Commit 59a7a298 authored by Masami Hiramatsu (Google)'s avatar Masami Hiramatsu (Google) Committed by Steven Rostedt (Google)
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fprobe: Add nr_maxactive to specify rethook_node pool size 

Add nr_maxactive to specify rethook_node pool size. This means
the maximum number of actively running target functions concurrently
for probing by exit_handler. Note that if the running function is
preempted or sleep, it is still counted as 'active'.

Link: https://lkml.kernel.org/r/167526697917.433354.17779774988245113106.stgit@mhiramat.roam.corp.google.com



Cc: Florent Revest <revest@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 34cabf8f

include/linux/fprobe.h

+2 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
 * @flags: The status flag.

 * @rethook: The rethook data structure. (internal data)

 * @entry_data_size: The private data storage size.

 * @nr_maxactive: The max number of active functions.

 * @entry_handler: The callback function for function entry.

 * @exit_handler: The callback function for function exit.

 */
@@ -31,6 +32,7 @@ struct fprobe { 
	unsigned int		flags;

	struct rethook		*rethook;

	size_t			entry_data_size;

	int			nr_maxactive;



	void (*entry_handler)(struct fprobe *fp, unsigned long entry_ip,

			      struct pt_regs *regs, void *entry_data);

kernel/trace/fprobe.c

+4 −1
Original line number Diff line number Diff line
@@ -143,6 +143,9 @@ static int fprobe_init_rethook(struct fprobe *fp, int num) 
	}



	/* Initialize rethook if needed */

	if (fp->nr_maxactive)

		size = fp->nr_maxactive;

	else

		size = num * num_possible_cpus() * 2;

	if (size < 0)

		return -E2BIG;