3 files changed, 40 insertions, 10 deletions

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 931919fd5121..07ddeed61766 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -19,6 +19,7 @@
 #include <asm/unistd.h>
 
 #include "ptrace.h"
+#include "signal.h"
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
@@ -35,7 +36,7 @@
 #define SWI_THUMB_SIGRETURN     (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
 #define SWI_THUMB_RT_SIGRETURN  (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
 
-static const unsigned long retcodes[4] = {
+const unsigned long sigreturn_codes[4] = {
         SWI_SYS_SIGRETURN,      SWI_THUMB_SIGRETURN,
         SWI_SYS_RT_SIGRETURN,   SWI_THUMB_RT_SIGRETURN
 };
@@ -500,17 +501,25 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka,
                 if (ka->sa.sa_flags & SA_SIGINFO)
                         idx += 2;
 
-                if (__put_user(retcodes[idx], rc))
+                if (__put_user(sigreturn_codes[idx], rc))
                         return 1;
 
-                /*
-                 * Ensure that the instruction cache sees
-                 * the return code written onto the stack.
-                 */
-                flush_icache_range((unsigned long)rc,
-                                   (unsigned long)(rc + 1));
-
-                retcode = ((unsigned long)rc) + thumb;
+                if (cpsr & MODE32_BIT) {
+                        /*
+                         * 32-bit code can use the new high-page
+                         * signal return code support.
+                         */
+                        retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
+                } else {
+                        /*
+                         * Ensure that the instruction cache sees
+                         * the return code written onto the stack.
+                         */
+                        flush_icache_range((unsigned long)rc,
+                                           (unsigned long)(rc + 1));
+
+                        retcode = ((unsigned long)rc) + thumb;
+                }
         }
 
         regs->ARM_r0 = usig;
diff --git a/arch/arm/kernel/signal.h b/arch/arm/kernel/signal.h
new file mode 100644
index 000000000000..91d26faca62b
--- /dev/null
+++ b/arch/arm/kernel/signal.h
@@ -0,0 +1,12 @@
+/*
+ *  linux/arch/arm/kernel/signal.h
+ *
+ *  Copyright (C) 2005 Russell King.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#define KERN_SIGRETURN_CODE     0xffff0500
+
+extern const unsigned long sigreturn_codes[4];
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 45d2a032d890..2fb0a4cfb37a 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -30,6 +30,7 @@
 #include <asm/traps.h>
 
 #include "ptrace.h"
+#include "signal.h"
 
 const char *processor_modes[]=
 { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
@@ -683,6 +684,14 @@ void __init trap_init(void)
         memcpy((void *)0xffff0000, __vectors_start, __vectors_end - __vectors_start);
         memcpy((void *)0xffff0200, __stubs_start, __stubs_end - __stubs_start);
         memcpy((void *)0xffff1000 - kuser_sz, __kuser_helper_start, kuser_sz);
+
+        /*
+         * Copy signal return handlers into the vector page, and
+         * set sigreturn to be a pointer to these.
+         */
+        memcpy((void *)KERN_SIGRETURN_CODE, sigreturn_codes,
+               sizeof(sigreturn_codes));
+
         flush_icache_range(0xffff0000, 0xffff0000 + PAGE_SIZE);
         modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
 }