Matt Corallo <ker...@bluematt.me> writes: > Hey, sorry for the delay on this. I had some apparently-unrelated > hangs that I believe were due to mpt3sas instability, and at the risk > of speaking too soon for a bug I couldn't reliably reproduce, this > patch appears to have resolved it, thanks!
Thanks. For the archives it went upstream in a slightly different form as: 579b9239c1f3 ("powerpc/radix: Fix kernel crash with mremap()") https://git.kernel.org/torvalds/c/579b9239c1f3 cheers >> On Jan 21, 2019, at 07:35, Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> >> wrote: >> >> >> Can you test this patch? >> >> From e511e79af9a314854848ea8fda9dfa6d7e07c5e4 Mon Sep 17 00:00:00 2001 >> From: "Aneesh Kumar K.V" <aneesh.ku...@linux.ibm.com> >> Date: Mon, 21 Jan 2019 16:43:17 +0530 >> Subject: [PATCH] arch/powerpc/radix: Fix kernel crash with mremap >> >> With support for split pmd lock, we use pmd page pmd_huge_pte pointer to >> store >> the deposited page table. In those config when we move page tables we need to >> make sure we move the depoisted page table to the right pmd page. Otherwise >> this >> can result in crash when we withdraw of deposited page table because we can >> find >> the pmd_huge_pte NULL. >> >> c0000000004a1230 __split_huge_pmd+0x1070/0x1940 >> c0000000004a0ff4 __split_huge_pmd+0xe34/0x1940 (unreliable) >> c0000000004a4000 vma_adjust_trans_huge+0x110/0x1c0 >> c00000000042fe04 __vma_adjust+0x2b4/0x9b0 >> c0000000004316e8 __split_vma+0x1b8/0x280 >> c00000000043192c __do_munmap+0x13c/0x550 >> c000000000439390 sys_mremap+0x220/0x7e0 >> c00000000000b488 system_call+0x5c/0x70 >> >> Fixes: 675d995297d4 ("powerpc/book3s64: Enable split pmd ptlock.") >> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> >> --- >> arch/powerpc/include/asm/book3s/64/pgtable.h | 2 -- >> 1 file changed, 2 deletions(-) >> >> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h >> b/arch/powerpc/include/asm/book3s/64/pgtable.h >> index 92eaea164700..86e62384256d 100644 >> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h >> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h >> @@ -1262,8 +1262,6 @@ static inline int pmd_move_must_withdraw(struct >> spinlock *new_pmd_ptl, >> struct spinlock *old_pmd_ptl, >> struct vm_area_struct *vma) >> { >> - if (radix_enabled()) >> - return false; >> /* >> * Archs like ppc64 use pgtable to store per pmd >> * specific information. So when we switch the pmd, >> -- >> 2.20.1 >>