[patch 2.6.17-rc3] i386: fix broken FP exception handling

[Chuck Ebbert]

The FXSAVE information leak patch introduced a bug in FP exception
handling: it clears FP exceptions only when there are already
none outstanding.  Mikael Pettersson reported that causes problems
with the Erlang runtime and has tested this fix.

Signed-off-by: Chuck Ebbert <76306.1226@xxxxxxxxxxxxxx>
Acked-by: Mikael Pettersson <mikpe@xxxxxxxx>

---

The same bug is in 2.6.16.9+ and this patch applies there as well.


--- 2.6.17-rc3-d4.orig/include/asm-i386/i387.h
+++ 2.6.17-rc3-d4/include/asm-i386/i387.h
@@ -58,13 +58,13 @@ static inline void __save_init_fpu( stru
 	alternative_input(
 		"fnsave %[fx] ;fwait;" GENERIC_NOP8 GENERIC_NOP4,
 		"fxsave %[fx]\n"
-		"bt $7,%[fsw] ; jc 1f ; fnclex\n1:",
+		"bt $7,%[fsw] ; jnc 1f ; fnclex\n1:",
 		X86_FEATURE_FXSR,
 		[fx] "m" (tsk->thread.i387.fxsave),
 		[fsw] "m" (tsk->thread.i387.fxsave.swd) : "memory");
 	/* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
 	   is pending.  Clear the x87 state here by setting it to fixed
-   	   values. __per_cpu_offset[0] is a random variable that should be in L1 */
+   	   values. safe_address is a random variable that should be in L1 */
 	alternative_input(
 		GENERIC_NOP8 GENERIC_NOP2,
 		"emms\n\t"	  	/* clear stack tags */
-- 
Chuck
"Penguins don't come from next door, they come from the Antarctic!"
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