[CRIU] [PATCH] arch/x86: push correct eip on the stack before lretq

[Andrei Vagin]

Right now we use pushq, but it pushes sign-extended value, so if the
parasite code is placed higher that 2Gb, we will see something like
this:

   0xf7efd5b0:	pushq  $0x23
   0xf7efd5b2:	pushq  $0xfffffffff7efd5b9
=> 0xf7efd5b7:	lretq

Actually we want to push 0xf7efd5b9 instead of 0xfffffffff7efd5b9.

Fixes: #398

Cc: Dmitry Safonov <dima at arista.com>
Cc: Cyrill Gorcunov <gorcunov at gmail.com>
Signed-off-by: Andrei Vagin <avagin at gmail.com>
---
 compel/arch/x86/src/lib/include/uapi/asm/sigframe.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/compel/arch/x86/src/lib/include/uapi/asm/sigframe.h b/compel/arch/x86/src/lib/include/uapi/asm/sigframe.h
index 51ca023f7..486c0c8e0 100644
--- a/compel/arch/x86/src/lib/include/uapi/asm/sigframe.h
+++ b/compel/arch/x86/src/lib/include/uapi/asm/sigframe.h
@@ -194,7 +194,9 @@ void rt_sigframe_erase_sigset(struct rt_sigframe *sigframe)
 #define ARCH_RT_SIGRETURN_COMPAT(new_sp)				\
 	asm volatile(							\
 		"pushq $"__stringify(USER32_CS)"		\n"	\
-		"pushq $1f					\n"	\
+		"xor %%rax, %%rax				\n"	\
+		"movl $1f, %%eax				\n"	\
+		"pushq   %%rax					\n"	\
 		"lretq						\n"	\
 		"1:						\n"	\
 		".code32					\n"	\
-- 
2.21.0