diff options
| author | Mans Rullgard <mans@mansr.com> | 2009-03-10 10:25:07 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2009-03-10 10:25:07 +0000 |
| commit | 0c35fb61ef0f8c1602f009c0d934ecf36934c31d (patch) | |
| tree | 862f4d3434c97e194342dae37f1cd7eac1fe41b9 /arch/arm/kernel | |
| parent | d379f9d8cbfa8e70273e40dc7904bf09c18bc85e (diff) | |
Workaround for Cortex-A8 erratum 451034
On Cortex-A8 r1p0 and r1p1, executing a NEON store with an integer
store in the store buffer, can cause a processor deadlock under
certain conditions.
Executing a DMB instruction before saving NEON/VFP registers and before
return to userspace makes it safe to run code which includes similar
counter-measures. Userspace code can still trigger the deadlock, so
a different workaround is required to safely run untrusted code.
See ARM Cortex-A8 Errata Notice (PR120-PRDC-008070) for full details.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index f89b9ca7f010..6c41587f3e1b 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -66,6 +66,10 @@ no_work_pending: /* perform architecture specific actions before user return */ arch_ret_to_user r1, lr +#ifdef CONFIG_ARM_ERRATUM_451034 + dmb +#endif + restore_user_regs fast = 0, offset = 0 ENDPROC(ret_to_user) |