diff options
| -rw-r--r-- | arch/um/kernel/skas/clone.c | 3 | ||||
| -rw-r--r-- | arch/x86/um/shared/sysdep/stub_32.h | 12 | ||||
| -rw-r--r-- | arch/x86/um/shared/sysdep/stub_64.h | 12 | ||||
| -rw-r--r-- | arch/x86/um/stub_segv.c | 3 |
4 files changed, 26 insertions, 4 deletions
diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c index 5afac0fef24e..ff5061f29167 100644 --- a/arch/um/kernel/skas/clone.c +++ b/arch/um/kernel/skas/clone.c @@ -24,8 +24,7 @@ void __attribute__ ((__section__ (".__syscall_stub"))) stub_clone_handler(void) { - int stack; - struct stub_data *data = (void *) ((unsigned long)&stack & ~(UM_KERN_PAGE_SIZE - 1)); + struct stub_data *data = get_stub_page(); long err; err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD, diff --git a/arch/x86/um/shared/sysdep/stub_32.h b/arch/x86/um/shared/sysdep/stub_32.h index b95db9daf0e8..4c6c2be0c899 100644 --- a/arch/x86/um/shared/sysdep/stub_32.h +++ b/arch/x86/um/shared/sysdep/stub_32.h @@ -101,4 +101,16 @@ static inline void remap_stack_and_trap(void) "memory"); } +static __always_inline void *get_stub_page(void) +{ + unsigned long ret; + + asm volatile ( + "movl %%esp,%0 ;" + "andl %1,%0" + : "=a" (ret) + : "g" (~(UM_KERN_PAGE_SIZE - 1))); + + return (void *)ret; +} #endif diff --git a/arch/x86/um/shared/sysdep/stub_64.h b/arch/x86/um/shared/sysdep/stub_64.h index 6e2626b77a2e..e9c4b2b38803 100644 --- a/arch/x86/um/shared/sysdep/stub_64.h +++ b/arch/x86/um/shared/sysdep/stub_64.h @@ -108,4 +108,16 @@ static inline void remap_stack_and_trap(void) __syscall_clobber, "r10", "r8", "r9"); } +static __always_inline void *get_stub_page(void) +{ + unsigned long ret; + + asm volatile ( + "movq %%rsp,%0 ;" + "andq %1,%0" + : "=a" (ret) + : "g" (~(UM_KERN_PAGE_SIZE - 1))); + + return (void *)ret; +} #endif diff --git a/arch/x86/um/stub_segv.c b/arch/x86/um/stub_segv.c index 21836eaf1725..f7eefba034f9 100644 --- a/arch/x86/um/stub_segv.c +++ b/arch/x86/um/stub_segv.c @@ -11,9 +11,8 @@ void __attribute__ ((__section__ (".__syscall_stub"))) stub_segv_handler(int sig, siginfo_t *info, void *p) { - int stack; + struct faultinfo *f = get_stub_page(); ucontext_t *uc = p; - struct faultinfo *f = (void *)(((unsigned long)&stack) & ~(UM_KERN_PAGE_SIZE - 1)); GET_FAULTINFO_FROM_MC(*f, &uc->uc_mcontext); trap_myself(); |