[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/include/longjmp.h b/arch/um/include/longjmp.h
index 1b5c013..e93c6d3 100644
--- a/arch/um/include/longjmp.h
+++ b/arch/um/include/longjmp.h
@@ -1,9 +1,12 @@
#ifndef __UML_LONGJMP_H
#define __UML_LONGJMP_H
-#include <setjmp.h>
+#include "sysdep/archsetjmp.h"
#include "os.h"
+extern int setjmp(jmp_buf);
+extern void longjmp(jmp_buf, int);
+
#define UML_LONGJMP(buf, val) do { \
longjmp(*buf, val); \
} while(0)
diff --git a/arch/um/include/sysdep-i386/archsetjmp.h b/arch/um/include/sysdep-i386/archsetjmp.h
new file mode 100644
index 0000000..ea1ba3d
--- /dev/null
+++ b/arch/um/include/sysdep-i386/archsetjmp.h
@@ -0,0 +1,19 @@
+/*
+ * arch/i386/include/klibc/archsetjmp.h
+ */
+
+#ifndef _KLIBC_ARCHSETJMP_H
+#define _KLIBC_ARCHSETJMP_H
+
+struct __jmp_buf {
+ unsigned int __ebx;
+ unsigned int __esp;
+ unsigned int __ebp;
+ unsigned int __esi;
+ unsigned int __edi;
+ unsigned int __eip;
+};
+
+typedef struct __jmp_buf jmp_buf[1];
+
+#endif /* _SETJMP_H */
diff --git a/arch/um/include/sysdep-x86_64/archsetjmp.h b/arch/um/include/sysdep-x86_64/archsetjmp.h
new file mode 100644
index 0000000..454fc60
--- /dev/null
+++ b/arch/um/include/sysdep-x86_64/archsetjmp.h
@@ -0,0 +1,21 @@
+/*
+ * arch/x86_64/include/klibc/archsetjmp.h
+ */
+
+#ifndef _KLIBC_ARCHSETJMP_H
+#define _KLIBC_ARCHSETJMP_H
+
+struct __jmp_buf {
+ unsigned long __rbx;
+ unsigned long __rsp;
+ unsigned long __rbp;
+ unsigned long __r12;
+ unsigned long __r13;
+ unsigned long __r14;
+ unsigned long __r15;
+ unsigned long __rip;
+};
+
+typedef struct __jmp_buf jmp_buf[1];
+
+#endif /* _SETJMP_H */
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index b98d3ca..3afde92 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 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)
diff --git a/arch/um/os-Linux/sys-i386/registers.c b/arch/um/os-Linux/sys-i386/registers.c
index 516f66d..1f90a2d 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_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 becd898..e730447 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_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 90b29ae..1df231a 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 865f6a6..bbb73a6 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 c47a2a7..3f5b151 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 @@
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;
}
diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index 374d61a..59cc702 100644
--- a/arch/um/sys-i386/Makefile
+++ b/arch/um/sys-i386/Makefile
@@ -1,5 +1,5 @@
obj-y = bugs.o checksum.o delay.o fault.o ksyms.o ldt.o ptrace.o \
- ptrace_user.o signal.o sigcontext.o syscalls.o sysrq.o \
+ ptrace_user.o setjmp.o signal.o sigcontext.o syscalls.o sysrq.o \
sys_call_table.o tls.o
obj-$(CONFIG_MODE_SKAS) += stub.o stub_segv.o
diff --git a/arch/um/sys-i386/setjmp.S b/arch/um/sys-i386/setjmp.S
new file mode 100644
index 0000000..b766792
--- /dev/null
+++ b/arch/um/sys-i386/setjmp.S
@@ -0,0 +1,58 @@
+#
+# arch/i386/setjmp.S
+#
+# setjmp/longjmp for the i386 architecture
+#
+
+#
+# The jmp_buf is assumed to contain the following, in order:
+# %ebx
+# %esp
+# %ebp
+# %esi
+# %edi
+# <return address>
+#
+
+ .text
+ .align 4
+ .globl setjmp
+ .type setjmp, @function
+setjmp:
+#ifdef _REGPARM
+ movl %eax,%edx
+#else
+ movl 4(%esp),%edx
+#endif
+ popl %ecx # Return address, and adjust the stack
+ xorl %eax,%eax # Return value
+ movl %ebx,(%edx)
+ movl %esp,4(%edx) # Post-return %esp!
+ pushl %ecx # Make the call/return stack happy
+ movl %ebp,8(%edx)
+ movl %esi,12(%edx)
+ movl %edi,16(%edx)
+ movl %ecx,20(%edx) # Return address
+ ret
+
+ .size setjmp,.-setjmp
+
+ .text
+ .align 4
+ .globl longjmp
+ .type longjmp, @function
+longjmp:
+#ifdef _REGPARM
+ xchgl %eax,%edx
+#else
+ movl 4(%esp),%edx # jmp_ptr address
+ movl 8(%esp),%eax # Return value
+#endif
+ movl (%edx),%ebx
+ movl 4(%edx),%esp
+ movl 8(%edx),%ebp
+ movl 12(%edx),%esi
+ movl 16(%edx),%edi
+ jmp *20(%edx)
+
+ .size longjmp,.-longjmp
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index c19794d..f41768b 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -5,8 +5,8 @@
#
obj-y = bugs.o delay.o fault.o ldt.o mem.o ptrace.o ptrace_user.o \
- sigcontext.o signal.o syscalls.o syscall_table.o sysrq.o ksyms.o \
- tls.o
+ setjmp.o sigcontext.o signal.o syscalls.o syscall_table.o sysrq.o \
+ ksyms.o tls.o
obj-$(CONFIG_MODE_SKAS) += stub.o stub_segv.o
obj-$(CONFIG_MODULES) += um_module.o
diff --git a/arch/um/sys-x86_64/setjmp.S b/arch/um/sys-x86_64/setjmp.S
new file mode 100644
index 0000000..45f547b
--- /dev/null
+++ b/arch/um/sys-x86_64/setjmp.S
@@ -0,0 +1,54 @@
+#
+# arch/x86_64/setjmp.S
+#
+# setjmp/longjmp for the x86-64 architecture
+#
+
+#
+# The jmp_buf is assumed to contain the following, in order:
+# %rbx
+# %rsp (post-return)
+# %rbp
+# %r12
+# %r13
+# %r14
+# %r15
+# <return address>
+#
+
+ .text
+ .align 4
+ .globl setjmp
+ .type setjmp, @function
+setjmp:
+ pop %rsi # Return address, and adjust the stack
+ xorl %eax,%eax # Return value
+ movq %rbx,(%rdi)
+ movq %rsp,8(%rdi) # Post-return %rsp!
+ push %rsi # Make the call/return stack happy
+ movq %rbp,16(%rdi)
+ movq %r12,24(%rdi)
+ movq %r13,32(%rdi)
+ movq %r14,40(%rdi)
+ movq %r15,48(%rdi)
+ movq %rsi,56(%rdi) # Return address
+ ret
+
+ .size setjmp,.-setjmp
+
+ .text
+ .align 4
+ .globl longjmp
+ .type longjmp, @function
+longjmp:
+ movl %esi,%eax # Return value (int)
+ movq (%rdi),%rbx
+ movq 8(%rdi),%rsp
+ movq 16(%rdi),%rbp
+ movq 24(%rdi),%r12
+ movq 32(%rdi),%r13
+ movq 40(%rdi),%r14
+ movq 48(%rdi),%r15
+ jmp *56(%rdi)
+
+ .size longjmp,.-longjmp
