From 4f775086a6eee07c6ae4be4734d736e13b537351 Mon Sep 17 00:00:00 2001 From: Longlong Xia Date: Fri, 14 Apr 2023 10:17:40 +0800 Subject: [PATCH] mm: memory-failure: refactor add_to_kill() Patch series "mm: ksm: support hwpoison for ksm page", v2. Currently, ksm does not support hwpoison. As ksm is being used more widely for deduplication at the system level, container level, and process level, supporting hwpoison for ksm has become increasingly important. However, ksm pages were not processed by hwpoison in 2009 [1]. The main method of implementation: 1. Refactor add_to_kill() and add new add_to_kill_*() to better accommodate the handling of different types of pages. 2. Add collect_procs_ksm() to collect processes when the error hit an ksm page. 3. Add task_in_to_kill_list() to avoid duplicate addition of tsk to the to_kill list. 4. Try_to_unmap ksm page (already supported). 5. Handle related processes such as sending SIGBUS. Tested with poisoning to ksm page from 1) different process 2) one process and with/without memory_failure_early_kill set, the processes are killed as expected with the patchset. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ commit/?h=01e00f880ca700376e1845cf7a2524ebe68e47d6 This patch (of 2): The page_address_in_vma() is used to find the user virtual address of page in add_to_kill(), but it doesn't support ksm due to the ksm page->index unusable, add an ksm_addr as parameter to add_to_kill(), let's the caller to pass it, also rename the function to __add_to_kill(), and adding add_to_kill_anon_file() for handling anonymous pages and file pages, adding add_to_kill_fsdax() for handling fsdax pages. Link: https://lkml.kernel.org/r/20230414021741.2597273-1-xialonglong1@huawei.com Link: https://lkml.kernel.org/r/20230414021741.2597273-2-xialonglong1@huawei.com Signed-off-by: Longlong Xia Tested-by: Naoya Horiguchi Reviewed-by: Kefeng Wang Cc: Kefeng Wang Cc: Miaohe Lin Cc: Nanyong Sun Signed-off-by: Andrew Morton --- mm/memory-failure.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index f761704d27d7..bb09999108ef 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -405,9 +405,9 @@ static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma, * 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, - struct list_head *to_kill) +static void __add_to_kill(struct task_struct *tsk, struct page *p, + struct vm_area_struct *vma, struct list_head *to_kill, + unsigned long ksm_addr, pgoff_t fsdax_pgoff) { struct to_kill *tk; @@ -417,7 +417,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, return; } - tk->addr = page_address_in_vma(p, vma); + tk->addr = ksm_addr ? ksm_addr : page_address_in_vma(p, vma); if (is_zone_device_page(p)) { if (fsdax_pgoff != FSDAX_INVALID_PGOFF) tk->addr = vma_pgoff_address(fsdax_pgoff, 1, vma); @@ -448,6 +448,13 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, list_add_tail(&tk->nd, to_kill); } +static void add_to_kill_anon_file(struct task_struct *tsk, struct page *p, + struct vm_area_struct *vma, + struct list_head *to_kill) +{ + __add_to_kill(tsk, p, vma, to_kill, 0, FSDAX_INVALID_PGOFF); +} + /* * Kill the processes that have been collected earlier. * @@ -573,7 +580,7 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, continue; if (!page_mapped_in_vma(page, vma)) continue; - add_to_kill(t, page, FSDAX_INVALID_PGOFF, vma, to_kill); + add_to_kill_anon_file(t, page, vma, to_kill); } } read_unlock(&tasklist_lock); @@ -609,8 +616,7 @@ 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, FSDAX_INVALID_PGOFF, vma, - to_kill); + add_to_kill_anon_file(t, page, vma, to_kill); } } read_unlock(&tasklist_lock); @@ -618,6 +624,13 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, } #ifdef CONFIG_FS_DAX +static void add_to_kill_fsdax(struct task_struct *tsk, struct page *p, + struct vm_area_struct *vma, + struct list_head *to_kill, pgoff_t pgoff) +{ + __add_to_kill(tsk, p, vma, to_kill, 0, pgoff); +} + /* * Collect processes when the error hit a fsdax page. */ @@ -637,7 +650,7 @@ static void collect_procs_fsdax(struct page *page, continue; vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { if (vma->vm_mm == t->mm) - add_to_kill(t, page, pgoff, vma, to_kill); + add_to_kill_fsdax(t, page, vma, to_kill, pgoff); } } read_unlock(&tasklist_lock);