x86/fpu/xstate: Use sizeof() instead of a constant

Use sizeof() instead of a constant in fpstate_sanitize_xstate().
Remove use of the address of the 0th array element of ->st_space and
->xmm_space which is equivalent to the array address itself:

No code changed:

  # arch/x86/kernel/fpu/xstate.o:

   text    data     bss     dec     hex filename
   9694     899       4   10597    2965 xstate.o.before
   9694     899       4   10597    2965 xstate.o.after

md5:
   5a43fc70bad8e2a1784f67f01b71aabb  xstate.o.before.asm
   5a43fc70bad8e2a1784f67f01b71aabb  xstate.o.after.asm

 [ bp: Massage commit message. ]

Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210122071925.41285-1-yejune.deng@gmail.com

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 5d8047441a0aafba0713aafd656d4346b92a348b..683749b80ae2829c0a3f56734c4e0da0bc3e4e0e 100644 (file)
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -167,14 +167,14 @@ void fpstate_sanitize_xstate(struct fpu *fpu)
                fx->fop = 0;
                fx->rip = 0;
                fx->rdp = 0;
-               memset(&fx->st_space[0], 0, 128);
+               memset(fx->st_space, 0, sizeof(fx->st_space));
        }
 
        /*
         * SSE is in init state
         */
        if (!(xfeatures & XFEATURE_MASK_SSE))
-               memset(&fx->xmm_space[0], 0, 256);
+               memset(fx->xmm_space, 0, sizeof(fx->xmm_space));
 
        /*
         * First two features are FPU and SSE, which above we handled