Messages in this thread Patch in this message | | | Date | Mon, 30 May 2022 09:47:40 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [PATCH v2 1/2] tracing: auto generate event name when create a group of events |
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Hi Linyu,
On Sun, 29 May 2022 11:34:53 +0800 Linyu Yuan <quic_linyyuan@quicinc.com> wrote:
> Currently when create a specific group of trace events, > take kprobe event as example, user must use the following format: > p:GRP/EVENT [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS], > which means user must enter EVENT name, one example is: echo > 'p:usb_gadget/config_usb_cfg_link config_usb_cfg_link $arg1' >> > kprobe_events, it is not simple if there are too many entries > because the event name is same as symbol name. > > This change allows user to specify no EVENT name, format changed as: > p:GRP/ [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS], > it will generate event name automatically and one example is: > echo 'p:usb_gadget/ config_usb_cfg_link $arg1' >> kprobe_events. > > Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> > --- > v2: fix review comments in V1: > change TP_ENAME_EMPTTY to TP_ENAME_EMPTY,
Thanks for update! And I think this return code is a bit redundant because those cases can be rephrased as follows;
TP_ENAME_GROUP_EVENT : event != NULL && group != (default) TP_ENAME_GROUP : event == NULL && group != (default) TP_ENAME_EVENT : event != NULL && group == (default) TP_ENAME_EMPTY : event == NULL && group == (default)
What about this (e.g. trace_kprobe.c)?
if (event) { /* event and group will be updated in this function */ ret = traceprobe_parse_event_name(&event, &group, gbuf, event - argv[0]); if (ret) goto parse_error; }
if (!event) { /* Make a new event name */ if (symbol) snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", is_return ? 'r' : 'p', symbol, offset); else snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", is_return ? 'r' : 'p', addr); sanitize_event_name(buf); event = buf; }
This makes the code clearer.
> add some space, > document the macros return by traceprobe_parse_event_name(), > updatea commit description. > > Documentation/trace/kprobetrace.rst | 8 ++++---- > Documentation/trace/uprobetracer.rst | 8 ++++---- > kernel/trace/trace_dynevent.c | 2 +- > kernel/trace/trace_eprobe.c | 20 ++++++++++++-------- > kernel/trace/trace_kprobe.c | 19 ++++++++++++------- > kernel/trace/trace_probe.c | 9 ++++++++- > kernel/trace/trace_probe.h | 4 ++++ > kernel/trace/trace_uprobe.c | 15 ++++++++++----- > 8 files changed, 55 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
Could you also update 'readme_msg' in kernel/trace/trace.c in this patch? e.g.
#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS) "\t accepts: event-definitions (one definition per line)\n" "\t Format: p[:[<group>/][<event>]] <place> [<args>]\n" "\t r[maxactive][:[<group>/][<event>]] <place> [<args>]\n" #ifdef CONFIG_HIST_TRIGGERS "\t s:[synthetic/]<event> <field> [<field>]\n" #endif "\t e[:[<group>/][<event>]] <attached-group>.<attached-event> [<args>]\n" "\t -:[<group>/]<event>\n"
And also, could you add *another patch* to update below testcases about dynevent to ensure this feature is working?
tools/testing/selftests/ftrace/test.d/dynevent/add_remove_kprobe.tc and tools/testing/selftests/ftrace/test.d/dynevent/add_remove_eprobe.tc
e.g.
if grep -q '\[<event>\]' README then (add your test...) fi
Thank you,
> > 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..13cd7fc 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 +868,17 @@ static int __trace_eprobe_create(int argc, const char *argv[]) > > trace_probe_log_init("event_probe", argc, argv); > > + ret = TP_ENAME_EMPTY; > 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 { > + } > + > + if (ret == TP_ENAME_EMPTY || ret == TP_ENAME_GROUP) { > strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN); > sanitize_event_name(buf1); > event = buf1; > @@ -882,9 +887,8 @@ 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..55822b6 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 +834,15 @@ static int __trace_kprobe_create(int argc, const char *argv[]) > } > > trace_probe_log_set_index(0); > + ret = TP_ENAME_EMPTY; > 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_EMPTY || 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..7390669 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 /* GRP/EVENT format, user defined group and event name */ > +#define TP_ENAME_EVENT 1 /* EVENT format, user defined event name, default group */ > +#define TP_ENAME_GROUP 2 /* GRP/ format, user defined group name, auto event name */ > +#define TP_ENAME_EMPTY 3 /* default group and auto event name */ > > enum probe_print_type { > PROBE_PRINT_NORMAL, > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 9711589..bc32361 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 +646,15 @@ static int __trace_uprobe_create(int argc, const char **argv) > > /* setup a probe */ > trace_probe_log_set_index(0); > + ret = TP_ENAME_EMPTY; > 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_EMPTY || ret == TP_ENAME_GROUP) { > char *tail; > char *ptr; > > -- > 2.7.4 >
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
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