summaryrefslogtreecommitdiff
path: root/kernel/trace/trace_remote.c
AgeCommit message (Collapse)Author
16 hourstracing/remotes: Fix struct_len in trace_remote_alloc_buffer()Vincent Donnefort
[ Upstream commit d471d4f86e8689ad15309e49da8e5e4e9bb9ce87 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
16 hourstracing/remotes: Fix leak in trace_remote_alloc_buffer() error pathVincent Donnefort
[ Upstream commit ec082d0b978b5fb4c11205ccce63587ac94c74e1 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.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>