ARC: sigaction: fold default sigrestorer into "C"

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

diff --git a/libc/sysdeps/linux/arc/Makefile.arch b/libc/sysdeps/linux/arc/Makefile.arch
index 656ea35..1a52fc9 100644 (file)
--- a/libc/sysdeps/linux/arc/Makefile.arch
+++ b/libc/sysdeps/linux/arc/Makefile.arch
@@ -7,5 +7,4 @@
 
 CSRC-y := syscall.c sigaction.c __syscall_error.c cacheflush.c
 
-SSRC-y := sigrestorer.S __longjmp.S setjmp.S bsd-setjmp.S bsd-_setjmp.S \
-       vfork.S clone.S
+SSRC-y := __longjmp.S setjmp.S bsd-setjmp.S bsd-_setjmp.S vfork.S clone.S

diff --git a/libc/sysdeps/linux/arc/sigaction.c b/libc/sysdeps/linux/arc/sigaction.c
index a34c7cf..96c9983 100644 (file)
--- a/libc/sysdeps/linux/arc/sigaction.c
+++ b/libc/sysdeps/linux/arc/sigaction.c
@@ -10,8 +10,13 @@
 #include <sys/syscall.h>
 #include <bits/kernel_sigaction.h>
 
-extern void __default_rt_sa_restorer(void);
-//libc_hidden_proto(__default_rt_sa_restorer);
+/*
+ * Default sigretrun stub if user doesn't specify SA_RESTORER
+ */
+static void __default_rt_sa_restorer(void)
+{
+       INTERNAL_SYSCALL_NCS(__NR_rt_sigreturn, , 0);
+}
 
 #define SA_RESTORER    0x04000000
 
@@ -25,11 +30,6 @@ __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
        /*
         * SA_RESTORER is only relevant for act != NULL case
         * (!act means caller only wants to know @oact)
-        *
-        * For the normal/default cases (user not providing SA_RESTORER) use
-        * a real sigreturn stub to avoid kernel synthesizing one on user stack
-        * at runtime, which needs PTE permissions update (hence TLB entry
-        * update) and costly cache line flushes for code modification
         */
        if (act && !(act->sa_flags & SA_RESTORER)) {
                kact.sa_restorer = __default_rt_sa_restorer;

diff --git a/libc/sysdeps/linux/arc/sigrestorer.S b/libc/sysdeps/linux/arc/sigrestorer.S
deleted file mode 100644 (file)
index 24531d8..0000000
--- a/libc/sysdeps/linux/arc/sigrestorer.S
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
- *
- * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
- */
-
-#include <sysdep.h>
-#include <sys/syscall.h>
-
-/*
- * Provide a real sigreturn stub to avoid kernel synthesizing one
- * on user stack at runtime, which needs PTE permissions update
- * (hence TLB entry update) and costly cache line flushes for
- * code modification
- */
-
-ENTRY(__default_rt_sa_restorer)
-    mov r8, __NR_rt_sigreturn
-    ARC_TRAP_INSN
-END(__default_rt_sa_restorer)
-libc_hidden_def(__default_rt_sa_restorer)