[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 1b5c0131a12ec7b321983e2bd5b1e23c93828399..e93c6d3e893b05c3ca17a9ce78ad91334f2d55cd 100644 (file)
--- 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 (file)
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 (file)
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 b98d3ca2cd1bdb5dba29e45aa6682c729f3425fc..3afde92ad2c03f5a51a2f5c05c3cf4ae3ee42bc3 100644 (file)
--- 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 7baf90fda58b971115a3becea1aef4e45e427ffd..50418a5e7134521f990afb820e1da2f9f39d0da0 100644 (file)
--- 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 516f66dd87e392ddb30725a1865285e8c48fc72a..1f90a2d713863156bcb8fbe6262fd8fd3c4386f7 100644 (file)
--- 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 becd898d9398b21f28e030e7bcbcaf6c83b0fb2d..e730447d6c026df722ac12ce07c5dcc106ee66ca 100644 (file)
--- 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 90b29ae9af46158ed52154d7e77ce1c4b100f83f..1df231a26244b0ee3e95982e98e3946a60fc51e3 100644 (file)
--- 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 865f6a6a25905924d3f17ab6a449451cd73ebb9c..bbb73a6503706d931dacf6b43bcc23d9e86e3fff 100644 (file)
--- 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 c47a2a7ce70e75614e425e7270b2e1364188b67d..3f5b1514e8a71a33513ccf613643fcb2e33fed5c 100644 (file)
--- 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;
 }

diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index 374d61a194392a11d91565bc6e5902d27bc3affc..59cc70275754afebfb030fc73b48ebc4a5ccde8a 100644 (file)
--- 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 (file)
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 c19794d435d68ddcd948e74fc66164f829ca1137..f41768b8e25eb25978093f8481e294dadbc1c8f4 100644 (file)
--- 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 (file)
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