[PATCH] uml: Use klibc setjmp/longjmp

This patch adds an implementation of setjmp and longjmp to UML, allowing
access to the inside of a jmpbuf without needing the access macros formerly
provided by libc.

The implementation is stolen from klibc.  I copy the relevant files into
arch/um.  I have another patch which avoids the copying, but requires klibc be
in the tree.

setjmp and longjmp users required some tweaking.  Includes of <setjmp.h> were
removed and includes of the UML longjmp.h were added where necessary.  There
are also replacements of siglongjmp with UML_LONGJMP which I somehow missed
earlier.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 7baf90f..50418a5 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -8,7 +8,6 @@
 #include <unistd.h>
 #include <errno.h>
 #include <signal.h>
-#include <setjmp.h>
 #include <sched.h>
 #include "ptrace_user.h"
 #include <sys/wait.h>
@@ -470,7 +469,7 @@
 	*switch_buf = &buf;
 	fork_buf = fb;
 	if(UML_SETJMP(&buf) == 0)
-		siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
+		UML_LONGJMP(fork_buf, INIT_JMP_REMOVE_SIGSTACK);
 }
 
 void switch_threads(void *me, void *next)