Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

Pull signal handling cleanups from Al Viro:
 "sigaltstack infrastructure + conversion for x86, alpha and um,
  COMPAT_SYSCALL_DEFINE infrastructure.

  Note that there are several conflicts between "unify
  SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline;
  resolution is trivial - just remove definitions of SS_ONSTACK and
  SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and
  include/uapi/linux/signal.h contains the unified variant."

Fixed up conflicts as per Al.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  alpha: switch to generic sigaltstack
  new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those
  generic compat_sys_sigaltstack()
  introduce generic sys_sigaltstack(), switch x86 and um to it
  new helper: compat_user_stack_pointer()
  new helper: restore_altstack()
  unify SS_ONSTACK/SS_DISABLE definitions
  new helper: current_user_stack_pointer()
  missing user_stack_pointer() instances
  Bury the conditionals from kernel_thread/kernel_execve series
  COMPAT_SYSCALL_DEFINE: infrastructure

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 03ca442d8f0d..942a08623a1a 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -133,6 +133,13 @@ static inline bool user_64bit_mode(struct pt_regs *regs)
         return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
 #endif
 }
+
+#define current_user_stack_pointer()    this_cpu_read(old_rsp)
+/* ia32 vs. x32 difference */
+#define compat_user_stack_pointer()     \
+        (test_thread_flag(TIF_IA32)     \
+         ? current_pt_regs()->sp        \
+         : this_cpu_read(old_rsp))
 #endif
 
 #ifdef CONFIG_X86_32