sh: Initial vsyscall page support.
This implements initial support for the vsyscall page on SH.
At the moment we leave it configurable due to having nommu
to support from the same code base. We hook it up for the
signal trampoline return at present, with more to be added
later, once uClibc catches up.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/signal.c b/arch/sh/kernel/signal.c
index 2f1c954..5213f5b 100644
--- a/arch/sh/kernel/signal.c
+++ b/arch/sh/kernel/signal.c
@@ -8,7 +8,6 @@
* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
*
*/
-
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
@@ -21,6 +20,7 @@
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/tty.h>
+#include <linux/elf.h>
#include <linux/personality.h>
#include <linux/binfmts.h>
@@ -29,8 +29,6 @@
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
-#undef DEBUG
-
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
/*
@@ -312,6 +310,11 @@
return (void __user *)((sp - frame_size) & -8ul);
}
+/* These symbols are defined with the addresses in the vsyscall page.
+ See vsyscall-trapa.S. */
+extern void __user __kernel_sigreturn;
+extern void __user __kernel_rt_sigreturn;
+
static int setup_frame(int sig, struct k_sigaction *ka,
sigset_t *set, struct pt_regs *regs)
{
@@ -340,6 +343,10 @@
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->pr = (unsigned long) ka->sa.sa_restorer;
+#ifdef CONFIG_VSYSCALL
+ } else if (likely(current->mm->context.vdso)) {
+ regs->pr = VDSO_SYM(&__kernel_sigreturn);
+#endif
} else {
/* Generate return code (system call to sigreturn) */
err |= __put_user(MOVW(7), &frame->retcode[0]);
@@ -416,6 +423,10 @@
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->pr = (unsigned long) ka->sa.sa_restorer;
+#ifdef CONFIG_VSYSCALL
+ } else if (likely(current->mm->context.vdso)) {
+ regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
+#endif
} else {
/* Generate return code (system call to rt_sigreturn) */
err |= __put_user(MOVW(7), &frame->retcode[0]);