diff options
| author | Ingo Molnar <mingo@kernel.org> | 2015-04-22 16:40:56 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-05-19 15:47:20 +0200 |
| commit | 3103ae3a6d3e66d51bb883bb17b55574e163b77d (patch) | |
| tree | 0499a374e7da23e5a9ac080a9ab8586c91f33417 | |
| parent | 416d49ac67ae3af8c98ecee2ebe0a883b95e213a (diff) | |
| download | linux-3103ae3a6d3e66d51bb883bb17b55574e163b77d.tar.bz2 | |
x86/fpu: Add debug check to kernel_fpu_disable()
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 <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 161820526ad3..9bc573a5c9db 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); |