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From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com,
	anshuman.khandual@arm.com, linux-mm@kvack.org,
	mm-commits@vger.kernel.org, torvalds@linux-foundation.org
Subject: [patch 08/25] mm/debug_vm_pgtable: fix kernel crash by checking for THP support
Date: Wed, 10 Jun 2020 18:41:44 -0700	[thread overview]
Message-ID: <20200611014144.9RP28D-oF%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200610184053.3fa7368ab80e23bfd44de71f@linux-foundation.org>

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Subject: mm/debug_vm_pgtable: fix kernel crash by checking for THP support

Architectures can have CONFIG_TRANSPARENT_HUGEPAGE enabled but no THP
support enabled based on platforms.  For ex: with 4K PAGE_SIZE ppc64
supports THP only with radix translation.

This results in below crash when running with hash translation and 4K
PAGE_SIZE.

kernel BUG at arch/powerpc/include/asm/book3s/64/hash-4k.h:140!
cpu 0x61: Vector: 700 (Program Check) at [c000000ff948f860]
    pc: c0000000018810f8: debug_vm_pgtable+0x480/0x8b0
    lr: c0000000018810ec: debug_vm_pgtable+0x474/0x8b0
...
[c000000ff948faf0] c000000001880fec debug_vm_pgtable+0x374/0x8b0 (unreliable)
[c000000ff948fbf0] c000000000011648 do_one_initcall+0x98/0x4f0
[c000000ff948fcd0] c000000001843928 kernel_init_freeable+0x330/0x3fc
[c000000ff948fdb0] c0000000000122ac kernel_init+0x24/0x148
[c000000ff948fe20] c00000000000cc44 ret_from_kernel_thread+0x5c/0x78

Check for THP support correctly

Link: http://lkml.kernel.org/r/20200608125252.407659-1-aneesh.kumar@linux.ibm.com
Fixes: 399145f9eb6c ("mm/debug: add tests validating architecture page table helpers")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/debug_vm_pgtable.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-fix-kernel-crash-by-checking-for-thp-support
+++ a/mm/debug_vm_pgtable.c
@@ -60,6 +60,9 @@ static void __init pmd_basic_tests(unsig
 {
 	pmd_t pmd = pfn_pmd(pfn, prot);
 
+	if (!has_transparent_hugepage())
+		return;
+
 	WARN_ON(!pmd_same(pmd, pmd));
 	WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
 	WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
@@ -79,6 +82,9 @@ static void __init pud_basic_tests(unsig
 {
 	pud_t pud = pfn_pud(pfn, prot);
 
+	if (!has_transparent_hugepage())
+		return;
+
 	WARN_ON(!pud_same(pud, pud));
 	WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
 	WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
_

  parent reply	other threads:[~2020-06-11  1:41 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-11  1:40 incoming Andrew Morton
2020-06-11  1:41 ` [patch 01/25] khugepaged: selftests: fix timeout condition in wait_for_scan() Andrew Morton
2020-06-11  1:41 ` [patch 02/25] scripts/spelling: add a few more typos Andrew Morton
2020-06-11  1:41 ` [patch 03/25] kcov: check kcov_softirq in kcov_remote_stop() Andrew Morton
2020-06-11  1:41   ` Andrew Morton
2020-06-11  1:41 ` [patch 04/25] lib/lz4/lz4_decompress.c: document deliberate use of `&' Andrew Morton
2020-06-11  1:41 ` [patch 05/25] nilfs2: fix null pointer dereference at nilfs_segctor_do_construct() Andrew Morton
2020-06-11  1:41 ` Andrew Morton
2020-06-11  1:41 ` [patch 06/25] checkpatch: correct check for kernel parameters doc Andrew Morton
2020-06-11  1:41 ` [patch 07/25] lib: fix bitmap_parse() on 64-bit big endian archs Andrew Morton
2020-06-11  1:41 ` Andrew Morton [this message]
2020-06-11  1:41 ` [patch 09/25] ocfs2: fix spelling mistake and grammar Andrew Morton
2020-06-11  1:41 ` [patch 10/25] mm: add comments on pglist_data zones Andrew Morton
2020-06-11  1:41 ` [patch 11/25] lib: test get_count_order/long in test_bitops.c Andrew Morton
2020-06-11  1:41 ` [patch 12/25] stacktrace: cleanup inconsistent variable type Andrew Morton
2020-06-11  1:41 ` [patch 13/25] kernel: move use_mm/unuse_mm to kthread.c Andrew Morton
2020-06-11  1:41   ` Andrew Morton
2020-06-11  1:42 ` [patch 14/25] " Andrew Morton
2020-06-11  1:42 ` [patch 15/25] kernel: better document the use_mm/unuse_mm API contract Andrew Morton
2020-06-11  1:42 ` [patch 16/25] kernel: set USER_DS in kthread_use_mm Andrew Morton
2020-06-11  1:42 ` [patch 17/25] mm/madvise: pass task and mm to do_madvise Andrew Morton
2020-06-11  1:42 ` [patch 18/25] mm/madvise: introduce process_madvise() syscall: an external memory hinting API Andrew Morton
2020-06-11  1:42 ` [patch 19/25] mm/madvise: check fatal signal pending of target process Andrew Morton
2020-06-11  1:42 ` [patch 20/25] pid: move pidfd_get_pid() to pid.c Andrew Morton
2020-06-11  1:42 ` [patch 21/25] mm/madvise: support both pid and pidfd for process_madvise Andrew Morton
2020-06-11  1:42 ` [patch 22/25] mm/madvise: allow KSM hints for remote API Andrew Morton
2020-06-11  1:42 ` [patch 23/25] mm: support vector address ranges for process_madvise Andrew Morton
2020-06-11  1:42 ` [patch 24/25] mm: use only pidfd for process_madvise syscall Andrew Morton
2020-06-11  2:09   ` Linus Torvalds
2020-06-11  3:10     ` Minchan Kim
2020-06-11  1:42 ` [patch 25/25] mm/madvise.c: remove duplicated include Andrew Morton
2020-06-11  5:25 ` [to-be-updated] mm-pass-task-and-mm-to-do_madvise.patch removed from -mm tree Andrew Morton
2020-06-11  5:26 ` [to-be-updated] mm-introduce-external-memory-hinting-api.patch " Andrew Morton
2020-06-11  5:26 ` [to-be-updated] mm-check-fatal-signal-pending-of-target-process.patch " Andrew Morton
2020-06-11  5:26 ` [to-be-updated] pid-move-pidfd_get_pid-function-to-pidc.patch " Andrew Morton
2020-06-11  5:26 ` [to-be-updated] mm-support-both-pid-and-pidfd-for-process_madvise.patch " Andrew Morton
2020-06-11  5:26 ` [to-be-updated] mm-madvise-allow-ksm-hints-for-remote-api.patch " Andrew Morton
2020-06-11  5:26 ` [to-be-updated] mm-support-vector-address-ranges-for-process_madvise.patch " Andrew Morton
2020-06-11  5:26 ` [to-be-updated] mm-use-only-pidfd-for-process_madvise-syscall.patch " Andrew Morton

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