kernel/samples, branch linux-6.15.y

samples/damon/wsse: fix boot time enable handling

2025-08-20T16:36:27Z

commit 0ed1165c37277822b519f519d0982d36efc30006 upstream. Patch series "mm/damon: fix misc bugs in DAMON modules". From manual code review, I found below bugs in DAMON modules. DAMON sample modules crash if those are enabled at boot time, via kernel command line. A similar issue was found and fixed on DAMON non-sample modules in the past, but we didn't check that for sample modules. DAMON non-sample modules are not setting 'enabled' parameters accordingly when real enabling is failed. Honggyu found and fixed[1] this type of bugs in DAMON sample modules, and my inspection was motivated by the great work. Kudos to Honggyu. Finally, DAMON_RECLIAM is mistakenly losing scheme internal status due to misuse of damon_commit_ctx(). DAMON_LRU_SORT has a similar misuse, but fortunately it is not causing real status loss. Fix the bugs. Since these are similar patterns of bugs that were found in the past, it would be better to add tests or refactor the code, in future. This patch (of 6): If 'enable' parameter of the 'wsse' DAMON sample module is set at boot time via the kernel command line, memory allocation is tried before the slab is initialized. As a result kernel NULL pointer dereference BUG can happen. Fix it by checking the initialization status. Link: https://lkml.kernel.org/r/20250706193207.39810-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250706193207.39810-2-sj@kernel.org Link: https://lore.kernel.org/20250702000205.1921-1-honggyu.kim@sk.com [1] Fixes: b757c6cfc696 ("samples/damon/wsse: start and stop DAMON as the user requests") Signed-off-by: SeongJae Park Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

samples: mei: Fix building on musl libc

2025-08-15T10:16:22Z

[ Upstream commit 239df3e4b4752524e7c0fb3417c218d8063654b4 ] The header bits/wordsize.h is glibc specific and on building on musl with allyesconfig results in samples/mei/mei-amt-version.c:77:10: fatal error: bits/wordsize.h: No such file or directory 77 | #include | ^~~~~~~~~~~~~~~~~ mei-amt-version.c build file without bits/wordsize.h on musl and glibc. However on musl we get the follwing error without sys/time.h samples/mei/mei-amt-version.c: In function 'mei_recv_msg': samples/mei/mei-amt-version.c:159:24: error: storage size of 'tv' isn't known 159 | struct timeval tv; | ^~ samples/mei/mei-amt-version.c:160:9: error: unknown type name 'fd_set' 160 | fd_set set; | ^~~~~~ samples/mei/mei-amt-version.c:168:9: error: implicit declaration of function 'FD_ZERO' [-Wimplicit-function-declaration] 168 | FD_ZERO(&set); | ^~~~~~~ samples/mei/mei-amt-version.c:169:9: error: implicit declaration of function 'FD_SET'; did you mean 'L_SET'? [-Wimplicit-function-declaration] 169 | FD_SET(me->fd, &set); | ^~~~~~ | L_SET samples/mei/mei-amt-version.c:170:14: error: implicit declaration of function 'select' [-Wimplicit-function-declaration] 170 | rc = select(me->fd + 1, &set, NULL, NULL, &tv); | ^~~~~~ samples/mei/mei-amt-version.c:171:23: error: implicit declaration of function 'FD_ISSET' [-Wimplicit-function-declaration] 171 | if (rc > 0 && FD_ISSET(me->fd, &set)) { | ^~~~~~~~ samples/mei/mei-amt-version.c:159:24: warning: unused variable 'tv' [-Wunused-variable] 159 | struct timeval tv; | ^~ Hence the the file has been included. Fixes: c52827cc4ddf ("staging/mei: add mei user space example") Signed-off-by: Brahmajit Das Link: https://lore.kernel.org/r/20250702135955.24955-1-listout@listout.xyz Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

samples/damon: fix damon sample wsse for start failure

2025-07-17T16:43:52Z

commit f1221c8442616a6927aff836327777144545cb29 upstream. The damon_sample_wsse_start() can fail so we must reset the "enable" parameter to "false" again for proper rollback. In such cases, setting Y to "enable" then N triggers the similar crash with wsse because damon sample start failed but the "enable" stays as Y. Link: https://lkml.kernel.org/r/20250702000205.1921-3-honggyu.kim@sk.com Fixes: b757c6cfc696 ("samples/damon/wsse: start and stop DAMON as the user requests") Signed-off-by: Honggyu Kim Reviewed-by: SeongJae Park Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

samples/damon: fix damon sample prcl for start failure

2025-07-17T16:43:52Z

commit d9e01c62b7a0c258a7481c083f84c766a8f5597c upstream. Patch series "mm/damon: fix divide by zero and its samples", v3. This series includes fixes against damon and its samples to make it safer when damon sample starting fails. It includes the following changes. - fix unexpected divide by zero crash for zero size regions - fix bugs for damon samples in case of start failures This patch (of 4): The damon_sample_prcl_start() can fail so we must reset the "enable" parameter to "false" again for proper rollback. In such cases, setting Y to "enable" then N triggers the following crash because damon sample start failed but the "enable" stays as Y. [ 2441.419649] damon_sample_prcl: start [ 2454.146817] damon_sample_prcl: stop [ 2454.146862] ------------[ cut here ]------------ [ 2454.146865] kernel BUG at mm/slub.c:546! [ 2454.148183] Oops: invalid opcode: 0000 [#1] SMP NOPTI ... [ 2454.167555] Call Trace: [ 2454.167822] [ 2454.168061] damon_destroy_ctx+0x78/0x140 [ 2454.168454] damon_sample_prcl_enable_store+0x8d/0xd0 [ 2454.168932] param_attr_store+0xa1/0x120 [ 2454.169315] module_attr_store+0x20/0x50 [ 2454.169695] sysfs_kf_write+0x72/0x90 [ 2454.170065] kernfs_fop_write_iter+0x150/0x1e0 [ 2454.170491] vfs_write+0x315/0x440 [ 2454.170833] ksys_write+0x69/0xf0 [ 2454.171162] __x64_sys_write+0x19/0x30 [ 2454.171525] x64_sys_call+0x18b2/0x2700 [ 2454.171900] do_syscall_64+0x7f/0x680 [ 2454.172258] ? exit_to_user_mode_loop+0xf6/0x180 [ 2454.172694] ? clear_bhb_loop+0x30/0x80 [ 2454.173067] ? clear_bhb_loop+0x30/0x80 [ 2454.173439] entry_SYSCALL_64_after_hwframe+0x76/0x7e Link: https://lkml.kernel.org/r/20250702000205.1921-1-honggyu.kim@sk.com Link: https://lkml.kernel.org/r/20250702000205.1921-2-honggyu.kim@sk.com Fixes: 2aca254620a8 ("samples/damon: introduce a skeleton of a smaple DAMON module for proactive reclamation") Signed-off-by: Honggyu Kim Reviewed-by: SeongJae Park Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

tracing: samples: Initialize trace_array_printk() with the correct function

2025-05-12T17:07:22Z

When using trace_array_printk() on a created instance, the correct function to use to initialize it is: trace_array_init_printk() Not trace_printk_init_buffer() The former is a proper function to use, the latter is for initializing trace_printk() and causes the NOTICE banner to be displayed. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Divya Indi Link: https://lore.kernel.org/20250509152657.0f6744d9@gandalf.local.home Fixes: 89ed42495ef4a ("tracing: Sample module to demonstrate kernel access to Ftrace instances.") Fixes: 38ce2a9e33db6 ("tracing: Add trace_array_init_printk() to initialize instance trace_printk() buffers") Signed-off-by: Steven Rostedt (Google)

samples/bpf: Fix compilation failure for samples/bpf on LoongArch Fedora

2025-04-25T16:32:02Z

When building the latest samples/bpf on LoongArch Fedora make M=samples/bpf There are compilation errors as follows: In file included from ./linux/samples/bpf/sockex2_kern.c:2: In file included from ./include/uapi/linux/in.h:25: In file included from ./include/linux/socket.h:8: In file included from ./include/linux/uio.h:9: In file included from ./include/linux/thread_info.h:60: In file included from ./arch/loongarch/include/asm/thread_info.h:15: In file included from ./arch/loongarch/include/asm/processor.h:13: In file included from ./arch/loongarch/include/asm/cpu-info.h:11: ./arch/loongarch/include/asm/loongarch.h:13:10: fatal error: 'larchintrin.h' file not found ^~~~~~~~~~~~~~~ 1 error generated. larchintrin.h is included in /usr/lib64/clang/14.0.6/include, and the header file location is specified at compile time. Test on LoongArch Fedora: https://github.com/fedora-remix-loongarch/releases-info Signed-off-by: Haoran Jiang Signed-off-by: zhangxi Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250425095042.838824-1-jianghaoran@kylinos.cn

samples/livepatch: add module descriptions

2025-04-12T00:32:38Z

Every module should have a description, so add one for each of these modules. [akpm@linux-foundation.org: match the livepatch-callbacks-mod.c description, per Petr] Link: https://lkml.kernel.org/r/20250324173242.1501003-3-arnd@kernel.org Fixes: 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()") Signed-off-by: Arnd Bergmann Reviewed-by: Petr Mladek Cc: Christophe Leroy Cc: Easwar Hariharan Cc: Jeff Johnson Cc: Jiri Kosina Cc: Joe Lawrence Cc: Josh Poimboeuf Cc: Masahiro Yamada Cc: Miroslav Benes Cc: Stehen Rothwell Signed-off-by: Andrew Morton

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12Z

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

Merge tag 'trace-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-04-03T16:52:44Z

Pull tracing fixes from Steven Rostedt: - Fix build error when CONFIG_PROBE_EVENTS_BTF_ARGS is not enabled The tracing of arguments in the function tracer depends on some functions that are only defined when PROBE_EVENTS_BTF_ARGS is enabled. In fact, PROBE_EVENTS_BTF_ARGS also depends on all the same configs as the function argument tracing requires. Just have the function argument tracing depend on PROBE_EVENTS_BTF_ARGS. - Free module_delta for persistent ring buffer instance When an instance holds the persistent ring buffer, it allocates a helper array to hold the deltas between where modules are loaded on the last boot and the current boot. This array needs to be freed when the instance is freed. - Add cond_resched() to loop in ftrace_graph_set_hash() The hash functions in ftrace loop over every function that can be enabled by ftrace. This can be 50,000 functions or more. This loop is known to trigger soft lockup warnings and requires a cond_resched(). The loop in ftrace_graph_set_hash() was missing it. - Fix the event format verifier to include "%*p.." arguments To prevent events from dereferencing stale pointers that can happen if a trace event uses a dereferece pointer to something that was not copied into the ring buffer and can be freed by the time the trace is read, a verifier is called. At boot or module load, the verifier scans the print format string for pointers that can be dereferenced and it checks the arguments to make sure they do not contain something that can be freed. The "%*p" was not handled, which would add another argument and cause the verifier to not only not verify this pointer, but it will look at the wrong argument for every pointer after that. - Fix mcount sorttable building for different endian type target When modifying the ELF file to sort the mcount_loc table in the sorttable.c code, the endianess of the file and the host is used to determine if the bytes need to be swapped when calculations are done. A change was made to the sorting of the mcount_loc that read the values from the ELF file into an array and the swap happened on the filling of the array. But one of the calculations of the array still did the swap when it did not need to. This caused building on a little endian machine for a big endian target to not find the mcount function in the 'nm' table and it zeroed it out, causing there to be no functions available to trace. - Add goto out_unlock jump to rv_register_monitor() on error path One of the error paths in rv_register_monitor() just returned the error when it should have jumped to the out_unlock label to release the mutex. * tag 'trace-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: rv: Fix missing unlock on double nested monitors return path scripts/sorttable: Fix endianness handling in build-time mcount sort tracing: Verify event formats that have "%*p.." ftrace: Add cond_resched() to ftrace_graph_set_hash() tracing: Free module_delta on freeing of persistent ring buffer ftrace: Have tracing function args depend on PROBE_EVENTS_BTF_ARGS

tracing: Verify event formats that have "%*p.."

2025-04-02T13:51:26Z

The trace event verifier checks the formats of trace events to make sure that they do not point at memory that is not in the trace event itself or in data that will never be freed. If an event references data that was allocated when the event triggered and that same data is freed before the event is read, then the kernel can crash by reading freed memory. The verifier runs at boot up (or module load) and scans the print formats of the events and checks their arguments to make sure that dereferenced pointers are safe. If the format uses "%*p.." the verifier will ignore it, and that could be dangerous. Cover this case as well. Also add to the sample code a use case of "%*pbl". Link: https://lore.kernel.org/all/bcba4d76-2c3f-4d11-baf0-02905db953dd@oracle.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Fixes: 5013f454a352c ("tracing: Add check of trace event print fmts for dereferencing pointers") Link: https://lore.kernel.org/20250327195311.2d89ec66@gandalf.local.home Reported-by: Libo Chen Reviewed-by: Libo Chen Tested-by: Libo Chen Signed-off-by: Steven Rostedt (Google)