x86: fix broken math-emu with lazy allocation of fpu area
Fix the math emulation that got broken with the recent lazy allocation of FPU
area. init_fpu() need to be added for the math-emulation path aswell
for the FPU area allocation.
math emulation enabled kernel booted fine with this, in the presence
of "no387 nofxsr" boot param.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: hpa@zytor.com
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/math-emu/fpu_entry.c b/arch/x86/math-emu/fpu_entry.c
index 6e38d87..c7b06fe 100644
--- a/arch/x86/math-emu/fpu_entry.c
+++ b/arch/x86/math-emu/fpu_entry.c
@@ -30,6 +30,7 @@
#include <asm/uaccess.h>
#include <asm/desc.h>
#include <asm/user.h>
+#include <asm/i387.h>
#include "fpu_system.h"
#include "fpu_emu.h"
@@ -146,6 +147,13 @@
unsigned long code_limit = 0; /* Initialized to stop compiler warnings */
struct desc_struct code_descriptor;
+ if (!used_math()) {
+ if (init_fpu(current)) {
+ do_group_exit(SIGKILL);
+ return;
+ }
+ }
+
#ifdef RE_ENTRANT_CHECKING
if (emulating) {
printk("ERROR: wm-FPU-emu is not RE-ENTRANT!\n");
@@ -153,11 +161,6 @@
RE_ENTRANT_CHECK_ON;
#endif /* RE_ENTRANT_CHECKING */
- if (!used_math()) {
- finit();
- set_used_math();
- }
-
SETUP_DATA_AREA(arg);
FPU_ORIG_EIP = FPU_EIP;