Commit 97ce89f8 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 fixes from Thomas Gleixner:
 "The final fixes for 4.11:

   - prevent a triple fault with function graph tracing triggered via
     suspend to ram

   - prevent optimizing for size when function graph tracing is enabled
     and the compiler does not support -mfentry

   - prevent mwaitx() being called with a zero timeout as mwaitx() might
     never return. Observed on the new Ryzen CPUs"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Prevent timer value 0 for MWAITX
  x86/build: convert function graph '-Os' error to warning
  ftrace/x86: Fix triple fault with graph tracing and suspend-to-ram
parents 14e07f02 88d879d2

arch/x86/Makefile

+8 −0
Original line number Diff line number Diff line
@@ -154,6 +154,14 @@ ifdef CONFIG_FUNCTION_GRAPH_TRACER 
  else

    ifeq ($(call cc-option-yn, -mfentry), n)

	ACCUMULATE_OUTGOING_ARGS := 1



	# GCC ignores '-maccumulate-outgoing-args' when used with '-Os'.

	# If '-Os' is enabled, disable it and print a warning.

        ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE

          undefine CONFIG_CC_OPTIMIZE_FOR_SIZE

	  $(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE.  Your compiler does not have -mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.)

        endif



    endif

  endif

endif

arch/x86/kernel/ftrace.c

+12 −6
Original line number Diff line number Diff line
@@ -29,12 +29,6 @@ 
#include <asm/ftrace.h>

#include <asm/nops.h>



#if defined(CONFIG_FUNCTION_GRAPH_TRACER) && \

	!defined(CC_USING_FENTRY) && \

	!defined(CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE)

# error The following combination is not supported: ((compiler missing -mfentry) || (CONFIG_X86_32 and !CONFIG_DYNAMIC_FTRACE)) && CONFIG_FUNCTION_GRAPH_TRACER && CONFIG_CC_OPTIMIZE_FOR_SIZE

#endif



#ifdef CONFIG_DYNAMIC_FTRACE



int ftrace_arch_code_modify_prepare(void)
@@ -989,6 +983,18 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, 
	unsigned long return_hooker = (unsigned long)

				&return_to_handler;



	/*

	 * When resuming from suspend-to-ram, this function can be indirectly

	 * called from early CPU startup code while the CPU is in real mode,

	 * which would fail miserably.  Make sure the stack pointer is a

	 * virtual address.

	 *

	 * This check isn't as accurate as virt_addr_valid(), but it should be

	 * good enough for this purpose, and it's fast.

	 */

	if (unlikely((long)__builtin_frame_address(0) >= 0))

		return;



	if (unlikely(ftrace_graph_is_dead()))

		return;

arch/x86/lib/delay.c

+7 −0
Original line number Diff line number Diff line
@@ -93,6 +93,13 @@ static void delay_mwaitx(unsigned long __loops) 
{

	u64 start, end, delay, loops = __loops;



	/*

	 * Timer value of 0 causes MWAITX to wait indefinitely, unless there

	 * is a store on the memory monitored by MONITORX.

	 */

	if (loops == 0)

		return;



	start = rdtsc_ordered();



	for (;;) {

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