user/sven/linux.git/fs/proc, branch v6.9.5

mm: /proc/pid/smaps_rollup: avoid skipping vma after getting mmap_lock again

2024-06-16T11:51:07Z

commit 6d065f507d82307d6161ac75c025111fb8b08a46 upstream. After switching smaps_rollup to use VMA iterator, searching for next entry is part of the condition expression of the do-while loop. So the current VMA needs to be addressed before the continue statement. Otherwise, with some VMAs skipped, userspace observed memory consumption from /proc/pid/smaps_rollup will be smaller than the sum of the corresponding fields from /proc/pid/smaps. Link: https://lkml.kernel.org/r/20240523183531.2535436-1-yzhong@purestorage.com Fixes: c4c84f06285e ("fs/proc/task_mmu: stop using linked list and highest_vm_end") Signed-off-by: Yuanyuan Zhong Reviewed-by: Mohamed Khalfella Cc: David Hildenbrand Cc: Matthew Wilcox (Oracle) Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm/ksm: fix ksm_zero_pages accounting

2024-06-16T11:51:06Z

commit c2dc78b86e0821ecf9a9d0c35dba2618279a5bb6 upstream. We normally ksm_zero_pages++ in ksmd when page is merged with zero page, but ksm_zero_pages-- is done from page tables side, where there is no any accessing protection of ksm_zero_pages. So we can read very exceptional value of ksm_zero_pages in rare cases, such as -1, which is very confusing to users. Fix it by changing to use atomic_long_t, and the same case with the mm->ksm_zero_pages. Link: https://lkml.kernel.org/r/20240528-b4-ksm-counters-v3-2-34bb358fdc13@linux.dev Fixes: e2942062e01d ("ksm: count all zero pages placed by KSM") Fixes: 6080d19f0704 ("ksm: add ksm zero pages for each process") Signed-off-by: Chengming Zhou Acked-by: David Hildenbrand Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Ran Xiaokai Cc: Stefan Roesch Cc: xu xin Cc: Yang Yang Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

proc: Move fdinfo PTRACE_MODE_READ check into the inode .permission operation

2024-06-16T11:50:56Z

commit 0a960ba49869ebe8ff859d000351504dd6b93b68 upstream. The following commits loosened the permissions of /proc//fdinfo/ directory, as well as the files within it, from 0500 to 0555 while also introducing a PTRACE_MODE_READ check between the current task and 's task: - commit 7bc3fa0172a4 ("procfs: allow reading fdinfo with PTRACE_MODE_READ") - commit 1927e498aee1 ("procfs: prevent unprivileged processes accessing fdinfo dir") Before those changes, inode based system calls like inotify_add_watch(2) would fail when the current task didn't have sufficient read permissions: [...] lstat("/proc/1/task/1/fdinfo", {st_mode=S_IFDIR|0500, st_size=0, ...}) = 0 inotify_add_watch(64, "/proc/1/task/1/fdinfo", IN_MODIFY|IN_ATTRIB|IN_MOVED_FROM|IN_MOVED_TO|IN_CREATE|IN_DELETE| IN_ONLYDIR|IN_DONT_FOLLOW|IN_EXCL_UNLINK) = -1 EACCES (Permission denied) [...] This matches the documented behavior in the inotify_add_watch(2) man page: ERRORS EACCES Read access to the given file is not permitted. After those changes, inotify_add_watch(2) started succeeding despite the current task not having PTRACE_MODE_READ privileges on the target task: [...] lstat("/proc/1/task/1/fdinfo", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0 inotify_add_watch(64, "/proc/1/task/1/fdinfo", IN_MODIFY|IN_ATTRIB|IN_MOVED_FROM|IN_MOVED_TO|IN_CREATE|IN_DELETE| IN_ONLYDIR|IN_DONT_FOLLOW|IN_EXCL_UNLINK) = 1757 openat(AT_FDCWD, "/proc/1/task/1/fdinfo", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = -1 EACCES (Permission denied) [...] This change in behavior broke .NET prior to v7. See the github link below for the v7 commit that inadvertently/quietly (?) fixed .NET after the kernel changes mentioned above. Return to the old behavior by moving the PTRACE_MODE_READ check out of the file .open operation and into the inode .permission operation: [...] lstat("/proc/1/task/1/fdinfo", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0 inotify_add_watch(64, "/proc/1/task/1/fdinfo", IN_MODIFY|IN_ATTRIB|IN_MOVED_FROM|IN_MOVED_TO|IN_CREATE|IN_DELETE| IN_ONLYDIR|IN_DONT_FOLLOW|IN_EXCL_UNLINK) = -1 EACCES (Permission denied) [...] Reported-by: Kevin Parsons (Microsoft) Link: https://github.com/dotnet/runtime/commit/89e5469ac591b82d38510fe7de98346cce74ad4f Link: https://stackoverflow.com/questions/75379065/start-self-contained-net6-build-exe-as-service-on-raspbian-system-unauthorizeda Fixes: 7bc3fa0172a4 ("procfs: allow reading fdinfo with PTRACE_MODE_READ") Cc: stable@vger.kernel.org Cc: Christian Brauner Cc: Christian König Cc: Jann Horn Cc: Kalesh Singh Cc: Hardik Garg Cc: Allen Pais Signed-off-by: Tyler Hicks (Microsoft) Link: https://lore.kernel.org/r/20240501005646.745089-1-code@tyhicks.com Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

fs/proc/task_mmu: fix uffd-wp confusion in pagemap_scan_pmd_entry()

2024-05-06T00:28:07Z

pagemap_scan_pmd_entry() checks if uffd-wp is set on each pte to avoid unnecessary if set. However it was previously checking with `pte_uffd_wp(ptep_get(pte))` without first confirming that the pte was present. It is only valid to call pte_uffd_wp() for present ptes. For swap ptes, pte_swp_uffd_wp() must be called because the uffd-wp bit may be kept in a different position, depending on the arch. This was leading to test failures in the pagemap_ioctl mm selftest, when bringing up uffd-wp support on arm64 due to incorrectly interpretting the uffd-wp status of migration entries. Let's fix this by using the correct check based on pte_present(). While we are at it, let's pass the pte to make_uffd_wp_pte() to avoid the pointless extra ptep_get() which can't be optimized out due to READ_ONCE() on many arches. Link: https://lkml.kernel.org/r/20240429114104.182890-1-ryan.roberts@arm.com Fixes: 12f6b01a0bcb ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag") Closes: https://lore.kernel.org/linux-arm-kernel/ZiuyGXt0XWwRgFh9@x1n/ Signed-off-by: Ryan Roberts Acked-by: David Hildenbrand Reviewed-by: Muhammad Usama Anjum Tested-by: Muhammad Usama Anjum Cc: Peter Xu Cc: Signed-off-by: Andrew Morton

fs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan

2024-05-06T00:28:06Z

make_uffd_wp_pte() was previously doing: pte = ptep_get(ptep); ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep, pte); But if another thread accessed or dirtied the pte between the first 2 calls, this could lead to loss of that information. Since ptep_modify_prot_start() gets and clears atomically, the following is the correct pattern and prevents any possible race. Any access after the first call would see an invalid pte and cause a fault: pte = ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep, pte); Link: https://lkml.kernel.org/r/20240429114017.182570-1-ryan.roberts@arm.com Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") Signed-off-by: Ryan Roberts Acked-by: David Hildenbrand Cc: Muhammad Usama Anjum Cc: Peter Xu Cc: Signed-off-by: Andrew Morton

mm: support page_mapcount() on page_has_type() pages

2024-04-25T02:34:26Z

Return 0 for pages which can't be mapped. This matches how page_mapped() works. It is more convenient for users to not have to filter out these pages. Link: https://lkml.kernel.org/r/20240321142448.1645400-5-willy@infradead.org Fixes: 9c5ccf2db04b ("mm: remove HUGETLB_PAGE_DTOR") Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: David Hildenbrand Acked-by: Vlastimil Babka Cc: Miaohe Lin Cc: Muchun Song Cc: Oscar Salvador Cc: Signed-off-by: Andrew Morton

fs/proc: Skip bootloader comment if no embedded kernel parameters

2024-04-09T14:36:18Z

If the "bootconfig" kernel command-line argument was specified or if the kernel was built with CONFIG_BOOT_CONFIG_FORCE, but if there are no embedded kernel parameter, omit the "# Parameters from bootloader:" comment from the /proc/bootconfig file. This will cause automation to fall back to the /proc/cmdline file, which will be identical to the comment in this no-embedded-kernel-parameters case. Link: https://lore.kernel.org/all/20240409044358.1156477-2-paulmck@kernel.org/ Fixes: 8b8ce6c75430 ("fs/proc: remove redundant comments from /proc/bootconfig") Signed-off-by: Masami Hiramatsu Signed-off-by: Paul E. McKenney Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google)

fs/proc: remove redundant comments from /proc/bootconfig

2024-04-09T14:31:54Z

commit 717c7c894d4b ("fs/proc: Add boot loader arguments as comment to /proc/bootconfig") adds bootloader argument comments into /proc/bootconfig. /proc/bootconfig shows boot_command_line[] multiple times following every xbc key value pair, that's duplicated and not necessary. Remove redundant ones. Output before and after the fix is like: key1 = value1 *bootloader argument comments* key2 = value2 *bootloader argument comments* key3 = value3 *bootloader argument comments* ... key1 = value1 key2 = value2 key3 = value3 *bootloader argument comments* ... Link: https://lore.kernel.org/all/20240409044358.1156477-1-paulmck@kernel.org/ Fixes: 717c7c894d4b ("fs/proc: Add boot loader arguments as comment to /proc/bootconfig") Signed-off-by: Zhenhua Huang Signed-off-by: Paul E. McKenney Cc: Cc: Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google)

kbuild: make -Woverride-init warnings more consistent

2024-03-31T02:32:26Z

The -Woverride-init warn about code that may be intentional or not, but the inintentional ones tend to be real bugs, so there is a bit of disagreement on whether this warning option should be enabled by default and we have multiple settings in scripts/Makefile.extrawarn as well as individual subsystems. Older versions of clang only supported -Wno-initializer-overrides with the same meaning as gcc's -Woverride-init, though all supported versions now work with both. Because of this difference, an earlier cleanup of mine accidentally turned the clang warning off for W=1 builds and only left it on for W=2, while it's still enabled for gcc with W=1. There is also one driver that only turns the warning off for newer versions of gcc but not other compilers, and some but not all the Makefiles still use a cc-disable-warning conditional that is no longer needed with supported compilers here. Address all of the above by removing the special cases for clang and always turning the warning off unconditionally where it got in the way, using the syntax that is supported by both compilers. Fixes: 2cd3271b7a31 ("kbuild: avoid duplicate warning options") Signed-off-by: Arnd Bergmann Acked-by: Hamza Mahfooz Acked-by: Jani Nikula Acked-by: Andrew Jeffery Signed-off-by: Jani Nikula Reviewed-by: Linus Walleij Signed-off-by: Masahiro Yamada

Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-03-15T00:43:30Z

Pull MM updates from Andrew Morton: - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames from hotplugged memory rather than only from main memory. Series "implement "memmap on memory" feature on s390". - More folio conversions from Matthew Wilcox in the series "Convert memcontrol charge moving to use folios" "mm: convert mm counter to take a folio" - Chengming Zhou has optimized zswap's rbtree locking, providing significant reductions in system time and modest but measurable reductions in overall runtimes. The series is "mm/zswap: optimize the scalability of zswap rb-tree". - Chengming Zhou has also provided the series "mm/zswap: optimize zswap lru list" which provides measurable runtime benefits in some swap-intensive situations. - And Chengming Zhou further optimizes zswap in the series "mm/zswap: optimize for dynamic zswap_pools". Measured improvements are modest. - zswap cleanups and simplifications from Yosry Ahmed in the series "mm: zswap: simplify zswap_swapoff()". - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has contributed several DAX cleanups as well as adding a sysfs tunable to control the memmap_on_memory setting when the dax device is hotplugged as system memory. - Johannes Weiner has added the large series "mm: zswap: cleanups", which does that. - More DAMON work from SeongJae Park in the series "mm/damon: make DAMON debugfs interface deprecation unignorable" "selftests/damon: add more tests for core functionalities and corner cases" "Docs/mm/damon: misc readability improvements" "mm/damon: let DAMOS feeds and tame/auto-tune itself" - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs extension" Rakie Kim has developed a new mempolicy interleaving policy wherein we allocate memory across nodes in a weighted fashion rather than uniformly. This is beneficial in heterogeneous memory environments appearing with CXL. - Christophe Leroy has contributed some cleanup and consolidation work against the ARM pagetable dumping code in the series "mm: ptdump: Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute". - Luis Chamberlain has added some additional xarray selftesting in the series "test_xarray: advanced API multi-index tests". - Muhammad Usama Anjum has reworked the selftest code to make its human-readable output conform to the TAP ("Test Anything Protocol") format. Amongst other things, this opens up the use of third-party tools to parse and process out selftesting results. - Ryan Roberts has added fork()-time PTE batching of THP ptes in the series "mm/memory: optimize fork() with PTE-mapped THP". Mainly targeted at arm64, this significantly speeds up fork() when the process has a large number of pte-mapped folios. - David Hildenbrand also gets in on the THP pte batching game in his series "mm/memory: optimize unmap/zap with PTE-mapped THP". It implements batching during munmap() and other pte teardown situations. The microbenchmark improvements are nice. - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte mappings"). Kernel build times on arm64 improved nicely. Ryan's series "Address some contpte nits" provides some followup work. - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has fixed an obscure hugetlb race which was causing unnecessary page faults. He has also added a reproducer under the selftest code. - In the series "selftests/mm: Output cleanups for the compaction test", Mark Brown did what the title claims. - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring". - Even more zswap material from Nhat Pham. The series "fix and extend zswap kselftests" does as claimed. - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in our handling of DAX on archiecctures which have virtually aliasing data caches. The arm architecture is the main beneficiary. - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic improvements in worst-case mmap_lock hold times during certain userfaultfd operations. - Some page_owner enhancements and maintenance work from Oscar Salvador in his series "page_owner: print stacks and their outstanding allocations" "page_owner: Fixup and cleanup" - Uladzislau Rezki has contributed some vmalloc scalability improvements in his series "Mitigate a vmap lock contention". It realizes a 12x improvement for a certain microbenchmark. - Some kexec/crash cleanup work from Baoquan He in the series "Split crash out from kexec and clean up related config items". - Some zsmalloc maintenance work from Chengming Zhou in the series "mm/zsmalloc: fix and optimize objects/page migration" "mm/zsmalloc: some cleanup for get/set_zspage_mapping()" - Zi Yan has taught the MM to perform compaction on folios larger than order=0. This a step along the path to implementaton of the merging of large anonymous folios. The series is named "Enable >0 order folio memory compaction". - Christoph Hellwig has done quite a lot of cleanup work in the pagecache writeback code in his series "convert write_cache_pages() to an iterator". - Some modest hugetlb cleanups and speedups in Vishal Moola's series "Handle hugetlb faults under the VMA lock". - Zi Yan has changed the page splitting code so we can split huge pages into sizes other than order-0 to better utilize large folios. The series is named "Split a folio to any lower order folios". - David Hildenbrand has contributed the series "mm: remove total_mapcount()", a cleanup. - Matthew Wilcox has sought to improve the performance of bulk memory freeing in his series "Rearrange batched folio freeing". - Gang Li's series "hugetlb: parallelize hugetlb page init on boot" provides large improvements in bootup times on large machines which are configured to use large numbers of hugetlb pages. - Matthew Wilcox's series "PageFlags cleanups" does that. - Qi Zheng's series "minor fixes and supplement for ptdesc" does that also. S390 is affected. - Cleanups to our pagemap utility functions from Peter Xu in his series "mm/treewide: Replace pXd_large() with pXd_leaf()". - Nico Pache has fixed a few things with our hugepage selftests in his series "selftests/mm: Improve Hugepage Test Handling in MM Selftests". - Also, of course, many singleton patches to many things. Please see the individual changelogs for details. * tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits) mm/zswap: remove the memcpy if acomp is not sleepable crypto: introduce: acomp_is_async to expose if comp drivers might sleep memtest: use {READ,WRITE}_ONCE in memory scanning mm: prohibit the last subpage from reusing the entire large folio mm: recover pud_leaf() definitions in nopmd case selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements selftests/mm: skip uffd hugetlb tests with insufficient hugepages selftests/mm: dont fail testsuite due to a lack of hugepages mm/huge_memory: skip invalid debugfs new_order input for folio split mm/huge_memory: check new folio order when split a folio mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure mm: add an explicit smp_wmb() to UFFDIO_CONTINUE mm: fix list corruption in put_pages_list mm: remove folio from deferred split list before uncharging it filemap: avoid unnecessary major faults in filemap_fault() mm,page_owner: drop unnecessary check mm,page_owner: check for null stack_record before bumping its refcount mm: swap: fix race between free_swap_and_cache() and swapoff() mm/treewide: align up pXd_leaf() retval across archs mm/treewide: drop pXd_large() ...