From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Mon, 20 Feb 2012 18:37:09 +0000 Subject: [PATCH] ARM: ptrace: fix ptrace_read_user for !CONFIG_MMU platforms Message-ID: <1329763029-18220-1-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 -EOI 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 Signed-off-by: Will Deacon --- arch/arm/kernel/ptrace.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index e33870f..b68b52b 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); } -- 1.7.4.1