Patchwork PATCH: Call x86-64 __mcount_internal/__sigjmp_save directly

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Submitter H.J. Lu
Date March 1, 2016, 11:30 p.m.
Message ID <20160301233058.GA3545@intel.com>
Download mbox | patch
Permalink /patch/11163/
State New
Headers show

Comments

H.J. Lu - March 1, 2016, 11:30 p.m.
Since __mcount_internal and __sigjmp_save are internal to x86-64 libc.so:

3532: 0000000000104530   289 FUNC    LOCAL  DEFAULT   13 __mcount_internal
3391: 0000000000034170    38 FUNC    LOCAL  DEFAULT   13 __sigjmp_save

they can be called directly without PLT.  I will check it in.

H.J.
	* sysdeps/x86_64/_mcount.S (C_LABEL(_mcount)): Call
	__mcount_internal directly.
	* sysdeps/x86_64/setjmp.S __sigsetjmp): Call __sigjmp_save
	directly.

Patch

diff --git a/sysdeps/x86_64/_mcount.S b/sysdeps/x86_64/_mcount.S
index 5d7edd2..ba13643 100644
--- a/sysdeps/x86_64/_mcount.S
+++ b/sysdeps/x86_64/_mcount.S
@@ -43,11 +43,7 @@  C_LABEL(_mcount)
 	movq	56(%rsp),%rsi
 	/* Get frompc via the frame pointer.  */
 	movq	8(%rbp),%rdi
-#ifdef PIC
-	call C_SYMBOL_NAME(__mcount_internal)@PLT
-#else
 	call C_SYMBOL_NAME(__mcount_internal)
-#endif
 	/* Pop the saved registers.  Please note that `mcount' has no
 	   return value.  */
 	movq	48(%rsp),%r9
@@ -84,11 +80,7 @@  C_LABEL(__fentry__)
 	movq	64(%rsp),%rsi
 	/* caller is the return address above it */
 	movq	72(%rsp),%rdi
-#ifdef PIC
-	call C_SYMBOL_NAME(__mcount_internal)@PLT
-#else
 	call C_SYMBOL_NAME(__mcount_internal)
-#endif
 	/* Pop the saved registers.  Please note that `__fentry__' has no
 	   return value.  */
 	movq	48(%rsp),%r9
diff --git a/sysdeps/x86_64/setjmp.S b/sysdeps/x86_64/setjmp.S
index 3e93967..e37c223 100644
--- a/sysdeps/x86_64/setjmp.S
+++ b/sysdeps/x86_64/setjmp.S
@@ -60,11 +60,7 @@  ENTRY (__sigsetjmp)
 	retq
 #else
 	/* Make a tail call to __sigjmp_save; it takes the same args.  */
-# ifdef	PIC
-	jmp C_SYMBOL_NAME (__sigjmp_save)@PLT
-# else
 	jmp __sigjmp_save
-# endif
 #endif
 END (__sigsetjmp)
 hidden_def (__sigsetjmp)