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2022-01-15mm/mempolicy: wire up syscall set_mempolicy_home_nodeAneesh Kumar K.V1-0/+1
Link: https://lkml.kernel.org/r/20211202123810.267175-4-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Ben Widawsky <ben.widawsky@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15dma/pool: create dma atomic pool only if dma zone has managed pagesBaoquan He1-2/+2
Currently three dma atomic pools are initialized as long as the relevant kernel codes are built in. While in kdump kernel of x86_64, this is not right when trying to create atomic_pool_dma, because there's no managed pages in DMA zone. In the case, DMA zone only has low 1M memory presented and locked down by memblock allocator. So no pages are added into buddy of DMA zone. Please check commit f1d4d47c5851 ("x86/setup: Always reserve the first 1M of RAM"). Then in kdump kernel of x86_64, it always prints below failure message: DMA: preallocated 128 KiB GFP_KERNEL pool for atomic allocations swapper/0: page allocation failure: order:5, mode:0xcc1(GFP_KERNEL|GFP_DMA), nodemask=(null),cpuset=/,mems_allowed=0 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-0.rc5.20210611git929d931f2b40.42.fc35.x86_64 #1 Hardware name: Dell Inc. PowerEdge R910/0P658H, BIOS 2.12.0 06/04/2018 Call Trace: dump_stack+0x7f/0xa1 warn_alloc.cold+0x72/0xd6 __alloc_pages_slowpath.constprop.0+0xf29/0xf50 __alloc_pages+0x24d/0x2c0 alloc_page_interleave+0x13/0xb0 atomic_pool_expand+0x118/0x210 __dma_atomic_pool_init+0x45/0x93 dma_atomic_pool_init+0xdb/0x176 do_one_initcall+0x67/0x320 kernel_init_freeable+0x290/0x2dc kernel_init+0xa/0x111 ret_from_fork+0x22/0x30 Mem-Info: ...... DMA: failed to allocate 128 KiB GFP_KERNEL|GFP_DMA pool for atomic allocation DMA: preallocated 128 KiB GFP_KERNEL|GFP_DMA32 pool for atomic allocations Here, let's check if DMA zone has managed pages, then create atomic_pool_dma if yes. Otherwise just skip it. Link: https://lkml.kernel.org/r/20211223094435.248523-3-bhe@redhat.com Fixes: 6f599d84231f ("x86/kdump: Always reserve the low 1M when the crashkernel option is specified") Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: John Donnelly <john.p.donnelly@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Laight <David.Laight@ACULAB.COM> Cc: David Rientjes <rientjes@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15mm/pagealloc: sysctl: change watermark_scale_factor max limit to 30%Suren Baghdasaryan1-1/+2
For embedded systems with low total memory, having to run applications with relatively large memory requirements, 10% max limitation for watermark_scale_factor poses an issue of triggering direct reclaim every time such application is started. This results in slow application startup times and bad end-user experience. By increasing watermark_scale_factor max limit we allow vendors more flexibility to choose the right level of kswapd aggressiveness for their device and workload requirements. Link: https://lkml.kernel.org/r/20211124193604.2758863-1-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Lukas Middendorf <kernel@tuxforce.de> Cc: Antti Palosaari <crope@iki.fi> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Zhang Yi <yi.zhang@huawei.com> Cc: Fengfei Xi <xi.fengfei@h3c.com> Cc: Mike Rapoport <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15mm: move anon_vma declarations to linux/mm_inline.hArnd Bergmann1-0/+1
The patch to add anonymous vma names causes a build failure in some configurations: include/linux/mm_types.h: In function 'is_same_vma_anon_name': include/linux/mm_types.h:924:37: error: implicit declaration of function 'strcmp' [-Werror=implicit-function-declaration] 924 | return name && vma_name && !strcmp(name, vma_name); | ^~~~~~ include/linux/mm_types.h:22:1: note: 'strcmp' is defined in header '<string.h>'; did you forget to '#include <string.h>'? This should not really be part of linux/mm_types.h in the first place, as that header is meant to only contain structure defintions and need a minimum set of indirect includes itself. While the header clearly includes more than it should at this point, let's not make it worse by including string.h as well, which would pull in the expensive (compile-speed wise) fortify-string logic. Move the new functions into a separate header that only needs to be included in a couple of locations. Link: https://lkml.kernel.org/r/20211207125710.2503446-1-arnd@kernel.org Fixes: "mm: add a field to store names for private anonymous memory" Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Colin Cross <ccross@google.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15mm: add a field to store names for private anonymous memoryColin Cross2-0/+65
In many userspace applications, and especially in VM based applications like Android uses heavily, there are multiple different allocators in use. At a minimum there is libc malloc and the stack, and in many cases there are libc malloc, the stack, direct syscalls to mmap anonymous memory, and multiple VM heaps (one for small objects, one for big objects, etc.). Each of these layers usually has its own tools to inspect its usage; malloc by compiling a debug version, the VM through heap inspection tools, and for direct syscalls there is usually no way to track them. On Android we heavily use a set of tools that use an extended version of the logic covered in Documentation/vm/pagemap.txt to walk all pages mapped in userspace and slice their usage by process, shared (COW) vs. unique mappings, backing, etc. This can account for real physical memory usage even in cases like fork without exec (which Android uses heavily to share as many private COW pages as possible between processes), Kernel SamePage Merging, and clean zero pages. It produces a measurement of the pages that only exist in that process (USS, for unique), and a measurement of the physical memory usage of that process with the cost of shared pages being evenly split between processes that share them (PSS). If all anonymous memory is indistinguishable then figuring out the real physical memory usage (PSS) of each heap requires either a pagemap walking tool that can understand the heap debugging of every layer, or for every layer's heap debugging tools to implement the pagemap walking logic, in which case it is hard to get a consistent view of memory across the whole system. Tracking the information in userspace leads to all sorts of problems. It either needs to be stored inside the process, which means every process has to have an API to export its current heap information upon request, or it has to be stored externally in a filesystem that somebody needs to clean up on crashes. It needs to be readable while the process is still running, so it has to have some sort of synchronization with every layer of userspace. Efficiently tracking the ranges requires reimplementing something like the kernel vma trees, and linking to it from every layer of userspace. It requires more memory, more syscalls, more runtime cost, and more complexity to separately track regions that the kernel is already tracking. This patch adds a field to /proc/pid/maps and /proc/pid/smaps to show a userspace-provided name for anonymous vmas. The names of named anonymous vmas are shown in /proc/pid/maps and /proc/pid/smaps as [anon:<name>]. Userspace can set the name for a region of memory by calling prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name) Setting the name to NULL clears it. The name length limit is 80 bytes including NUL-terminator and is checked to contain only printable ascii characters (including space), except '[',']','\','$' and '`'. Ascii strings are being used to have a descriptive identifiers for vmas, which can be understood by the users reading /proc/pid/maps or /proc/pid/smaps. Names can be standardized for a given system and they can include some variable parts such as the name of the allocator or a library, tid of the thread using it, etc. The name is stored in a pointer in the shared union in vm_area_struct that points to a null terminated string. Anonymous vmas with the same name (equivalent strings) and are otherwise mergeable will be merged. The name pointers are not shared between vmas even if they contain the same name. The name pointer is stored in a union with fields that are only used on file-backed mappings, so it does not increase memory usage. CONFIG_ANON_VMA_NAME kernel configuration is introduced to enable this feature. It keeps the feature disabled by default to prevent any additional memory overhead and to avoid confusing procfs parsers on systems which are not ready to support named anonymous vmas. The patch is based on the original patch developed by Colin Cross, more specifically on its latest version [1] posted upstream by Sumit Semwal. It used a userspace pointer to store vma names. In that design, name pointers could be shared between vmas. However during the last upstreaming attempt, Kees Cook raised concerns [2] about this approach and suggested to copy the name into kernel memory space, perform validity checks [3] and store as a string referenced from vm_area_struct. One big concern is about fork() performance which would need to strdup anonymous vma names. Dave Hansen suggested experimenting with worst-case scenario of forking a process with 64k vmas having longest possible names [4]. I ran this experiment on an ARM64 Android device and recorded a worst-case regression of almost 40% when forking such a process. This regression is addressed in the followup patch which replaces the pointer to a name with a refcounted structure that allows sharing the name pointer between vmas of the same name. Instead of duplicating the string during fork() or when splitting a vma it increments the refcount. [1] https://lore.kernel.org/linux-mm/20200901161459.11772-4-sumit.semwal@linaro.org/ [2] https://lore.kernel.org/linux-mm/202009031031.D32EF57ED@keescook/ [3] https://lore.kernel.org/linux-mm/202009031022.3834F692@keescook/ [4] https://lore.kernel.org/linux-mm/5d0358ab-8c47-2f5f-8e43-23b89d6a8e95@intel.com/ Changes for prctl(2) manual page (in the options section): PR_SET_VMA Sets an attribute specified in arg2 for virtual memory areas starting from the address specified in arg3 and spanning the size specified in arg4. arg5 specifies the value of the attribute to be set. Note that assigning an attribute to a virtual memory area might prevent it from being merged with adjacent virtual memory areas due to the difference in that attribute's value. Currently, arg2 must be one of: PR_SET_VMA_ANON_NAME Set a name for anonymous virtual memory areas. arg5 should be a pointer to a null-terminated string containing the name. The name length including null byte cannot exceed 80 bytes. If arg5 is NULL, the name of the appropriate anonymous virtual memory areas will be reset. The name can contain only printable ascii characters (including space), except '[',']','\','$' and '`'. This feature is available only if the kernel is built with the CONFIG_ANON_VMA_NAME option enabled. [surenb@google.com: docs: proc.rst: /proc/PID/maps: fix malformed table] Link: https://lkml.kernel.org/r/20211123185928.2513763-1-surenb@google.com [surenb: rebased over v5.15-rc6, replaced userpointer with a kernel copy, added input sanitization and CONFIG_ANON_VMA_NAME config. The bulk of the work here was done by Colin Cross, therefore, with his permission, keeping him as the author] Link: https://lkml.kernel.org/r/20211019215511.3771969-2-surenb@google.com Signed-off-by: Colin Cross <ccross@google.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Glauber <jan.glauber@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Landley <rob@landley.net> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Shaohua Li <shli@fusionio.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15trace/hwlat: make use of the helper function kthread_run_on_cpu()Cai Huoqing1-5/+1
Replace kthread_create_on_cpu/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-7-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15trace/osnoise: make use of the helper function kthread_run_on_cpu()Cai Huoqing1-2/+1
Replace kthread_create_on_cpu/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-6-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15rcutorture: make use of the helper function kthread_run_on_cpu()Cai Huoqing1-5/+2
Replace kthread_create_on_node/kthread_bind/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-5-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15ring-buffer: make use of the helper function kthread_run_on_cpu()Cai Huoqing1-5/+2
Replace kthread_create/kthread_bind/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-4-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15kthread: add the helper function kthread_run_on_cpu()Cai Huoqing1-0/+1
Add a new helper function kthread_run_on_cpu(), which includes kthread_create_on_cpu/wake_up_process(). In some cases, use kthread_run_on_cpu() directly instead of kthread_create_on_node/kthread_bind/wake_up_process() or kthread_create_on_cpu/wake_up_process() or kthreadd_create/kthread_bind/wake_up_process() to simplify the code. [akpm@linux-foundation.org: export kthread_create_on_cpu to modules] Link: https://lkml.kernel.org/r/20211022025711.3673-2-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Cai Huoqing <caihuoqing@baidu.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-07Merge branch 'for-5.16-fixes' of ↵Linus Torvalds3-43/+97
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "This contains the cgroup.procs permission check fixes so that they use the credentials at the time of open rather than write, which also fixes the cgroup namespace lifetime bug" * 'for-5.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: selftests: cgroup: Test open-time cgroup namespace usage for migration checks selftests: cgroup: Test open-time credential usage for migration checks selftests: cgroup: Make cg_create() use 0755 for permission instead of 0644 cgroup: Use open-time cgroup namespace for process migration perm checks cgroup: Allocate cgroup_file_ctx for kernfs_open_file->priv cgroup: Use open-time credentials for process migraton perm checks
2022-01-06Merge tag 'trace-v5.16-rc8' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Three minor tracing fixes: - Fix missing prototypes in sample module for direct functions - Fix check of valid buffer in get_trace_buf() - Fix annotations of percpu pointers" * tag 'trace-v5.16-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Tag trace_percpu_buffer as a percpu pointer tracing: Fix check for trace_percpu_buffer validity in get_trace_buf() ftrace/samples: Add missing prototypes direct functions
2022-01-06cgroup: Use open-time cgroup namespace for process migration perm checksTejun Heo2-9/+21
cgroup process migration permission checks are performed at write time as whether a given operation is allowed or not is dependent on the content of the write - the PID. This currently uses current's cgroup namespace which is a potential security weakness as it may allow scenarios where a less privileged process tricks a more privileged one into writing into a fd that it created. This patch makes cgroup remember the cgroup namespace at the time of open and uses it for migration permission checks instad of current's. Note that this only applies to cgroup2 as cgroup1 doesn't have namespace support. This also fixes a use-after-free bug on cgroupns reported in https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com Note that backporting this fix also requires the preceding patch. Reported-by: "Eric W. Biederman" <ebiederm@xmission.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Reported-by: syzbot+50f5cf33a284ce738b62@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com Fixes: 5136f6365ce3 ("cgroup: implement "nsdelegate" mount option") Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-06cgroup: Allocate cgroup_file_ctx for kernfs_open_file->privTejun Heo3-31/+65
of->priv is currently used by each interface file implementation to store private information. This patch collects the current two private data usages into struct cgroup_file_ctx which is allocated and freed by the common path. This allows generic private data which applies to multiple files, which will be used to in the following patch. Note that cgroup_procs iterator is now embedded as procs.iter in the new cgroup_file_ctx so that it doesn't need to be allocated and freed separately. v2: union dropped from cgroup_file_ctx and the procs iterator is embedded in cgroup_file_ctx as suggested by Linus. v3: Michal pointed out that cgroup1's procs pidlist uses of->priv too. Converted. Didn't change to embedded allocation as cgroup1 pidlists get stored for caching. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Michal Koutný <mkoutny@suse.com>
2022-01-06cgroup: Use open-time credentials for process migraton perm checksTejun Heo2-4/+12
cgroup process migration permission checks are performed at write time as whether a given operation is allowed or not is dependent on the content of the write - the PID. This currently uses current's credentials which is a potential security weakness as it may allow scenarios where a less privileged process tricks a more privileged one into writing into a fd that it created. This patch makes both cgroup2 and cgroup1 process migration interfaces to use the credentials saved at the time of open (file->f_cred) instead of current's. Reported-by: "Eric W. Biederman" <ebiederm@xmission.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Fixes: 187fe84067bd ("cgroup: require write perm on common ancestor when moving processes on the default hierarchy") Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-05tracing: Tag trace_percpu_buffer as a percpu pointerNaveen N. Rao1-2/+2
Tag trace_percpu_buffer as a percpu pointer to resolve warnings reported by sparse: /linux/kernel/trace/trace.c:3218:46: warning: incorrect type in initializer (different address spaces) /linux/kernel/trace/trace.c:3218:46: expected void const [noderef] __percpu *__vpp_verify /linux/kernel/trace/trace.c:3218:46: got struct trace_buffer_struct * /linux/kernel/trace/trace.c:3234:9: warning: incorrect type in initializer (different address spaces) /linux/kernel/trace/trace.c:3234:9: expected void const [noderef] __percpu *__vpp_verify /linux/kernel/trace/trace.c:3234:9: got int * Link: https://lkml.kernel.org/r/ebabd3f23101d89cb75671b68b6f819f5edc830b.1640255304.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Fixes: 07d777fe8c398 ("tracing: Add percpu buffers for trace_printk()") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-05tracing: Fix check for trace_percpu_buffer validity in get_trace_buf()Naveen N. Rao1-1/+1
With the new osnoise tracer, we are seeing the below splat: Kernel attempted to read user page (c7d880000) - exploit attempt? (uid: 0) BUG: Unable to handle kernel data access on read at 0xc7d880000 Faulting instruction address: 0xc0000000002ffa10 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries ... NIP [c0000000002ffa10] __trace_array_vprintk.part.0+0x70/0x2f0 LR [c0000000002ff9fc] __trace_array_vprintk.part.0+0x5c/0x2f0 Call Trace: [c0000008bdd73b80] [c0000000001c49cc] put_prev_task_fair+0x3c/0x60 (unreliable) [c0000008bdd73be0] [c000000000301430] trace_array_printk_buf+0x70/0x90 [c0000008bdd73c00] [c0000000003178b0] trace_sched_switch_callback+0x250/0x290 [c0000008bdd73c90] [c000000000e70d60] __schedule+0x410/0x710 [c0000008bdd73d40] [c000000000e710c0] schedule+0x60/0x130 [c0000008bdd73d70] [c000000000030614] interrupt_exit_user_prepare_main+0x264/0x270 [c0000008bdd73de0] [c000000000030a70] syscall_exit_prepare+0x150/0x180 [c0000008bdd73e10] [c00000000000c174] system_call_vectored_common+0xf4/0x278 osnoise tracer on ppc64le is triggering osnoise_taint() for negative duration in get_int_safe_duration() called from trace_sched_switch_callback()->thread_exit(). The problem though is that the check for a valid trace_percpu_buffer is incorrect in get_trace_buf(). The check is being done after calculating the pointer for the current cpu, rather than on the main percpu pointer. Fix the check to be against trace_percpu_buffer. Link: https://lkml.kernel.org/r/a920e4272e0b0635cf20c444707cbce1b2c8973d.1640255304.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: e2ace001176dc9 ("tracing: Choose static tp_printk buffer by explicit nesting count") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2021-12-25Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+11
Merge misc fixes from Andrew Morton: "9 patches. Subsystems affected by this patch series: mm (kfence, mempolicy, memory-failure, pagemap, pagealloc, damon, and memory-failure), core-kernel, and MAINTAINERS" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm/hwpoison: clear MF_COUNT_INCREASED before retrying get_any_page() mm/damon/dbgfs: protect targets destructions with kdamond_lock mm/page_alloc: fix __alloc_size attribute for alloc_pages_exact_nid mm: delete unsafe BUG from page_cache_add_speculative() mm, hwpoison: fix condition in free hugetlb page path MAINTAINERS: mark more list instances as moderated kernel/crash_core: suppress unknown crashkernel parameter warning mm: mempolicy: fix THP allocations escaping mempolicy restrictions kfence: fix memory leak when cat kfence objects
2021-12-25kernel/crash_core: suppress unknown crashkernel parameter warningPhilipp Rudo1-0/+11
When booting with crashkernel= on the kernel command line a warning similar to Kernel command line: ro console=ttyS0 crashkernel=256M Unknown kernel command line parameters "crashkernel=256M", will be passed to user space. is printed. This comes from crashkernel= being parsed independent from the kernel parameter handling mechanism. So the code in init/main.c doesn't know that crashkernel= is a valid kernel parameter and prints this incorrect warning. Suppress the warning by adding a dummy early_param handler for crashkernel=. Link: https://lkml.kernel.org/r/20211208133443.6867-1-prudo@redhat.com Fixes: 86d1919a4fb0 ("init: print out unknown kernel parameters") Signed-off-by: Philipp Rudo <prudo@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Andrew Halaney <ahalaney@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-23Merge branch 'ucount-rlimit-fixes-for-v5.16' of ↵Linus Torvalds1-6/+9
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ucount fix from Eric Biederman: "This fixes a silly logic bug in the ucount rlimits code, where it was comparing against the wrong limit" * 'ucount-rlimit-fixes-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ucounts: Fix rlimit max values check
2021-12-19Merge tag 'timers_urgent_for_v5.16_rc6' of ↵Linus Torvalds1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Borislav Petkov: - Make sure the CLOCK_REALTIME to CLOCK_MONOTONIC offset is never positive * tag 'timers_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timekeeping: Really make sure wall_to_monotonic isn't positive
2021-12-19Merge tag 'locking_urgent_for_v5.16_rc6' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fix from Borislav Petkov: - Fix the rtmutex condition checking when the optimistic spinning of a waiter needs to be terminated * tag 'locking_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/rtmutex: Fix incorrect condition in rtmutex_spin_on_owner()
2021-12-19Merge tag 'core_urgent_for_v5.16_rc6' of ↵Linus Torvalds1-0/+9
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull signal handlign fix from Borislav Petkov: - Prevent lock contention on the new sigaltstack lock on the common-case path, when no changes have been made to the alternative signal stack. * tag 'core_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: signal: Skip the altstack update when not needed
2021-12-18locking/rtmutex: Fix incorrect condition in rtmutex_spin_on_owner()Zqiang1-1/+1
Optimistic spinning needs to be terminated when the spinning waiter is not longer the top waiter on the lock, but the condition is negated. It terminates if the waiter is the top waiter, which is defeating the whole purpose. Fixes: c3123c431447 ("locking/rtmutex: Dont dereference waiter lockless") Signed-off-by: Zqiang <qiang1.zhang@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211217074207.77425-1-qiang1.zhang@intel.com
2021-12-17timekeeping: Really make sure wall_to_monotonic isn't positiveYu Liao1-2/+1
Even after commit e1d7ba873555 ("time: Always make sure wall_to_monotonic isn't positive") it is still possible to make wall_to_monotonic positive by running the following code: int main(void) { struct timespec time; clock_gettime(CLOCK_MONOTONIC, &time); time.tv_nsec = 0; clock_settime(CLOCK_REALTIME, &time); return 0; } The reason is that the second parameter of timespec64_compare(), ts_delta, may be unnormalized because the delta is calculated with an open coded substraction which causes the comparison of tv_sec to yield the wrong result: wall_to_monotonic = { .tv_sec = -10, .tv_nsec = 900000000 } ts_delta = { .tv_sec = -9, .tv_nsec = -900000000 } That makes timespec64_compare() claim that wall_to_monotonic < ts_delta, but actually the result should be wall_to_monotonic > ts_delta. After normalization, the result of timespec64_compare() is correct because the tv_sec comparison is not longer misleading: wall_to_monotonic = { .tv_sec = -10, .tv_nsec = 900000000 } ts_delta = { .tv_sec = -10, .tv_nsec = 100000000 } Use timespec64_sub() to ensure that ts_delta is normalized, which fixes the issue. Fixes: e1d7ba873555 ("time: Always make sure wall_to_monotonic isn't positive") Signed-off-by: Yu Liao <liaoyu15@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211213135727.1656662-1-liaoyu15@huawei.com
2021-12-16Merge tag 'audit-pr-20211216' of ↵Linus Torvalds1-11/+10
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit Pull audit fix from Paul Moore: "A single patch to fix a problem where the audit queue could grow unbounded when the audit daemon is forcibly stopped" * tag 'audit-pr-20211216' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: improve robustness of the audit queue handling
2021-12-16Merge tag 'net-5.16-rc6' of ↵Linus Torvalds1-17/+36
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Networking fixes, including fixes from mac80211, wifi, bpf. Relatively large batches of fixes from BPF and the WiFi stack, calm in general networking. Current release - regressions: - dpaa2-eth: fix buffer overrun when reporting ethtool statistics Current release - new code bugs: - bpf: fix incorrect state pruning for <8B spill/fill - iavf: - add missing unlocks in iavf_watchdog_task() - do not override the adapter state in the watchdog task (again) - mlxsw: spectrum_router: consolidate MAC profiles when possible Previous releases - regressions: - mac80211 fixes: - rate control, avoid driver crash for retransmitted frames - regression in SSN handling of addba tx - a memory leak where sta_info is not freed - marking TX-during-stop for TX in in_reconfig, prevent stall - cfg80211: acquire wiphy mutex on regulatory work - wifi drivers: fix build regressions and LED config dependency - virtio_net: fix rx_drops stat for small pkts - dsa: mv88e6xxx: unforce speed & duplex in mac_link_down() Previous releases - always broken: - bpf fixes: - kernel address leakage in atomic fetch - kernel address leakage in atomic cmpxchg's r0 aux reg - signed bounds propagation after mov32 - extable fixup offset - extable address check - mac80211: - fix the size used for building probe request - send ADDBA requests using the tid/queue of the aggregation session - agg-tx: don't schedule_and_wake_txq() under sta->lock, avoid deadlocks - validate extended element ID is present - mptcp: - never allow the PM to close a listener subflow (null-defer) - clear 'kern' flag from fallback sockets, prevent crash - fix deadlock in __mptcp_push_pending() - inet_diag: fix kernel-infoleak for UDP sockets - xsk: do not sleep in poll() when need_wakeup set - smc: avoid very long waits in smc_release() - sch_ets: don't remove idle classes from the round-robin list - netdevsim: - zero-initialize memory for bpf map's value, prevent info leak - don't let user space overwrite read only (max) ethtool parms - ixgbe: set X550 MDIO speed before talking to PHY - stmmac: - fix null-deref in flower deletion w/ VLAN prio Rx steering - dwmac-rk: fix oob read in rk_gmac_setup - ice: time stamping fixes - systemport: add global locking for descriptor life cycle" * tag 'net-5.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (89 commits) bpf, selftests: Fix racing issue in btf_skc_cls_ingress test selftest/bpf: Add a test that reads various addresses. bpf: Fix extable address check. bpf: Fix extable fixup offset. bpf, selftests: Add test case trying to taint map value pointer bpf: Make 32->64 bounds propagation slightly more robust bpf: Fix signed bounds propagation after mov32 sit: do not call ipip6_dev_free() from sit_init_net() net: systemport: Add global locking for descriptor lifecycle net/smc: Prevent smc_release() from long blocking net: Fix double 0x prefix print in SKB dump virtio_net: fix rx_drops stat for small pkts dsa: mv88e6xxx: fix debug print for SPEED_UNFORCED sfc_ef100: potential dereference of null pointer net: stmmac: dwmac-rk: fix oob read in rk_gmac_setup net: usb: lan78xx: add Allied Telesis AT29M2-AF net/packet: rx_owner_map depends on pg_vec netdevsim: Zero-initialize memory for new map's value in function nsim_bpf_map_alloc dpaa2-eth: fix ethtool statistics ixgbe: set X550 MDIO speed before talking to PHY ...
2021-12-16bpf: Make 32->64 bounds propagation slightly more robustDaniel Borkmann1-9/+15
Make the bounds propagation in __reg_assign_32_into_64() slightly more robust and readable by aligning it similarly as we did back in the __reg_combine_64_into_32() counterpart. Meaning, only propagate or pessimize them as a smin/smax pair. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-12-16bpf: Fix signed bounds propagation after mov32Daniel Borkmann1-0/+4
For the case where both s32_{min,max}_value bounds are positive, the __reg_assign_32_into_64() directly propagates them to their 64 bit counterparts, otherwise it pessimises them into [0,u32_max] universe and tries to refine them later on by learning through the tnum as per comment in mentioned function. However, that does not always happen, for example, in mov32 operation we call zext_32_to_64(dst_reg) which invokes the __reg_assign_32_into_64() as is without subsequent bounds update as elsewhere thus no refinement based on tnum takes place. Thus, not calling into the __update_reg_bounds() / __reg_deduce_bounds() / __reg_bound_offset() triplet as we do, for example, in case of ALU ops via adjust_scalar_min_max_vals(), will lead to more pessimistic bounds when dumping the full register state: Before fix: 0: (b4) w0 = -1 1: R0_w=invP4294967295 (id=0,imm=ffffffff, smin_value=4294967295,smax_value=4294967295, umin_value=4294967295,umax_value=4294967295, var_off=(0xffffffff; 0x0), s32_min_value=-1,s32_max_value=-1, u32_min_value=-1,u32_max_value=-1) 1: (bc) w0 = w0 2: R0_w=invP4294967295 (id=0,imm=ffffffff, smin_value=0,smax_value=4294967295, umin_value=4294967295,umax_value=4294967295, var_off=(0xffffffff; 0x0), s32_min_value=-1,s32_max_value=-1, u32_min_value=-1,u32_max_value=-1) Technically, the smin_value=0 and smax_value=4294967295 bounds are not incorrect, but given the register is still a constant, they break assumptions about const scalars that smin_value == smax_value and umin_value == umax_value. After fix: 0: (b4) w0 = -1 1: R0_w=invP4294967295 (id=0,imm=ffffffff, smin_value=4294967295,smax_value=4294967295, umin_value=4294967295,umax_value=4294967295, var_off=(0xffffffff; 0x0), s32_min_value=-1,s32_max_value=-1, u32_min_value=-1,u32_max_value=-1) 1: (bc) w0 = w0 2: R0_w=invP4294967295 (id=0,imm=ffffffff, smin_value=4294967295,smax_value=4294967295, umin_value=4294967295,umax_value=4294967295, var_off=(0xffffffff; 0x0), s32_min_value=-1,s32_max_value=-1, u32_min_value=-1,u32_max_value=-1) Without the smin_value == smax_value and umin_value == umax_value invariant being intact for const scalars, it is possible to leak out kernel pointers from unprivileged user space if the latter is enabled. For example, when such registers are involved in pointer arithmtics, then adjust_ptr_min_max_vals() will taint the destination register into an unknown scalar, and the latter can be exported and stored e.g. into a BPF map value. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: Kuee K1r0a <liulin063@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-12-15audit: improve robustness of the audit queue handlingPaul Moore1-11/+10
If the audit daemon were ever to get stuck in a stopped state the kernel's kauditd_thread() could get blocked attempting to send audit records to the userspace audit daemon. With the kernel thread blocked it is possible that the audit queue could grow unbounded as certain audit record generating events must be exempt from the queue limits else the system enter a deadlock state. This patch resolves this problem by lowering the kernel thread's socket sending timeout from MAX_SCHEDULE_TIMEOUT to HZ/10 and tweaks the kauditd_send_queue() function to better manage the various audit queues when connection problems occur between the kernel and the audit daemon. With this patch, the backlog may temporarily grow beyond the defined limits when the audit daemon is stopped and the system is under heavy audit pressure, but kauditd_thread() will continue to make progress and drain the queues as it would for other connection problems. For example, with the audit daemon put into a stopped state and the system configured to audit every syscall it was still possible to shutdown the system without a kernel panic, deadlock, etc.; granted, the system was slow to shutdown but that is to be expected given the extreme pressure of recording every syscall. The timeout value of HZ/10 was chosen primarily through experimentation and this developer's "gut feeling". There is likely no one perfect value, but as this scenario is limited in scope (root privileges would be needed to send SIGSTOP to the audit daemon), it is likely not worth exposing this as a tunable at present. This can always be done at a later date if it proves necessary. Cc: stable@vger.kernel.org Fixes: 5b52330bbfe63 ("audit: fix auditd/kernel connection state tracking") Reported-by: Gaosheng Cui <cuigaosheng1@huawei.com> Tested-by: Gaosheng Cui <cuigaosheng1@huawei.com> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-12-14bpf: Fix kernel address leakage in atomic cmpxchg's r0 aux regDaniel Borkmann1-1/+8
The implementation of BPF_CMPXCHG on a high level has the following parameters: .-[old-val] .-[new-val] BPF_R0 = cmpxchg{32,64}(DST_REG + insn->off, BPF_R0, SRC_REG) `-[mem-loc] `-[old-val] Given a BPF insn can only have two registers (dst, src), the R0 is fixed and used as an auxilliary register for input (old value) as well as output (returning old value from memory location). While the verifier performs a number of safety checks, it misses to reject unprivileged programs where R0 contains a pointer as old value. Through brute-forcing it takes about ~16sec on my machine to leak a kernel pointer with BPF_CMPXCHG. The PoC is basically probing for kernel addresses by storing the guessed address into the map slot as a scalar, and using the map value pointer as R0 while SRC_REG has a canary value to detect a matching address. Fix it by checking R0 for pointers, and reject if that's the case for unprivileged programs. Fixes: 5ffa25502b5a ("bpf: Add instructions for atomic_[cmp]xchg") Reported-by: Ryota Shiga (Flatt Security) Acked-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-12-14bpf: Fix kernel address leakage in atomic fetchDaniel Borkmann1-3/+9
The change in commit 37086bfdc737 ("bpf: Propagate stack bounds to registers in atomics w/ BPF_FETCH") around check_mem_access() handling is buggy since this would allow for unprivileged users to leak kernel pointers. For example, an atomic fetch/and with -1 on a stack destination which holds a spilled pointer will migrate the spilled register type into a scalar, which can then be exported out of the program (since scalar != pointer) by dumping it into a map value. The original implementation of XADD was preventing this situation by using a double call to check_mem_access() one with BPF_READ and a subsequent one with BPF_WRITE, in both cases passing -1 as a placeholder value instead of register as per XADD semantics since it didn't contain a value fetch. The BPF_READ also included a check in check_stack_read_fixed_off() which rejects the program if the stack slot is of __is_pointer_value() if dst_regno < 0. The latter is to distinguish whether we're dealing with a regular stack spill/ fill or some arithmetical operation which is disallowed on non-scalars, see also 6e7e63cbb023 ("bpf: Forbid XADD on spilled pointers for unprivileged users") for more context on check_mem_access() and its handling of placeholder value -1. One minimally intrusive option to fix the leak is for the BPF_FETCH case to initially check the BPF_READ case via check_mem_access() with -1 as register, followed by the actual load case with non-negative load_reg to propagate stack bounds to registers. Fixes: 37086bfdc737 ("bpf: Propagate stack bounds to registers in atomics w/ BPF_FETCH") Reported-by: <n4ke4mry@gmail.com> Acked-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-12-14signal: Skip the altstack update when not neededChang S. Bae1-0/+9
== Background == Support for large, "dynamic" fpstates was recently merged. This included code to ensure that sigaltstacks are sufficiently sized for these large states. A new lock was added to remove races between enabling large features and setting up sigaltstacks. == Problem == The new lock (sigaltstack_lock()) is acquired in the sigreturn path before restoring the old sigaltstack. Unfortunately, contention on the new lock causes a measurable signal handling performance regression [1]. However, the common case is that no *changes* are made to the sigaltstack state at sigreturn. == Solution == do_sigaltstack() acquires sigaltstack_lock() and is used for both sys_sigaltstack() and restoring the sigaltstack in sys_sigreturn(). Check for changes to the sigaltstack before taking the lock. If no changes were made, return before acquiring the lock. This removes lock contention from the common-case sigreturn path. [1] https://lore.kernel.org/lkml/20211207012128.GA16074@xsang-OptiPlex-9020/ Fixes: 3aac3ebea08f ("x86/signal: Implement sigaltstack size validation") Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20211210225503.12734-1-chang.seok.bae@intel.com
2021-12-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-7/+9
Merge misc fixes from Andrew Morton: "21 patches. Subsystems affected by this patch series: MAINTAINERS, mailmap, and mm (mlock, pagecache, damon, slub, memcg, hugetlb, and pagecache)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (21 commits) mm: bdi: initialize bdi_min_ratio when bdi is unregistered hugetlbfs: fix issue of preallocation of gigantic pages can't work mm/memcg: relocate mod_objcg_mlstate(), get_obj_stock() and put_obj_stock() mm/slub: fix endianness bug for alloc/free_traces attributes selftests/damon: split test cases selftests/damon: test debugfs file reads/writes with huge count selftests/damon: test wrong DAMOS condition ranges input selftests/damon: test DAMON enabling with empty target_ids case selftests/damon: skip test if DAMON is running mm/damon/vaddr-test: remove unnecessary variables mm/damon/vaddr-test: split a test function having >1024 bytes frame size mm/damon/vaddr: remove an unnecessary warning message mm/damon/core: remove unnecessary error messages mm/damon/dbgfs: remove an unnecessary error message mm/damon/core: use better timer mechanisms selection threshold mm/damon/core: fix fake load reports due to uninterruptible sleeps timers: implement usleep_idle_range() filemap: remove PageHWPoison check from next_uptodate_page() mailmap: update email address for Guo Ren MAINTAINERS: update kdump maintainers ...
2021-12-10timers: implement usleep_idle_range()SeongJae Park1-7/+9
Patch series "mm/damon: Fix fake /proc/loadavg reports", v3. This patchset fixes DAMON's fake load report issue. The first patch makes yet another variant of usleep_range() for this fix, and the second patch fixes the issue of DAMON by making it using the newly introduced function. This patch (of 2): Some kernel threads such as DAMON could need to repeatedly sleep in micro seconds level. Because usleep_range() sleeps in uninterruptible state, however, such threads would make /proc/loadavg reports fake load. To help such cases, this commit implements a variant of usleep_range() called usleep_idle_range(). It is same to usleep_range() but sets the state of the current task as TASK_IDLE while sleeping. Link: https://lkml.kernel.org/r/20211126145015.15862-1-sj@kernel.org Link: https://lkml.kernel.org/r/20211126145015.15862-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: John Stultz <john.stultz@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-10Merge tag 'trace-v5.16-rc4' of ↵Linus Torvalds2-6/+13
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Tracing, ftrace and tracefs fixes: - Have tracefs honor the gid mount option - Have new files in tracefs inherit the parent ownership - Have direct_ops unregister when it has no more functions - Properly clean up the ops when unregistering multi direct ops - Add a sample module to test the multiple direct ops - Fix memory leak in error path of __create_synth_event()" * tag 'trace-v5.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix possible memory leak in __create_synth_event() error path ftrace/samples: Add module to test multi direct modify interface ftrace: Add cleanup to unregister_ftrace_direct_multi ftrace: Use direct_ops hash in unregister_ftrace_direct tracefs: Set all files to the same group ownership as the mount option tracefs: Have new files inherit the ownership of their parent
2021-12-10Merge tag 'aio-poll-for-linus' of ↵Linus Torvalds1-0/+7
git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux Pull aio poll fixes from Eric Biggers: "Fix three bugs in aio poll, and one issue with POLLFREE more broadly: - aio poll didn't handle POLLFREE, causing a use-after-free. - aio poll could block while the file is ready. - aio poll called eventfd_signal() when it isn't allowed. - POLLFREE didn't handle multiple exclusive waiters correctly. This has been tested with the libaio test suite, as well as with test programs I wrote that reproduce the first two bugs. I am sending this pull request myself as no one seems to be maintaining this code" * tag 'aio-poll-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: aio: Fix incorrect usage of eventfd_signal_allowed() aio: fix use-after-free due to missing POLLFREE handling aio: keep poll requests on waitqueue until completed signalfd: use wake_up_pollfree() binder: use wake_up_pollfree() wait: add wake_up_pollfree()
2021-12-10bpf: Fix incorrect state pruning for <8B spill/fillPaul Chaignon1-4/+0
Commit 354e8f1970f8 ("bpf: Support <8-byte scalar spill and refill") introduced support in the verifier to track <8B spill/fills of scalars. The backtracking logic for the precision bit was however skipping spill/fills of less than 8B. That could cause state pruning to consider two states equivalent when they shouldn't be. As an example, consider the following bytecode snippet: 0: r7 = r1 1: call bpf_get_prandom_u32 2: r6 = 2 3: if r0 == 0 goto pc+1 4: r6 = 3 ... 8: [state pruning point] ... /* u32 spill/fill */ 10: *(u32 *)(r10 - 8) = r6 11: r8 = *(u32 *)(r10 - 8) 12: r0 = 0 13: if r8 == 3 goto pc+1 14: r0 = 1 15: exit The verifier first walks the path with R6=3. Given the support for <8B spill/fills, at instruction 13, it knows the condition is true and skips instruction 14. At that point, the backtracking logic kicks in but stops at the fill instruction since it only propagates the precision bit for 8B spill/fill. When the verifier then walks the path with R6=2, it will consider it safe at instruction 8 because R6 is not marked as needing precision. Instruction 14 is thus never walked and is then incorrectly removed as 'dead code'. It's also possible to lead the verifier to accept e.g. an out-of-bound memory access instead of causing an incorrect dead code elimination. This regression was found via Cilium's bpf-next CI where it was causing a conntrack map update to be silently skipped because the code had been removed by the verifier. This commit fixes it by enabling support for <8B spill/fills in the bactracking logic. In case of a <8B spill/fill, the full 8B stack slot will be marked as needing precision. Then, in __mark_chain_precision, any tracked register spilled in a marked slot will itself be marked as needing precision, regardless of the spill size. This logic makes two assumptions: (1) only 8B-aligned spill/fill are tracked and (2) spilled registers are only tracked if the spill and fill sizes are equal. Commit ef979017b837 ("bpf: selftest: Add verifier tests for <8-byte scalar spill and refill") covers the first assumption and the next commit in this patchset covers the second. Fixes: 354e8f1970f8 ("bpf: Support <8-byte scalar spill and refill") Signed-off-by: Paul Chaignon <paul@isovalent.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-12-09ucounts: Fix rlimit max values checkAlexey Gladkov1-6/+9
The semantics of the rlimit max values differs from ucounts itself. When creating a new userns, we store the current rlimit of the process in ucount_max. Thus, the value of the limit in the parent userns is saved in the created one. The problem is that now we are taking the maximum value for counter from the same userns. So for init_user_ns it will always be RLIM_INFINITY. To fix the problem we need to check the counter value with the max value stored in userns. Reproducer: su - test -c "ulimit -u 3; sleep 5 & sleep 6 & unshare -U --map-root-user sh -c 'sleep 7 & sleep 8 & date; wait'" Before: [1] 175 [2] 176 Fri Nov 26 13:48:20 UTC 2021 [1]- Done sleep 5 [2]+ Done sleep 6 After: [1] 167 [2] 168 sh: fork: retry: Resource temporarily unavailable sh: fork: retry: Resource temporarily unavailable sh: fork: retry: Resource temporarily unavailable sh: fork: retry: Resource temporarily unavailable sh: fork: retry: Resource temporarily unavailable sh: fork: retry: Resource temporarily unavailable sh: fork: retry: Resource temporarily unavailable sh: fork: Interrupted system call [1]- Done sleep 5 [2]+ Done sleep 6 Fixes: c54b245d0118 ("Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace") Reported-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Alexey Gladkov <legion@kernel.org> Link: https://lkml.kernel.org/r/024ec805f6e16896f0b23e094773790d171d2c1c.1638218242.git.legion@kernel.org Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2021-12-09Merge tag 'net-5.16-rc5' of ↵Linus Torvalds2-10/+3
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from bpf, can and netfilter. Current release - regressions: - bpf, sockmap: re-evaluate proto ops when psock is removed from sockmap Current release - new code bugs: - bpf: fix bpf_check_mod_kfunc_call for built-in modules - ice: fixes for TC classifier offloads - vrf: don't run conntrack on vrf with !dflt qdisc Previous releases - regressions: - bpf: fix the off-by-two error in range markings - seg6: fix the iif in the IPv6 socket control block - devlink: fix netns refcount leak in devlink_nl_cmd_reload() - dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's" - dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports Previous releases - always broken: - ethtool: do not perform operations on net devices being unregistered - udp: use datalen to cap max gso segments - ice: fix races in stats collection - fec: only clear interrupt of handling queue in fec_enet_rx_queue() - m_can: pci: fix incorrect reference clock rate - m_can: disable and ignore ELO interrupt - mvpp2: fix XDP rx queues registering Misc: - treewide: add missing includes masked by cgroup -> bpf.h dependency" * tag 'net-5.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (82 commits) net: dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports net: wwan: iosm: fixes unable to send AT command during mbim tx net: wwan: iosm: fixes net interface nonfunctional after fw flash net: wwan: iosm: fixes unnecessary doorbell send net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering MAINTAINERS: s390/net: remove myself as maintainer net/sched: fq_pie: prevent dismantle issue net: mana: Fix memory leak in mana_hwc_create_wq seg6: fix the iif in the IPv6 socket control block nfp: Fix memory leak in nfp_cpp_area_cache_add() nfc: fix potential NULL pointer deref in nfc_genl_dump_ses_done nfc: fix segfault in nfc_genl_dump_devices_done udp: using datalen to cap max gso segments net: dsa: mv88e6xxx: error handling for serdes_power functions can: kvaser_usb: get CAN clock frequency from device can: kvaser_pciefd: kvaser_pciefd_rx_error_frame(): increase correct stats->{rx,tx}_errors counter net: mvpp2: fix XDP rx queues registering vmxnet3: fix minimum vectors alloc issue net, neigh: clear whole pneigh_entry at alloc time net: dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's" ...
2021-12-09wait: add wake_up_pollfree()Eric Biggers1-0/+7
Several ->poll() implementations are special in that they use a waitqueue whose lifetime is the current task, rather than the struct file as is normally the case. This is okay for blocking polls, since a blocking poll occurs within one task; however, non-blocking polls require another solution. This solution is for the queue to be cleared before it is freed, using 'wake_up_poll(wq, EPOLLHUP | POLLFREE);'. However, that has a bug: wake_up_poll() calls __wake_up() with nr_exclusive=1. Therefore, if there are multiple "exclusive" waiters, and the wakeup function for the first one returns a positive value, only that one will be called. That's *not* what's needed for POLLFREE; POLLFREE is special in that it really needs to wake up everyone. Considering the three non-blocking poll systems: - io_uring poll doesn't handle POLLFREE at all, so it is broken anyway. - aio poll is unaffected, since it doesn't support exclusive waits. However, that's fragile, as someone could add this feature later. - epoll doesn't appear to be broken by this, since its wakeup function returns 0 when it sees POLLFREE. But this is fragile. Although there is a workaround (see epoll), it's better to define a function which always sends POLLFREE to all waiters. Add such a function. Also make it verify that the queue really becomes empty after all waiters have been woken up. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211209010455.42744-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2021-12-09tracing: Fix possible memory leak in __create_synth_event() error pathMiaoqian Lin1-5/+6
There's error paths in __create_synth_event() after the argv is allocated that fail to free it. Add a jump to free it when necessary. Link: https://lkml.kernel.org/r/20211209024317.11783-1-linmq006@gmail.com Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Miaoqian Lin <linmq006@gmail.com> [ Fixed up the patch and change log ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-08Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfJakub Kicinski2-10/+3
Daniel Borkmann says: ==================== bpf 2021-12-08 We've added 12 non-merge commits during the last 22 day(s) which contain a total of 29 files changed, 659 insertions(+), 80 deletions(-). The main changes are: 1) Fix an off-by-two error in packet range markings and also add a batch of new tests for coverage of these corner cases, from Maxim Mikityanskiy. 2) Fix a compilation issue on MIPS JIT for R10000 CPUs, from Johan Almbladh. 3) Fix two functional regressions and a build warning related to BTF kfunc for modules, from Kumar Kartikeya Dwivedi. 4) Fix outdated code and docs regarding BPF's migrate_disable() use on non- PREEMPT_RT kernels, from Sebastian Andrzej Siewior. 5) Add missing includes in order to be able to detangle cgroup vs bpf header dependencies, from Jakub Kicinski. 6) Fix regression in BPF sockmap tests caused by missing detachment of progs from sockets when they are removed from the map, from John Fastabend. 7) Fix a missing "no previous prototype" warning in x86 JIT caused by BPF dispatcher, from Björn Töpel. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Add selftests to cover packet access corner cases bpf: Fix the off-by-two error in range markings treewide: Add missing includes masked by cgroup -> bpf dependency tools/resolve_btfids: Skip unresolved symbol warning for empty BTF sets bpf: Fix bpf_check_mod_kfunc_call for built-in modules bpf: Make CONFIG_DEBUG_INFO_BTF depend upon CONFIG_BPF_SYSCALL mips, bpf: Fix reference to non-existing Kconfig symbol bpf: Make sure bpf_disable_instrumentation() is safe vs preemption. Documentation/locking/locktypes: Update migrate_disable() bits. bpf, sockmap: Re-evaluate proto ops when psock is removed from sockmap bpf, sockmap: Attach map progs to psock early for feature probes bpf, x86: Fix "no previous prototype" warning ==================== Link: https://lore.kernel.org/r/20211208155125.11826-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-08ftrace: Add cleanup to unregister_ftrace_direct_multiJiri Olsa1-0/+4
Adding ops cleanup to unregister_ftrace_direct_multi, so it can be reused in another register call. Link: https://lkml.kernel.org/r/20211206182032.87248-3-jolsa@kernel.org Cc: Ingo Molnar <mingo@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Fixes: f64dd4627ec6 ("ftrace: Add multi direct register/unregister interface") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-08ftrace: Use direct_ops hash in unregister_ftrace_directJiri Olsa1-1/+3
Now when we have *direct_multi interface the direct_functions hash is no longer owned just by direct_ops. It's also used by any other ftrace_ops passed to *direct_multi interface. Thus to find out that we are unregistering the last function from direct_ops, we need to check directly direct_ops's hash. Link: https://lkml.kernel.org/r/20211206182032.87248-2-jolsa@kernel.org Cc: Ingo Molnar <mingo@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Fixes: f64dd4627ec6 ("ftrace: Add multi direct register/unregister interface") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-05Merge tag 'timers_urgent_for_v5.16_rc4' of ↵Linus Torvalds2-1/+9
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Borislav Petkov: - Prevent a tick storm when a dedicated timekeeper CPU in nohz_full mode runs for prolonged periods with interrupts disabled and ends up programming the next tick in the past, leading to that storm * tag 'timers_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers/nohz: Last resort update jiffies on nohz_full IRQ entry
2021-12-05Merge tag 'sched_urgent_for_v5.16_rc4' of ↵Linus Torvalds2-6/+12
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Borislav Petkov: - Properly init uclamp_flags of a runqueue, on first enqueuing - Fix preempt= callback return values - Correct utime/stime resource usage reporting on nohz_full to return the proper times instead of shorter ones * tag 'sched_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/uclamp: Fix rq->uclamp_max not set on first enqueue preempt/dynamic: Fix setup_preempt_mode() return value sched/cputime: Fix getrusage(RUSAGE_THREAD) with nohz_full
2021-12-04sched/uclamp: Fix rq->uclamp_max not set on first enqueueQais Yousef1-1/+1
Commit d81ae8aac85c ("sched/uclamp: Fix initialization of struct uclamp_rq") introduced a bug where uclamp_max of the rq is not reset to match the woken up task's uclamp_max when the rq is idle. The code was relying on rq->uclamp_max initialized to zero, so on first enqueue static inline void uclamp_rq_inc_id(struct rq *rq, struct task_struct *p, enum uclamp_id clamp_id) { ... if (uc_se->value > READ_ONCE(uc_rq->value)) WRITE_ONCE(uc_rq->value, uc_se->value); } was actually resetting it. But since commit d81ae8aac85c changed the default to 1024, this no longer works. And since rq->uclamp_flags is also initialized to 0, neither above code path nor uclamp_idle_reset() update the rq->uclamp_max on first wake up from idle. This is only visible from first wake up(s) until the first dequeue to idle after enabling the static key. And it only matters if the uclamp_max of this task is < 1024 since only then its uclamp_max will be effectively ignored. Fix it by properly initializing rq->uclamp_flags = UCLAMP_FLAG_IDLE to ensure uclamp_idle_reset() is called which then will update the rq uclamp_max value as expected. Fixes: d81ae8aac85c ("sched/uclamp: Fix initialization of struct uclamp_rq") Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lkml.kernel.org/r/20211202112033.1705279-1-qais.yousef@arm.com
2021-12-04preempt/dynamic: Fix setup_preempt_mode() return valueAndrew Halaney1-2/+2
__setup() callbacks expect 1 for success and 0 for failure. Correct the usage here to reflect that. Fixes: 826bfeb37bb4 ("preempt/dynamic: Support dynamic preempt with preempt= boot option") Reported-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Halaney <ahalaney@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20211203233203.133581-1-ahalaney@redhat.com
2021-12-03bpf: Fix the off-by-two error in range markingsMaxim Mikityanskiy1-1/+1
The first commit cited below attempts to fix the off-by-one error that appeared in some comparisons with an open range. Due to this error, arithmetically equivalent pieces of code could get different verdicts from the verifier, for example (pseudocode): // 1. Passes the verifier: if (data + 8 > data_end) return early read *(u64 *)data, i.e. [data; data+7] // 2. Rejected by the verifier (should still pass): if (data + 7 >= data_end) return early read *(u64 *)data, i.e. [data; data+7] The attempted fix, however, shifts the range by one in a wrong direction, so the bug not only remains, but also such piece of code starts failing in the verifier: // 3. Rejected by the verifier, but the check is stricter than in #1. if (data + 8 >= data_end) return early read *(u64 *)data, i.e. [data; data+7] The change performed by that fix converted an off-by-one bug into off-by-two. The second commit cited below added the BPF selftests written to ensure than code chunks like #3 are rejected, however, they should be accepted. This commit fixes the off-by-two error by adjusting new_range in the right direction and fixes the tests by changing the range into the one that should actually fail. Fixes: fb2a311a31d3 ("bpf: fix off by one for range markings with L{T, E} patterns") Fixes: b37242c773b2 ("bpf: add test cases to bpf selftests to cover all access tests") Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211130181607.593149-1-maximmi@nvidia.com