introduce generic sys_sigaltstack(), switch x86 and um to it
Conditional on CONFIG_GENERIC_SIGALTSTACK; architectures that do not
select it are completely unaffected
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
index a582bfe..6ffa7f9 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -137,7 +137,7 @@
128 64 rt_sigtimedwait sys_rt_sigtimedwait
129 64 rt_sigqueueinfo sys_rt_sigqueueinfo
130 common rt_sigsuspend sys_rt_sigsuspend
-131 64 sigaltstack stub_sigaltstack
+131 64 sigaltstack sys_sigaltstack
132 common utime sys_utime
133 common mknod sys_mknod
134 64 uselib