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Commit 467ec085 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Arnaldo Carvalho de Melo
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perf probe: Fix --del option to delete events only with uprobe events 



Current perf probe --del doesn't work if only CONFIG_UPROBE_EVENTS=y
because it aborts when it fails to open kprobe_events file before
checking uprobe_events file.

This fixes --del option to delete dynamic events if it can open either
kprobe_events or uprobe_events. Only if it failed to open both of them,
it shows an error message and aborts.

Without this patch, if we run perf probe -d on the kernel configured
with CONFIG_KPROBE_EVENTS=n and CONFIG_UPROBE_EVENTS=y,

  # perf probe -d \*
  kprobe_events file does not exist - please rebuild kernel with CONFIG_KPROBE_EVENTS.
    Error: Failed to delete events.

With this patch,

  # perf probe -d \*
  Removed event: probe_perf:alloc_event

Changes in v2:
 - Use strerror_r instead of strerror.

Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Naohiro Aota <naota@elisp.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140813161250.26440.24028.stgit@kbuild-fedora.novalocal


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 5e45187c

tools/perf/util/probe-event.c

+26 −23
Original line number Diff line number Diff line
@@ -1803,6 +1803,23 @@ static void print_open_warning(int err, bool is_kprobe) 
			   strerror_r(-err, sbuf, sizeof(sbuf)));

}



static void print_both_open_warning(int kerr, int uerr)

{

	/* Both kprobes and uprobes are disabled, warn it. */

	if (kerr == -ENOTSUP && uerr == -ENOTSUP)

		pr_warning("Debugfs is not mounted.\n");

	else if (kerr == -ENOENT && uerr == -ENOENT)

		pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "

			   "or/and CONFIG_UPROBE_EVENTS.\n");

	else {

		char sbuf[128];

		pr_warning("Failed to open kprobe events: %s.\n",

			   strerror_r(-kerr, sbuf, sizeof(sbuf)));

		pr_warning("Failed to open uprobe events: %s.\n",

			   strerror_r(-uerr, sbuf, sizeof(sbuf)));

	}

}



static int open_probe_events(const char *trace_file, bool readwrite)

{

	char buf[PATH_MAX];
@@ -1960,20 +1977,7 @@ int show_perf_probe_events(void) 


	up_fd = open_uprobe_events(false);

	if (kp_fd < 0 && up_fd < 0) {

		/* Both kprobes and uprobes are disabled, warn it. */

		if (kp_fd == -ENOTSUP && up_fd == -ENOTSUP)

			pr_warning("Debugfs is not mounted.\n");

		else if (kp_fd == -ENOENT && up_fd == -ENOENT)

			pr_warning("Please rebuild kernel with "

				   "CONFIG_KPROBE_EVENTS or/and "

				   "CONFIG_UPROBE_EVENTS.\n");

		else {

			char sbuf[128];

			pr_warning("Failed to open kprobe events: %s.\n",

				   strerror_r(-kp_fd, sbuf, sizeof(sbuf)));

			pr_warning("Failed to open uprobe events: %s.\n",

				   strerror_r(-up_fd, sbuf, sizeof(sbuf)));

		}

		print_both_open_warning(kp_fd, up_fd);

		ret = kp_fd;

		goto out;

	}
@@ -2474,19 +2478,18 @@ int del_perf_probe_events(struct strlist *dellist) 


	/* Get current event names */

	kfd = open_kprobe_events(true);

	if (kfd < 0) {

		print_open_warning(kfd, true);

		return kfd;

	}



	if (kfd >= 0)

		namelist = get_probe_trace_event_names(kfd, true);

	ufd = open_uprobe_events(true);



	if (ufd < 0)

		print_open_warning(ufd, false);

	else

	ufd = open_uprobe_events(true);

	if (ufd >= 0)

		unamelist = get_probe_trace_event_names(ufd, true);



	if (kfd < 0 && ufd < 0) {

		print_both_open_warning(kfd, ufd);

		goto error;

	}



	if (namelist == NULL && unamelist == NULL)

		goto error;