Messages in this thread | | | Subject | Re: ARM64: kernel panics in DABT in sys_msync path | From | Richard Ruigrok <> | Date | Wed, 27 Sep 2017 12:00:06 -0600 |
| |
On 9/27/2017 9:50 AM, Will Deacon wrote: > On Tue, Sep 26, 2017 at 06:31:12PM +0100, Will Deacon wrote: >> On Tue, Sep 26, 2017 at 08:23:35AM -0600, Ruigrok, Richard wrote: >>> On 9/26/2017 4:23 AM, Will Deacon wrote: >>>> On Mon, Sep 25, 2017 at 01:54:57PM -0600, Ruigrok, Richard wrote: >>>>> I also found this issue with kernels from 4.11 through 4.13. In my tests, I >>>>> found that it reproduces only with 4K page and Transparent Huge Pages. With 64K >>>>> page I was not able to reproduce. RH also reported it here: https:// >>>>> bugzilla.redhat.com/show_bug.cgi?id=1491504 Linaro reported on the RPK kernel >>>>> (4.12) on Centriq2400 and ThunderX >>>>> >>>>> >>>>> https://bugs.linaro.org/show_bug.cgi?id=3191 >>>>> >>>>> https://bugs.linaro.org/show_bug.cgi?id=3068. >>>> These two aren't the same bug (that's a forward progress issue that we're >>>> currently working on). I don't have permission to look at the redhat one, >>>> but is it just an RCU stall or actually the Oops reported by Yury? >>>> >>>>> I was able to bisect down to a specific commit. >>>> I think we're chasing two different things here, so not sure I trust the >>>> bisect! >>>> >>> The RCU stall is side effect. The issue I'm seeing has the same stack >>> trace and same stimulus (rwtest). Following are the details. >> FWIW, I think I've worked out what's going on here and I should have a patch >> tomorrow. > Diff below. I'm going to follow up with a separate thread about this, > because the proper fix is going to be invasive. I'll keep you on cc. > > Out of curiosity: what version of GCC are you using to compile the kernel? I'm using gcc-linaro-6.3.1-2017.02-x86_64_aarch64-linux-gnu Thanks for the patch, test results to follow. Richard > > Will > > --->8 > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index bc4e92337d16..b46e54c2399b 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -401,7 +401,7 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd) > /* Find an entry in the third-level page table. */ > #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) > > -#define pte_offset_phys(dir,addr) (pmd_page_paddr(*(dir)) + pte_index(addr) * sizeof(pte_t)) > +#define pte_offset_phys(dir,addr) (pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t)) > #define pte_offset_kernel(dir,addr) ((pte_t *)__va(pte_offset_phys((dir), (addr)))) > > #define pte_offset_map(dir,addr) pte_offset_kernel((dir), (addr))
-- Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
| |