From ac87ca0ea0102ec5dfd17c95eb9fa87a8bf54d61 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 26 Aug 2022 10:18:14 -0700 Subject: mm/memory-failure: fall back to vma_address() when ->notify_failure() fails In the case where a filesystem is polled to take over the memory failure and receives -EOPNOTSUPP it indicates that page->index and page->mapping are valid for reverse mapping the failure address. Introduce FSDAX_INVALID_PGOFF to distinguish when add_to_kill() is being called from mf_dax_kill_procs() by a filesytem vs the typical memory_failure() path. Otherwise, vma_pgoff_address() is called with an invalid fsdax_pgoff which then trips this failing signature: kernel BUG at mm/memory-failure.c:319! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 13 PID: 1262 Comm: dax-pmd Tainted: G OE N 6.0.0-rc2+ #62 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:add_to_kill.cold+0x19d/0x209 [..] Call Trace: collect_procs.part.0+0x2c4/0x460 memory_failure+0x71b/0xba0 ? _printk+0x58/0x73 do_madvise.part.0.cold+0xaf/0xc5 Link: https://lkml.kernel.org/r/166153429427.2758201.14605968329933175594.stgit@dwillia2-xfh.jf.intel.com Fixes: c36e20249571 ("mm: introduce mf_dax_kill_procs() for fsdax case") Signed-off-by: Dan Williams Acked-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Reviewed-by: Christoph Hellwig Cc: Shiyang Ruan Cc: Darrick J. Wong Cc: Al Viro Cc: Dave Chinner Cc: Goldwyn Rodrigues Cc: Jane Chu Cc: Matthew Wilcox Cc: Ritesh Harjani Signed-off-by: Andrew Morton --- mm/memory-failure.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) (limited to 'mm/memory-failure.c') diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 8a4294afbfa0..e424a9dac749 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -345,13 +345,17 @@ static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma, * not much we can do. We just print a message and ignore otherwise. */ +#define FSDAX_INVALID_PGOFF ULONG_MAX + /* * Schedule a process for later kill. * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM. * - * Notice: @fsdax_pgoff is used only when @p is a fsdax page. - * In other cases, such as anonymous and file-backend page, the address to be - * killed can be caculated by @p itself. + * Note: @fsdax_pgoff is used only when @p is a fsdax page and a + * filesystem with a memory failure handler has claimed the + * memory_failure event. In all other cases, page->index and + * page->mapping are sufficient for mapping the page back to its + * corresponding user virtual address. */ static void add_to_kill(struct task_struct *tsk, struct page *p, pgoff_t fsdax_pgoff, struct vm_area_struct *vma, @@ -367,11 +371,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, tk->addr = page_address_in_vma(p, vma); if (is_zone_device_page(p)) { - /* - * Since page->mapping is not used for fsdax, we need - * calculate the address based on the vma. - */ - if (p->pgmap->type == MEMORY_DEVICE_FS_DAX) + if (fsdax_pgoff != FSDAX_INVALID_PGOFF) tk->addr = vma_pgoff_address(fsdax_pgoff, 1, vma); tk->size_shift = dev_pagemap_mapping_shift(vma, tk->addr); } else @@ -523,7 +523,8 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, if (!page_mapped_in_vma(page, vma)) continue; if (vma->vm_mm == t->mm) - add_to_kill(t, page, 0, vma, to_kill); + add_to_kill(t, page, FSDAX_INVALID_PGOFF, vma, + to_kill); } } read_unlock(&tasklist_lock); @@ -559,7 +560,8 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, * to be informed of all such data corruptions. */ if (vma->vm_mm == t->mm) - add_to_kill(t, page, 0, vma, to_kill); + add_to_kill(t, page, FSDAX_INVALID_PGOFF, vma, + to_kill); } } read_unlock(&tasklist_lock); -- cgit v1.2.3