- 29 Dec, 2023 40 commits
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Andrey Konovalov authored
Add a return value for kasan_mempool_poison_object that lets the caller know whether the allocation is affected by a double-free or an invalid-free bug. The caller can use this return value to stop operating on the object. Also introduce a check_page_allocation helper function to improve the code readability. Link: https://lkml.kernel.org/r/618af65273875fb9f56954285443279b15f1fcd9.1703024586.git.andreyknvl@google.comSigned-off-by:
Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Andrey Konovalov authored
Add documentation comment for kasan_mempool_poison_object. Link: https://lkml.kernel.org/r/af33ba8cabfa1ad731fe23a3f874bfc8d3b7fed4.1703024586.git.andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Move kasan_mempool_poison_object after all slab-related KASAN hooks. This is a preparatory change for the following patches in this series. No functional changes. Link: https://lkml.kernel.org/r/23ea215409f43c13cdf9ecc454501a264c107d67.1703024586.git.andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Patch series "kasan: save mempool stack traces". This series updates KASAN to save alloc and free stack traces for secondary-level allocators that cache and reuse allocations internally instead of giving them back to the underlying allocator (e.g. mempool). As a part of this change, introduce and document a set of KASAN hooks: bool kasan_mempool_poison_pages(struct page *page, unsigned int order); void kasan_mempool_unpoison_pages(struct page *page, unsigned int order); bool kasan_mempool_poison_object(void *ptr); void kasan_mempool_unpoison_object(void *ptr, size_t size); and use them in the mempool code. Besides mempool, skbuff and io_uring also cache allocations and already use KASAN hooks to poison those. Their code is updated to use the new mempool hooks. The new hooks save alloc and free stack traces (for normal kmalloc and slab objects; stack traces for large kmalloc objects and page_alloc are not supported by KASAN yet), improve the readability of the users' code, and also allow the users to prevent double-free and invalid-free bugs; see the patches for the details. This patch (of 21): Rename kasan_slab_free_mempool to kasan_mempool_poison_object. kasan_slab_free_mempool is a slightly confusing name: it is unclear whether this function poisons the object when it is freed into mempool or does something when the object is freed from mempool to the underlying allocator. The new name also aligns with other mempool-related KASAN hooks added in the following patches in this series. Link: https://lkml.kernel.org/r/cover.1703024586.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/c5618685abb7cdbf9fb4897f565e7759f601da84.1703024586.git.andreyknvl@google.comSigned-off-by:
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Matthew Wilcox (Oracle) authored
All callers are passing end_buffer_async_write as this argument, so we can hardcode references to it within __block_write_full_folio(). That lets us make end_buffer_async_write() static. Link: https://lkml.kernel.org/r/20231215200245.748418-15-willy@infradead.orgSigned-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
Jens Axboe <axboe@kernel.dk> Reviewed-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Matthew Wilcox (Oracle) authored
Convert the function to be compatible with writepage_t so that it can be passed to write_cache_pages() by blkdev. This removes a call to compound_head(). We can also remove the function export as both callers are built-in. Link: https://lkml.kernel.org/r/20231215200245.748418-14-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
If the filesystem implements migrate_folio and writepages, there is no need for a writepage implementation. Link: https://lkml.kernel.org/r/20231215200245.748418-13-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
If the filesystem implements migrate_folio and writepages, there is no need for a writepage implementation. Link: https://lkml.kernel.org/r/20231215200245.748418-12-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
If the filesystem implements migrate_folio and writepages, there is no need for a writepage implementation. Link: https://lkml.kernel.org/r/20231215200245.748418-11-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
If the filesystem implements migrate_folio and writepages, there is no need for a writepage implementation. Link: https://lkml.kernel.org/r/20231215200245.748418-10-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
The earlier commit to remove hfsplus_writepage only removed it from one of the aops. Remove it from the btree_aops as well. Link: https://lkml.kernel.org/r/20231215200245.748418-9-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
The earlier commit to remove hfs_writepage only removed it from one of the aops. Remove it from the btree_aops as well. Link: https://lkml.kernel.org/r/20231215200245.748418-8-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
If the filesystem implements migrate_folio and writepages, there is no need for a writepage implementation. Link: https://lkml.kernel.org/r/20231215200245.748418-7-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
If the filesystem implements migrate_folio and writepages, there is no need for a writepage implementation. Link: https://lkml.kernel.org/r/20231215200245.748418-6-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Some architectures support a very large PAGE_SIZE, so instead of the 8 pointers we see with a 4kB PAGE_SIZE, we can see 128 pointers with 64kB or so many on Hexagon that it trips compiler warnings about exceeding stack frame size. All we're doing with this array is checking for block contiguity, which we can as well do by remembering the address of the first block in the page and checking this block is at the appropriate offset from that address. Link: https://lkml.kernel.org/r/20231215200245.748418-5-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Some architectures support a very large PAGE_SIZE, so instead of the 8 pointers we see with a 4kB PAGE_SIZE, we can see 128 pointers with 64kB or so many on Hexagon that it trips compiler warnings about exceeding stack frame size. All we're doing with this array is checking for block contiguity, which we can as well do by remembering the address of the first block in the page and checking this block is at the appropriate offset from that address. Link: https://lkml.kernel.org/r/20231215200245.748418-4-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
The only caller already has a folio, so pass it in and use it throughout. Saves two calls to compound_head(). Link: https://lkml.kernel.org/r/20231215200245.748418-3-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Patch series "Clean up the writeback paths". Most of these patches verge on the trivial, converting filesystems that just use block_write_full_page() to use mpage_writepages(). But as we saw with Christoph's earlier patchset, there can be some "interesting" gotchas, and I clearly haven't tested the majority of filesystems I've touched here. Patches 3 & 4 get rid of a lot of stack usage on architectures with larger page sizes; 1024 bytes on 64-bit systems with 64KiB pages. It starts to open the door to larger folio sizes on all architectures, but it's certainly not enough yet. Patch 14 is kind of trivial, but it's nice to get that simplification in. This patch (of 14): This function has been unused since the removal of bdev_write_page(). Link: https://lkml.kernel.org/r/20231215200245.748418-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231215200245.748418-2-willy@infradead.orgSigned-off-by:
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Baolin Wang authored
When running stress-ng testing, we found below kernel crash after a few hours: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 pc : dentry_name+0xd8/0x224 lr : pointer+0x22c/0x370 sp : ffff800025f134c0 ...... Call trace: dentry_name+0xd8/0x224 pointer+0x22c/0x370 vsnprintf+0x1ec/0x730 vscnprintf+0x2c/0x60 vprintk_store+0x70/0x234 vprintk_emit+0xe0/0x24c vprintk_default+0x3c/0x44 vprintk_func+0x84/0x2d0 printk+0x64/0x88 __dump_page+0x52c/0x530 dump_page+0x14/0x20 set_migratetype_isolate+0x110/0x224 start_isolate_page_range+0xc4/0x20c offline_pages+0x124/0x474 memory_block_offline+0x44/0xf4 memory_subsys_offline+0x3c/0x70 device_offline+0xf0/0x120 ...... After analyzing the vmcore, I found this issue is caused by page migration. The scenario is that, one thread is doing page migration, and we will use the target page's ->mapping field to save 'anon_vma' pointer between page unmap and page move, and now the target page is locked and refcount is 1. Currently, there is another stress-ng thread performing memory hotplug, attempting to offline the target page that is being migrated. It discovers that the refcount of this target page is 1, preventing the offline operation, thus proceeding to dump the page. However, page_mapping() of the target page may return an incorrect file mapping to crash the system in dump_mapping(), since the target page->mapping only saves 'anon_vma' pointer without setting PAGE_MAPPING_ANON flag. There are seveval ways to fix this issue: (1) Setting the PAGE_MAPPING_ANON flag for target page's ->mapping when saving 'anon_vma', but this can confuse PageAnon() for PFN walkers, since the target page has not built mappings yet. (2) Getting the page lock to call page_mapping() in __dump_page() to avoid crashing the system, however, there are still some PFN walkers that call page_mapping() without holding the page lock, such as compaction. (3) Using target page->private field to save the 'anon_vma' pointer and 2 bits page state, just as page->mapping records an anonymous page, which can remove the page_mapping() impact for PFN walkers and also seems a simple way. So I choose option 3 to fix this issue, and this can also fix other potential issues for PFN walkers, such as compaction. Link: https://lkml.kernel.org/r/e60b17a88afc38cb32f84c3e30837ec70b343d2b.1702641709.git.baolin.wang@linux.alibaba.com Fixes: 64c8902e ("migrate_pages: split unmap_and_move() to _unmap() and _move()") Signed-off-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Xu Yu <xuyu@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Matthew Wilcox (Oracle) authored
shmem_swapin_cluster() immediately converts the page back to a folio, and swapin_readahead() may as well call folio_file_page() once instead of having each function call it. [willy@infradead.org: avoid NULL pointer deref] Link: https://lkml.kernel.org/r/ZYI7OcVlM1voKfBl@casper.infradead.org Link: https://lkml.kernel.org/r/20231213215842.671461-14-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
The only two callers simply call put_page() on the page returned, so they're happier calling folio_put(). Saves two calls to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-13-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
It's more efficient to get the swap_info_struct by calling swp_swap_info() directly. Link: https://lkml.kernel.org/r/20231213215842.671461-12-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
All callers have a folio, so pass it in, saving two calls to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-11-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
All callers have a folio, so pass it in. Saves a couple of calls to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-10-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Make it plain that this takes the head page (which before this point was just an assumption, but is now enforced by the compiler). Link: https://lkml.kernel.org/r/20231213215842.671461-9-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Make it plain that this takes the head page (which before this point was just an assumption, but is now enforced by the compiler). Link: https://lkml.kernel.org/r/20231213215842.671461-8-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Saves a call to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-7-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Saves a call to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-6-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Saves a call to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-5-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Saves several calls to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-4-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Both callers now have a folio, so pass that in instead of the page. Removes a few hidden calls to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-3-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Patch series "More swap folio conversions". These all seem like fairly straightforward conversions to me. A lot of compound_head() calls get removed. And page_swap_info(), which is nice. This patch (of 13): Move the folio->page conversion into the callers that actually want that. Most of the callers are happier with the folio anyway. If the page_allocated boolean is set, the folio allocated is of order-0, so it is safe to pass the page directly to swap_readpage(). Link: https://lkml.kernel.org/r/20231213215842.671461-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231213215842.671461-2-willy@infradead.orgSigned-off-by:
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Chengming Zhou authored
First of all, we need to rename acomp_ctx->dstmem field to buffer, since we are now using for purposes other than compression. Then we change per-cpu mutex and buffer to per-acomp_ctx, since them belong to the acomp_ctx and are necessary parts when used in the compress/decompress contexts. So we can remove the old per-cpu mutex and dstmem. Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-5-9382162bbf05@bytedance.comSigned-off-by:
Chengming Zhou <zhouchengming@bytedance.com> Acked-by: Chris Li <chrisl@kernel.org> (Google) Reviewed-by:
Nhat Pham <nphamcs@gmail.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by:
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Chengming Zhou authored
Also after the common decompress part goes to __zswap_load(), we can cleanup the zswap_writeback_entry() a little. Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-4-9382162bbf05@bytedance.comSigned-off-by:
Yosry Ahmed <yosryahmed@google.com> Reviewed-by:
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Chengming Zhou authored
After the common decompress part goes to __zswap_load(), we can cleanup the zswap_load() a little. Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-3-9382162bbf05@bytedance.comSigned-off-by:
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Chengming Zhou authored
zswap_load() and zswap_writeback_entry() have the same part that decompress the data from zswap_entry to page, so refactor out the common part as __zswap_load(entry, page). Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-2-9382162bbf05@bytedance.comSigned-off-by:
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Chengming Zhou authored
Patch series "mm/zswap: dstmem reuse optimizations and cleanups", v5. The problem this series tries to optimize is that zswap_load() and zswap_writeback_entry() have to malloc a temporary memory to support !zpool_can_sleep_mapped(). We can avoid it by reusing the percpu crypto_acomp_ctx->dstmem, which is also used by zswap_store() and protected by the same percpu crypto_acomp_ctx->mutex. This patch (of 5): In the !zpool_can_sleep_mapped() case such as zsmalloc, we need to first copy the entry->handle memory to a temporary memory, which is allocated using kmalloc. Obviously we can reuse the per-compressor dstmem to avoid allocating every time, since it's percpu-compressor and protected in percpu mutex. Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-0-9382162bbf05@bytedance.com Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-1-9382162bbf05@bytedance.comSigned-off-by:
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Stefan Roesch authored
This documents the KSM advisor and its new knobs in /sys/fs/kernel/mm. Link: https://lkml.kernel.org/r/20231218231054.1625219-5-shr@devkernel.ioSigned-off-by:
Stefan Roesch <shr@devkernel.io> Acked-by:
David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by:
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Stefan Roesch authored
This adds a new tracepoint for the ksm advisor. It reports the last scan time, the new setting of the pages_to_scan parameter and the average cpu percent usage of the ksmd background thread for the last scan. Link: https://lkml.kernel.org/r/20231218231054.1625219-4-shr@devkernel.ioSigned-off-by:
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Stefan Roesch authored
This adds four new knobs for the KSM advisor to influence its behaviour. The knobs are: - advisor_mode: none: no advisor (default) scan-time: scan time advisor - advisor_max_cpu: 70 (default, cpu usage percent) - advisor_min_pages_to_scan: 500 (default) - advisor_max_pages_to_scan: 30000 (default) - advisor_target_scan_time: 200 (default in seconds) The new values will take effect on the next scan round. Link: https://lkml.kernel.org/r/20231218231054.1625219-3-shr@devkernel.ioSigned-off-by:
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