diff options
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/include/sysdep-i386/stub.h | 29 | ||||
| -rw-r--r-- | arch/um/include/sysdep-x86_64/stub.h | 30 | ||||
| -rw-r--r-- | arch/um/kernel/skas/clone.c | 23 |
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 6ba8cbbe0d36..b492b12b4a10 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 c41689c13dc9..92e989f81761 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 cb37ce9124a6..47b812b3bca8 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(); } |