[Qemu-commits] [qemu/qemu] 2b8371: target/arm: Use correct mmu_idx for exception-retu...

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: 2b83714d4ea659899069a4b94aa2dfadc847a013
      
https://github.com/qemu/qemu/commit/2b83714d4ea659899069a4b94aa2dfadc847a013
  Author: Peter Maydell <address@hidden>
  Date:   2018-07-10 (Tue, 10 Jul 2018)

  Changed paths:
    M target/arm/helper.c

  Log Message:
  -----------
  target/arm: Use correct mmu_idx for exception-return unstacking

For M-profile exception returns, the mmu index to use for exception
return unstacking is supposed to be that of wherever we are returning to:
 * if returning to handler mode, privileged
 * if returning to thread mode, privileged or unprivileged depending on
   CONTROL.nPRIV for the destination security state

We were passing the wrong thing as the 'priv' argument to
arm_v7m_mmu_idx_for_secstate_and_priv(). The effect was that guests
which programmed the MPU to behave differently for privileged and
unprivileged code could get spurious MemManage Unstack exceptions.

Reported-by: Adithya Baglody <address@hidden>
Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
Message-id: address@hidden



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