[PATCH 1/3] x86_32: make restore_fpu ckecking

From: Jiri Slaby
Date: Wed Apr 08 2009 - 07:57:23 EST


Like on x86_64, return an error from restore_fpu and kill the task if it
fails.

Also rename restore_fpu to restore_fpu_checking which allows ifdefs to be
removed in math_state_restore.

Signed-off-by: Jiri Slaby <jirislaby@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
---
arch/x86/include/asm/i387.h | 9 ++++-----
arch/x86/kernel/traps.c | 5 +----
2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 71c9e51..09a2d6d 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -185,12 +185,10 @@ static inline void tolerant_fwait(void)
asm volatile("fnclex ; fwait");
}

-static inline void restore_fpu(struct task_struct *tsk)
+static inline int restore_fpu_checking(struct task_struct *tsk)
{
- if (task_thread_info(tsk)->status & TS_XSAVE) {
- xrstor_checking(&tsk->thread.xstate->xsave);
- return;
- }
+ if (task_thread_info(tsk)->status & TS_XSAVE)
+ return xrstor_checking(&tsk->thread.xstate->xsave);
/*
* The "nop" is needed to make the instructions the same
* length.
@@ -200,6 +198,7 @@ static inline void restore_fpu(struct task_struct *tsk)
"fxrstor %1",
X86_FEATURE_FXSR,
"m" (tsk->thread.xstate->fxsave));
+ return 0;
}

/* We need a safe address that is cheap to find and that is already
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index a1d2883..d696145 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -839,9 +839,6 @@ asmlinkage void math_state_restore(void)
}

clts(); /* Allow maths ops (or we recurse) */
-#ifdef CONFIG_X86_32
- restore_fpu(tsk);
-#else
/*
* Paranoid restore. send a SIGSEGV if we fail to restore the state.
*/
@@ -850,7 +847,7 @@ asmlinkage void math_state_restore(void)
force_sig(SIGSEGV, tsk);
return;
}
-#endif
+
thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
tsk->fpu_counter++;
}
--
1.6.2

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