Messages in this thread | | | Date | Mon, 30 May 2022 09:28:23 +0800 | Subject | Re: [PATCH v2 1/2] tracing: auto generate event name when create a group of events | From | Linyu Yuan <> |
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On 5/30/2022 8:47 AM, Masami Hiramatsu (Google) wrote: > 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. good idea, will follow it. > >> 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" sure. > > 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 thanks, will do it. > > > 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 >> >
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