From b774926c733850037b15c50f893383aa71bd8695 Mon Sep 17 00:00:00 2001 From: Linyu Yuan Date: Mon, 27 Jun 2022 10:19:05 +0800 Subject: tracing: eprobe: Add missing log index Add trace_probe_log_set_index(1) to allow report correct error if user input wrong SYSTEM.EVENT format. Link: https://lore.kernel.org/all/1656296348-16111-2-git-send-email-quic_linyyuan@quicinc.com/ Reviewed-by: Tom Zanussi Signed-off-by: Linyu Yuan Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_eprobe.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/trace/trace_eprobe.c') diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 7d4478525c66..b805b570305f 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -881,6 +881,7 @@ static int __trace_eprobe_create(int argc, const char *argv[]) if (!is_good_name(event) || !is_good_name(group)) goto parse_error; + trace_probe_log_set_index(1); sys_event = argv[1]; ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, sys_event - argv[1]); -- cgit v1.2.3 From f360ea5641dc9473ad485e882c8ac3b1aa2672ff Mon Sep 17 00:00:00 2001 From: Linyu Yuan Date: Mon, 27 Jun 2022 10:19:06 +0800 Subject: tracing: eprobe: Remove duplicate is_good_name() operation traceprobe_parse_event_name() already validate SYSTEM and EVENT name, there is no need to call is_good_name() after it. Link: https://lore.kernel.org/all/1656296348-16111-3-git-send-email-quic_linyyuan@quicinc.com/ Acked-by: Masami Hiramatsu (Google) Reviewed-by: Tom Zanussi Signed-off-by: Linyu Yuan Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_eprobe.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/trace/trace_eprobe.c') diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index b805b570305f..8979cb9ec37a 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -887,8 +887,6 @@ static int __trace_eprobe_create(int argc, const char *argv[]) sys_event - argv[1]); if (ret || !sys_name) goto parse_error; - if (!is_good_name(sys_event) || !is_good_name(sys_name)) - goto parse_error; mutex_lock(&event_mutex); event_call = find_and_get_event(sys_name, sys_event); -- cgit v1.2.3 From 95c104c378dc7d4cb3fb9f289dc5354bfc285fe0 Mon Sep 17 00:00:00 2001 From: Linyu Yuan Date: Mon, 27 Jun 2022 10:19:07 +0800 Subject: tracing: Auto generate event name when creating a group of events Currently when creating a specific group of trace events, take kprobe event as example, the 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 the 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. Link: https://lore.kernel.org/all/1656296348-16111-4-git-send-email-quic_linyyuan@quicinc.com/ Acked-by: Masami Hiramatsu (Google) Reviewed-by: Tom Zanussi Signed-off-by: Linyu Yuan Signed-off-by: Steven Rostedt (Google) --- Documentation/trace/kprobetrace.rst | 8 ++++---- Documentation/trace/uprobetracer.rst | 8 ++++---- kernel/trace/trace.c | 8 ++++---- kernel/trace/trace_dynevent.c | 2 +- kernel/trace/trace_eprobe.c | 25 +++++++++++++------------ kernel/trace/trace_kprobe.c | 16 ++++++++++------ kernel/trace/trace_probe.c | 4 ++++ kernel/trace/trace_uprobe.c | 12 ++++++++---- 8 files changed, 48 insertions(+), 35 deletions(-) (limited to 'kernel/trace/trace_eprobe.c') diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst index b175d88f31eb..4274cc6a2f94 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 a8e5938f609e..3a1797d707f4 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.c b/kernel/trace/trace.c index b8dd54627075..7eb5bce62500 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5569,13 +5569,13 @@ static const char readme_msg[] = #endif #if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS) "\t accepts: event-definitions (one definition per line)\n" - "\t Format: p[:[/]] []\n" - "\t r[maxactive][:[/]] []\n" + "\t Format: p[:[/][]] []\n" + "\t r[maxactive][:[/][]] []\n" #ifdef CONFIG_HIST_TRIGGERS "\t s:[synthetic/] []\n" #endif - "\t e[:[/]] . []\n" - "\t -:[/]\n" + "\t e[:[/][]] . []\n" + "\t -:[/][]\n" #ifdef CONFIG_KPROBE_EVENTS "\t place: [:][+]|\n" "place (kretprobe): [:][+]%return|\n" diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c index 076b447a1b88..154996684fb5 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 8979cb9ec37a..a30f21499e81 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: * =$[: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 gbuf[MAX_EVENT_NAME_LEN]; int ret = 0; int i; @@ -869,25 +871,24 @@ static int __trace_eprobe_create(int argc, const char *argv[]) event = strchr(&argv[0][1], ':'); if (event) { event++; - ret = traceprobe_parse_event_name(&event, &group, buf1, + ret = traceprobe_parse_event_name(&event, &group, gbuf, event - argv[0]); if (ret) goto parse_error; - } else { - strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN); - sanitize_event_name(buf1); - event = buf1; } - if (!is_good_name(event) || !is_good_name(group)) - goto parse_error; trace_probe_log_set_index(1); 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 (!sys_event || !sys_name) goto parse_error; + if (!event) { + strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN); + sanitize_event_name(buf1); + event = buf1; + } + mutex_lock(&event_mutex); event_call = find_and_get_event(sys_name, sys_event); ep = alloc_event_probe(group, event, event_call, argc - 2); diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index a245ea673715..23f7f0ec4f4c 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 gbuf[MAX_EVENT_NAME_LEN]; unsigned int flags = TPARG_FL_KERNEL; switch (argv[0][0]) { @@ -833,11 +835,13 @@ static int __trace_kprobe_create(int argc, const char *argv[]) trace_probe_log_set_index(0); if (event) { - ret = traceprobe_parse_event_name(&event, &group, buf, + ret = traceprobe_parse_event_name(&event, &group, gbuf, event - argv[0]); if (ret) goto parse_error; - } else { + } + + if (!event) { /* 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 80863c6508e5..850a88abd33b 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -257,6 +257,10 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup, } len = strlen(event); if (len == 0) { + if (slash) { + *pevent = NULL; + return 0; + } trace_probe_log_err(offset, NO_EVENT_NAME); return -EINVAL; } else if (len > MAX_EVENT_NAME_LEN) { diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index c3dc4f859a6b..a3fec28961d6 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 @@ end: /* * 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 gbuf[MAX_EVENT_NAME_LEN]; enum probe_print_type ptype; struct path path; unsigned long offset, ref_ctr_offset; @@ -644,11 +646,13 @@ static int __trace_uprobe_create(int argc, const char **argv) /* setup a probe */ trace_probe_log_set_index(0); if (event) { - ret = traceprobe_parse_event_name(&event, &group, buf, + ret = traceprobe_parse_event_name(&event, &group, gbuf, event - argv[0]); if (ret) goto fail_address_parse; - } else { + } + + if (!event) { char *tail; char *ptr; -- cgit v1.2.3 From 2f63e5d2e391837c70741311b5b70d2fbd15d138 Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Mon, 1 Aug 2022 11:32:15 +0900 Subject: tracing/eprobe: Show syntax error logs in error_log file Show the syntax errors for event probes in error_log file as same as other dynamic events, so that user can understand what is the problem. Link: https://lkml.kernel.org/r/165932113556.2850673.3483079297896607612.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_eprobe.c | 11 +++++++++-- kernel/trace/trace_probe.h | 5 ++++- 2 files changed, 13 insertions(+), 3 deletions(-) (limited to 'kernel/trace/trace_eprobe.c') diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index a30f21499e81..4a0e9d927443 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -839,8 +839,11 @@ static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[ if (ret) return ret; - if (ep->tp.args[i].code->op == FETCH_OP_TP_ARG) + if (ep->tp.args[i].code->op == FETCH_OP_TP_ARG) { ret = trace_eprobe_tp_arg_update(ep, i); + if (ret) + trace_probe_log_err(0, BAD_ATTACH_ARG); + } return ret; } @@ -880,8 +883,10 @@ static int __trace_eprobe_create(int argc, const char *argv[]) trace_probe_log_set_index(1); sys_event = argv[1]; ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, 0); - if (!sys_event || !sys_name) + if (!sys_event || !sys_name) { + trace_probe_log_err(0, NO_EVENT_INFO); goto parse_error; + } if (!event) { strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN); @@ -896,6 +901,8 @@ static int __trace_eprobe_create(int argc, const char *argv[]) if (IS_ERR(ep)) { ret = PTR_ERR(ep); + if (ret == -ENODEV) + trace_probe_log_err(0, BAD_ATTACH_EVENT); /* This must return -ENOMEM or missing event, else there is a bug */ WARN_ON_ONCE(ret != -ENOMEM && ret != -ENODEV); ep = NULL; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 92cc149af0fd..3b3869ae8cfd 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -442,7 +442,10 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, C(FAIL_REG_PROBE, "Failed to register probe event"),\ C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\ C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\ - C(SAME_PROBE, "There is already the exact same probe event"), + C(SAME_PROBE, "There is already the exact same probe event"),\ + C(NO_EVENT_INFO, "This requires both group and event name to attach"),\ + C(BAD_ATTACH_EVENT, "Attached event does not exist"),\ + C(BAD_ATTACH_ARG, "Attached event does not have this field"), #undef C #define C(a, b) TP_ERR_##a -- cgit v1.2.3 From d8a64313c171464aedd6289378a51c8f0f524acb Mon Sep 17 00:00:00 2001 From: Lukas Bulwahn Date: Thu, 11 Aug 2022 09:17:34 +0200 Subject: tracing: React to error return from traceprobe_parse_event_name() The function traceprobe_parse_event_name() may set the first two function arguments to a non-null value and still return -EINVAL to indicate an unsuccessful completion of the function. Hence, it is not sufficient to just check the result of the two function arguments for being not null, but the return value also needs to be checked. Commit 95c104c378dc ("tracing: Auto generate event name when creating a group of events") changed the error-return-value checking of the second traceprobe_parse_event_name() invocation in __trace_eprobe_create() and removed checking the return value to jump to the error handling case. Reinstate using the return value in the error-return-value checking. Link: https://lkml.kernel.org/r/20220811071734.20700-1-lukas.bulwahn@gmail.com Fixes: 95c104c378dc ("tracing: Auto generate event name when creating a group of events") Acked-by: Linyu Yuan Signed-off-by: Lukas Bulwahn Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_eprobe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace/trace_eprobe.c') diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 4a0e9d927443..550671985fd1 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -883,7 +883,7 @@ static int __trace_eprobe_create(int argc, const char *argv[]) trace_probe_log_set_index(1); sys_event = argv[1]; ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, 0); - if (!sys_event || !sys_name) { + if (ret || !sys_event || !sys_name) { trace_probe_log_err(0, NO_EVENT_INFO); goto parse_error; } -- cgit v1.2.3 From f04dec93466a0481763f3b56cdadf8076e28bfbf Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Sat, 20 Aug 2022 09:43:19 -0400 Subject: tracing/eprobes: Fix reading of string fields Currently when an event probe (eprobe) hooks to a string field, it does not display it as a string, but instead as a number. This makes the field rather useless. Handle the different kinds of strings, dynamic, static, relational/dynamic etc. Now when a string field is used, the ":string" type can be used to display it: echo "e:sw sched/sched_switch comm=$next_comm:string" > dynamic_events Link: https://lkml.kernel.org/r/20220820134400.959640191@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_eprobe.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'kernel/trace/trace_eprobe.c') diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 550671985fd1..a1d3423ab74f 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -311,6 +311,27 @@ static unsigned long get_event_field(struct fetch_insn *code, void *rec) addr = rec + field->offset; + if (is_string_field(field)) { + switch (field->filter_type) { + case FILTER_DYN_STRING: + val = (unsigned long)(rec + (*(unsigned int *)addr & 0xffff)); + break; + case FILTER_RDYN_STRING: + val = (unsigned long)(addr + (*(unsigned int *)addr & 0xffff)); + break; + case FILTER_STATIC_STRING: + val = (unsigned long)addr; + break; + case FILTER_PTR_STRING: + val = (unsigned long)(*(char *)addr); + break; + default: + WARN_ON_ONCE(1); + return 0; + } + return val; + } + switch (field->size) { case 1: if (field->is_signed) -- cgit v1.2.3 From 6a832ec3d680b3a4f4fad5752672827d71bae501 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Sat, 20 Aug 2022 09:43:20 -0400 Subject: tracing/eprobes: Have event probes be consistent with kprobes and uprobes Currently, if a symbol "@" is attempted to be used with an event probe (eprobes), it will cause a NULL pointer dereference crash. Both kprobes and uprobes can reference data other than the main registers. Such as immediate address, symbols and the current task name. Have eprobes do the same thing. For "comm", if "comm" is used and the event being attached to does not have the "comm" field, then make it the "$comm" that kprobes has. This is consistent to the way histograms and filters work. Link: https://lkml.kernel.org/r/20220820134401.136924220@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Masami Hiramatsu Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_eprobe.c | 70 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 64 insertions(+), 6 deletions(-) (limited to 'kernel/trace/trace_eprobe.c') diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index a1d3423ab74f..1783e3478912 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -227,6 +227,7 @@ static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i) struct probe_arg *parg = &ep->tp.args[i]; struct ftrace_event_field *field; struct list_head *head; + int ret = -ENOENT; head = trace_get_fields(ep->event); list_for_each_entry(field, head, link) { @@ -236,9 +237,20 @@ static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i) return 0; } } + + /* + * Argument not found on event. But allow for comm and COMM + * to be used to get the current->comm. + */ + if (strcmp(parg->code->data, "COMM") == 0 || + strcmp(parg->code->data, "comm") == 0) { + parg->code->op = FETCH_OP_COMM; + ret = 0; + } + kfree(parg->code->data); parg->code->data = NULL; - return -ENOENT; + return ret; } static int eprobe_event_define_fields(struct trace_event_call *event_call) @@ -363,16 +375,38 @@ static unsigned long get_event_field(struct fetch_insn *code, void *rec) static int get_eprobe_size(struct trace_probe *tp, void *rec) { + struct fetch_insn *code; struct probe_arg *arg; int i, len, ret = 0; for (i = 0; i < tp->nr_args; i++) { arg = tp->args + i; - if (unlikely(arg->dynamic)) { + if (arg->dynamic) { unsigned long val; - val = get_event_field(arg->code, rec); - len = process_fetch_insn_bottom(arg->code + 1, val, NULL, NULL); + code = arg->code; + retry: + switch (code->op) { + case FETCH_OP_TP_ARG: + val = get_event_field(code, rec); + break; + case FETCH_OP_IMM: + val = code->immediate; + break; + case FETCH_OP_COMM: + val = (unsigned long)current->comm; + break; + case FETCH_OP_DATA: + val = (unsigned long)code->data; + break; + case FETCH_NOP_SYMBOL: /* Ignore a place holder */ + code++; + goto retry; + default: + continue; + } + code++; + len = process_fetch_insn_bottom(code, val, NULL, NULL); if (len > 0) ret += len; } @@ -390,8 +424,28 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, { unsigned long val; - val = get_event_field(code, rec); - return process_fetch_insn_bottom(code + 1, val, dest, base); + retry: + switch (code->op) { + case FETCH_OP_TP_ARG: + val = get_event_field(code, rec); + break; + case FETCH_OP_IMM: + val = code->immediate; + break; + case FETCH_OP_COMM: + val = (unsigned long)current->comm; + break; + case FETCH_OP_DATA: + val = (unsigned long)code->data; + break; + case FETCH_NOP_SYMBOL: /* Ignore a place holder */ + code++; + goto retry; + default: + return -EILSEQ; + } + code++; + return process_fetch_insn_bottom(code, val, dest, base); } NOKPROBE_SYMBOL(process_fetch_insn) @@ -866,6 +920,10 @@ static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[ trace_probe_log_err(0, BAD_ATTACH_ARG); } + /* Handle symbols "@" */ + if (!ret) + ret = traceprobe_update_arg(&ep->tp.args[i]); + return ret; } -- cgit v1.2.3