[PATCH 07/33] x86/asm/xen: Create stack frames in xen-asm.S

From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org
Cc: linux-kernel@vger.kernel.org, live-patching@vger.kernel.org,
	Michal Marek <mmarek@suse.cz>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andi Kleen <andi@firstfloor.org>, Pedro Alves <palves@redhat.com>,
	Namhyung Kim <namhyung@gmail.com>,
	Bernd Petrovitsch <bernd@petrovitsch.priv.at>,
	Chris J Arges <chris.j.arges@canonical.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jiri Slaby <jslaby@suse.cz>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	David Vrabel <david.vrabel@citrix.com>
Subject: [PATCH 07/33] x86/asm/xen: Create stack frames in xen-asm.S
Date: Thu, 21 Jan 2016 16:49:11 -0600	[thread overview]
Message-ID: <a8340ad3fc72ba9ed34da9b3af9cdd6f1a896e17.1453405861.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1453405861.git.jpoimboe@redhat.com>

xen_irq_enable_direct(), xen_restore_fl_direct(), and check_events() are
callable non-leaf functions which don't honor CONFIG_FRAME_POINTER,
which can result in bad stack traces.

Create stack frames for them when CONFIG_FRAME_POINTER is enabled.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
---
 arch/x86/xen/xen-asm.S | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 3e45aa0..eff224d 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -14,6 +14,7 @@
 #include <asm/asm-offsets.h>
 #include <asm/percpu.h>
 #include <asm/processor-flags.h>
+#include <asm/frame.h>
 
 #include "xen-asm.h"
 
@@ -23,6 +24,7 @@
  * then enter the hypervisor to get them handled.
  */
 ENTRY(xen_irq_enable_direct)
+	FRAME_BEGIN
 	/* Unmask events */
 	movb $0, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
 
@@ -39,6 +41,7 @@ ENTRY(xen_irq_enable_direct)
 2:	call check_events
 1:
 ENDPATCH(xen_irq_enable_direct)
+	FRAME_END
 	ret
 	ENDPROC(xen_irq_enable_direct)
 	RELOC(xen_irq_enable_direct, 2b+1)
@@ -82,6 +85,7 @@ ENDPATCH(xen_save_fl_direct)
  * enters the hypervisor to get them delivered if so.
  */
 ENTRY(xen_restore_fl_direct)
+	FRAME_BEGIN
 #ifdef CONFIG_X86_64
 	testw $X86_EFLAGS_IF, %di
 #else
@@ -100,6 +104,7 @@ ENTRY(xen_restore_fl_direct)
 2:	call check_events
 1:
 ENDPATCH(xen_restore_fl_direct)
+	FRAME_END
 	ret
 	ENDPROC(xen_restore_fl_direct)
 	RELOC(xen_restore_fl_direct, 2b+1)
@@ -109,7 +114,8 @@ ENDPATCH(xen_restore_fl_direct)
  * Force an event check by making a hypercall, but preserve regs
  * before making the call.
  */
-check_events:
+ENTRY(check_events)
+	FRAME_BEGIN
 #ifdef CONFIG_X86_32
 	push %eax
 	push %ecx
@@ -139,4 +145,6 @@ check_events:
 	pop %rcx
 	pop %rax
 #endif
+	FRAME_END
 	ret
+ENDPROC(check_events)
-- 
2.4.3
