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| author | Ingo Molnar <mingo@elte.hu> | 2008-07-30 19:32:39 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-30 19:32:39 +0200 |
| commit | b2d9d33412b9d13a40cd314d93ab517950fc5950 (patch) | |
| tree | 78dd37783657520d46a57e462b799826c4a9d54a | |
| parent | x86: add apic probe for genapic 64bit - fix (diff) | |
| parent | x64, fpu: fix possible FPU leakage in error conditions (diff) | |
| download | linux-b2d9d33412b9d13a40cd314d93ab517950fc5950.tar.xz linux-b2d9d33412b9d13a40cd314d93ab517950fc5950.zip | |
Merge branch 'x86/fpu' into x86/core
| -rw-r--r-- | arch/x86/kernel/signal_64.c | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/traps_64.c | 9 | ||||
| -rw-r--r-- | include/asm-x86/i387.h | 2 |
3 files changed, 18 insertions, 4 deletions
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c index b45ef8ddd651..ca316b5b742c 100644 --- a/arch/x86/kernel/signal_64.c +++ b/arch/x86/kernel/signal_64.c @@ -104,7 +104,16 @@ static inline int restore_i387(struct _fpstate __user *buf) clts(); task_thread_info(current)->status |= TS_USEDFPU; } - return restore_fpu_checking((__force struct i387_fxsave_struct *)buf); + err = restore_fpu_checking((__force struct i387_fxsave_struct *)buf); + if (unlikely(err)) { + /* + * Encountered an error while doing the restore from the + * user buffer, clear the fpu state. + */ + clear_fpu(tsk); + clear_used_math(); + } + return err; } /* diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c index 3f18d73f420c..513caaca7115 100644 --- a/arch/x86/kernel/traps_64.c +++ b/arch/x86/kernel/traps_64.c @@ -1131,7 +1131,14 @@ asmlinkage void math_state_restore(void) } clts(); /* Allow maths ops (or we recurse) */ - restore_fpu_checking(&me->thread.xstate->fxsave); + /* + * Paranoid restore. send a SIGSEGV if we fail to restore the state. + */ + if (unlikely(restore_fpu_checking(&me->thread.xstate->fxsave))) { + stts(); + force_sig(SIGSEGV, me); + return; + } task_thread_info(me)->status |= TS_USEDFPU; me->fpu_counter++; } diff --git a/include/asm-x86/i387.h b/include/asm-x86/i387.h index 6f60a6b89973..3958de6aad0e 100644 --- a/include/asm-x86/i387.h +++ b/include/asm-x86/i387.h @@ -62,8 +62,6 @@ static inline int restore_fpu_checking(struct i387_fxsave_struct *fx) #else : [fx] "cdaSDb" (fx), "m" (*fx), "0" (0)); #endif - if (unlikely(err)) - init_fpu(current); return err; } |