From: Oleg Nesterov <o...@redhat.com> fx_finit() has 2 users but only fpu_finit() needs to nullify xstate, alloc_bootmem_align() in setup_init_fpu_buf() returns zero-filled memory.
And note that both memset()'s look confusing. Yes, offsetof() is 0 for ->fxsave or ->fsave, but it would be more clean to turn them into a single memset() which nullifies fpu->state. Signed-off-by: Oleg Nesterov <o...@redhat.com> Acked-by: Rik van Riel <r...@redhat.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Tavis Ormandy <tav...@google.com> Cc: <x...@kernel.org> Link: http://lkml.kernel.org/r/20150302183257.gc23...@redhat.com Signed-off-by: Borislav Petkov <b...@suse.de> --- arch/x86/include/asm/fpu-internal.h | 1 - arch/x86/kernel/i387.c | 3 ++- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 61609b963eab..5fa1be21ac2a 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -135,7 +135,6 @@ static __always_inline __pure bool use_fxsr(void) static inline void fx_finit(struct i387_fxsave_struct *fx) { - memset(fx, 0, xstate_size); fx->cwd = 0x37f; fx->mxcsr = MXCSR_DEFAULT; } diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 03cc0add8694..0f3de6674ae3 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -224,11 +224,12 @@ void fpu_finit(struct fpu *fpu) return; } + memset(fpu->state, 0, xstate_size); + if (cpu_has_fxsr) { fx_finit(&fpu->state->fxsave); } else { struct i387_fsave_struct *fp = &fpu->state->fsave; - memset(fp, 0, xstate_size); fp->cwd = 0xffff037fu; fp->swd = 0xffff0000u; fp->twd = 0xffffffffu; -- 2.2.0.33.gc18b867 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
