libc/amd64: Do not export .cerror.

For some reason, libc exports the symbol .cerror (HIDENAME(cerror)), albeit
in the FBSDprivate_1.0 version. It looks like there is no reason for this
since it is not used from other libraries. Given that it cannot be accessed
from C and its strange calling convention, it is rather unlikely that other
things rely on it. Perhaps it is from a time when symbols could not be
hidden.

Most of the amd64 assembler code jumps to .cerror using the GOT. It can jump
to it directly now, as in non-PIC mode.

There are also some minor size optimizations to instructions but they yield
virtually no benefit in the size of libc.so.7 due to padding.

Reviewed by:	kib

12 files changed, 9 insertions, 88 deletions

diff --git a/lib/libc/amd64/SYS.h b/lib/libc/amd64/SYS.h
index 61d7ab4..a232383 100644
--- a/lib/libc/amd64/SYS.h
+++ b/lib/libc/amd64/SYS.h
@@ -36,38 +36,20 @@
 #include <sys/syscall.h>
 #include <machine/asm.h>
 
-#ifdef PIC
 #define	RSYSCALL(x)	ENTRY(__CONCAT(__sys_,x));			\
 			.weak CNAME(x);					\
 			.set CNAME(x),CNAME(__CONCAT(__sys_,x));	\
 			.weak CNAME(__CONCAT(_,x));			\
 			.set CNAME(__CONCAT(_,x)),CNAME(__CONCAT(__sys_,x)); \
-			mov __CONCAT($SYS_,x),%rax; KERNCALL; jb 2f; ret; \
-			2: movq PIC_GOT(HIDENAME(cerror)),%rcx; jmp *%rcx; \
+			mov __CONCAT($SYS_,x),%eax; KERNCALL;		\
+			jb HIDENAME(cerror); ret;			\
 			END(__CONCAT(__sys_,x))
 
 #define	PSEUDO(x)	ENTRY(__CONCAT(__sys_,x));			\
 			.weak CNAME(__CONCAT(_,x));			\
 			.set CNAME(__CONCAT(_,x)),CNAME(__CONCAT(__sys_,x)); \
-			mov __CONCAT($SYS_,x),%rax; KERNCALL; jb 2f; ret ; \
-			2: movq PIC_GOT(HIDENAME(cerror)),%rcx; jmp *%rcx; \
+			mov __CONCAT($SYS_,x),%eax; KERNCALL;		\
+			jb HIDENAME(cerror); ret;			\
 			END(__CONCAT(__sys_,x))
-#else
-#define	RSYSCALL(x)	ENTRY(__CONCAT(__sys_,x));			\
-			.weak CNAME(x);					\
-			.set CNAME(x),CNAME(__CONCAT(__sys_,x));	\
-			.weak CNAME(__CONCAT(_,x));			\
-			.set CNAME(__CONCAT(_,x)),CNAME(__CONCAT(__sys_,x)); \
-			mov __CONCAT($SYS_,x),%rax; KERNCALL; jb 2f; ret; \
-			2: jmp HIDENAME(cerror);			\
-			END(__CONCAT(__sys_,x))
-
-#define	PSEUDO(x)	ENTRY(__CONCAT(__sys_,x));			\
-			.weak CNAME(__CONCAT(_,x));			\
-			.set CNAME(__CONCAT(_,x)),CNAME(__CONCAT(__sys_,x)); \
-			mov __CONCAT($SYS_,x),%rax; KERNCALL; jb 2f; ret; \
-			2: jmp HIDENAME(cerror);			\
-			END(__CONCAT(__sys_,x))
-#endif
 
 #define KERNCALL	movq %rcx, %r10; syscall
diff --git a/lib/libc/amd64/Symbol.map b/lib/libc/amd64/Symbol.map
index 9997cc2..bbf6113 100644
--- a/lib/libc/amd64/Symbol.map
+++ b/lib/libc/amd64/Symbol.map
@@ -66,7 +66,6 @@ FBSDprivate_1.0 {
 	.curbrk;
 	.minbrk;
 	_brk;
-	.cerror;
 	_end;
 	__sys_vfork;
 	_vfork;
diff --git a/lib/libc/amd64/gen/rfork_thread.S b/lib/libc/amd64/gen/rfork_thread.S
index 9720e08..5e764db 100644
--- a/lib/libc/amd64/gen/rfork_thread.S
+++ b/lib/libc/amd64/gen/rfork_thread.S
@@ -93,12 +93,7 @@ ENTRY(rfork_thread)
 2:
 	popq	%r12
 	popq	%rbx
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)), %rdx
-	jmp	*%rdx
-#else
 	jmp	HIDENAME(cerror)
-#endif
 END(rfork_thread)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/amd64/sys/brk.S b/lib/libc/amd64/sys/brk.S
index 2319417..4048ae6 100644
--- a/lib/libc/amd64/sys/brk.S
+++ b/lib/libc/amd64/sys/brk.S
@@ -76,12 +76,7 @@ ok:
 	ret
 err:
 	addq	$8, %rsp
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)),%rdx
-	jmp	*%rdx
-#else
 	jmp	HIDENAME(cerror)
-#endif
 END(brk)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/amd64/sys/exect.S b/lib/libc/amd64/sys/exect.S
index 81dc8e5..04a97ed 100644
--- a/lib/libc/amd64/sys/exect.S
+++ b/lib/libc/amd64/sys/exect.S
@@ -47,12 +47,7 @@ ENTRY(exect)
 	pushq	%r8
 	popfq
 	KERNCALL
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)),%rdx
-	jmp	*%rdx
-#else
 	jmp	HIDENAME(cerror)
-#endif
 END(exect)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/amd64/sys/getcontext.S b/lib/libc/amd64/sys/getcontext.S
index ea29adb..1128796 100644
--- a/lib/libc/amd64/sys/getcontext.S
+++ b/lib/libc/amd64/sys/getcontext.S
@@ -42,16 +42,9 @@ ENTRY(__sys_getcontext)
 	movq	(%rsp),%rsi	/* save getcontext return address */
 	mov	$SYS_getcontext,%rax
 	KERNCALL
-	jb	1f
+	jb	HIDENAME(cerror)
 	addq	$8,%rsp		/* remove stale (setcontext) return address */
 	jmp	*%rsi		/* restore return address */
-1:
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)),%rdx
-	jmp	*%rdx
-#else
-	jmp	HIDENAME(cerror)
-#endif
 END(__sys_getcontext)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/amd64/sys/pipe.S b/lib/libc/amd64/sys/pipe.S
index 59c1ac1c..8d089db 100644
--- a/lib/libc/amd64/sys/pipe.S
+++ b/lib/libc/amd64/sys/pipe.S
@@ -45,18 +45,11 @@ __FBSDID("$FreeBSD$");
 ENTRY(__sys_pipe)
 	mov	$SYS_pipe,%rax
 	KERNCALL
-	jb	1f
+	jb	HIDENAME(cerror)
 	movl	%eax,(%rdi)	/* %rdi is preserved by syscall */
 	movl	%edx,4(%rdi)
 	movq	$0,%rax
 	ret
-1:
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)),%rdx
-	jmp	*%rdx
-#else
-	jmp	HIDENAME(cerror)
-#endif
 END(__sys_pipe)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/amd64/sys/ptrace.S b/lib/libc/amd64/sys/ptrace.S
index 6235390..9c4628d 100644
--- a/lib/libc/amd64/sys/ptrace.S
+++ b/lib/libc/amd64/sys/ptrace.S
@@ -48,15 +48,8 @@ ENTRY(ptrace)
 #endif
 	mov	$SYS_ptrace,%eax
 	KERNCALL
-	jb	err
+	jb	HIDENAME(cerror)
 	ret
-err:
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)),%rdx
-	jmp	*%rdx
-#else
-	jmp	HIDENAME(cerror)
-#endif
 END(ptrace)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/amd64/sys/reboot.S b/lib/libc/amd64/sys/reboot.S
index e79ca79..fd04ef4 100644
--- a/lib/libc/amd64/sys/reboot.S
+++ b/lib/libc/amd64/sys/reboot.S
@@ -45,15 +45,8 @@ __FBSDID("$FreeBSD$");
 ENTRY(__sys_reboot)
 	mov	$SYS_reboot,%rax
 	KERNCALL
-	jb	1f
+	jb	HIDENAME(cerror)
 	iretq
-1:
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)),%rdx
-	jmp	*%rdx
-#else
-	jmp	HIDENAME(cerror)
-#endif
 END(__sys_reboot)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/amd64/sys/sbrk.S b/lib/libc/amd64/sys/sbrk.S
index 3e4d8aa..0332aae 100644
--- a/lib/libc/amd64/sys/sbrk.S
+++ b/lib/libc/amd64/sys/sbrk.S
@@ -79,12 +79,7 @@ back:
 	ret
 err:
 	addq	$8, %rsp
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)),%rdx
-	jmp	*%rdx
-#else
 	jmp	HIDENAME(cerror)
-#endif
 END(sbrk)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/amd64/sys/setlogin.S b/lib/libc/amd64/sys/setlogin.S
index 23692b9..a451491 100644
--- a/lib/libc/amd64/sys/setlogin.S
+++ b/lib/libc/amd64/sys/setlogin.S
@@ -47,7 +47,7 @@ __FBSDID("$FreeBSD$");
 ENTRY(__sys_setlogin)
 	mov	$SYS_setlogin,%rax
 	KERNCALL
-	jb	1f
+	jb	HIDENAME(cerror)
 #ifdef PIC
 	movq	PIC_GOT(CNAME(_logname_valid)),%rdx
 	movl	$0,(%rdx)
@@ -55,13 +55,6 @@ ENTRY(__sys_setlogin)
 	movl	$0,CNAME(_logname_valid)(%rip)
 #endif
 	ret				/* setlogin(name) */
-1:
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)),%rdx
-	jmp	*%rdx
-#else
-	jmp	HIDENAME(cerror)
-#endif
 END(__sys_setlogin)
 
 	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/amd64/sys/vfork.S b/lib/libc/amd64/sys/vfork.S
index 555c3ca..2afba58 100644
--- a/lib/libc/amd64/sys/vfork.S
+++ b/lib/libc/amd64/sys/vfork.S
@@ -50,12 +50,7 @@ ENTRY(__sys_vfork)
 	jmp	*%rsi
 1:
 	pushq	%rsi
-#ifdef PIC
-	movq	PIC_GOT(HIDENAME(cerror)),%rdx
-	jmp	*%rdx
-#else
 	jmp	HIDENAME(cerror)
-#endif
 END(__sys_vfork)
 
 	.section .note.GNU-stack,"",%progbits