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authorIngo Molnar <mingo@elte.hu>2008-08-14 11:18:08 +0200
committerIngo Molnar <mingo@elte.hu>2008-08-14 11:18:08 +0200
commit31677619650cac2bcc9f50920824323b005e3d8a (patch)
tree9735dbf085ed0cb4a37eb3c285099850e0fb3742 /arch
parentx86: cleanup for setup code crashes during IST probe (diff)
parentx64, fpu: fix possible FPU leakage in error conditions (diff)
downloadlinux-31677619650cac2bcc9f50920824323b005e3d8a.tar.xz
linux-31677619650cac2bcc9f50920824323b005e3d8a.zip
Merge branch 'x86/fpu' into x86/urgent
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/signal_64.c11
-rw-r--r--arch/x86/kernel/traps_64.c9
2 files changed, 18 insertions, 2 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++;
}