x86,ftrace: Use SIZEOF_PTREGS

There's a convenient macro for 'SS+8' called FRAME_SIZE. Use it to
clarify things.

(entry/calling.h calls this SIZEOF_PTREGS but we're using
asm/ptrace-abi.h)

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200416115118.808485515@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 7657dc782828818e5802ff98297ba215546cf9b4..be9aff20dd5f5def8a275564dcb4e7fab09572a7 100644 (file)
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -23,7 +23,7 @@
 #endif /* CONFIG_FRAME_POINTER */
 
 /* Size of stack used to save mcount regs in save_mcount_regs */
-#define MCOUNT_REG_SIZE                (SS+8 + MCOUNT_FRAME_SIZE)
+#define MCOUNT_REG_SIZE                (FRAME_SIZE + MCOUNT_FRAME_SIZE)
 
 /*
  * gcc -pg option adds a call to 'mcount' in most functions.
@@ -77,7 +77,7 @@
        /*
         * We add enough stack to save all regs.
         */
-       subq $(MCOUNT_REG_SIZE - MCOUNT_FRAME_SIZE), %rsp
+       subq $(FRAME_SIZE), %rsp
        movq %rax, RAX(%rsp)
        movq %rcx, RCX(%rsp)
        movq %rdx, RDX(%rsp)