Messages in this thread Patch in this message | | | Date | Tue, 24 May 2022 18:31:59 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH 1/2] tracing/probes: auto generate events name when create a group of events |
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[ Adding Masami (kprobe maintainer) and Tom (dynamic event maintainer) ]
On Sun, 1 May 2022 17:34:10 +0800 Linyu Yuan <quic_linyyuan@quicinc.com> wrote:
> change traceprobe_parse_event_name() and return GRP/EVENT types, > TP_ENAME_GROUP_EVENT means user input GRP/EVENT format, > TP_ENAME_EVENT means user only input EVENT format, > TP_ENAME_GROUP means user only input GRP/ format, > > it allow no event name input when create a group of events, > and will auto generate event name according second argument.
Sorry, but I can't understand the above. Can you reword it, and perhaps include an example of what this patch does.
After reading the code, I guess you are trying to make it so that you can leave out the event name and only have the group name, if you add the slash.
echo 'p:group/ schedule' > kprobe_events
And that will create a kprobe "schedule" event under the "group" system?
Also, for some reason, patch 2 of the series never came to me. But it is in my LKML folder :-/
> > Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> > --- > Documentation/trace/kprobetrace.rst | 8 ++++---- > Documentation/trace/uprobetracer.rst | 8 ++++---- > kernel/trace/trace_dynevent.c | 2 +- > kernel/trace/trace_eprobe.c | 19 +++++++++++-------- > kernel/trace/trace_kprobe.c | 18 +++++++++++------- > kernel/trace/trace_probe.c | 9 ++++++++- > kernel/trace/trace_probe.h | 4 ++++ > kernel/trace/trace_uprobe.c | 14 +++++++++----- > 8 files changed, 52 insertions(+), 30 deletions(-) > > diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst > index b175d88..4274cc6 100644 > --- a/Documentation/trace/kprobetrace.rst > +++ b/Documentation/trace/kprobetrace.rst > @@ -28,10 +28,10 @@ Synopsis of kprobe_events > ------------------------- > :: > > - p[:[GRP/]EVENT] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS] : Set a probe > - r[MAXACTIVE][:[GRP/]EVENT] [MOD:]SYM[+0] [FETCHARGS] : Set a return probe > - p:[GRP/]EVENT] [MOD:]SYM[+0]%return [FETCHARGS] : Set a return probe > - -:[GRP/]EVENT : Clear a probe > + p[:[GRP/][EVENT]] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS] : Set a probe > + r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]SYM[+0] [FETCHARGS] : Set a return probe > + p[:[GRP/][EVENT]] [MOD:]SYM[+0]%return [FETCHARGS] : Set a return probe > + -:[GRP/][EVENT] : Clear a probe > > GRP : Group name. If omitted, use "kprobes" for it. > EVENT : Event name. If omitted, the event name is generated > diff --git a/Documentation/trace/uprobetracer.rst b/Documentation/trace/uprobetracer.rst > index a8e5938..3a1797d7 100644 > --- a/Documentation/trace/uprobetracer.rst > +++ b/Documentation/trace/uprobetracer.rst > @@ -26,10 +26,10 @@ Synopsis of uprobe_tracer > ------------------------- > :: > > - p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe > - r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe) > - p[:[GRP/]EVENT] PATH:OFFSET%return [FETCHARGS] : Set a return uprobe (uretprobe) > - -:[GRP/]EVENT : Clear uprobe or uretprobe event > + p[:[GRP/][EVENT]] PATH:OFFSET [FETCHARGS] : Set a uprobe > + r[:[GRP/][EVENT]] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe) > + p[:[GRP/][EVENT]] PATH:OFFSET%return [FETCHARGS] : Set a return uprobe (uretprobe) > + -:[GRP/][EVENT] : Clear uprobe or uretprobe event > > GRP : Group name. If omitted, "uprobes" is the default value. > EVENT : Event name. If omitted, the event name is generated based > diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c > index e34e8182..033248d 100644 > --- a/kernel/trace/trace_dynevent.c > +++ b/kernel/trace/trace_dynevent.c > @@ -101,7 +101,7 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type > event = p + 1; > *p = '\0'; > } > - if (event[0] == '\0') { > + if (!system && event[0] == '\0') { > ret = -EINVAL; > goto out; > } > diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c > index 7d44785..b16e067 100644 > --- a/kernel/trace/trace_eprobe.c > +++ b/kernel/trace/trace_eprobe.c > @@ -125,6 +125,7 @@ static bool eprobe_dyn_event_match(const char *system, const char *event, > * We match the following: > * event only - match all eprobes with event name > * system and event only - match all system/event probes > + * system only - match all system probes > * > * The below has the above satisfied with more arguments: > * > @@ -143,7 +144,7 @@ static bool eprobe_dyn_event_match(const char *system, const char *event, > return false; > > /* Must match the event name */ > - if (strcmp(trace_probe_name(&ep->tp), event) != 0) > + if (event[0] != '\0' && strcmp(trace_probe_name(&ep->tp), event) != 0) > return false; > > /* No arguments match all */ > @@ -848,7 +849,7 @@ static int __trace_eprobe_create(int argc, const char *argv[]) > { > /* > * Argument syntax: > - * e[:[GRP/]ENAME] SYSTEM.EVENT [FETCHARGS] > + * e[:[GRP/][ENAME]] SYSTEM.EVENT [FETCHARGS] > * Fetch args: > * <name>=$<field>[:TYPE] > */ > @@ -858,6 +859,7 @@ static int __trace_eprobe_create(int argc, const char *argv[]) > struct trace_eprobe *ep = NULL; > char buf1[MAX_EVENT_NAME_LEN]; > char buf2[MAX_EVENT_NAME_LEN]; > + char grp_buf[MAX_EVENT_NAME_LEN]; > int ret = 0; > int i; > > @@ -866,14 +868,16 @@ static int __trace_eprobe_create(int argc, const char *argv[]) > > trace_probe_log_init("event_probe", argc, argv); > > + ret = TP_ENAME_EMPTTY;
EMPTY is spelled wrong.
> event = strchr(&argv[0][1], ':'); > if (event) { > event++; > - ret = traceprobe_parse_event_name(&event, &group, buf1, > + ret = traceprobe_parse_event_name(&event, &group, grp_buf, > event - argv[0]); > - if (ret) > + if (ret < 0) > goto parse_error; > - } else { > + }
add space.
> + if (ret == TP_ENAME_EMPTTY || ret == TP_ENAME_GROUP) { > strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN); > sanitize_event_name(buf1); > event = buf1;
I'd like to see Masami's and Tom's comments on this one.
-- Steve
> @@ -882,9 +886,8 @@ static int __trace_eprobe_create(int argc, const char *argv[]) > goto parse_error; > > sys_event = argv[1]; > - ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, > - sys_event - argv[1]); > - if (ret || !sys_name) > + ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, 0); > + if (ret != TP_ENAME_GROUP_EVENT) > goto parse_error; > if (!is_good_name(sys_event) || !is_good_name(sys_name)) > goto parse_error; > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index 47cebef..2cd8ef9 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -163,7 +163,8 @@ static bool trace_kprobe_match(const char *system, const char *event, > { > struct trace_kprobe *tk = to_trace_kprobe(ev); > > - return strcmp(trace_probe_name(&tk->tp), event) == 0 && > + return (event[0] == '\0' || > + strcmp(trace_probe_name(&tk->tp), event) == 0) && > (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) && > trace_kprobe_match_command_head(tk, argc, argv); > } > @@ -708,11 +709,11 @@ static int __trace_kprobe_create(int argc, const char *argv[]) > /* > * Argument syntax: > * - Add kprobe: > - * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] > + * p[:[GRP/][EVENT]] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] > * - Add kretprobe: > - * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] > + * r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]KSYM[+0] [FETCHARGS] > * Or > - * p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS] > + * p[:[GRP/][EVENT]] [MOD:]KSYM[+0]%return [FETCHARGS] > * > * Fetch args: > * $retval : fetch return value > @@ -739,6 +740,7 @@ static int __trace_kprobe_create(int argc, const char *argv[]) > long offset = 0; > void *addr = NULL; > char buf[MAX_EVENT_NAME_LEN]; > + char grp_buf[MAX_EVENT_NAME_LEN]; > unsigned int flags = TPARG_FL_KERNEL; > > switch (argv[0][0]) { > @@ -832,12 +834,14 @@ static int __trace_kprobe_create(int argc, const char *argv[]) > } > > trace_probe_log_set_index(0); > + ret = TP_ENAME_EMPTTY; > if (event) { > - ret = traceprobe_parse_event_name(&event, &group, buf, > + ret = traceprobe_parse_event_name(&event, &group, grp_buf, > event - argv[0]); > - if (ret) > + if (ret < 0) > goto parse_error; > - } else { > + } > + if (ret == TP_ENAME_EMPTTY || ret == TP_ENAME_GROUP) { > /* Make a new event name */ > if (symbol) > snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c > index 80863c6..7fd50ab 100644 > --- a/kernel/trace/trace_probe.c > +++ b/kernel/trace/trace_probe.c > @@ -257,6 +257,9 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup, > } > len = strlen(event); > if (len == 0) { > + if (slash) > + return TP_ENAME_GROUP; > + > trace_probe_log_err(offset, NO_EVENT_NAME); > return -EINVAL; > } else if (len > MAX_EVENT_NAME_LEN) { > @@ -267,7 +270,11 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup, > trace_probe_log_err(offset, BAD_EVENT_NAME); > return -EINVAL; > } > - return 0; > + > + if (slash) > + return TP_ENAME_GROUP_EVENT; > + > + return TP_ENAME_EVENT; > } > > #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) > diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h > index 92cc149..d726769 100644 > --- a/kernel/trace/trace_probe.h > +++ b/kernel/trace/trace_probe.h > @@ -364,6 +364,10 @@ extern void traceprobe_free_probe_arg(struct probe_arg *arg); > extern int traceprobe_split_symbol_offset(char *symbol, long *offset); > int traceprobe_parse_event_name(const char **pevent, const char **pgroup, > char *buf, int offset); > +#define TP_ENAME_GROUP_EVENT 0 > +#define TP_ENAME_EVENT 1 > +#define TP_ENAME_GROUP 2 > +#define TP_ENAME_EMPTTY 3 > > enum probe_print_type { > PROBE_PRINT_NORMAL, > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 9711589..a935c08 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -312,7 +312,8 @@ static bool trace_uprobe_match(const char *system, const char *event, > { > struct trace_uprobe *tu = to_trace_uprobe(ev); > > - return strcmp(trace_probe_name(&tu->tp), event) == 0 && > + return (event[0] == '\0' || > + strcmp(trace_probe_name(&tu->tp), event) == 0) && > (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && > trace_uprobe_match_command_head(tu, argc, argv); > } > @@ -532,7 +533,7 @@ static int register_trace_uprobe(struct trace_uprobe *tu) > > /* > * Argument syntax: > - * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET[%return][(REF)] [FETCHARGS] > + * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS] > */ > static int __trace_uprobe_create(int argc, const char **argv) > { > @@ -540,6 +541,7 @@ static int __trace_uprobe_create(int argc, const char **argv) > const char *event = NULL, *group = UPROBE_EVENT_SYSTEM; > char *arg, *filename, *rctr, *rctr_end, *tmp; > char buf[MAX_EVENT_NAME_LEN]; > + char grp_buf[MAX_EVENT_NAME_LEN]; > enum probe_print_type ptype; > struct path path; > unsigned long offset, ref_ctr_offset; > @@ -644,12 +646,14 @@ static int __trace_uprobe_create(int argc, const char **argv) > > /* setup a probe */ > trace_probe_log_set_index(0); > + ret = TP_ENAME_EMPTTY; > if (event) { > - ret = traceprobe_parse_event_name(&event, &group, buf, > + ret = traceprobe_parse_event_name(&event, &group, grp_buf, > event - argv[0]); > - if (ret) > + if (ret < 0) > goto fail_address_parse; > - } else { > + } > + if (ret == TP_ENAME_EMPTTY || ret == TP_ENAME_GROUP) { > char *tail; > char *ptr; >
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