- 03 Feb, 2023 40 commits
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Christoph Hellwig authored
swap_readpage always returns 0, and no caller checks the return value. [akpm@linux-foundation.org: fix void-returning swap_readpage() stub, per Keith] Link: https://lkml.kernel.org/r/20230125133436.447864-3-hch@lst.deSigned-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Keith Busch <kbusch@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Christoph Hellwig authored
Patch series "remove ->rw_page". This series removes the ->rw_page block_device_operation, which is an old and clumsy attempt at a simple read/write fast path for the block layer. It isn't actually used by the fastest block layer operations that we support (polled I/O through io_uring), but only used by the mpage buffered I/O helpers which are some of the slowest I/O we have and do not make any difference there at all, and zram which is a block device abused to duplicate the zram functionality. Given that zram is heavily used we need to make sure there is a good replacement for synchronous I/O, so this series adds a new flag for drivers that complete I/O synchronously and uses that flag to use on-stack bios and synchronous submission for them in the swap code. This patch (of 7): These are micro-optimizations for synchronous I/O, which do not matter compared to all the other inefficiencies in the legacy buffer_head based mpage code. Link: https://lkml.kernel.org/r/20230125133436.447864-1-hch@lst.de Link: https://lkml.kernel.org/r/20230125133436.447864-2-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Move the VM_FLUSH_RESET_PERMS to the caller and rename the function to better describe what it is doing. Link: https://lkml.kernel.org/r/20230121071051.1143058-11-hch@lst.deSigned-off-by:
Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by:
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Christoph Hellwig authored
vunmap only needs to find and free the vmap_area and vm_strut, so open code that there and merge the rest of the code into vfree. Link: https://lkml.kernel.org/r/20230121071051.1143058-10-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
All these checks apply to the free_vm_area interface as well, so move them to the common routine. Link: https://lkml.kernel.org/r/20230121071051.1143058-9-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Use the common helper to find and remove a vmap_area instead of open coding it. Link: https://lkml.kernel.org/r/20230121071051.1143058-8-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
__remove_vm_area is the only part of va_remove_mappings that requires a vmap_area. Move the call out to the caller and only pass the vm_struct to va_remove_mappings. Link: https://lkml.kernel.org/r/20230121071051.1143058-7-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
This adds an extra, never taken, in_interrupt() branch, but will allow to cut down the maze of vfree helpers. Link: https://lkml.kernel.org/r/20230121071051.1143058-6-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Move these two functions around a bit to avoid forward declarations. Link: https://lkml.kernel.org/r/20230121071051.1143058-5-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Fold __vfree_deferred into vfree_atomic, and call vfree_atomic early on from vfree if called from interrupt context so that the extra low-level helper can be avoided. Link: https://lkml.kernel.org/r/20230121071051.1143058-4-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
__vfree is a subset of vfree that just skips a few checks, and which is only used by vfree and an error cleanup path. Fold __vfree into vfree and switch the only other caller to call vfree() instead. Link: https://lkml.kernel.org/r/20230121071051.1143058-3-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Patch series "cleanup vfree and vunmap". This little series untangles the vfree and vunmap code path a bit. This patch (of 10): VM_FLUSH_RESET_PERMS is just for use with vmalloc as it is tied to freeing the underlying pages. Link: https://lkml.kernel.org/r/20230121071051.1143058-1-hch@lst.de Link: https://lkml.kernel.org/r/20230121071051.1143058-2-hch@lst.deSigned-off-by:
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Mel Gorman authored
Commit 7efc3b72 ("mm/compaction: fix set skip in fast_find_migrateblock") address an issue where a pageblock selected by fast_find_migrateblock() was ignored. Unfortunately, the same fix resulted in numerous reports of khugepaged or kcompactd stalling for long periods of time or consuming 100% of CPU. Tracing showed that there was a lot of rescanning between a small subset of pageblocks because the conditions for marking the block skip are not met. The scan is not reaching the end of the pageblock because enough pages were isolated but none were migrated successfully. Eventually it circles back to the same block. Pageblock skip tracking tries to minimise both latency and excessive scanning but tracking exactly when a block is fully scanned requires an excessive amount of state. This patch forcibly rescans a pageblock when all isolated pages fail to migrate even though it could be for transient reasons such as page writeback or page dirty. This will sometimes migrate too many pages but pageblocks will be marked skip and forward progress will be made. "Usemen" from the mmtests configuration workload-usemem-stress-numa-compact was used to stress compaction. The compaction trace events were recorded using a 6.2-rc5 kernel that includes commit 7efc3b72 and count of unique ranges were measured. The top 5 ranges were 3076 range=(0x10ca00-0x10cc00) 3076 range=(0x110a00-0x110c00) 3098 range=(0x13b600-0x13b800) 3104 range=(0x141c00-0x141e00) 11424 range=(0x11b600-0x11b800) While this workload is very different than what the bugs reported, the pattern of the same subset of blocks being repeatedly scanned is observed. At one point, *only* the range range=(0x11b600 ~ 0x11b800) was scanned for 2 seconds. 14 seconds passed between the first migration-related event and the last. With the series applied including this patch, the top 5 ranges were 1 range=(0x11607e-0x116200) 1 range=(0x116200-0x116278) 1 range=(0x116278-0x116400) 1 range=(0x116400-0x116424) 1 range=(0x116424-0x116600) Only unique ranges were scanned and the time between the first migration-related event was 0.11 milliseconds. Link: https://lkml.kernel.org/r/20230125134434.18017-5-mgorman@techsingularity.net Fixes: 7efc3b72 ("mm/compaction: fix set skip in fast_find_migrateblock") Signed-off-by:
Mel Gorman <mgorman@techsingularity.net> Cc: Chuyi Zhou <zhouchuyi@bytedance.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Maxim Levitsky <mlevitsk@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pedro Falcato <pedro.falcato@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Mel Gorman authored
cc->finish_pageblock is set when the current pageblock should be rescanned but fast_find_migrateblock can select an alternative block. Disable fast_find_migrateblock when the current pageblock scan should be completed. Link: https://lkml.kernel.org/r/20230125134434.18017-4-mgorman@techsingularity.netSigned-off-by:
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Mel Gorman authored
If a page has been captured then draining is unnecssary so check first for a captured page. Link: https://lkml.kernel.org/r/20230125134434.18017-3-mgorman@techsingularity.netSigned-off-by:
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Mel Gorman authored
Patch series "Fix excessive CPU usage during compaction". Commit 7efc3b72 ("mm/compaction: fix set skip in fast_find_migrateblock") fixed a problem where pageblocks found by fast_find_migrateblock() were ignored. Unfortunately there were numerous bug reports complaining about high CPU usage and massive stalls once 6.1 was released. Due to the severity, the patch was reverted by Vlastimil as a short-term fix[1] to -stable. The underlying problem for each of the bugs is suspected to be the repeated scanning of the same pageblocks. This series should guarantee forward progress even with commit 7efc3b72. More information is in the changelog for patch 4. [1] http://lore.kernel.org/r/20230113173345.9692-1-vbabka@suse.cz This patch (of 4): The rescan field was not well named albeit accurate at the time. Rename the field to finish_pageblock to indicate that the remainder of the pageblock should be scanned regardless of COMPACT_CLUSTER_MAX. The intent is that pageblocks with transient failures get marked for skipping to avoid revisiting the same pageblock. Link: https://lkml.kernel.org/r/20230125134434.18017-2-mgorman@techsingularity.netSigned-off-by:
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Jongwoo Han authored
Link: https://lkml.kernel.org/r/20230125180847.4542-1-jongwooo.han@gmail.comSigned-off-by:
Jongwoo Han <jongwooo.han@gmail.com> Signed-off-by:
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Andrey Konovalov authored
The implementation of page_alloc poisoning sampling assumed that tag_clear_highpage resets page tags for __GFP_ZEROTAGS allocations. However, this is no longer the case since commit 70c248ac ("mm: kasan: Skip unpoisoning of user pages"). This leads to kernel crashes when MTE-enabled userspace mappings are used with Hardware Tag-Based KASAN enabled. Reset page tags for __GFP_ZEROTAGS allocations in post_alloc_hook(). Also clarify and fix related comments. [andreyknvl@google.com: update comment] Link: https://lkml.kernel.org/r/5dbd866714b4839069e2d8469ac45b60953db290.1674592780.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/24ea20c1b19c2b4b56cf9f5b354915f8dbccfc77.1674592496.git.andreyknvl@google.com Fixes: 44383cef ("kasan: allow sampling page_alloc allocations for HW_TAGS") Signed-off-by:
Andrey Konovalov <andreyknvl@google.com> Reported-by:
Peter Collingbourne <pcc@google.com> Tested-by:
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Mike Rapoport authored
W=1 build with clangs complains: mm/sparse.c:347:27: warning: unused function 'pgdat_to_phys' [-Wunused-function] static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat) ^ 1 warning generated. pgdat_to_phys() is only used by functions defined when CONFIG_MEMORY_HOTREMOVE=y. Move pgdat_to_phys() under #ifdef CONFIG_MEMORY_HOTREMOVE to make clang happy. Link: https://lkml.kernel.org/r/20230121101151.1703292-1-rppt@kernel.orgSigned-off-by:Mike Rapoport <rppt@kernel.org> Reported-by:
kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/all/202301210155.1E5zABb5-lkp@intel.com Cc: Miles Chen <miles.chen@mediatek.com> Signed-off-by:
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Hyeonggon Yoo authored
When allocating a high-order page, separate allocation timestamp is recorded for each sub-page resulting in different timestamp values between them. This behavior is not consistent with the behavior when recording free timestamp and caused confusion when analyzing memory dumps. Record single timestamp for the entire allocation, aligning with the behavior for free timestamps. Link: https://lkml.kernel.org/r/20230121165054.520507-1-42.hyeyoo@gmail.comSigned-off-by:
Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Jiaqi Yan authored
Add documentation for memory_failure's per NUMA node sysfs entries Link: https://lkml.kernel.org/r/20230120034622.2698268-4-jiaqiyan@google.comSigned-off-by:
Jiaqi Yan <jiaqiyan@google.com> Acked-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: David Rientjes <rientjes@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by:
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Jiaqi Yan authored
Right before memory_failure finishes its handling, accumulate poisoned page's resolution counters to pglist_data's memory_failure_stats, so as to update the corresponding sysfs entries. Tested: 1) Start an application to allocate memory buffer chunks 2) Convert random memory buffer addresses to physical addresses 3) Inject memory errors using EINJ at chosen physical addresses 4) Access poisoned memory buffer and recover from SIGBUS 5) Check counter values under /sys/devices/system/node/node*/memory_failure/* Link: https://lkml.kernel.org/r/20230120034622.2698268-3-jiaqiyan@google.comSigned-off-by:
David Rientjes <rientjes@google.com> Acked-by:
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Jiaqi Yan authored
Patch series "Introduce per NUMA node memory error statistics", v2. Background ========== In the RFC for Kernel Support of Memory Error Detection [1], one advantage of software-based scanning over hardware patrol scrubber is the ability to make statistics visible to system administrators. The statistics include 2 categories: * Memory error statistics, for example, how many memory error are encountered, how many of them are recovered by the kernel. Note these memory errors are non-fatal to kernel: during the machine check exception (MCE) handling kernel already classified MCE's severity to be unnecessary to panic (but either action required or optional). * Scanner statistics, for example how many times the scanner have fully scanned a NUMA node, how many errors are first detected by the scanner. The memory error statistics are useful to userspace and actually not specific to scanner detected memory errors, and are the focus of this patchset. Motivation ========== Memory error stats are important to userspace but insufficient in kernel today. Datacenter administrators can better monitor a machine's memory health with the visible stats. For example, while memory errors are inevitable on servers with 10+ TB memory, starting server maintenance when there are only 1~2 recovered memory errors could be overreacting; in cloud production environment maintenance usually means live migrate all the workload running on the server and this usually causes nontrivial disruption to the customer. Providing insight into the scope of memory errors on a system helps to determine the appropriate follow-up action. In addition, the kernel's existing memory error stats need to be standardized so that userspace can reliably count on their usefulness. Today kernel provides following memory error info to userspace, but they are not sufficient or have disadvantages: * HardwareCorrupted in /proc/meminfo: number of bytes poisoned in total, not per NUMA node stats though * ras:memory_failure_event: only available after explicitly enabled * /dev/mcelog provides many useful info about the MCEs, but doesn't capture how memory_failure recovered memory MCEs * kernel logs: userspace needs to process log text Exposing memory error stats is also a good start for the in-kernel memory error detector. Today the data source of memory error stats are either direct memory error consumption, or hardware patrol scrubber detection (either signaled as UCNA or SRAO). Once in-kernel memory scanner is implemented, it will be the main source as it is usually configured to scan memory DIMMs constantly and faster than hardware patrol scrubber. How Implemented =============== As Naoya pointed out [2], exposing memory error statistics to userspace is useful independent of software or hardware scanner. Therefore we implement the memory error statistics independent of the in-kernel memory error detector. It exposes the following per NUMA node memory error counters: /sys/devices/system/node/node${X}/memory_failure/total /sys/devices/system/node/node${X}/memory_failure/recovered /sys/devices/system/node/node${X}/memory_failure/ignored /sys/devices/system/node/node${X}/memory_failure/failed /sys/devices/system/node/node${X}/memory_failure/delayed These counters describe how many raw pages are poisoned and after the attempted recoveries by the kernel, their resolutions: how many are recovered, ignored, failed, or delayed respectively. This approach can be easier to extend for future use cases than /proc/meminfo, trace event, and log. The following math holds for the statistics: * total = recovered + ignored + failed + delayed These memory error stats are reset during machine boot. The 1st commit introduces these sysfs entries. The 2nd commit populates memory error stats every time memory_failure attempts memory error recovery. The 3rd commit adds documentations for introduced stats. [1] https://lore.kernel.org/linux-mm/7E670362-C29E-4626-B546-26530D54F937@gmail.com/T/#mc22959244f5388891c523882e61163c6e4d703af [2] https://lore.kernel.org/linux-mm/7E670362-C29E-4626-B546-26530D54F937@gmail.com/T/#m52d8d7a333d8536bd7ce74253298858b1c0c0ac6 This patch (of 3): Today kernel provides following memory error info to userspace, but each has its own disadvantage * HardwareCorrupted in /proc/meminfo: number of bytes poisoned in total, not per NUMA node stats though * ras:memory_failure_event: only available after explicitly enabled * /dev/mcelog provides many useful info about the MCEs, but doesn't capture how memory_failure recovered memory MCEs * kernel logs: userspace needs to process log text Exposes per NUMA node memory error stats as sysfs entries: /sys/devices/system/node/node${X}/memory_failure/total /sys/devices/system/node/node${X}/memory_failure/recovered /sys/devices/system/node/node${X}/memory_failure/ignored /sys/devices/system/node/node${X}/memory_failure/failed /sys/devices/system/node/node${X}/memory_failure/delayed These counters describe how many raw pages are poisoned and after the attempted recoveries by the kernel, their resolutions: how many are recovered, ignored, failed, or delayed respectively. The following math holds for the statistics: * total = recovered + ignored + failed + delayed Link: https://lkml.kernel.org/r/20230120034622.2698268-1-jiaqiyan@google.com Link: https://lkml.kernel.org/r/20230120034622.2698268-2-jiaqiyan@google.comSigned-off-by: -
T.J. Alumbaugh authored
Update the folio generation in place with or without current->reclaim_state->mm_walk. The LRU lock is held for longer, if mm_walk is NULL and the number of folios to update is more than PAGEVEC_SIZE. This causes a measurable regression from the LRU lock contention during a microbencmark. But a tiny regression is not worth the complexity. Link: https://lkml.kernel.org/r/20230118001827.1040870-8-talumbau@google.comSigned-off-by:
T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by:
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T.J. Alumbaugh authored
Improve readability of walk_pmd_range() and walk_pmd_range_locked(). Link: https://lkml.kernel.org/r/20230118001827.1040870-7-talumbau@google.comSigned-off-by:
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T.J. Alumbaugh authored
Add warnings and poison ->next. Link: https://lkml.kernel.org/r/20230118001827.1040870-6-talumbau@google.comSigned-off-by:
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T.J. Alumbaugh authored
Move memcg LRU code into a dedicated section. Improve the design doc to outline its architecture. Link: https://lkml.kernel.org/r/20230118001827.1040870-5-talumbau@google.comSigned-off-by:
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T.J. Alumbaugh authored
Move Bloom filters code into a dedicated section. Improve the design doc to explain Bloom filter usage and connection between aging and eviction in their use. Link: https://lkml.kernel.org/r/20230118001827.1040870-4-talumbau@google.comSigned-off-by:
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T.J. Alumbaugh authored
Add a section for lru_gen_look_around() in the code and the design doc. Link: https://lkml.kernel.org/r/20230118001827.1040870-3-talumbau@google.comSigned-off-by:
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T.J. Alumbaugh authored
Patch series "mm: multi-gen LRU: improve". This patch series improves a few MGLRU functions, collects related functions, and adds additional documentation. This patch (of 7): Add a section for working set protection in the code and the design doc. The admin doc already contains its usage. Link: https://lkml.kernel.org/r/20230118001827.1040870-1-talumbau@google.com Link: https://lkml.kernel.org/r/20230118001827.1040870-2-talumbau@google.comSigned-off-by:
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Zhaoyang Huang authored
Have the kmemleak's source code and Kconfig items be in the same directory. Link: https://lkml.kernel.org/r/1674091345-14799-1-git-send-email-zhaoyang.huang@unisoc.comSigned-off-by:
Zhaoyang Huang <zhaoyang.huang@unisoc.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Cc: ke.wang <ke.wang@unisoc.com> Cc: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:
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SeongJae Park authored
Add a simple unit test for damon_update_monitoring_results() function. Link: https://lkml.kernel.org/r/20230119013831.1911-4-sj@kernel.orgSigned-off-by:
SeongJae Park <sj@kernel.org> Cc: Brendan Higgins <brendanhiggins@google.com> Signed-off-by:
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SeongJae Park authored
region->nr_accesses is the number of sampling intervals in the last aggregation interval that access to the region has found, and region->age is the number of aggregation intervals that its access pattern has maintained. Hence, the real meaning of the two fields' values is depending on current sampling and aggregation intervals. This means the values need to be updated for every sampling and/or aggregation intervals updates. As DAMON core doesn't, it is a duty of in-kernel DAMON framework applications like DAMON sysfs interface, or the userspace users. Handling it in userspace or in-kernel DAMON application is complicated, inefficient, and repetitive compared to doing the update in DAMON core. Do the update in DAMON core. Link: https://lkml.kernel.org/r/20230119013831.1911-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Patch series "mm/damon: misc fixes". This patchset contains three miscellaneous simple fixes for DAMON online tuning. This patch (of 3): Commit cbeaa77b ("mm/damon/core: use a dedicated struct for monitoring attributes") moved monitoring intervals from damon_ctx to a new struct, damon_attrs, but a comment in the header file has not updated for the change. Update it. Link: https://lkml.kernel.org/r/20230119013831.1911-1-sj@kernel.org Link: https://lkml.kernel.org/r/20230119013831.1911-2-sj@kernel.org Fixes: cbeaa77b ("mm/damon/core: use a dedicated struct for monitoring attributes") Signed-off-by:
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Waiman Long authored
Commit 6edda04c ("mm/kmemleak: prevent soft lockup in first object iteration loop of kmemleak_scan()") fixes soft lockup problem in kmemleak_scan() by periodically doing a cond_resched(). It does take a reference of the current object before doing it. Unfortunately, if the object has been deleted from the object_list, the next object pointed to by its next pointer may no longer be valid after coming back from cond_resched(). This can result in use-after-free and other nasty problem. Fix this problem by adding a del_state flag into kmemleak_object structure to synchronize the object deletion process between kmemleak_cond_resched() and __remove_object() to make sure that the object remained in the object_list in the duration of the cond_resched() call. Link: https://lkml.kernel.org/r/20230119040111.350923-3-longman@redhat.com Fixes: 6edda04c ("mm/kmemleak: prevent soft lockup in first object iteration loop of kmemleak_scan()") Signed-off-by:
Waiman Long <longman@redhat.com> Reviewed-by:
Catalin Marinas <catalin.marinas@arm.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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Waiman Long authored
Patch series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF", v2. It was found that a KASAN use-after-free error was reported in the kmemleak_scan() function. After further examination, it is believe that even though a reference is taken from the current object, it does not prevent the object pointed to by the next pointer from going away after a cond_resched(). To fix that, additional flags are added to make sure that the current object won't be removed from the object_list during the duration of the cond_resched() to ensure the validity of the next pointer. While making the change, I also simplify the current usage of kmemleak_cond_resched() to make it easier to understand. This patch (of 2): The presence of a pinned argument and the 64k loop count make kmemleak_cond_resched() a bit more complex to read. The pinned argument is used only by first kmemleak_scan() loop. Simplify the usage of kmemleak_cond_resched() by removing the pinned argument and always do a get_object()/put_object() sequence. In addition, the 64k loop is removed by using need_resched() to decide if kmemleak_cond_resched() should be called. Link: https://lkml.kernel.org/r/20230119040111.350923-1-longman@redhat.com Link: https://lkml.kernel.org/r/20230119040111.350923-2-longman@redhat.comSigned-off-by:
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Kees Cook authored
Add some tests to cover the new PR_SET_MDWE prctl. Link: https://lkml.kernel.org/r/20230119160344.54358-3-joey.gouly@arm.comCo-developed-by:
Joey Gouly <joey.gouly@arm.com> Signed-off-by:
Kees Cook <keescook@chromium.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jeremy Linton <jeremy.linton@arm.com> Cc: Lennart Poettering <lennart@poettering.net> Cc: Mark Brown <broonie@kernel.org> Cc: nd <nd@arm.com> Cc: Szabolcs Nagy <szabolcs.nagy@arm.com> Cc: Topi Miettinen <toiwoton@gmail.com> Cc: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> Cc: David Hildenbrand <david@redhat.com> Signed-off-by:
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Joey Gouly authored
Patch series "mm: In-kernel support for memory-deny-write-execute (MDWE)", v2. The background to this is that systemd has a configuration option called MemoryDenyWriteExecute [2], implemented as a SECCOMP BPF filter. Its aim is to prevent a user task from inadvertently creating an executable mapping that is (or was) writeable. Since such BPF filter is stateless, it cannot detect mappings that were previously writeable but subsequently changed to read-only. Therefore the filter simply rejects any mprotect(PROT_EXEC). The side-effect is that on arm64 with BTI support (Branch Target Identification), the dynamic loader cannot change an ELF section from PROT_EXEC to PROT_EXEC|PROT_BTI using mprotect(). For libraries, it can resort to unmapping and re-mapping but for the main executable it does not have a file descriptor. The original bug report in the Red Hat bugzilla - [3] - and subsequent glibc workaround for libraries - [4]. This series adds in-kernel support for this feature as a prctl PR_SET_MDWE, that is inherited on fork(). The prctl denies PROT_WRITE | PROT_EXEC mappings. Like the systemd BPF filter it also denies adding PROT_EXEC to mappings. However unlike the BPF filter it only denies it if the mapping didn't previous have PROT_EXEC. This allows to PROT_EXEC -> PROT_EXEC | PROT_BTI with mprotect(), which is a problem with the BPF filter. This patch (of 2): The aim of such policy is to prevent a user task from creating an executable mapping that is also writeable. An example of mmap() returning -EACCESS if the policy is enabled: mmap(0, size, PROT_READ | PROT_WRITE | PROT_EXEC, flags, 0, 0); Similarly, mprotect() would return -EACCESS below: addr = mmap(0, size, PROT_READ | PROT_EXEC, flags, 0, 0); mprotect(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC); The BPF filter that systemd MDWE uses is stateless, and disallows mprotect() with PROT_EXEC completely. This new prctl allows PROT_EXEC to be enabled if it was already PROT_EXEC, which allows the following case: addr = mmap(0, size, PROT_READ | PROT_EXEC, flags, 0, 0); mprotect(addr, size, PROT_READ | PROT_EXEC | PROT_BTI); where PROT_BTI enables branch tracking identification on arm64. Link: https://lkml.kernel.org/r/20230119160344.54358-1-joey.gouly@arm.com Link: https://lkml.kernel.org/r/20230119160344.54358-2-joey.gouly@arm.comSigned-off-by:
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Herton R. Krzesinski authored
Right now there is no way to provide additional cflags/ldflags when building tools/vm binaries. And using eg. make CFLAGS=<options> will override the CFLAGS being set in the Makefile, making the build fail since it requires the include of the ../lib dir (for libapi). This change then allows you to specify: CFLAGS=<options> LDFLAGS=<options> make V=1 -C tools/vm And the options will be correctly appended as can be seen from the make output. Link: https://lkml.kernel.org/r/20230116224921.4106324-1-herton@redhat.comSigned-off-by:
Herton R. Krzesinski <herton@redhat.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Justin Forbes <jforbes@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Scott Weaver <scweaver@redhat.com> Signed-off-by:
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Deming Wang authored
We should use highmem replace higmem. Link: https://lkml.kernel.org/r/20230118025403.1531-1-wangdeming@inspur.comSigned-off-by:
Deming Wang <wangdeming@inspur.com> Reviewed-by:
Ira Weiny <ira.weiny@intel.com> Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
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