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7 daysMerge tag 'trace-rv-v7.1-rc6-2' of ↵Linus Torvalds4-14/+9
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull runtime verifier fixes from Steven Rostedt: - Fix reset ordering on per-task destruction Reset the task before dropping the slot instead of after, which was causing out-of-bound memory accesses. - Fix HA monitor synchronization and cleanup Ensure synchronous cleanup for HA monitors by running timer callbacks in RCU read-side critical sections and using synchronize_rcu() during destruction. - Avoid armed timers after tasks exit Add automatic cleanup for per-task HA monitors to prevent timers from firing after task exit. - Fix memory ordering for DA/HA monitors Fix race conditions during monitor start by using release-acquire semantics for the monitoring flag. - Fix initialization for DA/HA monitors Ensure monitors are not initialized relying on potentially corrupted state like the monitoring flag, that is not reset by all monitors type and may have an unknown state in monitors reusing the storage (per-task). - Fix memory safety in per-task and per-object monitors Prevent use-after-free and out-of-bounds access by synchronizing with in-flight tracepoint probes using tracepoint_synchronize_unregister() before freeing monitor storage or releasing task slots. - Adjust monitors for preemptible tracepoints Fix monitors that relied on tracepoints disabling preemption. Explicitly disable task migration when per-CPU monitors handle events to avoid accessing the wrong state and update the opid monitor logic. - Fix incorrect __user specifier usage Remove __user from a non-pointer variable in the extract_params() helper. - Fix bugs in the rv tool Ensure strings are NUL-terminated, fix substring matching in monitor searches, and improve cleanup and exit status handling. - Fix several bugs in rvgen Fix LTL literal stringification, subparsers' options handling, and suffix stripping in dot2k. * tag 'trace-rv-v7.1-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: verification/rvgen: Fix ltl2k writing True as a literal verification/rvgen: Fix options shared among commands verification/rvgen: Fix suffix strip in dot2k tools/rv: Fix cleanup after failed trace setup tools/rv: Fix substring match when listing container monitors tools/rv: Fix substring match bug in monitor name search tools/rv: Ensure monitor name and desc are NUL-terminated rv: Use 0 to check preemption enabled in opid rv: Prevent task migration while handling per-CPU events rv: Ensure synchronous cleanup for HA monitors rv: Add automatic cleanup handlers for per-task HA monitors rv: Do not rely on clean monitor when initialising HA rv: Fix monitor start ordering and memory ordering for monitoring flag rv: Ensure all pending probes terminate on per-obj monitor destroy rv: Prevent in-flight per-task handlers from using invalid slots rv: Reset per-task DA monitors before releasing the slot rv: Fix __user specifier usage in extract_params()
13 daysrv: Use 0 to check preemption enabled in opidGabriele Monaco1-7/+1
Tracepoint handlers no longer run with preemption disabled by default since a46023d5616 ("tracing: Guard __DECLARE_TRACE() use of __DO_TRACE_CALL() with SRCU-fast"), the opid monitor should now count 1 in the preemption count as preemption disabled. Change the rule for preempt_off to preempt > 0. Reviewed-by: Nam Cao <namcao@linutronix.de> Link: https://lore.kernel.org/r/20260601153840.124372-11-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
13 daysrv: Add automatic cleanup handlers for per-task HA monitorsGabriele Monaco3-6/+6
Hybrid automata monitors may start timers, depending on the model, these may remain active on an exiting task and cause false positives or even access freed memory. Add an enable/disable hook in the HA code, currently only populated by the per-task handler for registration and deregistration. This hooks to the sched_process_exit event and ensures the timer is stopped for every exiting task. The handler is enabled automatically but may be disabled, for instance if the monitor uses the event for another purpose (but should still manually ensure timers are stopped). Fixes: f5587d1b6ec9 ("rv: Add Hybrid Automata monitor type") Reviewed-by: Nam Cao <namcao@linutronix.de> Link: https://lore.kernel.org/r/20260601153840.124372-8-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
13 daysrv: Fix __user specifier usage in extract_params()Gabriele Monaco1-1/+2
The attributes variables extracted from syscalls in the helper are both defined with the __user specifier although only the actual pointer to user data should be marked. Remove the __user specifier from attr. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202604150820.Ny143u6X-lkp@intel.com Fixes: b133207deb72 ("rv: Add nomiss deadline monitor") Reviewed-by: Wen Yang <wen.yang@linux.dev> Reviewed-by: Nam Cao <namcao@linutronix.de> Link: https://lore.kernel.org/r/20260601153840.124372-2-gmonaco@redhat.com Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2026-05-30tracing/probes: Point the error offset correctly for eprobe argument errorMasami Hiramatsu (Google)1-2/+0
Fix to point the error offset correctly for eprobe argument error. In the cleanup commit 1b8b0cd754cd ("tracing/probes: Move event parameter fetching code to common parser"), due to incorrect backward compatibility aimed at conforming to the test specifications, the error location was set to 0 when a non-existent formal parameter was specified for Eprobe. However, this should be corrected in both the test and the implementation to point correct error position. Link: https://lore.kernel.org/all/177967567399.209006.1451571244515632097.stgit@devnote2/ Fixes: 1b8b0cd754cd ("tracing/probes: Move event parameter fetching code to common parser") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-22Merge tag 'trace-v7.1-rc4' of ↵Linus Torvalds2-8/+15
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Avoid NULL return from hist_field_name() The function hist_field_name() is directly passed to a strcat() which does not handle "NULL" characters. Return a zero length string when size is greater than the limit. This is used only to output already created histograms and no field currently is greater than the limit. But it should still not return NULL. - Do not call map->ops->elt_free() on allocation failure When elt_alloc() fails, it should not call the map->ops->elt_free() function if it exists, as that function may not be able to handle the free on allocation failures. The ->elt_free() should only be called when elt_alloc() succeeds. * tag 'trace-v7.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Do not call map->ops->elt_free() if elt_alloc() fails tracing: Avoid NULL return from hist_field_name() on truncation
2026-05-21tracing: Do not call map->ops->elt_free() if elt_alloc() failsMasami Hiramatsu (Google)1-4/+13
In paths where tracing_map_elt_alloc() failed to allocate objects, the map->ops->elt_alloc() call was never successful. In this case, map->ops->elt_free() should not be called. Link: https://sashiko.dev/#/patchset/20260520223101.34710-1-rosenp%40gmail.com Cc: stable@vger.kernel.org Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Rosen Penev <rosenp@gmail.com> Reported-by: Sashiko <sashiko-bot@kernel.org> Fixes: 2734b629525a ("tracing: Add per-element variable support to tracing_map") Link: https://patch.msgid.link/177933895460.108746.5396070821443932634.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-21tracing: Create output file from cmd_check_undefinedThomas Weißschuh1-1/+2
As the output file is currently never created, the check will run every time, even if the inputs have not changed. Create an empty output file which allows make to skip the execution when it is not necessary. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Link: https://patch.msgid.link/20260520-tracing-ringbuffer-check-v1-1-d979cfab1338@weissschuh.net Fixes: 1211907ac0b5 ("tracing: Generate undef symbols allowlist for simple_ring_buffer") Fixes: 58b4bd18390e ("tracing: Adjust cmd_check_undefined to show unexpected undefined symbols") Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-21tracing: Fix unload_page for simple_ring_buffer init rollbackVincent Donnefort1-1/+1
The unload_page callback expects the return value of load_page() as its argument: ret = load_page(va); unload(ret). Fix the rollback code in simple_ring_buffer_init_mm() where the descriptor's VA is used instead of the loaded page address. Link: https://patch.msgid.link/20260512141614.1759430-1-vdonnefort@google.com Fixes: 635923081c79 ("tracing: load/unload page callbacks for simple_ring_buffer") Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-21tracing: Fix nr_subbufs initialization in simple_ring_buffer_init_mm()David Carlier1-1/+1
nr_subbufs in the ring buffer metadata is always initialized to zero because it is assigned from cpu_buffer->nr_pages before the page initialization loop has run. While nr_subbufs is not currently read by the kernel, it should reflect the actual buffer geometry in the meta page for correctness. Move the assignment after the page loop so that cpu_buffer->nr_pages holds the final count. Link: https://patch.msgid.link/20260512135420.99194-1-devnexen@gmail.com Fixes: 34e5b958bdad ("tracing: Introduce simple_ring_buffer") Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Assisted-by: Claude:claude-opus-4-7 Signed-off-by: David Carlier <devnexen@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-21ring-buffer: Flush and stop persistent ring buffer on panicMasami Hiramatsu (Google)1-0/+22
On real hardware, panic and machine reboot may not flush hardware cache to memory. This means the persistent ring buffer, which relies on a coherent state of memory, may not have its events written to the buffer and they may be lost. Moreover, there may be inconsistency with the counters which are used for validation of the integrity of the persistent ring buffer which may cause all data to be discarded. To avoid this issue, stop recording of the ring buffer on panic and flush the cache of the ring buffer's memory. Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance") Cc: stable@vger.kernel.org Cc: Will Deacon <will@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ian Rogers <irogers@google.com> Link: https://patch.msgid.link/177751969602.2136606.12031934362587643488.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-21ring-buffer: Fix reporting of missed events in iteratorSteven Rostedt1-5/+3
When tracing is active while reading the trace file, if the iterator reading the buffer detects that the writer has passed the iterator head, it will reset and set a "missed events" flag. This flag is passed to the output processing to show the user that events were missed: CPU:4 [LOST EVENTS] The problem is that the flag is reset after it is checked in ring_buffer_iter_dropped(). But the "trace" file iterates over all the CPU ring buffers and it will check if they are dropped when figuring out which buffer to print next. This prematurely clears the missed_events flag if the CPU buffer with the missed events is not the one that is printed next. On the iteration where the CPU buffer with the missed events is printed, the check if it had missed events would return false and the output does not show that events were missed. Do not reset the missed_events flag when checking if there were missed events, but instead clear it when moving the iterator head to the next event. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20260520220801.4fd09d13@fedora Fixes: c9b7a4a72ff64 ("ring-buffer/tracing: Have iterator acknowledge dropped events") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-20tracing: Avoid NULL return from hist_field_name() on truncationDavid Carlier1-4/+2
hist_field_name() returns "" everywhere except the fully-qualified VAR_REF/EXPR case, where snprintf() truncation returns NULL early and bypasses the bottom NULL->"" guard. Callers don't expect NULL: strcat(expr, hist_field_name(field, 0)) at trace_events_hist.c:1758 and the strcmp() in the sort-key match loop at :4804 both deref it. system and event_name are bounded by MAX_EVENT_NAME_LEN, but the field name on a VAR_REF is kstrdup'd from a histogram variable name parsed out of the trigger string and has no length cap, so a long enough var name in a fully qualified reference can reach the truncation path. Keep the length check but leave field_name as "" on overflow. Link: https://patch.msgid.link/20260508195747.25492-1-devnexen@gmail.com Fixes: 5ec1d1e97de1 ("tracing: Rebuild full_name on each hist_field_name() call") Signed-off-by: David Carlier <devnexen@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-17Merge tag 'trace-v7.1-rc3' of ↵Linus Torvalds2-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Add more functions to the remote allowed list randconfig found more functions that are allowed for the remote code for s390 and arm. Add them to the allowed list. - Fix remote_test error path If one of the simple ring buffers fails to load, the code is supposed to rollback its initialized buffers. Instead of rolling back the buffers for the failed load, it uses the global variable and rolls back all the successfully loaded buffers. * tag 'trace-v7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Fix desc in error path for the trace remote test module ring-buffer remote: Avoid unexpected symbol warnings (arm, s390)
2026-05-16tracing: Fix desc in error path for the trace remote test moduleVincent Donnefort1-2/+2
During initialisation in remote_test_load(), if one of the simple_ring_buffer fails to initialise, the error path attempts to rollback initialised buffers. However, the rollback incorrectly uses the global pointer to the trace descriptor, which is only set upon successful load completion. Fix the error path by using the local pointer to the descriptor. Link: https://patch.msgid.link/20260515201616.337469-1-vdonnefort@google.com Fixes: ea908a2b79c8 ("tracing: Add a trace remote module for testing") Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> base-commit: 5d6919055dec134de3c40167a490f33c74c12581 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-15ring-buffer remote: Avoid unexpected symbol warnings (arm, s390)Arnd Bergmann1-2/+2
The now more verbose check found more architecture specific symbol missing from the whitelist, during randconfig testing on s390 and 32-bit arm: Unexpected symbols in kernel/trace/simple_ring_buffer.o: U __aeabi_unwind_cpp_pr1 Unexpected symbols in kernel/trace/simple_ring_buffer.o: U __s390_indirect_jump_r1 U __s390_indirect_jump_r10 U __s390_indirect_jump_r14 U __s390_indirect_jump_r2 U __s390_indirect_jump_r5 U __s390_indirect_jump_r7 U __s390_indirect_jump_r8 U __s390_indirect_jump_r9 make[6]: *** [/home/arnd/arm-soc/kernel/trace/Makefile:160: kernel/trace/simple_ring_buffer.o.checked] Error 1 Add these to the list and keep it roughly sorted into sanitizer and architecture symbols. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Link: https://patch.msgid.link/20260515105717.1023007-1-arnd@kernel.org Fixes: 1211907ac0b5 ("tracing: Generate undef symbols allowlist for simple_ring_buffer") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-11fprobe: Fix unregister_fprobe() to wait for RCU grace periodMasami Hiramatsu (Google)2-3/+23
Commit 4346ba1604093 ("fprobe: Rewrite fprobe on function-graph tracer") changed fprobe to register struct fprobe to an rcu-hlist, but it forgot to wait for RCU GP. Thus there can be use-after-free if the fprobe is released right after unregistering. This can be happened on fprobe event and sample module code. To fix this issue, add synchronize_rcu() in unregister_fprobe(). Note that BPF is OK because fprobe is used as a part of bpf_kprobe_multi_link. This unregisters its fprobe in bpf_kprobe_multi_link_release() and it is deallocated via bpf_kprobe_multi_link_dealloc(), which is invoked from bpf_link_defer_dealloc_rcu_gp() RCU callback. For BPF, this also introduced unregister_fprobe_async() which does NOT wait for RCU grace priod. Link: https://lore.kernel.org/all/177813998919.256460.2809243930741138224.stgit@mhiramat.tok.corp.google.com/ Fixes: 4346ba1604093 ("fprobe: Rewrite fprobe on function-graph tracer") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-04-29tracing/probes: Limit size of event probe to 3KSteven Rostedt2-1/+9
There currently isn't a max limit an event probe can be. One could make an event greater than PAGE_SIZE, which makes the event useless because if it's bigger than the max event that can be recorded into the ring buffer, then it will never be recorded. A event probe should never need to be greater than 3K, so make that the max size. As long as the max is less than the max that can be recorded onto the ring buffer, it should be fine. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Fixes: 93ccae7a22274 ("tracing/kprobes: Support basic types on dynamic events") Link: https://patch.msgid.link/20260428122302.706610ba@gandalf.local.home Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-04-28tracing: branch: Fix inverted check on stat tracer registrationBreno Leitao1-4/+4
init_annotated_branch_stats() and all_annotated_branch_stats() check the return value of register_stat_tracer() with "if (!ret)", but register_stat_tracer() returns 0 on success and a negative errno on failure. The inverted check causes the warning to be printed on every successful registration, e.g.: Warning: could not register annotated branches stats while leaving real failures silent. The initcall also returned a hard-coded 1 instead of the actual error. Invert the check and propagate ret so that the warning fires on real errors and the initcall reports the correct status. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: https://patch.msgid.link/20260420-tracing-v1-1-d8f4cd0d6af1@debian.org Fixes: 002bb86d8d42 ("tracing/ftrace: separate events tracing and stats tracing engine") Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-04-24Merge tag 'trace-ring-buffer-v7.1-3' of ↵Linus Torvalds1-6/+7
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ring-buffer fix from Steven Rostedt: - Fix accounting of persistent ring buffer rewind On boot up, the head page is moved back to the earliest point of the saved ring buffer. This is because the ring buffer being read by user space on a crash may not save the part it read. Rewinding the head page back to the earliest saved position helps keep those events from being lost. The number of events is also read during boot up and displayed in the stats file in the tracefs directory. It's also used for other accounting as well. On boot up, the "reader page" is accounted for but a rewind may put it back into the buffer and then the reader page may be accounted for again. Save off the original reader page and skip accounting it when scanning the pages in the ring buffer. * tag 'trace-ring-buffer-v7.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Do not double count the reader_page
2026-04-24ring-buffer: Do not double count the reader_pageMasami Hiramatsu (Google)1-6/+7
Since the cpu_buffer->reader_page is updated if there are unwound pages. After that update, we should skip the page if it is the original reader_page, because the original reader_page is already checked. Cc: stable@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ian Rogers <irogers@google.com> Link: https://patch.msgid.link/177701353063.2223789.1471163147644103306.stgit@mhiramat.tok.corp.google.com Fixes: ca296d32ece3 ("tracing: ring_buffer: Rewind persistent ring buffer on reboot") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-04-22Merge tag 'trace-ring-buffer-v7.1-2' of ↵Linus Torvalds3-32/+32
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ring-buffer fix from Steven Rostedt: - Make undefsyms_base.c into a real file The file undefsyms_base.c is used to catch any symbols used by a remote ring buffer that is made for use of a pKVM hypervisor. As it doesn't share the same text as the rest of the kernel, referencing any symbols within the kernel will make it fail to be built for the standalone hypervisor. A file was created by the Makefile that checked for any symbols that could cause issues. There's no reason to have this file created by the Makefile, just create it as a normal file instead. * tag 'trace-ring-buffer-v7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Make undefsyms_base.c a first-class citizen
2026-04-22tracing: Make undefsyms_base.c a first-class citizenPaolo Bonzini3-32/+32
Linus points out that dumping undefsyms_base.c form the Makefile is rather ugly, and that a much better course of action would be to have this file as a first-class citizen in the git tree. This allows some extra cleanup in the Makefile, and the removal of the .gitignore file in kernel/trace. Cc: Marc Zyngier <maz@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/CAHk-=wieqGd_XKpu8UxDoyADZx8TDe8CF3RmkUXt5N_9t5Pf_w@mail.gmail.com Link: https://lore.kernel.org/all/20260421095446.2951646-1-maz@kernel.org/ Link: https://patch.msgid.link/20260421100455.324333-1-pbonzini@redhat.com Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-04-22tracing/fprobe: Fix to unregister ftrace_ops if it is empty on module unloadingMasami Hiramatsu (Google)1-65/+159
Fix fprobe to unregister ftrace_ops if corresponding type of fprobe does not exist on the fprobe_ip_table and it is expected to be empty when unloading modules. Since ftrace thinks that the empty hash means everything to be traced, if we set fprobes only on the unloaded module, all functions are traced unexpectedly after unloading module. e.g. # modprobe xt_LOG.ko # echo 'f:test log_tg*' > dynamic_events # echo 1 > events/fprobes/test/enable # cat enabled_functions log_tg [xt_LOG] (1) tramp: 0xffffffffa0004000 (fprobe_ftrace_entry+0x0/0x490) ->fprobe_ftrace_entry+0x0/0x490 log_tg_check [xt_LOG] (1) tramp: 0xffffffffa0004000 (fprobe_ftrace_entry+0x0/0x490) ->fprobe_ftrace_entry+0x0/0x490 log_tg_destroy [xt_LOG] (1) tramp: 0xffffffffa0004000 (fprobe_ftrace_entry+0x0/0x490) ->fprobe_ftrace_entry+0x0/0x490 # rmmod xt_LOG # wc -l enabled_functions 34085 enabled_functions Link: https://lore.kernel.org/all/177669368776.132053.10042301916765771279.stgit@mhiramat.tok.corp.google.com/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-04-22tracing/fprobe: Check the same type fprobe on table as the unregistered oneMasami Hiramatsu (Google)1-17/+65
Commit 2c67dc457bc6 ("tracing: fprobe: optimization for entry only case") introduced a different ftrace_ops for entry-only fprobes. However, when unregistering an fprobe, the kernel only checks if another fprobe exists at the same address, without checking which type of fprobe it is. If different fprobes are registered at the same address, the same address will be registered in both fgraph_ops and ftrace_ops, but only one of them will be deleted when unregistering. (the one removed first will not be deleted from the ops). This results in junk entries remaining in either fgraph_ops or ftrace_ops. For example: ======= cd /sys/kernel/tracing # 'Add entry and exit events on the same place' echo 'f:event1 vfs_read' >> dynamic_events echo 'f:event2 vfs_read%return' >> dynamic_events # 'Enable both of them' echo 1 > events/fprobes/enable cat enabled_functions vfs_read (2) ->arch_ftrace_ops_list_func+0x0/0x210 # 'Disable and remove exit event' echo 0 > events/fprobes/event2/enable echo -:event2 >> dynamic_events # 'Disable and remove all events' echo 0 > events/fprobes/enable echo > dynamic_events # 'Add another event' echo 'f:event3 vfs_open%return' > dynamic_events cat dynamic_events f:fprobes/event3 vfs_open%return echo 1 > events/fprobes/enable cat enabled_functions vfs_open (1) tramp: 0xffffffffa0001000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60 subops: {ent:fprobe_fgraph_entry+0x0/0x620 ret:fprobe_return+0x0/0x150} vfs_read (1) tramp: 0xffffffffa0001000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60 subops: {ent:fprobe_fgraph_entry+0x0/0x620 ret:fprobe_return+0x0/0x150} ======= As you can see, an entry for the vfs_read remains. To fix this issue, when unregistering, the kernel should also check if there is the same type of fprobes still exist at the same address, and if not, delete its entry from either fgraph_ops or ftrace_ops. Link: https://lore.kernel.org/all/177669367993.132053.10553046138528674802.stgit@mhiramat.tok.corp.google.com/ Fixes: 2c67dc457bc6 ("tracing: fprobe: optimization for entry only case") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-04-22tracing/fprobe: Avoid kcalloc() in rcu_read_lock sectionMasami Hiramatsu (Google)1-47/+45
fprobe_remove_node_in_module() is called under RCU read locked, but this invokes kcalloc() if there are more than 8 fprobes installed on the module. Sashiko warns it because kcalloc() can sleep [1]. [1] https://sashiko.dev/#/patchset/177552432201.853249.5125045538812833325.stgit%40mhiramat.tok.corp.google.com To fix this issue, expand the batch size to 128 and do not expand the fprobe_addr_list, but just cancel walking on fprobe_ip_table, update fgraph/ftrace_ops and retry the loop again. Link: https://lore.kernel.org/all/177669367206.132053.1493637946869032744.stgit@mhiramat.tok.corp.google.com/ Fixes: 0de4c70d04a4 ("tracing: fprobe: use rhltable for fprobe_ip_table") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-04-21tracing/fprobe: Remove fprobe from hash in failure pathMasami Hiramatsu (Google)1-43/+47
When register_fprobe_ips() fails, it tries to remove a list of fprobe_hash_node from fprobe_ip_table, but it missed to remove fprobe itself from fprobe_table. Moreover, when removing the fprobe_hash_node which is added to rhltable once, it must use kfree_rcu() after removing from rhltable. To fix these issues, this reuses unregister_fprobe() internal code to rollback the half-way registered fprobe. Link: https://lore.kernel.org/all/177669366417.132053.17874946321744910456.stgit@mhiramat.tok.corp.google.com/ Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-04-21tracing/fprobe: Unregister fprobe even if memory allocation failsMasami Hiramatsu (Google)1-10/+15
unregister_fprobe() can fail under memory pressure because of memory allocation failure, but this maybe called from module unloading, and usually there is no way to retry it. Moreover. trace_fprobe does not check the return value. To fix this problem, unregister fprobe and fprobe_hash_node even if working memory allocation fails. Anyway, if the last fprobe is removed, the filter will be freed. Link: https://lore.kernel.org/all/177669365629.132053.8433032896213721288.stgit@mhiramat.tok.corp.google.com/ Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-04-21tracing/fprobe: Reject registration of a registered fprobe before initMasami Hiramatsu (Google)1-11/+10
Reject registration of a registered fprobe which is on the fprobe hash table before initializing fprobe. The add_fprobe_hash() checks this re-register fprobe, but since fprobe_init() clears hlist_array field, it is too late to check it. It has to check the re-registration before touncing fprobe. Link: https://lore.kernel.org/all/177669364845.132053.18375367916162315835.stgit@mhiramat.tok.corp.google.com/ Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-04-20tracing: tell git to ignore the generated 'undefsyms_base.c' fileLinus Torvalds1-0/+1
This odd file was added to automatically figure out tool-generated symbols. Honestly, it *should* have been just a real honest-to-goodness regular file in git, instead of having strange code to generate it in the Makefile, but that is not how that silly thing works. So now we need to ignore it explicitly. Fixes: 1211907ac0b5 ("tracing: Generate undef symbols allowlist for simple_ring_buffer") Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marc Zyngier <maz@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-04-17Merge tag 'trace-latency-v7.1' of ↵Linus Torvalds1-1/+53
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing latency update from Steven Rostedt: - Add TIMERLAT_ALIGN osnoise option Add a timer alignment option for timerlat that makes it work like the cyclictest -A option. timelat creates threads to test the latency of the kernel. The alignment option will have these threads trigger at the alignment offsets from each other. Instead of having each thread wake up at the exact same time, if the alignment is set to "20" each thread will wake up at 20 microseconds from the previous one. * tag 'trace-latency-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/osnoise: Add option to align tlat threads
2026-04-17Merge tag 'trace-v7.1' of ↵Linus Torvalds10-1227/+1285
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Fix printf format warning for bprintf sunrpc uses a trace_printk() that triggers a printf warning during the compile. Move the __printf() attribute around for when debugging is not enabled the warning will go away - Remove redundant check for EVENT_FILE_FL_FREED in event_filter_write() The FREED flag is checked in the call to event_file_file() and then checked again right afterward, which is unneeded - Clean up event_file_file() and event_file_data() helpers These helper functions played a different role in the past, but now with eventfs, the READ_ONCE() isn't needed. Simplify the code a bit and also add a warning to event_file_data() if the file or its data is not present - Remove updating file->private_data in tracing open All access to the file private data is handled by the helper functions, which do not use file->private_data. Stop updating it on open - Show ENUM names in function arguments via BTF in function tracing When showing the function arguments when func-args option is set for function tracing, if one of the arguments is found to be an enum, show the name of the enum instead of its number - Add new trace_call__##name() API for tracepoints Tracepoints are enabled via static_branch() blocks, where when not enabled, there's only a nop that is in the code where the execution will just skip over it. When tracing is enabled, the nop is converted to a direct jump to the tracepoint code. Sometimes more calculations are required to be performed to update the parameters of the tracepoint. In this case, trace_##name##_enabled() is called which is a static_branch() that gets enabled only when the tracepoint is enabled. This allows the extra calculations to also be skipped by the nop: if (trace_foo_enabled()) { x = bar(); trace_foo(x); } Where the x=bar() is only performed when foo is enabled. The problem with this approach is that there's now two static_branch() calls. One for checking if the tracepoint is enabled, and then again to know if the tracepoint should be called. The second one is redundant Introduce trace_call__foo() that will call the foo() tracepoint directly without doing a static_branch(): if (trace_foo_enabled()) { x = bar(); trace_call__foo(); } - Update various locations to use the new trace_call__##name() API - Move snapshot code out of trace.c Cleaning up trace.c to not be a "dump all", move the snapshot code out of it and into a new trace_snapshot.c file - Clean up some "%*.s" to "%*s" - Allow boot kernel command line options to be called multiple times Have options like: ftrace_filter=foo ftrace_filter=bar ftrace_filter=zoo Equal to: ftrace_filter=foo,bar,zoo - Fix ipi_raise event CPU field to be a CPU field The ipi_raise target_cpus field is defined as a __bitmask(). There is now a __cpumask() field definition. Update the field to use that - Have hist_field_name() use a snprintf() and not a series of strcat() It's safer to use snprintf() that a series of strcat() - Fix tracepoint regfunc balancing A tracepoint can define a "reg" and "unreg" function that gets called before the tracepoint is enabled, and after it is disabled respectively. But on error, after the "reg" func is called and the tracepoint is not enabled, the "unreg" function is not called to tear down what the "reg" function performed - Fix output that shows what histograms are enabled Event variables are displayed incorrectly in the histogram output Instead of "sched.sched_wakeup.$var", it is showing "$sched.sched_wakeup.var" where the '$' is in the incorrect location - Some other simple cleanups * tag 'trace-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (24 commits) selftests/ftrace: Add test case for fully-qualified variable references tracing: Fix fully-qualified variable reference printing in histograms tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func() tracing: Rebuild full_name on each hist_field_name() call tracing: Report ipi_raise target CPUs as cpumask tracing: Remove duplicate latency_fsnotify() stub tracing: Preserve repeated trace_trigger boot parameters tracing: Append repeated boot-time tracing parameters tracing: Remove spurious default precision from show_event_trigger/filter formats cpufreq: Use trace_call__##name() at guarded tracepoint call sites tracing: Remove tracing_alloc_snapshot() when snapshot isn't defined tracing: Move snapshot code out of trace.c and into trace_snapshot.c mm: damon: Use trace_call__##name() at guarded tracepoint call sites btrfs: Use trace_call__##name() at guarded tracepoint call sites spi: Use trace_call__##name() at guarded tracepoint call sites i2c: Use trace_call__##name() at guarded tracepoint call sites kernel: Use trace_call__##name() at guarded tracepoint call sites tracepoint: Add trace_call__##name() API tracing: trace_mmap.h: fix a kernel-doc warning tracing: Pretty-print enum parameters in function arguments ...
2026-04-17Merge tag 'probes-v7.1' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull fprobe update from Masami Hiramatsu: - do not zero out unused fgraph_data. This removes unneeded memset of fgraph_data in fprobe entry handler. * tag 'probes-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: fprobe: do not zero out unused fgraph_data
2026-04-17Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2-9/+64
Pull kvm updates from Paolo Bonzini: "Arm: - Add support for tracing in the standalone EL2 hypervisor code, which should help both debugging and performance analysis. This uses the new infrastructure for 'remote' trace buffers that can be exposed by non-kernel entities such as firmware, and which came through the tracing tree - Add support for GICv5 Per Processor Interrupts (PPIs), as the starting point for supporting the new GIC architecture in KVM - Finally add support for pKVM protected guests, where pages are unmapped from the host as they are faulted into the guest and can be shared back from the guest using pKVM hypercalls. Protected guests are created using a new machine type identifier. As the elusive guestmem has not yet delivered on its promises, anonymous memory is also supported This is only a first step towards full isolation from the host; for example, the CPU register state and DMA accesses are not yet isolated. Because this does not really yet bring fully what it promises, it is hidden behind CONFIG_ARM_PKVM_GUEST + 'kvm-arm.mode=protected', and also triggers TAINT_USER when a VM is created. Caveat emptor - Rework the dreaded user_mem_abort() function to make it more maintainable, reducing the amount of state being exposed to the various helpers and rendering a substantial amount of state immutable - Expand the Stage-2 page table dumper to support NV shadow page tables on a per-VM basis - Tidy up the pKVM PSCI proxy code to be slightly less hard to follow - Fix both SPE and TRBE in non-VHE configurations so that they do not generate spurious, out of context table walks that ultimately lead to very bad HW lockups - A small set of patches fixing the Stage-2 MMU freeing in error cases - Tighten-up accepted SMC immediate value to be only #0 for host SMCCC calls - The usual cleanups and other selftest churn LoongArch: - Use CSR_CRMD_PLV for kvm_arch_vcpu_in_kernel() - Add DMSINTC irqchip in kernel support RISC-V: - Fix steal time shared memory alignment checks - Fix vector context allocation leak - Fix array out-of-bounds in pmu_ctr_read() and pmu_fw_ctr_read_hi() - Fix double-free of sdata in kvm_pmu_clear_snapshot_area() - Fix integer overflow in kvm_pmu_validate_counter_mask() - Fix shift-out-of-bounds in make_xfence_request() - Fix lost write protection on huge pages during dirty logging - Split huge pages during fault handling for dirty logging - Skip CSR restore if VCPU is reloaded on the same core - Implement kvm_arch_has_default_irqchip() for KVM selftests - Factored-out ISA checks into separate sources - Added hideleg to struct kvm_vcpu_config - Factored-out VCPU config into separate sources - Support configuration of per-VM HGATP mode from KVM user space s390: - Support for ESA (31-bit) guests inside nested hypervisors - Remove restriction on memslot alignment, which is not needed anymore with the new gmap code - Fix LPSW/E to update the bear (which of course is the breaking event address register) x86: - Shut up various UBSAN warnings on reading module parameter before they were initialized - Don't zero-allocate page tables that are used for splitting hugepages in the TDP MMU, as KVM is guaranteed to set all SPTEs in the page table and thus write all bytes - As an optimization, bail early when trying to unsync 4KiB mappings if the target gfn can just be mapped with a 2MiB hugepage x86 generic: - Copy single-chunk MMIO write values into struct kvm_vcpu (more precisely struct kvm_mmio_fragment) to fix use-after-free stack bugs where KVM would dereference stack pointer after an exit to userspace - Clean up and comment the emulated MMIO code to try to make it easier to maintain (not necessarily "easy", but "easier") - Move VMXON+VMXOFF and EFER.SVME toggling out of KVM (not *all* of VMX and SVM enabling) as it is needed for trusted I/O - Advertise support for AVX512 Bit Matrix Multiply (BMM) instructions - Immediately fail the build if a required #define is missing in one of KVM's headers that is included multiple times - Reject SET_GUEST_DEBUG with -EBUSY if there's an already injected exception, mostly to prevent syzkaller from abusing the uAPI to trigger WARNs, but also because it can help prevent userspace from unintentionally crashing the VM - Exempt SMM from CPUID faulting on Intel, as per the spec - Misc hardening and cleanup changes x86 (AMD): - Fix and optimize IRQ window inhibit handling for AVIC; make it per-vCPU so that KVM doesn't prematurely re-enable AVIC if multiple vCPUs have to-be-injected IRQs - Clean up and optimize the OSVW handling, avoiding a bug in which KVM would overwrite state when enabling virtualization on multiple CPUs in parallel. This should not be a problem because OSVW should usually be the same for all CPUs - Drop a WARN in KVM_MEMORY_ENCRYPT_REG_REGION where KVM complains about a "too large" size based purely on user input - Clean up and harden the pinning code for KVM_MEMORY_ENCRYPT_REG_REGION - Disallow synchronizing a VMSA of an already-launched/encrypted vCPU, as doing so for an SNP guest will crash the host due to an RMP violation page fault - Overhaul KVM's APIs for detecting SEV+ guests so that VM-scoped queries are required to hold kvm->lock, and enforce it by lockdep. Fix various bugs where sev_guest() was not ensured to be stable for the whole duration of a function or ioctl - Convert a pile of kvm->lock SEV code to guard() - Play nicer with userspace that does not enable KVM_CAP_EXCEPTION_PAYLOAD, for which KVM needs to set CR2 and DR6 as a response to ioctls such as KVM_GET_VCPU_EVENTS (even if the payload would end up in EXITINFO2 rather than CR2, for example). Only set CR2 and DR6 when consumption of the payload is imminent, but on the other hand force delivery of the payload in all paths where userspace retrieves CR2 or DR6 - Use vcpu->arch.cr2 when updating vmcb12's CR2 on nested #VMEXIT instead of vmcb02->save.cr2. The value is out of sync after a save/restore or after a #PF is injected into L2 - Fix a class of nSVM bugs where some fields written by the CPU are not synchronized from vmcb02 to cached vmcb12 after VMRUN, and so are not up-to-date when saved by KVM_GET_NESTED_STATE - Fix a class of bugs where the ordering between KVM_SET_NESTED_STATE and KVM_SET_{S}REGS could cause vmcb02 to be incorrectly initialized after save+restore - Add a variety of missing nSVM consistency checks - Fix several bugs where KVM failed to correctly update VMCB fields on nested #VMEXIT - Fix several bugs where KVM failed to correctly synthesize #UD or #GP for SVM-related instructions - Add support for save+restore of virtualized LBRs (on SVM) - Refactor various helpers and macros to improve clarity and (hopefully) make the code easier to maintain - Aggressively sanitize fields when copying from vmcb12, to guard against unintentionally allowing L1 to utilize yet-to-be-defined features - Fix several bugs where KVM botched rAX legality checks when emulating SVM instructions. There are remaining issues in that KVM doesn't handle size prefix overrides for 64-bit guests - Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails instead of somewhat arbitrarily synthesizing #GP (i.e. don't double down on AMD's architectural but sketchy behavior of generating #GP for "unsupported" addresses) - Cache all used vmcb12 fields to further harden against TOCTOU bugs x86 (Intel): - Drop obsolete branch hint prefixes from the VMX instruction macros - Use ASM_INPUT_RM() in __vmcs_writel() to coerce clang into using a register input when appropriate - Code cleanups guest_memfd: - Don't mark guest_memfd folios as accessed, as guest_memfd doesn't support reclaim, the memory is unevictable, and there is no storage to write back to LoongArch selftests: - Add KVM PMU test cases s390 selftests: - Enable more memory selftests x86 selftests: - Add support for Hygon CPUs in KVM selftests - Fix a bug in the MSR test where it would get false failures on AMD/Hygon CPUs with exactly one of RDPID or RDTSCP - Add an MADV_COLLAPSE testcase for guest_memfd as a regression test for a bug where the kernel would attempt to collapse guest_memfd folios against KVM's will" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (373 commits) KVM: x86: use inlines instead of macros for is_sev_*guest x86/virt: Treat SVM as unsupported when running as an SEV+ guest KVM: SEV: Goto an existing error label if charging misc_cg for an ASID fails KVM: SVM: Move lock-protected allocation of SEV ASID into a separate helper KVM: SEV: use mutex guard in snp_handle_guest_req() KVM: SEV: use mutex guard in sev_mem_enc_unregister_region() KVM: SEV: use mutex guard in sev_mem_enc_ioctl() KVM: SEV: use mutex guard in snp_launch_updat