Commit ad9e202a authored by Dave Martin's avatar Dave Martin Committed by Catalin Marinas

arm64/ptrace: Reject attempts to set incomplete hardware breakpoint fields

We cannot preserve partial fields for hardware breakpoints, because
the values written by userspace to the hardware breakpoint
registers can't subsequently be recovered intact from the hardware.

So, just reject attempts to write incomplete fields with -EINVAL.

Cc: <stable@vger.kernel.org> # 3.7.x-
Fixes: 478fcb2c ("arm64: Debugging support")
Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
Acked-by: default avatarWill Deacon <Will.Deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent aeb1f39d
......@@ -551,6 +551,8 @@ static int hw_break_set(struct task_struct *target,
/* (address, ctrl) registers */
limit = regset->n * regset->size;
while (count && offset < limit) {
if (count < PTRACE_HBP_ADDR_SZ)
return -EINVAL;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
offset, offset + PTRACE_HBP_ADDR_SZ);
if (ret)
......@@ -560,6 +562,8 @@ static int hw_break_set(struct task_struct *target,
return ret;
offset += PTRACE_HBP_ADDR_SZ;
if (!count)
break;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
offset, offset + PTRACE_HBP_CTRL_SZ);
if (ret)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment