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authorAl Viro <viro@zeniv.linux.org.uk>2012-12-14 14:47:53 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2012-12-19 18:07:41 -0500
commit9026843952adac5b123c7b8dc961e5c15828d9e1 (patch)
tree4ef89cf05cf97427ceb2587fed94a6a12833d527 /kernel
parent6bf9adfc90370b695cb111116e15fdc0e1906270 (diff)
downloadlinaro-lsk-9026843952adac5b123c7b8dc961e5c15828d9e1.tar.gz
generic compat_sys_sigaltstack()
Again, conditional on CONFIG_GENERIC_SIGALTSTACK Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/signal.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index f05f4c4150d..aee85bd76b8 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
/**