiny.config index 4b429df..550cd50 100644 --- a/arch/x86/configs/tiny.config +++ b/arch/x86/configs/tiny.config @@ -1,3 +1,5 @@ CONFIG_NOHIGHMEM=y # CONFIG_HIGHMEM4G is not set # CONFIG_HIGHMEM64G is not set +CONFIG_GUESS_UNWINDER=y +# CONFIG_FRAME_POINTER_UNWINDER is not set diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h index 25b8d31a..e9f793e 100644 --- a/arch/x86/include/asm/unwind.h +++ b/arch/x86/include/asm/unwind.h @@ -16,7 +16,7 @@ struct unwind_state { bool signal, full_regs; unsigned long sp, bp, ip; struct pt_regs *regs; -#elif defined(CONFIG_FRAME_POINTER) +#elif defined(CONFIG_FRAME_POINTER_UNWINDER) bool got_irq; unsigned long *bp, *orig_sp, ip; struct pt_regs *regs; @@ -50,7 +50,7 @@ void unwind_start(struct unwind_state *state, struct task_struct *task, __unwind_start(state, task, regs, first_frame); } -#if defined(CONFIG_ORC_UNWINDER) || defined(CONFIG_FRAME_POINTER) +#if defined(CONFIG_ORC_UNWINDER) || defined(CONFIG_FRAME_POINTER_UNWINDER) static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state) { if (unwind_done(state)) |