Commit 5a4f5da5 authored Feb 21, 2012 by Will Deacon Committed by Russell King Mar 30, 2012

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>

parent fa0d1dbf

arch/arm/kernel/ptrace.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -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);
		}

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