[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>

7 files changed, 14 insertions, 19 deletions

diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index b98d3ca2cd1b..3afde92ad2c0 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -7,7 +7,6 @@
 #include <stdio.h>
 #include <errno.h>
 #include <signal.h>
-#include <setjmp.h>
 #include <linux/unistd.h>
 #include <sys/mman.h>
 #include <sys/wait.h>
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 7baf90fda58b..50418a5e7134 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 @@ void thread_wait(void *sw, void *fb)
         *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)
diff --git a/arch/um/os-Linux/sys-i386/registers.c b/arch/um/os-Linux/sys-i386/registers.c
index 516f66dd87e3..1f90a2d71386 100644
--- a/arch/um/os-Linux/sys-i386/registers.c
+++ b/arch/um/os-Linux/sys-i386/registers.c
@@ -5,12 +5,12 @@
 
 #include <errno.h>
 #include <string.h>
-#include <setjmp.h>
 #include "sysdep/ptrace_user.h"
 #include "sysdep/ptrace.h"
 #include "uml-config.h"
 #include "skas_ptregs.h"
 #include "registers.h"
+#include "longjmp.h"
 #include "user.h"
 
 /* These are set once at boot time and not changed thereafter */
@@ -132,9 +132,9 @@ void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
 
 void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer)
 {
-        struct __jmp_buf_tag *jmpbuf = buffer;
+        struct __jmp_buf *jmpbuf = buffer;
 
-        UPT_SET(uml_regs, EIP, jmpbuf->__jmpbuf[JB_PC]);
-        UPT_SET(uml_regs, UESP, jmpbuf->__jmpbuf[JB_SP]);
-        UPT_SET(uml_regs, EBP, jmpbuf->__jmpbuf[JB_BP]);
+        UPT_SET(uml_regs, EIP, jmpbuf->__eip);
+        UPT_SET(uml_regs, UESP, jmpbuf->__esp);
+        UPT_SET(uml_regs, EBP, jmpbuf->__ebp);
 }
diff --git a/arch/um/os-Linux/sys-x86_64/registers.c b/arch/um/os-Linux/sys-x86_64/registers.c
index becd898d9398..e730447d6c02 100644
--- a/arch/um/os-Linux/sys-x86_64/registers.c
+++ b/arch/um/os-Linux/sys-x86_64/registers.c
@@ -5,11 +5,11 @@
 
 #include <errno.h>
 #include <string.h>
-#include <setjmp.h>
 #include "ptrace_user.h"
 #include "uml-config.h"
 #include "skas_ptregs.h"
 #include "registers.h"
+#include "longjmp.h"
 #include "user.h"
 
 /* These are set once at boot time and not changed thereafter */
@@ -80,9 +80,9 @@ void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
 
 void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer)
 {
-        struct __jmp_buf_tag *jmpbuf = buffer;
+        struct __jmp_buf *jmpbuf = buffer;
 
-        UPT_SET(uml_regs, RIP, jmpbuf->__jmpbuf[JB_PC]);
-        UPT_SET(uml_regs, RSP, jmpbuf->__jmpbuf[JB_RSP]);
-        UPT_SET(uml_regs, RBP, jmpbuf->__jmpbuf[JB_RBP]);
+        UPT_SET(uml_regs, RIP, jmpbuf->__rip);
+        UPT_SET(uml_regs, RSP, jmpbuf->__rsp);
+        UPT_SET(uml_regs, RBP, jmpbuf->__rbp);
 }
diff --git a/arch/um/os-Linux/trap.c b/arch/um/os-Linux/trap.c
index 90b29ae9af46..1df231a26244 100644
--- a/arch/um/os-Linux/trap.c
+++ b/arch/um/os-Linux/trap.c
@@ -5,7 +5,6 @@
 
 #include <stdlib.h>
 #include <signal.h>
-#include <setjmp.h>
 #include "kern_util.h"
 #include "user_util.h"
 #include "os.h"
diff --git a/arch/um/os-Linux/uaccess.c b/arch/um/os-Linux/uaccess.c
index 865f6a6a2590..bbb73a650370 100644
--- a/arch/um/os-Linux/uaccess.c
+++ b/arch/um/os-Linux/uaccess.c
@@ -4,8 +4,7 @@
  * Licensed under the GPL
  */
 
-#include <setjmp.h>
-#include <string.h>
+#include <stddef.h>
 #include "longjmp.h"
 
 unsigned long __do_user_copy(void *to, const void *from, int n,
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index c47a2a7ce70e..3f5b1514e8a7 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -7,7 +7,6 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <limits.h>
-#include <setjmp.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <sys/utsname.h>
@@ -107,11 +106,11 @@ int setjmp_wrapper(void (*proc)(void *, void *), ...)
         jmp_buf buf;
         int n;
 
-        n = sigsetjmp(buf, 1);
+        n = UML_SETJMP(&buf);
         if(n == 0){
                 va_start(args, proc);
                 (*proc)(&buf, &args);
         }
         va_end(args);
-        return(n);
+        return n;
 }