---

yaml --- r: 99964 b: refs/heads/master c: a00394f h: refs/heads/master v: v3
git-mirror · Jul 8, 2008 · 8a1a27c · 8a1a27c
1 parent df33425
commit 8a1a27c
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Showing 3 changed files with 12 additions and 2 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6680415481c7bd38967cf7488787f509f17ba307
+refs/heads/master: a00394f81f419beb6fb9f7023bd4d15913dc625d
diff --git a/trunk/include/asm-x86/irqflags.h b/trunk/include/asm-x86/irqflags.h
@@ -111,6 +111,7 @@ static inline unsigned long __raw_local_irq_save(void)
 #define DISABLE_INTERRUPTS(x)	cli
 
 #ifdef CONFIG_X86_64
+#define SWAPGS_UNSAFE_STACK	swapgs
 #define INTERRUPT_RETURN	iretq
 #define USERGS_SYSRET64				\
 	swapgs;					\
@@ -185,7 +186,6 @@ static inline void trace_hardirqs_fixup(void)
  * Either way, this is a good way to document that we don't
  * have a reliable stack. x86_64 only.
  */
-#define SWAPGS_UNSAFE_STACK	swapgs
 #define ARCH_TRACE_IRQS_ON		call trace_hardirqs_on_thunk
 #define ARCH_TRACE_IRQS_OFF		call trace_hardirqs_off_thunk
 #define ARCH_LOCKDEP_SYS_EXIT		call lockdep_sys_exit_thunk

diff --git a/trunk/include/asm-x86/paravirt.h b/trunk/include/asm-x86/paravirt.h
@@ -1522,6 +1522,16 @@ static inline unsigned long __raw_local_irq_save(void)
 
 
 #else	/* !CONFIG_X86_32 */
+
+/*
+ * If swapgs is used while the userspace stack is still current,
+ * there's no way to call a pvop.  The PV replacement *must* be
+ * inlined, or the swapgs instruction must be trapped and emulated.
+ */
+#define SWAPGS_UNSAFE_STACK						\
+	PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_swapgs), CLBR_NONE,	\
+		  swapgs)
+
 #define SWAPGS								\
 	PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_swapgs), CLBR_NONE,	\
 		  PV_SAVE_REGS;						\