- 02 12月, 2019 4 次提交
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由 Uladzislau Rezki (Sony) 提交于
When fit type is NE_FIT_TYPE there is a need in one extra object. Usually the "ne_fit_preload_node" per-CPU variable has it and there is no need in GFP_NOWAIT allocation, but there are exceptions. This commit just adds more explanations, as a result giving answers on questions like when it can occur, how often, under which conditions and what happens if GFP_NOWAIT gets failed. Link: http://lkml.kernel.org/r/20191016095438.12391-3-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Daniel Wagner <dwagner@suse.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
Allocation functions should comply with the given gfp_mask as much as possible. The preallocation code in alloc_vmap_area doesn't follow that pattern and it is using a hardcoded GFP_KERNEL. Although this doesn't really make much difference because vmalloc is not GFP_NOWAIT compliant in general (e.g. page table allocations are GFP_KERNEL) there is no reason to spread that bad habit and it is good to fix the antipattern. [mhocko@suse.com: rewrite changelog] Link: http://lkml.kernel.org/r/20191016095438.12391-2-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Daniel Wagner <dwagner@suse.de> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
Some background. The preemption was disabled before to guarantee that a preloaded object is available for a CPU, it was stored for. That was achieved by combining the disabling the preemption and taking the spin lock while the ne_fit_preload_node is checked. The aim was to not allocate in atomic context when spinlock is taken later, for regular vmap allocations. But that approach conflicts with CONFIG_PREEMPT_RT philosophy. It means that calling spin_lock() with disabled preemption is forbidden in the CONFIG_PREEMPT_RT kernel. Therefore, get rid of preempt_disable() and preempt_enable() when the preload is done for splitting purpose. As a result we do not guarantee now that a CPU is preloaded, instead we minimize the case when it is not, with this change, by populating the per cpu preload pointer under the vmap_area_lock. This implies that at least each caller that has done the preallocation will not fallback to an atomic allocation later. It is possible that the preallocation would be pointless or that no preallocation is done because of the race but the data shows that this is really rare. For example i run the special test case that follows the preload pattern and path. 20 "unbind" threads run it and each does 1000000 allocations. Only 3.5 times among 1000000 a CPU was not preloaded. So it can happen but the number is negligible. [mhocko@suse.com: changelog additions] Link: http://lkml.kernel.org/r/20191016095438.12391-1-urezki@gmail.com Fixes: 82dd23e8 ("mm/vmalloc.c: preload a CPU with one object for split purpose") Signed-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: NDaniel Wagner <dwagner@suse.de> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Liu Xiang 提交于
gfpflags_allow_blocking() does not care about __GFP_HIGHMEM, so highmem_mask can be removed. Link: http://lkml.kernel.org/r/1568812319-3467-1-git-send-email-liuxiang_1999@126.comSigned-off-by: NLiu Xiang <liuxiang_1999@126.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 18 11月, 2019 1 次提交
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由 Andrii Nakryiko 提交于
Add ability to memory-map contents of BPF array map. This is extremely useful for working with BPF global data from userspace programs. It allows to avoid typical bpf_map_{lookup,update}_elem operations, improving both performance and usability. There had to be special considerations for map freezing, to avoid having writable memory view into a frozen map. To solve this issue, map freezing and mmap-ing is happening under mutex now: - if map is already frozen, no writable mapping is allowed; - if map has writable memory mappings active (accounted in map->writecnt), map freezing will keep failing with -EBUSY; - once number of writable memory mappings drops to zero, map freezing can be performed again. Only non-per-CPU plain arrays are supported right now. Maps with spinlocks can't be memory mapped either. For BPF_F_MMAPABLE array, memory allocation has to be done through vmalloc() to be mmap()'able. We also need to make sure that array data memory is page-sized and page-aligned, so we over-allocate memory in such a way that struct bpf_array is at the end of a single page of memory with array->value being aligned with the start of the second page. On deallocation we need to accomodate this memory arrangement to free vmalloc()'ed memory correctly. One important consideration regarding how memory-mapping subsystem functions. Memory-mapping subsystem provides few optional callbacks, among them open() and close(). close() is called for each memory region that is unmapped, so that users can decrease their reference counters and free up resources, if necessary. open() is *almost* symmetrical: it's called for each memory region that is being mapped, **except** the very first one. So bpf_map_mmap does initial refcnt bump, while open() will do any extra ones after that. Thus number of close() calls is equal to number of open() calls plus one more. Signed-off-by: NAndrii Nakryiko <andriin@fb.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NSong Liu <songliubraving@fb.com> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/bpf/20191117172806.2195367-4-andriin@fb.com
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- 26 9月, 2019 1 次提交
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由 Michel Lespinasse 提交于
Add RB_DECLARE_CALLBACKS_MAX, which generates augmented rbtree callbacks for the case where the augmented value is a scalar whose definition follows a max(f(node)) pattern. This actually covers all present uses of RB_DECLARE_CALLBACKS, and saves some (source) code duplication in the various RBCOMPUTE function definitions. [walken@google.com: fix mm/vmalloc.c] Link: http://lkml.kernel.org/r/CANN689FXgK13wDYNh1zKxdipeTuALG4eKvKpsdZqKFJ-rvtGiQ@mail.gmail.com [walken@google.com: re-add check to check_augmented()] Link: http://lkml.kernel.org/r/20190727022027.GA86863@google.com Link: http://lkml.kernel.org/r/20190703040156.56953-3-walken@google.comSigned-off-by: NMichel Lespinasse <walken@google.com> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 9月, 2019 3 次提交
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由 Austin Kim 提交于
If !area->pages statement is true where memory allocation fails, area is freed. In this case 'area->pages = pages' should not executed. So move 'area->pages = pages' after if statement. [akpm@linux-foundation.org: give area->pages the same treatment] Link: http://lkml.kernel.org/r/20190830035716.GA190684@LGEARND20B15Signed-off-by: NAustin Kim <austindh.kim@gmail.com> Acked-by: NMichal Hocko <mhocko@suse.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Roman Penyaev <rpenyaev@suse.de> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Pengfei Li 提交于
Objective --------- The current implementation of struct vmap_area wasted space. After applying this commit, sizeof(struct vmap_area) has been reduced from 11 words to 8 words. Description ----------- 1) Pack "subtree_max_size", "vm" and "purge_list". This is no problem because A) "subtree_max_size" is only used when vmap_area is in "free" tree B) "vm" is only used when vmap_area is in "busy" tree C) "purge_list" is only used when vmap_area is in vmap_purge_list 2) Eliminate "flags". ;Since only one flag VM_VM_AREA is being used, and the same thing can be done by judging whether "vm" is NULL, then the "flags" can be eliminated. Link: http://lkml.kernel.org/r/20190716152656.12255-3-lpf.vector@gmail.comSigned-off-by: NPengfei Li <lpf.vector@gmail.com> Suggested-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Roman Gushchin <guro@fb.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
The busy tree can be quite big, even though the area is freed or unmapped it still stays there until "purge" logic removes it. 1) Optimize and reduce the size of "busy" tree by removing a node from it right away as soon as user triggers free paths. It is possible to do so, because the allocation is done using another augmented tree. The vmalloc test driver shows the difference, for example the "fix_size_alloc_test" is ~11% better comparing with default configuration: sudo ./test_vmalloc.sh performance <default> Summary: fix_size_alloc_test loops: 1000000 avg: 993985 usec Summary: full_fit_alloc_test loops: 1000000 avg: 973554 usec Summary: long_busy_list_alloc_test loops: 1000000 avg: 12617652 usec <default> <this patch> Summary: fix_size_alloc_test loops: 1000000 avg: 882263 usec Summary: full_fit_alloc_test loops: 1000000 avg: 973407 usec Summary: long_busy_list_alloc_test loops: 1000000 avg: 12593929 usec <this patch> 2) Since the busy tree now contains allocated areas only and does not interfere with lazily free nodes, introduce the new function show_purge_info() that dumps "unpurged" areas that is propagated through "/proc/vmallocinfo". 3) Eliminate VM_LAZY_FREE flag. Link: http://lkml.kernel.org/r/20190716152656.12255-2-lpf.vector@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: NPengfei Li <lpf.vector@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 04 9月, 2019 1 次提交
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由 Christoph Hellwig 提交于
The arm architecture had a VM_ARM_DMA_CONSISTENT flag to mark DMA coherent remapping for a while. Lift this flag to common code so that we can use it generically. We also check it in the only place VM_USERMAP is directly check so that we can entirely replace that flag as well (although I'm not even sure why we'd want to allow remapping DMA appings, but I'd rather not change behavior). Signed-off-by: NChristoph Hellwig <hch@lst.de>
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- 14 8月, 2019 1 次提交
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Recent changes to the vmalloc code by commit 68ad4a33 ("mm/vmalloc.c: keep track of free blocks for vmap allocation") can cause spurious percpu allocation failures. These, in turn, can result in panic()s in the slub code. One such possible panic was reported by Dave Hansen in following link https://lkml.org/lkml/2019/6/19/939. Another related panic observed is, RIP: 0033:0x7f46f7441b9b Call Trace: dump_stack+0x61/0x80 pcpu_alloc.cold.30+0x22/0x4f mem_cgroup_css_alloc+0x110/0x650 cgroup_apply_control_enable+0x133/0x330 cgroup_mkdir+0x41b/0x500 kernfs_iop_mkdir+0x5a/0x90 vfs_mkdir+0x102/0x1b0 do_mkdirat+0x7d/0xf0 do_syscall_64+0x5b/0x180 entry_SYSCALL_64_after_hwframe+0x44/0xa9 VMALLOC memory manager divides the entire VMALLOC space (VMALLOC_START to VMALLOC_END) into multiple VM areas (struct vm_areas), and it mainly uses two lists (vmap_area_list & free_vmap_area_list) to track the used and free VM areas in VMALLOC space. And pcpu_get_vm_areas(offsets[], sizes[], nr_vms, align) function is used for allocating congruent VM areas for percpu memory allocator. In order to not conflict with VMALLOC users, pcpu_get_vm_areas allocates VM areas near the end of the VMALLOC space. So the search for free vm_area for the given requirement starts near VMALLOC_END and moves upwards towards VMALLOC_START. Prior to commit 68ad4a33, the search for free vm_area in pcpu_get_vm_areas() involves following two main steps. Step 1: Find a aligned "base" adress near VMALLOC_END. va = free vm area near VMALLOC_END Step 2: Loop through number of requested vm_areas and check, Step 2.1: if (base < VMALLOC_START) 1. fail with error Step 2.2: // end is offsets[area] + sizes[area] if (base + end > va->vm_end) 1. Move the base downwards and repeat Step 2 Step 2.3: if (base + start < va->vm_start) 1. Move to previous free vm_area node, find aligned base address and repeat Step 2 But Commit 68ad4a33 removed Step 2.2 and modified Step 2.3 as below: Step 2.3: if (base + start < va->vm_start || base + end > va->vm_end) 1. Move to previous free vm_area node, find aligned base address and repeat Step 2 Above change is the root cause of spurious percpu memory allocation failures. For example, consider a case where a relatively large vm_area (~ 30 TB) was ignored in free vm_area search because it did not pass the base + end < vm->vm_end boundary check. Ignoring such large free vm_area's would lead to not finding free vm_area within boundary of VMALLOC_start to VMALLOC_END which in turn leads to allocation failures. So modify the search algorithm to include Step 2.2. Link: http://lkml.kernel.org/r/20190729232139.91131-1-sathyanarayanan.kuppuswamy@linux.intel.com Fixes: 68ad4a33 ("mm/vmalloc.c: keep track of free blocks for vmap allocation") Signed-off-by: NKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reported-by: NDave Hansen <dave.hansen@intel.com> Acked-by: NDennis Zhou <dennis@kernel.org> Reviewed-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: sathyanarayanan kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 22 7月, 2019 1 次提交
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由 Joerg Roedel 提交于
On x86-32 with PTI enabled, parts of the kernel page-tables are not shared between processes. This can cause mappings in the vmalloc/ioremap area to persist in some page-tables after the region is unmapped and released. When the region is re-used the processes with the old mappings do not fault in the new mappings but still access the old ones. This causes undefined behavior, in reality often data corruption, kernel oopses and panics and even spontaneous reboots. Fix this problem by activly syncing unmaps in the vmalloc/ioremap area to all page-tables in the system before the regions can be re-used. References: https://bugzilla.suse.com/show_bug.cgi?id=1118689 Fixes: 5d72b4fb ('x86, mm: support huge I/O mapping capability I/F') Signed-off-by: NJoerg Roedel <jroedel@suse.de> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Reviewed-by: NDave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20190719184652.11391-4-joro@8bytes.org
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- 13 7月, 2019 7 次提交
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由 Roman Gushchin 提交于
Vmalloc() is getting more and more used these days (kernel stacks, bpf and percpu allocator are new top users), and the total % of memory consumed by vmalloc() can be pretty significant and changes dynamically. /proc/meminfo is the best place to display this information: its top goal is to show top consumers of the memory. Since the VmallocUsed field in /proc/meminfo is not in use for quite a long time (it has been defined to 0 by a5ad88ce ("mm: get rid of 'vmalloc_info' from /proc/meminfo")), let's reuse it for showing the actual physical memory consumption of vmalloc(). Link: http://lkml.kernel.org/r/20190417194002.12369-3-guro@fb.comSigned-off-by: NRoman Gushchin <guro@fb.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NVlastimil Babka <vbabka@suse.cz> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Geert Uytterhoeven 提交于
Link: http://lkml.kernel.org/r/20190607113509.15032-1-geert+renesas@glider.beSigned-off-by: NGeert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Acked-by: NSouptick Joarder <jrdr.linux@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
Trigger a warning if an object that is about to be freed is detached. We used to have a BUG_ON(), but even though it is considered as faulty behaviour that is not a good reason to break a system. Link: http://lkml.kernel.org/r/20190606120411.8298-5-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
It does not make sense to try to "unlink" the node that is definitely not linked with a list nor tree. On the first merge step VA just points to the previously disconnected busy area. On the second step, check if the node has been merged and do "unlink" if so, because now it points to an object that must be linked. Link: http://lkml.kernel.org/r/20190606120411.8298-4-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: NHillf Danton <hdanton@sina.com> Reviewed-by: NRoman Gushchin <guro@fb.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
Refactor the NE_FIT_TYPE split case when it comes to an allocation of one extra object. We need it in order to build a remaining space. The preload is done per CPU in non-atomic context with GFP_KERNEL flags. More permissive parameters can be beneficial for systems which are suffer from high memory pressure or low memory condition. For example on my KVM system(4xCPUs, no swap, 256MB RAM) i can simulate the failure of page allocation with GFP_NOWAIT flags. Using "stress-ng" tool and starting N workers spinning on fork() and exit(), i can trigger below trace: <snip> [ 179.815161] stress-ng-fork: page allocation failure: order:0, mode:0x40800(GFP_NOWAIT|__GFP_COMP), nodemask=(null),cpuset=/,mems_allowed=0 [ 179.815168] CPU: 0 PID: 12612 Comm: stress-ng-fork Not tainted 5.2.0-rc3+ #1003 [ 179.815170] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 179.815171] Call Trace: [ 179.815178] dump_stack+0x5c/0x7b [ 179.815182] warn_alloc+0x108/0x190 [ 179.815187] __alloc_pages_slowpath+0xdc7/0xdf0 [ 179.815191] __alloc_pages_nodemask+0x2de/0x330 [ 179.815194] cache_grow_begin+0x77/0x420 [ 179.815197] fallback_alloc+0x161/0x200 [ 179.815200] kmem_cache_alloc+0x1c9/0x570 [ 179.815202] alloc_vmap_area+0x32c/0x990 [ 179.815206] __get_vm_area_node+0xb0/0x170 [ 179.815208] __vmalloc_node_range+0x6d/0x230 [ 179.815211] ? _do_fork+0xce/0x3d0 [ 179.815213] copy_process.part.46+0x850/0x1b90 [ 179.815215] ? _do_fork+0xce/0x3d0 [ 179.815219] _do_fork+0xce/0x3d0 [ 179.815226] ? __do_page_fault+0x2bf/0x4e0 [ 179.815229] do_syscall_64+0x55/0x130 [ 179.815231] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 179.815234] RIP: 0033:0x7fedec4c738b ... [ 179.815237] RSP: 002b:00007ffda469d730 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 [ 179.815239] RAX: ffffffffffffffda RBX: 00007ffda469d730 RCX: 00007fedec4c738b [ 179.815240] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 [ 179.815241] RBP: 00007ffda469d780 R08: 00007fededd6e300 R09: 00007ffda47f50a0 [ 179.815242] R10: 00007fededd6e5d0 R11: 0000000000000246 R12: 0000000000000000 [ 179.815243] R13: 0000000000000020 R14: 0000000000000000 R15: 0000000000000000 [ 179.815245] Mem-Info: [ 179.815249] active_anon:12686 inactive_anon:14760 isolated_anon:0 active_file:502 inactive_file:61 isolated_file:70 unevictable:2 dirty:0 writeback:0 unstable:0 slab_reclaimable:2380 slab_unreclaimable:7520 mapped:15069 shmem:14813 pagetables:10833 bounce:0 free:1922 free_pcp:229 free_cma:0 <snip> Link: http://lkml.kernel.org/r/20190606120411.8298-3-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Roman Gushchin <guro@fb.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
Patch series "Some cleanups for the KVA/vmalloc", v5. This patch (of 4): Remove unused argument from the __alloc_vmap_area() function. Link: http://lkml.kernel.org/r/20190606120411.8298-2-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Reviewed-by: NRoman Gushchin <guro@fb.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Anshuman Khandual 提交于
Drop the pgtable_t variable from all implementation for pte_fn_t as none of them use it. apply_to_pte_range() should stop computing it as well. Should help us save some cycles. Link: http://lkml.kernel.org/r/1556803126-26596-1-git-send-email-anshuman.khandual@arm.comSigned-off-by: NAnshuman Khandual <anshuman.khandual@arm.com> Acked-by: NMatthew Wilcox <willy@infradead.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <jglisse@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 29 6月, 2019 1 次提交
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由 Arnd Bergmann 提交于
gcc gets confused in pcpu_get_vm_areas() because there are too many branches that affect whether 'lva' was initialized before it gets used: mm/vmalloc.c: In function 'pcpu_get_vm_areas': mm/vmalloc.c:991:4: error: 'lva' may be used uninitialized in this function [-Werror=maybe-uninitialized] insert_vmap_area_augment(lva, &va->rb_node, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ &free_vmap_area_root, &free_vmap_area_list); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/vmalloc.c:916:20: note: 'lva' was declared here struct vmap_area *lva; ^~~ Add an intialization to NULL, and check whether this has changed before the first use. [akpm@linux-foundation.org: tweak comments] Link: http://lkml.kernel.org/r/20190618092650.2943749-1-arnd@arndb.de Fixes: 68ad4a33 ("mm/vmalloc.c: keep track of free blocks for vmap allocation") Signed-off-by: NArnd Bergmann <arnd@arndb.de> Reviewed-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Cc: Joel Fernandes <joelaf@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 6月, 2019 1 次提交
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由 Ard Biesheuvel 提交于
Wire up the special helper functions to manipulate aliases of vmalloc regions in the linear map. Acked-by: NWill Deacon <will@kernel.org> Signed-off-by: NArd Biesheuvel <ard.biesheuvel@arm.com> Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
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- 03 6月, 2019 2 次提交
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由 Rick Edgecombe 提交于
In a rare case, flush_tlb_kernel_range() could be called with a start higher than the end. In vm_remove_mappings(), in case page_address() returns 0 for all pages (for example they were all in highmem), _vm_unmap_aliases() will be called with start = ULONG_MAX, end = 0 and flush = 1. If at the same time, the vmalloc purge operation is triggered by something else while the current operation is between remove_vm_area() and _vm_unmap_aliases(), then the vm mapping just removed will be already purged. In this case the call of vm_unmap_aliases() may not find any other mappings to flush and so end up flushing start = ULONG_MAX, end = 0. So only set flush = true if we find something in the direct mapping that we need to flush, and this way this can't happen. Signed-off-by: NRick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Meelis Roos <mroos@linux.ee> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 868b104d ("mm/vmalloc: Add flag for freeing of special permsissions") Link: https://lkml.kernel.org/r/20190527211058.2729-3-rick.p.edgecombe@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Rick Edgecombe 提交于
The calculation of the direct map address range to flush was wrong. This could cause the RO direct map alias to not get flushed. Today this shouldn't be a problem because this flush is only needed on x86 right now and the spurious fault handler will fix cached RO->RW translations. In the future though, it could cause the permissions to remain RO in the TLB for the direct map alias, and then the page would return from the page allocator to some other component as RO and cause a crash. So fix fix the address range calculation so the flush will include the direct map range. Signed-off-by: NRick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Meelis Roos <mroos@linux.ee> Cc: Nadav Amit <namit@vmware.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 868b104d ("mm/vmalloc: Add flag for freeing of special permsissions") Link: https://lkml.kernel.org/r/20190527211058.2729-2-rick.p.edgecombe@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 02 6月, 2019 1 次提交
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由 Andrew Morton 提交于
Reported-by: NNicholas Joll <najoll@posteo.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 21 5月, 2019 1 次提交
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由 Thomas Gleixner 提交于
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 19 5月, 2019 3 次提交
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由 Uladzislau Rezki (Sony) 提交于
This macro adds some debug code to check that vmap allocations are happened in ascending order. By default this option is set to 0 and not active. It requires recompilation of the kernel to activate it. Set to 1, compile the kernel. [urezki@gmail.com: v4] Link: http://lkml.kernel.org/r/20190406183508.25273-4-urezki@gmail.com Link: http://lkml.kernel.org/r/20190402162531.10888-4-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NRoman Gushchin <guro@fb.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Joel Fernandes <joelaf@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
This macro adds some debug code to check that the augment tree is maintained correctly, meaning that every node contains valid subtree_max_size value. By default this option is set to 0 and not active. It requires recompilation of the kernel to activate it. Set to 1, compile the kernel. [urezki@gmail.com: v4] Link: http://lkml.kernel.org/r/20190406183508.25273-3-urezki@gmail.com Link: http://lkml.kernel.org/r/20190402162531.10888-3-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NRoman Gushchin <guro@fb.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Joel Fernandes <joelaf@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
Patch series "improve vmap allocation", v3. Objective --------- Please have a look for the description at: https://lkml.org/lkml/2018/10/19/786 but let me also summarize it a bit here as well. The current implementation has O(N) complexity. Requests with different permissive parameters can lead to long allocation time. When i say "long" i mean milliseconds. Description ----------- This approach organizes the KVA memory layout into free areas of the 1-ULONG_MAX range, i.e. an allocation is done over free areas lookups, instead of finding a hole between two busy blocks. It allows to have lower number of objects which represent the free space, therefore to have less fragmented memory allocator. Because free blocks are always as large as possible. It uses the augment tree where all free areas are sorted in ascending order of va->va_start address in pair with linked list that provides O(1) access to prev/next elements. Since the tree is augment, we also maintain the "subtree_max_size" of VA that reflects a maximum available free block in its left or right sub-tree. Knowing that, we can easily traversal toward the lowest (left most path) free area. Allocation: ~O(log(N)) complexity. It is sequential allocation method therefore tends to maximize locality. The search is done until a first suitable block is large enough to encompass the requested parameters. Bigger areas are split. I copy paste here the description of how the area is split, since i described it in https://lkml.org/lkml/2018/10/19/786 <snip> A free block can be split by three different ways. Their names are FL_FIT_TYPE, LE_FIT_TYPE/RE_FIT_TYPE and NE_FIT_TYPE, i.e. they correspond to how requested size and alignment fit to a free block. FL_FIT_TYPE - in this case a free block is just removed from the free list/tree because it fully fits. Comparing with current design there is an extra work with rb-tree updating. LE_FIT_TYPE/RE_FIT_TYPE - left/right edges fit. In this case what we do is just cutting a free block. It is as fast as a current design. Most of the vmalloc allocations just end up with this case, because the edge is always aligned to 1. NE_FIT_TYPE - Is much less common case. Basically it happens when requested size and alignment does not fit left nor right edges, i.e. it is between them. In this case during splitting we have to build a remaining left free area and place it back to the free list/tree. Comparing with current design there are two extra steps. First one is we have to allocate a new vmap_area structure. Second one we have to insert that remaining free block to the address sorted list/tree. In order to optimize a first case there is a cache with free_vmap objects. Instead of allocating from slab we just take an object from the cache and reuse it. Second one is pretty optimized. Since we know a start point in the tree we do not do a search from the top. Instead a traversal begins from a rb-tree node we split. <snip> De-allocation. ~O(log(N)) complexity. An area is not inserted straight away to the tree/list, instead we identify the spot first, checking if it can be merged around neighbors. The list provides O(1) access to prev/next, so it is pretty fast to check it. Summarizing. If merged then large coalesced areas are created, if not the area is just linked making more fragments. There is one more thing that i should mention here. After modification of VA node, its subtree_max_size is updated if it was/is the biggest area in its left or right sub-tree. Apart of that it can also be populated back to upper levels to fix the tree. For more details please have a look at the __augment_tree_propagate_from() function and the description. Tests and stressing ------------------- I use the "test_vmalloc.sh" test driver available under "tools/testing/selftests/vm/" since 5.1-rc1 kernel. Just trigger "sudo ./test_vmalloc.sh" to find out how to deal with it. Tested on different platforms including x86_64/i686/ARM64/x86_64_NUMA. Regarding last one, i do not have any physical access to NUMA system, therefore i emulated it. The time of stressing is days. If you run the test driver in "stress mode", you also need the patch that is in Andrew's tree but not in Linux 5.1-rc1. So, please apply it: http://git.cmpxchg.org/cgit.cgi/linux-mmotm.git/commit/?id=e0cf7749bade6da318e98e934a24d8b62fab512c After massive testing, i have not identified any problems like memory leaks, crashes or kernel panics. I find it stable, but more testing would be good. Performance analysis -------------------- I have used two systems to test. One is i5-3320M CPU @ 2.60GHz and another is HiKey960(arm64) board. i5-3320M runs on 4.20 kernel, whereas Hikey960 uses 4.15 kernel. I have both system which could run on 5.1-rc1 as well, but the results have not been ready by time i an writing this. Currently it consist of 8 tests. There are three of them which correspond to different types of splitting(to compare with default). We have 3 ones(see above). Another 5 do allocations in different conditions. a) sudo ./test_vmalloc.sh performance When the test driver is run in "performance" mode, it runs all available tests pinned to first online CPU with sequential execution test order. We do it in order to get stable and repeatable results. Take a look at time difference in "long_busy_list_alloc_test". It is not surprising because the worst case is O(N). # i5-3320M How many cycles all tests took: CPU0=646919905370(default) cycles vs CPU0=193290498550(patched) cycles # See detailed table with results here: ftp://vps418301.ovh.net/incoming/vmap_test_results_v2/i5-3320M_performance_default.txt ftp://vps418301.ovh.net/incoming/vmap_test_results_v2/i5-3320M_performance_patched.txt # Hikey960 8x CPUs How many cycles all tests took: CPU0=3478683207 cycles vs CPU0=463767978 cycles # See detailed table with results here: ftp://vps418301.ovh.net/incoming/vmap_test_results_v2/HiKey960_performance_default.txt ftp://vps418301.ovh.net/incoming/vmap_test_results_v2/HiKey960_performance_patched.txt b) time sudo ./test_vmalloc.sh test_repeat_count=1 With this configuration, all tests are run on all available online CPUs. Before running each CPU shuffles its tests execution order. It gives random allocation behaviour. So it is rough comparison, but it puts in the picture for sure. # i5-3320M <default> vs <patched> real 101m22.813s real 0m56.805s user 0m0.011s user 0m0.015s sys 0m5.076s sys 0m0.023s # See detailed table with results here: ftp://vps418301.ovh.net/incoming/vmap_test_results_v2/i5-3320M_test_repeat_count_1_default.txt ftp://vps418301.ovh.net/incoming/vmap_test_results_v2/i5-3320M_test_repeat_count_1_patched.txt # Hikey960 8x CPUs <default> vs <patched> real unknown real 4m25.214s user unknown user 0m0.011s sys unknown sys 0m0.670s I did not manage to complete this test on "default Hikey960" kernel version. After 24 hours it was still running, therefore i had to cancel it. That is why real/user/sys are "unknown". This patch (of 3): Currently an allocation of the new vmap area is done over busy list iteration(complexity O(n)) until a suitable hole is found between two busy areas. Therefore each new allocation causes the list being grown. Due to over fragmented list and different permissive parameters an allocation can take a long time. For example on embedded devices it is milliseconds. This patch organizes the KVA memory layout into free areas of the 1-ULONG_MAX range. It uses an augment red-black tree that keeps blocks sorted by their offsets in pair with linked list keeping the free space in order of increasing addresses. Nodes are augmented with the size of the maximum available free block in its left or right sub-tree. Thus, that allows to take a decision and traversal toward the block that will fit and will have the lowest start address, i.e. it is sequential allocation. Allocation: to allocate a new block a search is done over the tree until a suitable lowest(left most) block is large enough to encompass: the requested size, alignment and vstart point. If the block is bigger than requested size - it is split. De-allocation: when a busy vmap area is freed it can either be merged or inserted to the tree. Red-black tree allows efficiently find a spot whereas a linked list provides a constant-time access to previous and next blocks to check if merging can be done. In case of merging of de-allocated memory chunk a large coalesced area is created. Complexity: ~O(log(N)) [urezki@gmail.com: v3] Link: http://lkml.kernel.org/r/20190402162531.10888-2-urezki@gmail.com [urezki@gmail.com: v4] Link: http://lkml.kernel.org/r/20190406183508.25273-2-urezki@gmail.com Link: http://lkml.kernel.org/r/20190321190327.11813-2-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NRoman Gushchin <guro@fb.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joel Fernandes <joelaf@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 15 5月, 2019 2 次提交
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由 Uladzislau Rezki (Sony) 提交于
vmap_lazy_nr variable has atomic_t type that is 4 bytes integer value on both 32 and 64 bit systems. lazy_max_pages() deals with "unsigned long" that is 8 bytes on 64 bit system, thus vmap_lazy_nr should be 8 bytes on 64 bit as well. Link: http://lkml.kernel.org/r/20190131162452.25879-1-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Joel Fernandes <joelaf@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
Commit 763b218d ("mm: add preempt points into __purge_vmap_area_lazy()") introduced some preempt points, one of those is making an allocation more prioritized over lazy free of vmap areas. Prioritizing an allocation over freeing does not work well all the time, i.e. it should be rather a compromise. 1) Number of lazy pages directly influences the busy list length thus on operations like: allocation, lookup, unmap, remove, etc. 2) Under heavy stress of vmalloc subsystem I run into a situation when memory usage gets increased hitting out_of_memory -> panic state due to completely blocking of logic that frees vmap areas in the __purge_vmap_area_lazy() function. Establish a threshold passing which the freeing is prioritized back over allocation creating a balance between each other. Using vmalloc test driver in "stress mode", i.e. When all available test cases are run simultaneously on all online CPUs applying a pressure on the vmalloc subsystem, my HiKey 960 board runs out of memory due to the fact that __purge_vmap_area_lazy() logic simply is not able to free pages in time. How I run it: 1) You should build your kernel with CONFIG_TEST_VMALLOC=m 2) ./tools/testing/selftests/vm/test_vmalloc.sh stress During this test "vmap_lazy_nr" pages will go far beyond acceptable lazy_max_pages() threshold, that will lead to enormous busy list size and other problems including allocation time and so on. Link: http://lkml.kernel.org/r/20190124115648.9433-3-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joel Fernandes <joelaf@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Joel Fernandes <joel@joelfernandes.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 30 4月, 2019 1 次提交
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由 Rick Edgecombe 提交于
Add a new flag VM_FLUSH_RESET_PERMS, for enabling vfree operations to immediately clear executable TLB entries before freeing pages, and handle resetting permissions on the directmap. This flag is useful for any kind of memory with elevated permissions, or where there can be related permissions changes on the directmap. Today this is RO+X and RO memory. Although this enables directly vfreeing non-writeable memory now, non-writable memory cannot be freed in an interrupt because the allocation itself is used as a node on deferred free list. So when RO memory needs to be freed in an interrupt the code doing the vfree needs to have its own work queue, as was the case before the deferred vfree list was added to vmalloc. For architectures with set_direct_map_ implementations this whole operation can be done with one TLB flush when centralized like this. For others with directmap permissions, currently only arm64, a backup method using set_memory functions is used to reset the directmap. When arm64 adds set_direct_map_ functions, this backup can be removed. When the TLB is flushed to both remove TLB entries for the vmalloc range mapping and the direct map permissions, the lazy purge operation could be done to try to save a TLB flush later. However today vm_unmap_aliases could flush a TLB range that does not include the directmap. So a helper is added with extra parameters that can allow both the vmalloc address and the direct mapping to be flushed during this operation. The behavior of the normal vm_unmap_aliases function is unchanged. Suggested-by: NDave Hansen <dave.hansen@intel.com> Suggested-by: NAndy Lutomirski <luto@kernel.org> Suggested-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NRick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-17-namit@vmware.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 06 3月, 2019 9 次提交
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由 Mike Rapoport 提交于
Many kernel-doc comments in mm/ have the return value descriptions either misformatted or omitted at all which makes kernel-doc script unhappy: $ make V=1 htmldocs ... ./mm/util.c:36: info: Scanning doc for kstrdup ./mm/util.c:41: warning: No description found for return value of 'kstrdup' ./mm/util.c:57: info: Scanning doc for kstrdup_const ./mm/util.c:66: warning: No description found for return value of 'kstrdup_const' ./mm/util.c:75: info: Scanning doc for kstrndup ./mm/util.c:83: warning: No description found for return value of 'kstrndup' ... Fixing the formatting and adding the missing return value descriptions eliminates ~100 such warnings. Link: http://lkml.kernel.org/r/1549549644-4903-4-git-send-email-rppt@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mike Rapoport 提交于
Some kernel-doc comments in mm/vmalloc.c have leading tab in indentation. This leads to excessive indentation in the generated HTML and to the inconsistency of its layout ([1] vs [2]). Besides, multi-line Note: sections are not handled properly with extra indentation. [1] https://www.kernel.org/doc/html/v4.20/core-api/mm-api.html?#c.vm_map_ram [2] https://www.kernel.org/doc/html/v4.20/core-api/mm-api.html?#c.vfree Link: http://lkml.kernel.org/r/1549549644-4903-2-git-send-email-rppt@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
One of the vmalloc stress test case triggers the kernel BUG(): <snip> [60.562151] ------------[ cut here ]------------ [60.562154] kernel BUG at mm/vmalloc.c:512! [60.562206] invalid opcode: 0000 [#1] PREEMPT SMP PTI [60.562247] CPU: 0 PID: 430 Comm: vmalloc_test/0 Not tainted 4.20.0+ #161 [60.562293] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [60.562351] RIP: 0010:alloc_vmap_area+0x36f/0x390 <snip> it can happen due to big align request resulting in overflowing of calculated address, i.e. it becomes 0 after ALIGN()'s fixup. Fix it by checking if calculated address is within vstart/vend range. Link: http://lkml.kernel.org/r/20190124115648.9433-2-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Joel Fernandes <joelaf@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uladzislau Rezki (Sony) 提交于
Export __vmaloc_node_range() function if CONFIG_TEST_VMALLOC_MODULE is enabled. Some test cases in vmalloc test suite module require and make use of that function. Please note, that it is not supposed to be used for other purposes. We need it only for performance analysis, stressing and stability check of vmalloc allocator. Link: http://lkml.kernel.org/r/20190103142108.20744-2-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Roman Penyaev 提交于
vmalloc_user*() calls differ from normal vmalloc() only in that they set VM_USERMAP flags for the area. During the whole history of vmalloc.c changes now it is possible simply to pass VM_USERMAP flags directly to __vmalloc_node_range() call instead of finding the area (which obviously takes time) after the allocation. Link: http://lkml.kernel.org/r/20190103145954.16942-4-rpenyaev@suse.deSigned-off-by: NRoman Penyaev <rpenyaev@suse.de> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Joe Perches <joe@perches.com> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Roman Penyaev 提交于
__vmalloc_area_node() calls vfree() on error path, which in turn calls kmemleak_free(), but area is not yet accounted by kmemleak_vmalloc(). Link: http://lkml.kernel.org/r/20190103145954.16942-3-rpenyaev@suse.deSigned-off-by: NRoman Penyaev <rpenyaev@suse.de> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Joe Perches <joe@perches.com> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Roman Penyaev 提交于
When VM_NO_GUARD is not set area->size includes adjacent guard page, thus for correct size checking get_vm_area_size() should be used, but not area->size. This fixes possible kernel oops when userspace tries to mmap an area on 1 page bigger than was allocated by vmalloc_user() call: the size check inside remap_vmalloc_range_partial() accounts non-existing guard page also, so check successfully passes but vmalloc_to_page() returns NULL (guard page does not physically exist). The following code pattern example should trigger an oops: static int oops_mmap(struct file *file, struct vm_area_struct *vma) { void *mem; mem = vmalloc_user(4096); BUG_ON(!mem); /* Do not care about mem leak */ return remap_vmalloc_range(vma, mem, 0); } And userspace simply mmaps size + PAGE_SIZE: mmap(NULL, 8192, PROT_WRITE|PROT_READ, MAP_PRIVATE, fd, 0); Possible candidates for oops which do not have any explicit size checks: *** drivers/media/usb/stkwebcam/stk-webcam.c: v4l_stk_mmap[789] ret = remap_vmalloc_range(vma, sbuf->buffer, 0); Or the following one: *** drivers/video/fbdev/core/fbmem.c static int fb_mmap(struct file *file, struct vm_area_struct * vma) ... res = fb->fb_mmap(info, vma); Where fb_mmap callback calls remap_vmalloc_range() directly without any explicit checks: *** drivers/video/fbdev/vfb.c static int vfb_mmap(struct fb_info *info, struct vm_area_struct *vma) { return remap_vmalloc_range(vma, (void *)info->fix.smem_start, vma->vm_pgoff); } Link: http://lkml.kernel.org/r/20190103145954.16942-2-rpenyaev@suse.deSigned-off-by: NRoman Penyaev <rpenyaev@suse.de> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Joe Perches <joe@perches.com> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Roman Penyaev 提交于
This patch repeats the original one from David S Miller: 2dca6999 ("mm, perf_event: Make vmalloc_user() align base kernel virtual address to SHMLBA") but for missed vmalloc_32_user() case, which also requires correct alignment of virtual address on kernel side to avoid D-caches aliases. A bit of copy-paste from original patch to recover in memory of what is all about: When a vmalloc'd area is mmap'd into userspace, some kind of co-ordination is necessary for this to work on platforms with cpu D-caches which can have aliases. Otherwise kernel side writes won't be seen properly in userspace and vice versa. If the kernel side mapping and the user side one have the same alignment, modulo SHMLBA, this can work as long as VM_SHARED is shared of VMA and for all current users this is true. VM_SHARED will force SHMLBA alignment of the user side mmap on platforms with D-cache aliasing matters. David S. Miller > What are the user-visible runtime effects of this change? In simple words: proper alignment avoids possible difference in data, seen by different virtual mapings: userspace and kernel in our case. I.e. userspace reads cache line A, kernel writes to cache line B. Both cache lines correspond to the same physical memory (thus aliases). So this should fix data corruption for archs with vivt and vipt caches, e.g. armv6. Personally I've never worked with this archs, I just spotted the strange difference in code: for one case we do alignment, for another - not. I have a strong feeling that David simply missed vmalloc_32_user() case. > > Is a -stable backport needed? No, I do not think so. The only one user of vmalloc_32_user() is virtual frame buffer device drivers/video/fbdev/vfb.c, which has in the description "The main use of this frame buffer device is testing and debugging the frame buffer subsystem. Do NOT enable it for normal systems!". And it seems to me that this vfb.c does not need 32bit addressable pages (vmalloc_32_user() case), because it is virtual device and should not care about things like dma32 zones, etc. Probably is better to clean the code and switch vfb.c from vmalloc_32_user() to vmalloc_user() case and wipe out vmalloc_32_user() from vmalloc.c completely. But I'm not very much sure that this is worth to do, that's so minor, so we can leave it as is. Link: http://lkml.kernel.org/r/20190108110944.23591-1-rpenyaev@suse.deSigned-off-by: NRoman Penyaev <rpenyaev@suse.de> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Michal Hocko <mhocko@suse.com> Cc: David S. Miller <davem@davemloft.net> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Liviu Dudau 提交于
find_vmap_area() can return a NULL pointer and we're going to dereference it without checking it first. Use the existing find_vm_area() function which does exactly what we want and checks for the NULL pointer. Link: http://lkml.kernel.org/r/20181228171009.22269-1-liviu@dudau.co.uk Fixes: f3c01d2f ("mm: vmalloc: avoid racy handling of debugobjects in vunmap") Signed-off-by: NLiviu Dudau <liviu@dudau.co.uk> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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