We are not supposed to call kernel_fpu_disable() if we have not previously enabled it.
Also use kernel_fpu_disable()/enable() in the __kernel_fpu_begin/end() primitives, instead of writing to in_kernel_fpu directly, so that we get the debugging checks. Reviewed-by: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/fpu/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 587e4ab46f59..bcf705751d02 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -17,6 +17,7 @@ static void kernel_fpu_disable(void) static void kernel_fpu_enable(void) { + WARN_ON_ONCE(!this_cpu_read(in_kernel_fpu)); this_cpu_write(in_kernel_fpu, false); } @@ -77,7 +78,7 @@ void __kernel_fpu_begin(void) { struct task_struct *me = current; - this_cpu_write(in_kernel_fpu, true); + kernel_fpu_disable(); if (__thread_has_fpu(me)) { __save_init_fpu(me); @@ -100,7 +101,7 @@ void __kernel_fpu_end(void) stts(); } - this_cpu_write(in_kernel_fpu, false); + kernel_fpu_enable(); } EXPORT_SYMBOL(__kernel_fpu_end); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
