summaryrefslogtreecommitdiff
path: root/kernel/trace/trace_remote.c
AgeCommit message (Collapse)Author
2026-07-23tracing: Propagate errors from remote event bulk updatesJackie Liu
remote_events_dir_enable_write() ignores the return value from trace_remote_enable_event(). If a remote rejects an event state change, the write therefore reports success even though the affected event remains in its previous state. Keep trying all events, but retain and return the first error. This matches __ftrace_set_clr_event_nolock(), which permits partial updates while notifying userspace when an operation fails. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260715074455.3897-1-liu.yun@linux.dev Fixes: 775cb093bc50 ("tracing: Add events/ root files to trace remotes") Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-22tracing/remotes: Fix page_va[] access before counter update in ↵Fuad Tabba
trace_remote_alloc_buffer() page_va[] is annotated __counted_by(nr_page_va), so nr_page_va must cover an index before that element is accessed. The allocation loop writes page_va[id] while nr_page_va is still id and increments it only afterwards, so every write is one element past the declared count. The store is out of bounds with respect to the annotation: a build with CONFIG_UBSAN_BOUNDS on a toolchain that honours __counted_by (clang >= 20.1, gcc >= 15.1) flags it as an array-index overflow. Increment nr_page_va before writing the element it now covers. A failed allocation then leaves the slot counted but NULL; the error path frees it with free_page(0), which is a no-op. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260713072823.2668323-1-fuad.tabba@linux.dev Fixes: 96e43537af546 ("tracing: Introduce trace remotes") Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev> Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Tested-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-10tracing/remotes: Fix struct_len in trace_remote_alloc_buffer()Vincent Donnefort
Pre-calculate desc->struct_len up-front in trace_remote_alloc_buffer() with trace_buffer_desc_size() to fix double-counting. While at it, use the accessor __first_ring_buffer_desc(). Link: https://patch.msgid.link/20260709160017.1729517-3-vdonnefort@google.com Fixes: 96e43537af54 ("tracing: Introduce trace remotes") Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-10tracing/remotes: Fix leak in trace_remote_alloc_buffer() error pathVincent Donnefort
If page allocation fails in trace_remote_alloc_buffer(), desc->nr_cpus is not yet incremented for the current CPU. As a consequence, on error, half-allocated rb_desc will not be freed in trace_remote_free_buffer(). Increment desc->nr_cpus as soon as the first allocation for the current CPU has succeeded. Link: https://patch.msgid.link/20260709160017.1729517-2-vdonnefort@google.com Fixes: 96e43537af54 ("tracing: Introduce trace remotes") Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-21tracing: Remove redundant IS_ERR() check in trace_pipe_open()Yash Suthar
in trace_pipe_open() already check the IS_ERR(iter) and return early on error,so iter after will be valid and it is safe to return 0 at end. Link: https://patch.msgid.link/20260420101236.223919-1-yashsuthar983@gmail.com Signed-off-by: Yash Suthar <yashsuthar983@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-04-02tracing: Non-consuming read for trace remotes with an offline CPUVincent Donnefort
When a trace_buffer is created while a CPU is offline, this CPU is cleared from the trace_buffer CPU mask, preventing the creation of a non-consuming iterator (ring_buffer_iter). For trace remotes, it means the iterator fails to be allocated (-ENOMEM) even though there are available ring buffers in the trace_buffer. For non-consuming reads of trace remotes, skip missing ring_buffer_iter to allow reading the available ring buffers. Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Link: https://patch.msgid.link/20260401045100.3394299-2-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-09tracing: Add events/ root files to trace remotesVincent Donnefort
Just like for the kernel events directory, add 'enable', 'header_page' and 'header_event' at the root of the trace remote events/ directory. Link: https://patch.msgid.link/20260309162516.2623589-11-vdonnefort@google.com Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-09tracing: Add events to trace remotesVincent Donnefort
An event is predefined point in the writer code that allows to log data. Following the same scheme as kernel events, add remote events, described to user-space within the events/ tracefs directory found in the corresponding trace remote. Remote events are expected to be described during the trace remote registration. Add also a .enable_event callback for trace_remote to toggle the event logging, if supported. Link: https://patch.msgid.link/20260309162516.2623589-10-vdonnefort@google.com Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-09tracing: Add init callback to trace remotesVincent Donnefort
Add a .init call back so the trace remote callers can add entries to the tracefs directory. Link: https://patch.msgid.link/20260309162516.2623589-9-vdonnefort@google.com Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-09tracing: Add non-consuming read to trace remotesVincent Donnefort
Allow reading the trace file for trace remotes. This performs a non-consuming read of the trace buffer. Link: https://patch.msgid.link/20260309162516.2623589-8-vdonnefort@google.com Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-09tracing: Add reset to trace remotesVincent Donnefort
Allow to reset the trace remote buffer by writing to the Tracefs "trace" file. This is similar to the regular Tracefs interface. Link: https://patch.msgid.link/20260309162516.2623589-7-vdonnefort@google.com Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-09tracing: Introduce trace remotesVincent Donnefort
A trace remote relies on ring-buffer remotes to read and control compatible tracing buffers, written by entity such as firmware or hypervisor. Add a Tracefs directory remotes/ that contains all instances of trace remotes. Each instance follows the same hierarchy as any other to ease the support by existing user-space tools. This currently does not provide any event support, which will come later. Link: https://patch.msgid.link/20260309162516.2623589-6-vdonnefort@google.com Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>