linux/kernel/trace/ftrace.c, branch v6.12

sysctl: treewide: constify the ctl_table argument of proc_handlers

2024-07-24T18:59:29Z

const qualify the struct ctl_table argument in the proc_handler function signatures. This is a prerequisite to moving the static ctl_table structs into .rodata data which will ensure that proc_handler function pointers cannot be modified. This patch has been generated by the following coccinelle script: ``` virtual patch @r1@ identifier ctl, write, buffer, lenp, ppos; identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)"; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos); @r2@ identifier func, ctl, write, buffer, lenp, ppos; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos) { ... } @r3@ identifier func; @@ int func( - struct ctl_table * + const struct ctl_table * ,int , void *, size_t *, loff_t *); @r4@ identifier func, ctl; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int , void *, size_t *, loff_t *); @r5@ identifier func, write, buffer, lenp, ppos; @@ int func( - struct ctl_table * + const struct ctl_table * ,int write, void *buffer, size_t *lenp, loff_t *ppos); ``` * Code formatting was adjusted in xfs_sysctl.c to comply with code conventions. The xfs_stats_clear_proc_handler, xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where adjusted. * The ctl_table argument in proc_watchdog_common was const qualified. This is called from a proc_handler itself and is calling back into another proc_handler, making it necessary to change it as part of the proc_handler migration. Co-developed-by: Thomas Weißschuh Signed-off-by: Thomas Weißschuh Co-developed-by: Joel Granados Signed-off-by: Joel Granados

Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-07-22T00:15:46Z

Pull MM updates from Andrew Morton: - In the series "mm: Avoid possible overflows in dirty throttling" Jan Kara addresses a couple of issues in the writeback throttling code. These fixes are also targetted at -stable kernels. - Ryusuke Konishi's series "nilfs2: fix potential issues related to reserved inodes" does that. This should actually be in the mm-nonmm-stable tree, along with the many other nilfs2 patches. My bad. - More folio conversions from Kefeng Wang in the series "mm: convert to folio_alloc_mpol()" - Kemeng Shi has sent some cleanups to the writeback code in the series "Add helper functions to remove repeated code and improve readability of cgroup writeback" - Kairui Song has made the swap code a little smaller and a little faster in the series "mm/swap: clean up and optimize swap cache index". - In the series "mm/memory: cleanly support zeropage in vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David Hildenbrand has reworked the rather sketchy handling of the use of the zeropage in MAP_SHARED mappings. I don't see any runtime effects here - more a cleanup/understandability/maintainablity thing. - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of higher addresses, for aarch64. The (poorly named) series is "Restructure va_high_addr_switch". - The core TLB handling code gets some cleanups and possible slight optimizations in Bang Li's series "Add update_mmu_tlb_range() to simplify code". - Jane Chu has improved the handling of our fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the series "Enhance soft hwpoison handling and injection". - Jeff Johnson has sent a billion patches everywhere to add MODULE_DESCRIPTION() to everything. Some landed in this pull. - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has simplified migration's use of hardware-offload memory copying. - Yosry Ahmed performs more folio API conversions in his series "mm: zswap: trivial folio conversions". - In the series "large folios swap-in: handle refault cases first", Chuanhua Han inches us forward in the handling of large pages in the swap code. This is a cleanup and optimization, working toward the end objective of full support of large folio swapin/out. - In the series "mm,swap: cleanup VMA based swap readahead window calculation", Huang Ying has contributed some cleanups and a possible fixlet to his VMA based swap readahead code. - In the series "add mTHP support for anonymous shmem" Baolin Wang has taught anonymous shmem mappings to use multisize THP. By default this is a no-op - users must opt in vis sysfs controls. Dramatic improvements in pagefault latency are realized. - David Hildenbrand has some cleanups to our remaining use of page_mapcount() in the series "fs/proc: move page_mapcount() to fs/proc/internal.h". - David also has some highmem accounting cleanups in the series "mm/highmem: don't track highmem pages manually". - Build-time fixes and cleanups from John Hubbard in the series "cleanups, fixes, and progress towards avoiding "make headers"". - Cleanups and consolidation of the core pagemap handling from Barry Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers and utilize them". - Lance Yang's series "Reclaim lazyfree THP without splitting" has reduced the latency of the reclaim of pmd-mapped THPs under fairly common circumstances. A 10x speedup is seen in a microbenchmark. It does this by punting to aother CPU but I guess that's a win unless all CPUs are pegged. - hugetlb_cgroup cleanups from Xiu Jianfeng in the series "mm/hugetlb_cgroup: rework on cftypes". - Miaohe Lin's series "Some cleanups for memory-failure" does just that thing. - Someone other than SeongJae has developed a DAMON feature in Honggyu Kim's series "DAMON based tiered memory management for CXL memory". This adds DAMON features which may be used to help determine the efficiency of our placement of CXL/PCIe attached DRAM. - DAMON user API centralization and simplificatio work in SeongJae Park's series "mm/damon: introduce DAMON parameters online commit function". - In the series "mm: page_type, zsmalloc and page_mapcount_reset()" David Hildenbrand does some maintenance work on zsmalloc - partially modernizing its use of pageframe fields. - Kefeng Wang provides more folio conversions in the series "mm: remove page_maybe_dma_pinned() and page_mkclean()". - More cleanup from David Hildenbrand, this time in the series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline() pages" and permits the removal of some virtio-mem hacks. - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and __folio_add_anon_rmap()" is a cleanup to the anon folio handling in preparation for mTHP (multisize THP) swapin. - Kefeng Wang's series "mm: improve clear and copy user folio" implements more folio conversions, this time in the area of large folio userspace copying. - The series "Docs/mm/damon/maintaier-profile: document a mailing tool and community meetup series" tells people how to get better involved with other DAMON developers. From SeongJae Park. - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does that. - David Hildenbrand sends along more cleanups, this time against the migration code. The series is "mm/migrate: move NUMA hinting fault folio isolation + checks under PTL". - Jan Kara has found quite a lot of strangenesses and minor errors in the readahead code. He addresses this in the series "mm: Fix various readahead quirks". - SeongJae Park's series "selftests/damon: test DAMOS tried regions and {min,max}_nr_regions" adds features and addresses errors in DAMON's self testing code. - Gavin Shan has found a userspace-triggerable WARN in the pagecache code. The series "mm/filemap: Limit page cache size to that supported by xarray" addresses this. The series is marked cc:stable. - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations and cleanup" cleans up and slightly optimizes KSM. - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of code motion. The series (which also makes the memcg-v1 code Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put under config option" and "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1" - Dan Schatzberg's series "Add swappiness argument to memory.reclaim" adds an additional feature to this cgroup-v2 control file. - The series "Userspace controls soft-offline pages" from Jiaqi Yan permits userspace to stop the kernel's automatic treatment of excessive correctable memory errors. In order to permit userspace to monitor and handle this situation. - Kefeng Wang's series "mm: migrate: support poison recover from migrate folio" teaches the kernel to appropriately handle migration from poisoned source folios rather than simply panicing. - SeongJae Park's series "Docs/damon: minor fixups and improvements" does those things. - In the series "mm/zsmalloc: change back to per-size_class lock" Chengming Zhou improves zsmalloc's scalability and memory utilization. - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare refcount increments. So these paes can first be moved aside if they reside in the movable zone or a CMA block. - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps for much faster reading of vma information. The series is "query VMAs from /proc//maps". - In the series "mm: introduce per-order mTHP split counters" Lance Yang improves the kernel's presentation of developer information related to multisize THP splitting. - Michael Ellerman has developed the series "Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64)". This permits userspace to use all available huge page sizes. - In the series "revert unconditional slab and page allocator fault injection calls" Vlastimil Babka removes a performance-affecting and not very useful feature from slab fault injection. * tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits) mm/mglru: fix ineffective protection calculation mm/zswap: fix a white space issue mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio mm/hugetlb: fix possible recursive locking detected warning mm/gup: clear the LRU flag of a page before adding to LRU batch mm/numa_balancing: teach mpol_to_str about the balancing mode mm: memcg1: convert charge move flags to unsigned long long alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting lib: reuse page_ext_data() to obtain codetag_ref lib: add missing newline character in the warning message mm/mglru: fix overshooting shrinker memory mm/mglru: fix div-by-zero in vmpressure_calc_level() mm/kmemleak: replace strncpy() with strscpy() mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB mm: ignore data-race in __swap_writepage hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr mm: shmem: rename mTHP shmem counters mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async() mm/migrate: putback split folios when numa hint migration fails ...

Merge tag 'ftrace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2024-07-18T20:36:33Z

Pull ftrace updates from Steven Rostedt: "Rewrite of function graph tracer to allow multiple users Up until now, the function graph tracer could only have a single user attached to it. If another user tried to attach to the function graph tracer while one was already attached, it would fail. Allowing function graph tracer to have more than one user has been asked for since 2009, but it required a rewrite to the logic to pull it off so it never happened. Until now! There's three systems that trace the return of a function. That is kretprobes, function graph tracer, and BPF. kretprobes and function graph tracing both do it similarly. The difference is that kretprobes uses a shadow stack per callback and function graph tracer creates a shadow stack for all tasks. The function graph tracer method makes it possible to trace the return of all functions. As kretprobes now needs that feature too, allowing it to use function graph tracer was needed. BPF also wants to trace the return of many probes and its method doesn't scale either. Having it use function graph tracer would improve that. By allowing function graph tracer to have multiple users allows both kretprobes and BPF to use function graph tracer in these cases. This will allow kretprobes code to be removed in the future as it's version will no longer be needed. Note, function graph tracer is only limited to 16 simultaneous users, due to shadow stack size and allocated slots" * tag 'ftrace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (49 commits) fgraph: Use str_plural() in test_graph_storage_single() function_graph: Add READ_ONCE() when accessing fgraph_array[] ftrace: Add missing kerneldoc parameters to unregister_ftrace_direct() function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove it function_graph: Fix up ftrace_graph_ret_addr() function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACE function_graph: Rename BYTE_NUMBER to CHAR_NUMBER in selftests fgraph: Remove some unused functions ftrace: Hide one more entry in stack trace when ftrace_pid is enabled function_graph: Do not update pid func if CONFIG_DYNAMIC_FTRACE not enabled function_graph: Make fgraph_do_direct static key static ftrace: Fix prototypes for ftrace_startup/shutdown_subops() ftrace: Assign RCU list variable with rcu_assign_ptr() ftrace: Assign ftrace_list_end to ftrace_ops_list type cast to RCU ftrace: Declare function_trace_op in header to quiet sparse warning ftrace: Add comments to ftrace_hash_move() and friends ftrace: Convert "inc" parameter to bool in ftrace_hash_rec_update_modify() ftrace: Add comments to ftrace_hash_rec_disable/enable() ftrace: Remove "filter_hash" parameter from __ftrace_hash_rec_update() ftrace: Rename dup_hash() and comment it ...

ftrace: unpoison ftrace_regs in ftrace_ops_list_func()

2024-07-04T02:30:21Z

Patch series "kmsan: Enable on s390", v7. Architectures use assembly code to initialize ftrace_regs and call ftrace_ops_list_func(). Therefore, from the KMSAN's point of view, ftrace_regs is poisoned on ftrace_ops_list_func entry(). This causes KMSAN warnings when running the ftrace testsuite. Fix by trusting the architecture-specific assembly code and always unpoisoning ftrace_regs in ftrace_ops_list_func. The issue was not encountered on x86_64 so far only by accident: assembly-allocated ftrace_regs was overlapping a stale partially unpoisoned stack frame. Poisoning stack frames before returns [1] makes the issue appear on x86_64 as well. [1] https://github.com/iii-i/llvm-project/commits/msan-poison-allocas-before-returning-2024-06-12/ Link: https://lkml.kernel.org/r/20240621113706.315500-1-iii@linux.ibm.com Link: https://lkml.kernel.org/r/20240621113706.315500-2-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich Reviewed-by: Alexander Potapenko Acked-by: Steven Rostedt (Google) Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Heiko Carstens Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim Cc: Cc: Marco Elver Cc: Mark Rutland Cc: Masami Hiramatsu (Google) Cc: Pekka Enberg Cc: Roman Gushchin Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Vlastimil Babka Signed-off-by: Andrew Morton

kallsyms: rework symbol lookup return codes

2024-06-27T15:43:40Z

Building with W=1 in some configurations produces a false positive warning for kallsyms: kernel/kallsyms.c: In function '__sprint_symbol.isra': kernel/kallsyms.c:503:17: error: 'strcpy' source argument is the same as destination [-Werror=restrict] 503 | strcpy(buffer, name); | ^~~~~~~~~~~~~~~~~~~~ This originally showed up while building with -O3, but later started happening in other configurations as well, depending on inlining decisions. The underlying issue is that the local 'name' variable is always initialized to the be the same as 'buffer' in the called functions that fill the buffer, which gcc notices while inlining, though it could see that the address check always skips the copy. The calling conventions here are rather unusual, as all of the internal lookup functions (bpf_address_lookup, ftrace_mod_address_lookup, ftrace_func_address_lookup, module_address_lookup and kallsyms_lookup_buildid) already use the provided buffer and either return the address of that buffer to indicate success, or NULL for failure, but the callers are written to also expect an arbitrary other buffer to be returned. Rework the calling conventions to return the length of the filled buffer instead of its address, which is simpler and easier to follow as well as avoiding the warning. Leave only the kallsyms_lookup() calling conventions unchanged, since that is called from 16 different functions and adapting this would be a much bigger change. Link: https://lore.kernel.org/lkml/20200107214042.855757-1-arnd@arndb.de/ Link: https://lore.kernel.org/lkml/20240326130647.7bfb1d92@gandalf.local.home/ Tested-by: Geert Uytterhoeven Reviewed-by: Luis Chamberlain Acked-by: Steven Rostedt (Google) Signed-off-by: Arnd Bergmann

ftrace: Add missing kerneldoc parameters to unregister_ftrace_direct()

2024-06-11T15:18:24Z

Add the description to the parameters addr and free_filters of the function unregister_ftrace_direct(). Link: https://lore.kernel.org/linux-trace-kernel/20240606132520.1397567-1-marilene.agarcia@gmail.com Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Shuah Khan Cc: Javier Carrasco Signed-off-by: Marilene A Garcia Signed-off-by: Steven Rostedt (Google)

ftrace: Assign RCU list variable with rcu_assign_ptr()

2024-06-06T19:22:18Z

Use rcu_assign_ptr() to assign the list pointer as it is marked as RCU, and this quiets the sparse warning: kernel/trace/ftrace.c:313:23: warning: incorrect type in assignment (different address spaces) kernel/trace/ftrace.c:313:23: expected struct ftrace_ops [noderef] __rcu * kernel/trace/ftrace.c:313:23: got struct ftrace_ops * Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.613471310@goodmis.org Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

ftrace: Assign ftrace_list_end to ftrace_ops_list type cast to RCU

2024-06-06T19:22:18Z

Use a type cast to convert ftrace_list_end to RCU when assigning ftrace_ops_list. This will quiet the sparse warning: kernel/trace/ftrace.c:125:59: warning: incorrect type in initializer (different address spaces) kernel/trace/ftrace.c:125:59: expected struct ftrace_ops [noderef] __rcu *[addressable] [toplevel] ftrace_ops_list kernel/trace/ftrace.c:125:59: got struct ftrace_ops * Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.450784356@goodmis.org Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

ftrace: Add comments to ftrace_hash_move() and friends

2024-06-06T19:22:03Z

Describe what ftrace_hash_move() does and add some more comments to some other functions to make it easier to understand. Link: https://lore.kernel.org/linux-trace-kernel/20240605180409.179520305@goodmis.org Cc: Mathieu Desnoyers Cc: Andrew Morton Acked-by: Mark Rutland Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

ftrace: Convert "inc" parameter to bool in ftrace_hash_rec_update_modify()

2024-06-06T19:21:28Z

The parameter "inc" in the function ftrace_hash_rec_update_modify() is boolean. Change it to be such. Also add documentation to what the function does. Link: https://lore.kernel.org/linux-trace-kernel/20240605180409.021080462@goodmis.org Cc: Mathieu Desnoyers Cc: Andrew Morton Acked-by: Masami Hiramatsu (Google) Acked-by: Mark Rutland Signed-off-by: Steven Rostedt (Google)