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authorDavid S. Miller <davem@davemloft.net>2015-08-27 21:45:31 -0700
committerDavid S. Miller <davem@davemloft.net>2015-08-27 21:45:31 -0700
commit0d36938bb82a7775c21ce0a7429f08ba13d025b6 (patch)
treef502caf5555591ee237e14e5fa96b2c005a85036 /arch/x86/include/asm/switch_to.h
parentMerge branch 'iff_no_queue_fixups' (diff)
parentMerge tag 'powerpc-4.2-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux (diff)
downloadlinux-dev-0d36938bb82a7775c21ce0a7429f08ba13d025b6.tar.xz
linux-dev-0d36938bb82a7775c21ce0a7429f08ba13d025b6.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Diffstat (limited to 'arch/x86/include/asm/switch_to.h')
-rw-r--r--arch/x86/include/asm/switch_to.h12
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index 751bf4b7bf11..d7f3b3b78ac3 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -79,12 +79,12 @@ do { \
#else /* CONFIG_X86_32 */
/* frame pointer must be last for get_wchan */
-#define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t"
-#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\t"
+#define SAVE_CONTEXT "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
+#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"
#define __EXTRA_CLOBBER \
, "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
- "r12", "r13", "r14", "r15", "flags"
+ "r12", "r13", "r14", "r15"
#ifdef CONFIG_CC_STACKPROTECTOR
#define __switch_canary \
@@ -100,11 +100,7 @@ do { \
#define __switch_canary_iparam
#endif /* CC_STACKPROTECTOR */
-/*
- * There is no need to save or restore flags, because flags are always
- * clean in kernel mode, with the possible exception of IOPL. Kernel IOPL
- * has no effect.
- */
+/* Save restore flags to clear handle leaking NT */
#define switch_to(prev, next, last) \
asm volatile(SAVE_CONTEXT \
"movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \