From 5a4f5da543b169d555a19e889850780ddceb8f98 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@arm.com>
Date: Tue, 21 Feb 2012 12:29:03 +0100
Subject: [PATCH] ARM: 7337/1: ptrace: fix ptrace_read_user for !CONFIG_MMU
platforms
Commit 68b7f715 ("nommu: ptrace support") added definitions for
PT_TEXT_ADDR and friends, as well as adding ptrace support for reading
from these magic offsets.
Unfortunately, this has probably never worked, since ptrace_read_user
predicates reading on off < sizeof(struct user), returning -EIO
otherwise.
This patch moves the offset size check until after we have tried to
match it against either a magic value or an offset into pt_regs.
Cc: Paul Brook <paul@codesourcery.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/kernel/ptrace.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 45956c9d0ef0..80abafb9bf33 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -256,7 +256,7 @@ static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
{
unsigned long tmp;
- if (off & 3 || off >= sizeof(struct user))
+ if (off & 3)
return -EIO;
tmp = 0;
@@ -268,6 +268,8 @@ static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
tmp = tsk->mm->end_code;
else if (off < sizeof(struct pt_regs))
tmp = get_user_reg(tsk, off >> 2);
+ else if (off >= sizeof(struct user))
+ return -EIO;
return put_user(tmp, ret);
}