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-rw-r--r--arch/um/include/sysdep-i386/stub.h29
-rw-r--r--arch/um/include/sysdep-x86_64/stub.h30
-rw-r--r--arch/um/kernel/skas/clone.c23
3 files changed, 46 insertions, 36 deletions
diff --git a/arch/um/include/sysdep-i386/stub.h b/arch/um/include/sysdep-i386/stub.h
index 6ba8cbbe0d3..b492b12b4a1 100644
--- a/arch/um/include/sysdep-i386/stub.h
+++ b/arch/um/include/sysdep-i386/stub.h
@@ -6,8 +6,12 @@
#ifndef __SYSDEP_STUB_H
#define __SYSDEP_STUB_H
+#include <sys/mman.h>
#include <asm/ptrace.h>
#include <asm/unistd.h>
+#include "stub-data.h"
+#include "kern_constants.h"
+#include "uml-config.h"
extern void stub_segv_handler(int sig);
extern void stub_clone_handler(void);
@@ -76,23 +80,22 @@ static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
return ret;
}
-static inline long stub_syscall6(long syscall, long arg1, long arg2, long arg3,
- long arg4, long arg5, long arg6)
+static inline void trap_myself(void)
{
- long ret;
-
- __asm__ volatile ("push %%ebp ; movl %%eax,%%ebp ; movl %1,%%eax ; "
- "int $0x80 ; pop %%ebp"
- : "=a" (ret)
- : "g" (syscall), "b" (arg1), "c" (arg2), "d" (arg3),
- "S" (arg4), "D" (arg5), "0" (arg6));
-
- return ret;
+ __asm("int3");
}
-static inline void trap_myself(void)
+static inline void remap_stack(int fd, unsigned long offset)
{
- __asm("int3");
+ __asm__ volatile ("movl %%eax,%%ebp ; movl %0,%%eax ; int $0x80 ;"
+ "movl %7, %%ebx ; movl %%eax, (%%ebx)"
+ : : "g" (STUB_MMAP_NR), "b" (UML_CONFIG_STUB_DATA),
+ "c" (UM_KERN_PAGE_SIZE),
+ "d" (PROT_READ | PROT_WRITE),
+ "S" (MAP_FIXED | MAP_SHARED), "D" (fd),
+ "a" (offset),
+ "i" (&((struct stub_data *) UML_CONFIG_STUB_DATA)->err)
+ : "memory");
}
#endif
diff --git a/arch/um/include/sysdep-x86_64/stub.h b/arch/um/include/sysdep-x86_64/stub.h
index c41689c13dc..92e989f8176 100644
--- a/arch/um/include/sysdep-x86_64/stub.h
+++ b/arch/um/include/sysdep-x86_64/stub.h
@@ -6,8 +6,12 @@
#ifndef __SYSDEP_STUB_H
#define __SYSDEP_STUB_H
+#include <sys/mman.h>
#include <asm/unistd.h>
#include <sysdep/ptrace_user.h>
+#include "stub-data.h"
+#include "kern_constants.h"
+#include "uml-config.h"
extern void stub_segv_handler(int sig);
extern void stub_clone_handler(void);
@@ -81,23 +85,23 @@ static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
return ret;
}
-static inline long stub_syscall6(long syscall, long arg1, long arg2, long arg3,
- long arg4, long arg5, long arg6)
+static inline void trap_myself(void)
{
- long ret;
-
- __asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; "
- "movq %7, %%r9; " __syscall : "=a" (ret)
- : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
- "g" (arg4), "g" (arg5), "g" (arg6)
- : __syscall_clobber, "r10", "r8", "r9" );
-
- return ret;
+ __asm("int3");
}
-static inline void trap_myself(void)
+static inline void remap_stack(long fd, unsigned long offset)
{
- __asm("int3");
+ __asm__ volatile ("movq %4,%%r10 ; movq %5,%%r8 ; "
+ "movq %6, %%r9; " __syscall "; movq %7, %%rbx ; "
+ "movq %%rax, (%%rbx)":
+ : "a" (STUB_MMAP_NR), "D" (UML_CONFIG_STUB_DATA),
+ "S" (UM_KERN_PAGE_SIZE),
+ "d" (PROT_READ | PROT_WRITE),
+ "g" (MAP_FIXED | MAP_SHARED), "g" (fd),
+ "g" (offset),
+ "i" (&((struct stub_data *) UML_CONFIG_STUB_DATA)->err)
+ : __syscall_clobber, "r10", "r8", "r9" );
}
#endif
diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c
index cb37ce9124a..47b812b3bca 100644
--- a/arch/um/kernel/skas/clone.c
+++ b/arch/um/kernel/skas/clone.c
@@ -18,11 +18,10 @@
* on some systems.
*/
-#define STUB_DATA(field) (((struct stub_data *) UML_CONFIG_STUB_DATA)->field)
-
void __attribute__ ((__section__ (".__syscall_stub")))
stub_clone_handler(void)
{
+ struct stub_data *data = (struct stub_data *) UML_CONFIG_STUB_DATA;
long err;
err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
@@ -35,17 +34,21 @@ stub_clone_handler(void)
if(err)
goto out;
- err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL,
- (long) &STUB_DATA(timer), 0);
+ err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL,
+ (long) &data->timer, 0);
if(err)
goto out;
- err = stub_syscall6(STUB_MMAP_NR, UML_CONFIG_STUB_DATA,
- UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
- MAP_FIXED | MAP_SHARED, STUB_DATA(fd),
- STUB_DATA(offset));
+ remap_stack(data->fd, data->offset);
+ goto done;
+
out:
- /* save current result. Parent: pid; child: retcode of mmap */
- STUB_DATA(err) = err;
+ /* save current result.
+ * Parent: pid;
+ * child: retcode of mmap already saved and it jumps around this
+ * assignment
+ */
+ data->err = err;
+ done:
trap_myself();
}