Add support to enable libc to be compiled in ELF format. (#ifdef __ELF__)

In a nutshell, this macroizes the local/global symbol scoping rules
that are different in a.out and ELF.  It also makes the i386 assembler
stubs conform to i386 PIC calling conventions - the a.out ld.so didn't
object, but the ELF one needs it as it implements PIC jumps via PLT's as
well as calls.  The a.out rtld only worked because it was accidently
snooping the grandparent calling function's return address off the stack..

This also affects the libc_r code a little, because of cpp macro nesting.

1 files changed, 16 insertions, 17 deletions

diff --git a/lib/libc/i386/SYS.h b/lib/libc/i386/SYS.h
index 9e989e5..caea98f 100644
--- a/lib/libc/i386/SYS.h
+++ b/lib/libc/i386/SYS.h
@@ -35,7 +35,7 @@
  *
  *	from: @(#)SYS.h	5.5 (Berkeley) 5/7/91
  *
- *	$Id: SYS.h,v 1.2 1994/08/05 01:17:57 wollman Exp $
+ *	$Id: SYS.h,v 1.3 1996/01/22 00:00:51 julian Exp $
  */
 
 #include <sys/syscall.h>
@@ -61,28 +61,27 @@
 #define PIC_GOTOFF(x)   x
 #endif
 
-#define	SYSCALL(x)	2: jmp cerror; ENTRY(x); lea SYS_/**/x,%eax; LCALL(7,0); jb 2b
+#define	SYSCALL(x)	2: PIC_PROLOGUE; jmp PIC_PLT(HIDENAME(cerror)); ENTRY(x); lea __CONCAT(SYS_,x),%eax; KERNCALL; jb 2b
 #define	RSYSCALL(x)	SYSCALL(x); ret
 
-#ifdef _THREAD_SAFE
 /*
- * Support for user-space threads which require that some syscalls be
- * private to the threaded library.
+ * For the thread_safe versions, we prepend _thread_sys_ to the function
+ * name so that the 'C' wrapper can go around the real name.
  */
-#define	PSYSCALL(x)	2: jmp cerror; ENTRY(_thread_sys_/**/x); lea SYS_/**/x,%eax; LCALL(7,0); jb 2b
-#else
-/*
- * The non-threaded library defaults to traditional syscalls where
- * the function name matches the syscall name.
- */
-#define	PSYSCALL(x)	SYSCALL(x)
+#ifdef _THREAD_SAFE	/* in case */
+#define	PSYSCALL(x,y)	2: PIC_PROLOGUE; jmp PIC_PLT(HIDENAME(cerror)); ENTRY(y); lea __CONCAT(SYS_,x),%eax; KERNCALL; jb 2b
+#define	PRSYSCALL(x,y)	PSYSCALL(x,y); ret
 #endif
-#define	PRSYSCALL(x)	PSYSCALL(x); ret
-#define	PSEUDO(x,y)	ENTRY(x); lea SYS_/**/y, %eax; ; LCALL(7,0); ret
-#define	CALL(x,y)	call _/**/y; addl $4*x,%esp
+
+#define	PSEUDO(x,y)	ENTRY(x); lea __CONCAT(SYS_,y), %eax; KERNCALL; ret
+#define	CALL(x,y)	call CNAME(y); addl $4*x,%esp
 /* gas fucks up offset -- although we don't currently need it, do for BCS */
 #define	LCALL(x,y)	.byte 0x9a ; .long y; .word x
 
-#define	ASMSTR		.asciz
+#ifdef __ELF__
+#define KERNCALL	int $0x80	/* Faster */
+#else
+#define KERNCALL	LCALL(7,0)	/* The old way */
+#endif
 
-	.globl	cerror
+#define	ASMSTR		.asciz