qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] [Bug 749522] Re: qemu-system-arm reads wrong entry in L1 pa


From: Peter Maydell
Subject: [Qemu-devel] [Bug 749522] Re: qemu-system-arm reads wrong entry in L1 page table for cortex-a8
Date: Thu, 15 Dec 2011 19:12:24 -0000

"(We do seem to not quite be getting the effect of TTBCR.N right,
though: if N > 0 then although we correctly take more bits from TTBR0
(by adjusting c2_base_mask) we aren't masking out the high bits
[31..32-N] of the MVA. But that's a different problem.)"

Looking more closely, I was wrong here. In the case where N>0 and we're
using TTBR0 then we are guaranteed that [31..32-N] of the MVA are zero,
because that is exactly the condition that controls using TTBR0 rather
than TTBR1. So the code as it stands is correct.

"Why do you think this is wrong?"

Since the bug submitter never replied to this, and the code is as far as
I can tell correct both in theory and in practice, I'm going to resolve
this bug as invalid.


** Changed in: qemu
       Status: New => Invalid

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/749522

Title:
  qemu-system-arm reads wrong entry in L1 page table for cortex-a8

Status in QEMU:
  Invalid

Bug description:
  target-arm/helper.c:920
  [current] table |= (address >> 18) & 0x3ffc
  [fix] table |= (address >> 20) & 0xfff

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/749522/+subscriptions



reply via email to

[Prev in Thread] Current Thread [Next in Thread]