kernel/linux.git/tools/testing/selftests/proc/Makefile, branch v6.19.11

Merge tag 'mm-nonmm-stable-2025-10-02-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-10-03T01:44:54+00:00

Pull non-MM updates from Andrew Morton: - "ida: Remove the ida_simple_xxx() API" from Christophe Jaillet completes the removal of this legacy IDR API - "panic: introduce panic status function family" from Jinchao Wang provides a number of cleanups to the panic code and its various helpers, which were rather ad-hoc and scattered all over the place - "tools/delaytop: implement real-time keyboard interaction support" from Fan Yu adds a few nice user-facing usability changes to the delaytop monitoring tool - "efi: Fix EFI boot with kexec handover (KHO)" from Evangelos Petrongonas fixes a panic which was happening with the combination of EFI and KHO - "Squashfs: performance improvement and a sanity check" from Phillip Lougher teaches squashfs's lseek() about SEEK_DATA/SEEK_HOLE. A mere 150x speedup was measured for a well-chosen microbenchmark - plus another 50-odd singleton patches all over the place * tag 'mm-nonmm-stable-2025-10-02-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (75 commits) Squashfs: reject negative file sizes in squashfs_read_inode() kallsyms: use kmalloc_array() instead of kmalloc() MAINTAINERS: update Sibi Sankar's email address Squashfs: add SEEK_DATA/SEEK_HOLE support Squashfs: add additional inode sanity checking lib/genalloc: fix device leak in of_gen_pool_get() panic: remove CONFIG_PANIC_ON_OOPS_VALUE ocfs2: fix double free in user_cluster_connect() checkpatch: suppress strscpy warnings for userspace tools cramfs: fix incorrect physical page address calculation kernel: prevent prctl(PR_SET_PDEATHSIG) from racing with parent process exit Squashfs: fix uninit-value in squashfs_get_parent kho: only fill kimage if KHO is finalized ocfs2: avoid extra calls to strlen() after ocfs2_sprintf_system_inode_name() kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths sched/task.h: fix the wrong comment on task_lock() nesting with tasklist_lock coccinelle: platform_no_drv_owner: handle also built-in drivers coccinelle: of_table: handle SPI device ID tables lib/decompress: use designated initializers for struct compress_format efi: support booting with kexec handover (KHO) ...

proc: test lseek on /proc/net/dev

2025-09-14T00:32:48+00:00

This line in tools/testing/selftests/proc/read.c was added to catch oopses, not to verify lseek correctness: (void)lseek(fd, 0, SEEK_SET); Oh, well. Prevent more embarassement with simple test. Link: https://lkml.kernel.org/r/aKTCfMuRXOpjBXxI@p183 Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton

selftests/proc: add tests for new pidns APIs

2025-09-02T09:40:20+00:00

Signed-off-by: Aleksa Sarai Link: https://lore.kernel.org/20250805-procfs-pidns-api-v4-4-705f984940e7@cyphar.com Signed-off-by: Christian Brauner

selftests/proc: add /proc/pid/maps tearing from vma split test

2025-07-25T02:12:36+00:00

Patch series "use per-vma locks for /proc/pid/maps reads", v8. Reading /proc/pid/maps requires read-locking mmap_lock which prevents any other task from concurrently modifying the address space. This guarantees coherent reporting of virtual address ranges, however it can block important updates from happening. Oftentimes /proc/pid/maps readers are low priority monitoring tasks and them blocking high priority tasks results in priority inversion. Locking the entire address space is required to present fully coherent picture of the address space, however even current implementation does not strictly guarantee that by outputting vmas in page-size chunks and dropping mmap_lock in between each chunk. Address space modifications are possible while mmap_lock is dropped and userspace reading the content is expected to deal with possible concurrent address space modifications. Considering these relaxed rules, holding mmap_lock is not strictly needed as long as we can guarantee that a concurrently modified vma is reported either in its original form or after it was modified. This patchset switches from holding mmap_lock while reading /proc/pid/maps to taking per-vma locks as we walk the vma tree. This reduces the contention with tasks modifying the address space because they would have to contend for the same vma as opposed to the entire address space. Previous version of this patchset [1] tried to perform /proc/pid/maps reading under RCU, however its implementation is quite complex and the results are worse than the new version because it still relied on mmap_lock speculation which retries if any part of the address space gets modified. New implementaion is both simpler and results in less contention. Note that similar approach would not work for /proc/pid/smaps reading as it also walks the page table and that's not RCU-safe. Paul McKenney's designed a test [2] to measure mmap/munmap latencies while concurrently reading /proc/pid/maps. The test has a pair of processes scanning /proc/PID/maps, and another process unmapping and remapping 4K pages from a 128MB range of anonymous memory. At the end of each 10 second run, the latency of each mmap() or munmap() operation is measured, and for each run the maximum and mean latency is printed. The map/unmap process is started first, its PID is passed to the scanners, and then the map/unmap process waits until both scanners are running before starting its timed test. The scanners keep scanning until the specified /proc/PID/maps file disappears. The latest results from Paul: Stock mm-unstable, all of the runs had maximum latencies in excess of 0.5 milliseconds, and with 80% of the runs' latencies exceeding a full millisecond, and ranging up beyond 4 full milliseconds. In contrast, 99% of the runs with this patch series applied had maximum latencies of less than 0.5 milliseconds, with the single outlier at only 0.608 milliseconds. From a median-performance (as opposed to maximum-latency) viewpoint, this patch series also looks good, with stock mm weighing in at 11 microseconds and patch series at 6 microseconds, better than a 2x improvement. Before the change: ./run-proc-vs-map.sh --nsamples 100 --rawdata -- --busyduration 2 0.011 0.008 0.521 0.011 0.008 0.552 0.011 0.008 0.590 0.011 0.008 0.660 ... 0.011 0.015 2.987 0.011 0.015 3.038 0.011 0.016 3.431 0.011 0.016 4.707 After the change: ./run-proc-vs-map.sh --nsamples 100 --rawdata -- --busyduration 2 0.006 0.005 0.026 0.006 0.005 0.029 0.006 0.005 0.034 0.006 0.005 0.035 ... 0.006 0.006 0.421 0.006 0.006 0.423 0.006 0.006 0.439 0.006 0.006 0.608 The patchset also adds a number of tests to check for /proc/pid/maps data coherency. They are designed to detect any unexpected data tearing while performing some common address space modifications (vma split, resize and remap). Even before these changes, reading /proc/pid/maps might have inconsistent data because the file is read page-by-page with mmap_lock being dropped between the pages. An example of user-visible inconsistency can be that the same vma is printed twice: once before it was modified and then after the modifications. For example if vma was extended, it might be found and reported twice. What is not expected is to see a gap where there should have been a vma both before and after modification. This patchset increases the chances of such tearing, therefore it's even more important now to test for unexpected inconsistencies. In [3] Lorenzo identified the following possible vma merging/splitting scenarios: Merges with changes to existing vmas: 1 Merge both - mapping a vma over another one and between two vmas which can be merged after this replacement; 2. Merge left full - mapping a vma at the end of an existing one and completely over its right neighbor; 3. Merge left partial - mapping a vma at the end of an existing one and partially over its right neighbor; 4. Merge right full - mapping a vma before the start of an existing one and completely over its left neighbor; 5. Merge right partial - mapping a vma before the start of an existing one and partially over its left neighbor; Merges without changes to existing vmas: 6. Merge both - mapping a vma into a gap between two vmas which can be merged after the insertion; 7. Merge left - mapping a vma at the end of an existing one; 8. Merge right - mapping a vma before the start end of an existing one; Splits 9. Split with new vma at the lower address; 10. Split with new vma at the higher address; If such merges or splits happen concurrently with the /proc/maps reading we might report a vma twice, once before the modification and once after it is modified: Case 1 might report overwritten and previous vma along with the final merged vma; Case 2 might report previous and the final merged vma; Case 3 might cause us to retry once we detect the temporary gap caused by shrinking of the right neighbor; Case 4 might report overritten and the final merged vma; Case 5 might cause us to retry once we detect the temporary gap caused by shrinking of the left neighbor; Case 6 might report previous vma and the gap along with the final marged vma; Case 7 might report previous and the final merged vma; Case 8 might report the original gap and the final merged vma covering the gap; Case 9 might cause us to retry once we detect the temporary gap caused by shrinking of the original vma at the vma start; Case 10 might cause us to retry once we detect the temporary gap caused by shrinking of the original vma at the vma end; In all these cases the retry mechanism prevents us from reporting possible temporary gaps. [1] https://lore.kernel.org/all/20250418174959.1431962-1-surenb@google.com/ [2] https://github.com/paulmckrcu/proc-mmap_sem-test [3] https://lore.kernel.org/all/e1863f40-39ab-4e5b-984a-c48765ffde1c@lucifer.local/ The /proc/pid/maps file is generated page by page, with the mmap_lock released between pages. This can lead to inconsistent reads if the underlying vmas are concurrently modified. For instance, if a vma split or merge occurs at a page boundary while /proc/pid/maps is being read, the same vma might be seen twice: once before and once after the change. This duplication is considered acceptable for userspace handling. However, observing a "hole" where a vma should be (e.g., due to a vma being replaced and the space temporarily being empty) is unacceptable. Implement a test that: 1. Forks a child process which continuously modifies its address space, specifically targeting a vma at the boundary between two pages. 2. The parent process repeatedly reads the child's /proc/pid/maps. 3. The parent process checks the last vma of the first page and the first vma of the second page for consistency, looking for the effects of vma splits or merges. The test duration is configurable via DURATION environment variable expressed in seconds. The default test duration is 5 seconds. Example Command: DURATION=10 ./proc-maps-race Link: https://lore.kernel.org/all/20250418174959.1431962-1-surenb@google.com/ [1] Link: https://github.com/paulmckrcu/proc-mmap_sem-test [2] Link: https://lore.kernel.org/all/e1863f40-39ab-4e5b-984a-c48765ffde1c@lucifer.local/ [3] Link: https://lkml.kernel.org/r/20250719182854.3166724-1-surenb@google.com Link: https://lkml.kernel.org/r/20250719182854.3166724-2-surenb@google.com Signed-off-by: Suren Baghdasaryan Cc: Alexey Dobriyan Cc: Andrii Nakryiko Cc: Christian Brauner Cc: Christophe Leroy Cc: David Hildenbrand Cc: Jann Horn Cc: Jeongjun Park Cc: Johannes Weiner Cc: Josef Bacik Cc: Kalesh Singh Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Oscar Salvador Cc: "Paul E . McKenney" Cc: Peter Xu Cc: Ryan Roberts Cc: Shuah Khan Cc: Thomas Weißschuh Cc: T.J. Mercier Cc: Vlastimil Babka Cc: Ye Bin Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-07-22T00:56:22+00:00

Pull non-MM updates from Andrew Morton: - In the series "treewide: Refactor heap related implementation", Kuan-Wei Chiu has significantly reworked the min_heap library code and has taught bcachefs to use the new more generic implementation. - Yury Norov's series "Cleanup cpumask.h inclusion in core headers" reworks the cpumask and nodemask headers to make things generally more rational. - Kuan-Wei Chiu has sent along some maintenance work against our sorting library code in the series "lib/sort: Optimizations and cleanups". - More library maintainance work from Christophe Jaillet in the series "Remove usage of the deprecated ida_simple_xx() API". - Ryusuke Konishi continues with the nilfs2 fixes and clanups in the series "nilfs2: eliminate the call to inode_attach_wb()". - Kuan-Ying Lee has some fixes to the gdb scripts in the series "Fix GDB command error". - Plus the usual shower of singleton patches all over the place. Please see the relevant changelogs for details. * tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (98 commits) ia64: scrub ia64 from poison.h watchdog/perf: properly initialize the turbo mode timestamp and rearm counter tsacct: replace strncpy() with strscpy() lib/bch.c: use swap() to improve code test_bpf: convert comma to semicolon init/modpost: conditionally check section mismatch to __meminit* init: remove unused __MEMINIT* macros nilfs2: Constify struct kobj_type nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro math: rational: add missing MODULE_DESCRIPTION() macro lib/zlib: add missing MODULE_DESCRIPTION() macro fs: ufs: add MODULE_DESCRIPTION() lib/rbtree.c: fix the example typo ocfs2: add bounds checking to ocfs2_check_dir_entry() fs: add kernel-doc comments to ocfs2_prepare_orphan_dir() coredump: simplify zap_process() selftests/fpu: add missing MODULE_DESCRIPTION() macro compiler.h: simplify data_race() macro build-id: require program headers to be right after ELF header resource: add missing MODULE_DESCRIPTION() ...

selftests/proc: add PROCMAP_QUERY ioctl tests

2024-07-12T22:52:12+00:00

Extend existing proc-pid-vm.c tests with PROCMAP_QUERY ioctl() API. Test a few successful and negative cases, validating querying filtering and exact vs next VMA logic works as expected. Link: https://lkml.kernel.org/r/20240627170900.1672542-7-andrii@kernel.org Signed-off-by: Andrii Nakryiko Acked-by: Liam R. Howlett Cc: Alexey Dobriyan Cc: Al Viro Cc: Christian Brauner Cc: Greg Kroah-Hartman Cc: Mike Rapoport (IBM) Cc: Suren Baghdasaryan Cc: Andi Kleen Cc: Arnd Bergmann Cc: Stephen Rothwell Signed-off-by: Andrew Morton

selftests: centralize -D_GNU_SOURCE= to CFLAGS in lib.mk

2024-07-10T19:14:51+00:00

Centralize the _GNU_SOURCE definition to CFLAGS in lib.mk. Remove redundant defines from Makefiles that import lib.mk. Convert any usage of "#define _GNU_SOURCE 1" to "#define _GNU_SOURCE". This uses the form "-D_GNU_SOURCE=", which is equivalent to "#define _GNU_SOURCE". Otherwise using "-D_GNU_SOURCE" is equivalent to "-D_GNU_SOURCE=1" and "#define _GNU_SOURCE 1", which is less commonly seen in source code and would require many changes in selftests to avoid redefinition warnings. Link: https://lkml.kernel.org/r/20240625223454.1586259-2-edliaw@google.com Signed-off-by: Edward Liaw Suggested-by: John Hubbard Acked-by: Shuah Khan Reviewed-by: Muhammad Usama Anjum Cc: Albert Ou Cc: André Almeida Cc: Darren Hart Cc: Dave Hansen Cc: Davidlohr Bueso Cc: David S. Miller Cc: Eric Dumazet Cc: Eric W. Biederman Cc: Fenghua Yu Cc: Ingo Molnar Cc: Jakub Kicinski Cc: Jarkko Sakkinen Cc: Jason Gunthorpe Cc: Kees Cook Cc: Kevin Tian Cc: Palmer Dabbelt Cc: Paolo Abeni Cc: Paolo Bonzini Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Reinette Chatre Cc: Sean Christopherson Cc: Thomas Gleixner Signed-off-by: Andrew Morton

proc: test "Kthread:" field

2024-06-25T05:25:08+00:00

/proc/${pid}/status got Kthread field recently. Test that userspace program is not reported as kernel thread. Test that kernel thread is reported as kernel thread. Use kthreadd with pid 2 for this. Link: https://lkml.kernel.org/r/818c4c41-8668-4566-97a9-7254abf819ee@p183 Signed-off-by: Alexey Dobriyan Cc: Chunguang Wu Cc: Shuah Khan Signed-off-by: Andrew Morton

proc: test how it holds up with mapping'less process

2022-10-12T01:51:11+00:00

Create process without mappings and check /proc/*/maps /proc/*/numa_maps /proc/*/smaps /proc/*/smaps_rollup They must be empty (excluding vsyscall page) or full of zeroes. Retroactively this test should've caught embarassing /proc/*/smaps_rollup oops: [17752.703567] BUG: kernel NULL pointer dereference, address: 0000000000000000 [17752.703580] #PF: supervisor read access in kernel mode [17752.703583] #PF: error_code(0x0000) - not-present page [17752.703587] PGD 0 P4D 0 [17752.703593] Oops: 0000 [#1] PREEMPT SMP PTI [17752.703598] CPU: 0 PID: 60649 Comm: cat Tainted: G W 5.19.9-100.fc35.x86_64 #1 [17752.703603] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X99 Extreme6/3.1, BIOS P3.30 08/05/2016 [17752.703607] RIP: 0010:show_smaps_rollup+0x159/0x2e0 Note 1: ProtectionKey field in /proc/*/smaps is optional, so check most of its contents, not everything. Note 2: due to the nature of this test, child process hardly can signal its readiness (after unmapping everything!) to parent. I feel like "sleep(1)" is justified. If you know how to do it without sleep please tell me. Note 3: /proc/*/statm is not tested but can be. Link: https://lkml.kernel.org/r/Yz3liL6Dn+n2SD8Q@localhost.localdomain Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton

procfs: do not list TID 0 in /proc//task

2021-11-09T18:02:48+00:00

If a task exits concurrently, task_pid_nr_ns may return 0. [akpm@linux-foundation.org: coding style tweaks] [adobriyan@gmail.com: test that /proc/*/task doesn't contain "0"] Link: https://lkml.kernel.org/r/YV88AnVzHxPafQ9o@localhost.localdomain Link: https://lkml.kernel.org/r/8735pn5dx7.fsf@oldenburg.str.redhat.com Signed-off-by: Florian Weimer Signed-off-by: Alexey Dobriyan Acked-by: Christian Brauner Reviewed-by: Alexey Dobriyan Cc: Kees Cook Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds