4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> commit fc72ae40e30327aa24eb88a24b9c7058f938bd36 upstream. The ORC unwinder has been stable in testing so far. Give it much wider testing by making it the default in kconfig for x86_64. It's not yet supported for 32-bit, so leave frame pointers as the default there. Suggested-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/9b1237bbe7244ed9cdf8db2dcb1253e37e1c341e.1507924831.git.jpoimboe@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/Kconfig.debug | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -359,27 +359,13 @@ config PUNIT_ATOM_DEBUG choice prompt "Choose kernel unwinder" - default UNWINDER_FRAME_POINTER + default UNWINDER_ORC if X86_64 + default UNWINDER_FRAME_POINTER if X86_32 ---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 UNWINDER_FRAME_POINTER - 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 UNWINDER_ORC bool "ORC unwinder" depends on X86_64 @@ -396,6 +382,21 @@ config UNWINDER_ORC Enabling this option will increase the kernel's runtime memory usage by roughly 2-4MB, depending on your kernel config. +config UNWINDER_FRAME_POINTER + 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 UNWINDER_GUESS bool "Guess unwinder" depends on EXPERT