diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index f05f4c4150d9..aee85bd76b8a 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -31,6 +31,7 @@ #include <linux/nsproxy.h> #include <linux/user_namespace.h> #include <linux/uprobes.h> +#include <linux/compat.h> #define CREATE_TRACE_POINTS #include <trace/events/signal.h> @@ -3116,6 +3117,50 @@ int restore_altstack(const stack_t __user *uss) return err == -EFAULT ? err : 0; } +#ifdef CONFIG_COMPAT +#ifdef CONFIG_GENERIC_SIGALTSTACK +asmlinkage long compat_sys_sigaltstack(const compat_stack_t __user *uss_ptr, + compat_stack_t __user *uoss_ptr) +{ + stack_t uss, uoss; + int ret; + mm_segment_t seg; + + if (uss_ptr) { + compat_stack_t uss32; + + memset(&uss, 0, sizeof(stack_t)); + if (copy_from_user(&uss32, uss_ptr, sizeof(compat_stack_t))) + return -EFAULT; + uss.ss_sp = compat_ptr(uss32.ss_sp); + uss.ss_flags = uss32.ss_flags; + uss.ss_size = uss32.ss_size; + } + seg = get_fs(); + set_fs(KERNEL_DS); + ret = do_sigaltstack((stack_t __force __user *) (uss_ptr ? &uss : NULL), + (stack_t __force __user *) &uoss, + compat_user_stack_pointer()); + set_fs(seg); + if (ret >= 0 && uoss_ptr) { + if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(compat_stack_t)) || + __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) || + __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) || + __put_user(uoss.ss_size, &uoss_ptr->ss_size)) + ret = -EFAULT; + } + return ret; +} + +int compat_restore_altstack(const compat_stack_t __user *uss) +{ + int err = compat_sys_sigaltstack(uss, NULL); + /* squash all but -EFAULT for now */ + return err == -EFAULT ? err : 0; +} +#endif +#endif + #ifdef __ARCH_WANT_SYS_SIGPENDING /** |