[PATCH] Fix "Remove the use of _syscallX macros in UML"

Fix commit 5f4c6bc1: it spits out warnings
about missing syscall prototype (it is in <unistd.h>) and it does not
recognize that two uses of _syscallX are to be resolved against kernel
headers in the source tree, not against _syscallX; they in fact do not
compile and would not work anyway.

If _syscallX macros will be removed from the kernel tree altogether, the
only reasonable solution for that piece of code is switching to open-coded
inline assembly (it's remapping the whole executable from memory, except
the page containing this code).
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/um/os-Linux/sys-i386/tls.c

 #include <errno.h>
 #include <linux/unistd.h>
+
 #include <sys/syscall.h>
+#include <unistd.h>
+
 #include "sysdep/tls.h"
 #include "user_util.h"
 

arch/um/os-Linux/tls.c

 #include <errno.h>
 #include <sys/ptrace.h>
 #include <sys/syscall.h>
+#include <unistd.h>
 #include <asm/ldt.h>
 #include "sysdep/tls.h"
 #include "uml-config.h"

arch/um/sys-i386/unmap.c

@@ -5,17 +5,20 @@
 
 #include <linux/mman.h>
 #include <asm/unistd.h>
-#include <sys/syscall.h>
 
+static int errno;
+
+static inline _syscall2(int,munmap,void *,start,size_t,len)
+static inline _syscall6(void *,mmap2,void *,addr,size_t,len,int,prot,int,flags,int,fd,off_t,offset)
 int switcheroo(int fd, int prot, void *from, void *to, int size)
 {
-	if (syscall(__NR_munmap, to, size) < 0){
+	if(munmap(to, size) < 0){
 		return(-1);
 	}
-	if (syscall(__NR_mmap2, to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) == (void*) -1 ){
+	if(mmap2(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) == (void*) -1 ){
 		return(-1);
 	}
-	if (syscall(__NR_munmap, from, size) < 0){
+	if(munmap(from, size) < 0){
 		return(-1);
 	}
 	return(0);

arch/um/sys-x86_64/unmap.c

@@ -5,17 +5,20 @@
 
 #include <linux/mman.h>
 #include <asm/unistd.h>
-#include <sys/syscall.h>
 
+static int errno;
+
+static inline _syscall2(int,munmap,void *,start,size_t,len)
+static inline _syscall6(void *,mmap,void *,addr,size_t,len,int,prot,int,flags,int,fd,off_t,offset)
 int switcheroo(int fd, int prot, void *from, void *to, int size)
 {
-	if (syscall(__NR_munmap, to, size) < 0){
+	if(munmap(to, size) < 0){
 		return(-1);
 	}
-	if (syscall(__NR_mmap, to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) == (void*) -1){
+	if(mmap(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) == (void*) -1){
 		return(-1);
 	}
-	if (syscall(__NR_munmap, from, size) < 0){
+	if(munmap(from, size) < 0){
 		return(-1);
 	}
 	return(0);