Revert "x86/entry/64: Add missing irqflags tracing to native_load_gs_index()"

This reverts commit f9a64e23a9da528e7d8aa1bd2c7bb92be4ebb724 which is
commit 0d794d0d018f23fb09c50f6ae26868bd6ae343d6 upstream.

Andy writes:

	I think the thing to do is to revert the patch from -stable.
	The bug it fixes is very minor, and the regression is that it
	made a pre-existing bug in some nearly-undebuggable core resume
	code much easier to hit.  I don't feel comfortable with a
	backport of the latter fix until it has a good long soak in
	Linus' tree.

Reported-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 518d928..2e956af 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -51,19 +51,15 @@ ENTRY(native_usergs_sysret64)
 END(native_usergs_sysret64)
 #endif /* CONFIG_PARAVIRT */
 
-.macro TRACE_IRQS_FLAGS flags:req
+.macro TRACE_IRQS_IRETQ
 #ifdef CONFIG_TRACE_IRQFLAGS
-       bt      $9, \flags              /* interrupts off? */
+       bt      $9, EFLAGS(%rsp)                /* interrupts off? */
        jnc     1f
        TRACE_IRQS_ON
 1:
 #endif
 .endm
 
-.macro TRACE_IRQS_IRETQ
-       TRACE_IRQS_FLAGS EFLAGS(%rsp)
-.endm
-
 /*
  * When dynamic function tracer is enabled it will add a breakpoint
  * to all locations that it is about to modify, sync CPUs, update
@@ -927,13 +923,11 @@ ENTRY(native_load_gs_index)
        FRAME_BEGIN
        pushfq
        DISABLE_INTERRUPTS(CLBR_ANY & ~CLBR_RDI)
-       TRACE_IRQS_OFF
        SWAPGS
 .Lgs_change:
        movl    %edi, %gs
 2:     ALTERNATIVE "", "mfence", X86_BUG_SWAPGS_FENCE
        SWAPGS
-       TRACE_IRQS_FLAGS (%rsp)
        popfq
        FRAME_END
        ret