Commit ade2105e authored by Elijah Wright's avatar Elijah Wright Committed by Steven Rostedt (Google)
Browse files

tracing: Move buffer in trace_seq to end of struct 

TRACE_SEQ_BUFFER_SIZE is dependent on the architecture for its size. on 64-bit
systems, it is 8148 bytes. forced 8-byte alignment in size_t and seq_buf means
that trace_seq is 8200 bytes on 64-bit systems. moving the buffer to the end
of the struct fixes the issue. there shouldn't be any side effects, i.e.
pointer arithmetic on trace_seq

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250821053917.23301-1-git@elijahs.space


Signed-off-by: default avatarElijah Wright <git@elijahs.space>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 1d67d67a

include/linux/trace_seq.h

+1 −1
Original line number Diff line number Diff line
@@ -21,10 +21,10 @@ 
	(sizeof(struct seq_buf) + sizeof(size_t) + sizeof(int)))



struct trace_seq {

	char			buffer[TRACE_SEQ_BUFFER_SIZE];

	struct seq_buf		seq;

	size_t			readpos;

	int			full;

	char                    buffer[TRACE_SEQ_BUFFER_SIZE];

};



static inline void