arm: fix singal restart when Old EABI enabled
 

Signed-off-by: Saeed Bishara <saeed@marvell.com>
---
arch/arm/kernel/signal.c | 41 +++++++++++++++++------------------------
arch/arm/kernel/signal.h | 4 +++-
arch/arm/kernel/traps.c | 4 +++-
3 files changed, 23 insertions(+), 26 deletions(-)
mode change 100644 => 100755 arch/arm/kernel/signal.c

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
old mode 100644
new mode 100755
index f6bc5d4..b09af17
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -1,7 +1,7 @@
/*
* linux/arch/arm/kernel/signal.c
*
- * Copyright (C) 1995-2002 Russell King
+ * Copyright (C) 1995-2009 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
@@ -28,6 +28,7 @@
*/
#define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BA SE))
#define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL _BASE))
+#define SWI_SYS_RESTART (0xef000000|__NR_restart_syscall|__NR_OABI_SYSCALL _BASE)

/*
* With EABI, the syscall number has to be loaded into r7.
@@ -50,6 +51,18 @@ const unsigned long sigreturn_codes[7] = {
static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);

/*
+ * Either we support OABI only, or we have EABI with the OABI
+ * compat layer enabled. In the later case we don't know if
+ * user space is EABI or not, and if not we must not clobber r7.
+ * Always using the OABI syscall solves that issue and works for
+ * all those cases.
+ */
+const unsigned long syscall_restart_code[2] = {
+ SWI_SYS_RESTART, /* swi __NR_restart_syscall */
+ 0xe49df004, /* ldr pc, [sp], #4 */
+};
+
+/*
* atomically swap in the new signal mask, and wait for a signal.
*/
asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask,
old_sigset_t mask, struct pt_regs *regs)
@@ -663,32 +676,12 @@ static int do_signal(sigset_t *oldset, struct
pt_regs *regs, int syscall)
regs->ARM_pc -= 4;
#else
u32 __user *usp;
- u32 swival = __NR_restart_syscall;

- regs->ARM_sp -= 12;
+ regs->ARM_sp -= 4;
usp = (u32 __user *)regs->ARM_sp;

- /*
- * Either we supports OABI only, or we have
- * EABI with the OABI compat layer enabled.
- * In the later case we don't know if user
- * space is EABI or not, and if not we must
- * not clobber r7. Always using the OABI
- * syscall solves that issue and works for
- * all those cases.
- */
- swival = swival - __NR_SYSCALL_BASE + __NR_OABI_SYSCALL_BASE;
-
- put_user(regs->ARM_pc, &usp[0]);
- /* swi __NR_restart_syscall */
- put_user(0xef000000 | swival, &usp[1]);
- /* ldr pc, [sp], #12 */
- put_user(0xe49df00c, &usp[2]);
-
- flush_icache_range((unsigned long)usp,
- (unsigned long)(usp + 3));
-
- regs->ARM_pc = regs->ARM_sp + 4;
+ put_user(regs->ARM_pc, usp);
+ regs->ARM_pc = KERN_RESTART_CODE;
#endif
}
}
diff --git a/arch/arm/kernel/signal.h b/arch/arm/kernel/signal.h
index 27beece..6fcfe83 100644
--- a/arch/arm/kernel/signal.h
+++ b/arch/arm/kernel/signal.h
@@ -1,12 +1,14 @@
/*
* linux/arch/arm/kernel/signal.h
*
- * Copyright (C) 2005 Russell King.
+ * Copyright (C) 2005-2009 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 (CONFIG_VECTORS_BASE + 0x00000500)
+#define KERN_RESTART_CODE (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes))

extern const unsigned long sigreturn_codes[7];
+extern const unsigned long syscall_restart_code[2];
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 57eb0f6..9cc19c9 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -1,7 +1,7 @@
/*
* linux/arch/arm/kernel/traps.c
*
- * Copyright (C) 1995-2002 Russell King
+ * Copyright (C) 1995-2009 Russell King
* Fragments that appear the same as linux/arch/i386/kernel/traps.c
(C) Linus Torvalds
*
* This program is free software; you can redistribute it and/or modify
@@ -742,6 +742,8 @@ void __init early_trap_init(void)
*/
memcpy((void *)KERN_SIGRETURN_CODE, sigreturn_codes,
sizeof(sigreturn_codes));
+ memcpy((void *)KERN_RESTART_CODE, syscall_restart_code,
+ sizeof(syscall_restart_code));

flush_icache_range(vectors, vectors + PAGE_SIZE);
modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
--
1.6.3.3

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