Commit-ID:  87b240cbe3e51bf070fe2839fecb6450323aaef4
Gitweb:     http://git.kernel.org/tip/87b240cbe3e51bf070fe2839fecb6450323aaef4
Author:     Josh Poimboeuf <jpoim...@redhat.com>
AuthorDate: Thu, 21 Jan 2016 16:49:13 -0600
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Wed, 24 Feb 2016 08:35:42 +0100

x86/paravirt: Create a stack frame in PV_CALLEE_SAVE_REGS_THUNK

A function created with the PV_CALLEE_SAVE_REGS_THUNK macro doesn't set
up a new stack frame before the call instruction, which breaks frame
pointer convention if CONFIG_FRAME_POINTER is enabled and can result in
a bad stack trace.  Also, the thunk functions aren't annotated as ELF
callable functions.

Create a stack frame when CONFIG_FRAME_POINTER is enabled and add the
ELF function type.

Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
Reviewed-by: Borislav Petkov <b...@suse.de>
Cc: Alok Kataria <akata...@vmware.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
Cc: Bernd Petrovitsch <be...@petrovitsch.priv.at>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Brian Gerst <brge...@gmail.com>
Cc: Chris J Arges <chris.j.ar...@canonical.com>
Cc: Chris Wright <chr...@sous-sol.org>
Cc: Denys Vlasenko <dvlas...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Jeremy Fitzhardinge <jer...@goop.org>
Cc: Jiri Slaby <jsl...@suse.cz>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Michal Marek <mma...@suse.cz>
Cc: Namhyung Kim <namhy...@gmail.com>
Cc: Pedro Alves <pal...@redhat.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Rusty Russell <ru...@rustcorp.com.au>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: live-patch...@vger.kernel.org
Link: 
http://lkml.kernel.org/r/a2cad74e87c4aba7fd0f54a1af312e66a824a575.1453405861.git.jpoim...@redhat.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
 arch/x86/include/asm/paravirt.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index f619250..601f1b8 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -13,6 +13,7 @@
 #include <linux/bug.h>
 #include <linux/types.h>
 #include <linux/cpumask.h>
+#include <asm/frame.h>
 
 static inline int paravirt_enabled(void)
 {
@@ -756,15 +757,19 @@ static __always_inline void __ticket_unlock_kick(struct 
arch_spinlock *lock,
  * call. The return value in rax/eax will not be saved, even for void
  * functions.
  */
+#define PV_THUNK_NAME(func) "__raw_callee_save_" #func
 #define PV_CALLEE_SAVE_REGS_THUNK(func)                                        
\
        extern typeof(func) __raw_callee_save_##func;                   \
                                                                        \
        asm(".pushsection .text;"                                       \
-           ".globl __raw_callee_save_" #func " ; "                     \
-           "__raw_callee_save_" #func ": "                             \
+           ".globl " PV_THUNK_NAME(func) ";"                           \
+           ".type " PV_THUNK_NAME(func) ", @function;"                 \
+           PV_THUNK_NAME(func) ":"                                     \
+           FRAME_BEGIN                                                 \
            PV_SAVE_ALL_CALLER_REGS                                     \
            "call " #func ";"                                           \
            PV_RESTORE_ALL_CALLER_REGS                                  \
+           FRAME_END                                                   \
            "ret;"                                                      \
            ".popsection")
 

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