Messages in this thread | | | Subject | Re: [PATCH v3 15/18] arm64: arch_timer: Enable CNTVCT_EL0 trap if workaround is enabled | From | Marc Zyngier <> | Date | Mon, 24 Apr 2017 10:33:29 +0100 |
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On 24/04/17 10:14, Hanjun Guo wrote: > On 2017/4/24 16:40, Marc Zyngier wrote: >> On 24/04/17 09:25, Lixiaoping (Timmy) wrote: >>> Hi Marc, >>> >>> Sorry about previous email's confidential info. Please forget it. >>> >>> +#define ESR_ELx_SYS64_ISS_SYS_CNTFRQ (ESR_ELx_SYS64_ISS_SYS_VAL(3, 3, 14, 0, 0) | \ >>> + ESR_ELx_SYS64_ISS_DIR_READ) >>> >>> I think (3, 3, 14, 0, 0) should be (3, 3, 0, 14, 0)? >> Thanks for spotting this. I assumed that the sys_reg() and >> SR_ELx_SYS64_ISS_SYS_VAL() macros took their arguments in the same >> order. That would have been too easy... ;-) >> >> Amended patch below, please let me know if it works for you. >> >> Thanks, >> >> M. >> >> >From 4444c86a97c1a487e12c319fdc197c88631d72b5 Mon Sep 17 00:00:00 2001 >> From: Marc Zyngier <marc.zyngier@arm.com> >> Date: Mon, 24 Apr 2017 09:04:03 +0100 >> Subject: [PATCH] arm64: Add CNTFRQ_EL0 trap handler >> >> We now trap accesses to CNTVCT_EL0 when the counter is broken >> enough to require the kernel to mediate the access. But it >> turns out that some existing userspace (such as OpenMPI) do >> probe for the counter frequency, leading to an UNDEF exception >> as CNTVCT_EL0 and CNTFRQ_EL0 share the same control bit. >> >> The fix is to handle the exception the same way we do for CNTVCT_EL0. >> >> Fixes: a86bd139f2ae ("arm64: arch_timer: Enable CNTVCT_EL0 trap if workaround is enabled") >> Reported-by: Hanjun Guo <guohanjun@huawei.com> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> >> --- > > I tested this patch and the undefined instruction error is gone, I can > get the FREQ in the user space now, thank you very much for the quick > response. > > Tested-by: Hanjun Guo <guohanjun@huawei.com> > Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Thanks for giving it a go. Catalin, can you queue this via the arm64 tree?
Thanks,
M. -- Jazz is not dead. It just smells funny...
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