From eca0d916f6429785bbc88db3ff66631cde62b432 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 10 Sep 2009 19:53:38 -0400 Subject: tracing/kprobes: Add argument name support Add argument name assignment support and remove "alias" lines from format. This allows user to assign unique name to each argument. For example, $ echo p do_sys_open dfd=a0 filename=a1 flags=a2 mode=a3 > kprobe_events This assigns dfd, filename, flags, and mode to 1st - 4th arguments respectively. Trace buffer shows those names too. <...>-1439 [000] 1200885.933147: do_sys_open+0x0/0xdf: dfd=ffffff9c filename=bfa898ac flags=8000 mode=0 This helps users to know what each value means. Users can filter each events by these names too. Note that you can not filter by argN anymore. Signed-off-by: Masami Hiramatsu Cc: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: Tom Zanussi LKML-Reference: <20090910235337.22412.77383.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker --- kernel/trace/trace_kprobe.c | 128 ++++++++++++++++++++++---------------------- 1 file changed, 64 insertions(+), 64 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 730e992d28da..44dad1aa95d3 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -176,9 +176,14 @@ static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data) } /** - * kprobe_trace_core + * Kprobe tracer core functions */ +struct probe_arg { + struct fetch_func fetch; + const char *name; +}; + struct trace_probe { struct list_head list; struct kretprobe rp; /* Use rp.kp for kprobe use */ @@ -187,12 +192,12 @@ struct trace_probe { struct ftrace_event_call call; struct trace_event event; unsigned int nr_args; - struct fetch_func args[]; + struct probe_arg args[]; }; #define SIZEOF_TRACE_PROBE(n) \ (offsetof(struct trace_probe, args) + \ - (sizeof(struct fetch_func) * (n))) + (sizeof(struct probe_arg) * (n))) static int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_trace_func(struct kretprobe_instance *ri, @@ -301,15 +306,21 @@ error: return ERR_PTR(-ENOMEM); } +static void free_probe_arg(struct probe_arg *arg) +{ + if (arg->fetch.func == fetch_symbol) + free_symbol_cache(arg->fetch.data); + else if (arg->fetch.func == fetch_indirect) + free_indirect_fetch_data(arg->fetch.data); + kfree(arg->name); +} + static void free_trace_probe(struct trace_probe *tp) { int i; for (i = 0; i < tp->nr_args; i++) - if (tp->args[i].func == fetch_symbol) - free_symbol_cache(tp->args[i].data); - else if (tp->args[i].func == fetch_indirect) - free_indirect_fetch_data(tp->args[i].data); + free_probe_arg(&tp->args[i]); kfree(tp->call.name); kfree(tp->symbol); @@ -532,11 +543,13 @@ static int create_trace_probe(int argc, char **argv) * %REG : fetch register REG * Indirect memory fetch: * +|-offs(ARG) : fetch memory at ARG +|- offs address. + * Alias name of args: + * NAME=FETCHARG : set NAME as alias of FETCHARG. */ struct trace_probe *tp; int i, ret = 0; int is_return = 0; - char *symbol = NULL, *event = NULL; + char *symbol = NULL, *event = NULL, *arg = NULL; unsigned long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN]; @@ -596,12 +609,21 @@ static int create_trace_probe(int argc, char **argv) /* parse arguments */ ret = 0; for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { - if (strlen(argv[i]) > MAX_ARGSTR_LEN) { - pr_info("Argument%d(%s) is too long.\n", i, argv[i]); + /* Parse argument name */ + arg = strchr(argv[i], '='); + if (arg) + *arg++ = '\0'; + else + arg = argv[i]; + tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); + + /* Parse fetch argument */ + if (strlen(arg) > MAX_ARGSTR_LEN) { + pr_info("Argument%d(%s) is too long.\n", i, arg); ret = -ENOSPC; goto error; } - ret = parse_probe_arg(argv[i], &tp->args[i], is_return); + ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return); if (ret) goto error; } @@ -664,12 +686,12 @@ static int probes_seq_show(struct seq_file *m, void *v) seq_printf(m, " 0x%p", tp->rp.kp.addr); for (i = 0; i < tp->nr_args; i++) { - ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]); + ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch); if (ret < 0) { pr_warning("Argument%d decoding error(%d).\n", i, ret); return ret; } - seq_printf(m, " %s", buf); + seq_printf(m, " %s=%s", tp->args[i].name, buf); } seq_printf(m, "\n"); return 0; @@ -824,7 +846,7 @@ static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) entry->nargs = tp->nr_args; entry->ip = (unsigned long)kp->addr; for (i = 0; i < tp->nr_args; i++) - entry->args[i] = call_fetch(&tp->args[i], regs); + entry->args[i] = call_fetch(&tp->args[i].fetch, regs); if (!filter_current_check_discard(buffer, call, entry, event)) trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); @@ -858,7 +880,7 @@ static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri, entry->func = (unsigned long)tp->rp.kp.addr; entry->ret_ip = (unsigned long)ri->ret_addr; for (i = 0; i < tp->nr_args; i++) - entry->args[i] = call_fetch(&tp->args[i], regs); + entry->args[i] = call_fetch(&tp->args[i].fetch, regs); if (!filter_current_check_discard(buffer, call, entry, event)) trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); @@ -872,9 +894,13 @@ print_kprobe_event(struct trace_iterator *iter, int flags) { struct kprobe_trace_entry *field; struct trace_seq *s = &iter->seq; + struct trace_event *event; + struct trace_probe *tp; int i; field = (struct kprobe_trace_entry *)iter->ent; + event = ftrace_find_event(field->ent.type); + tp = container_of(event, struct trace_probe, event); if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) goto partial; @@ -883,7 +909,8 @@ print_kprobe_event(struct trace_iterator *iter, int flags) goto partial; for (i = 0; i < field->nargs; i++) - if (!trace_seq_printf(s, " 0x%lx", field->args[i])) + if (!trace_seq_printf(s, " %s=%lx", + tp->args[i].name, field->args[i])) goto partial; if (!trace_seq_puts(s, "\n")) @@ -899,9 +926,13 @@ print_kretprobe_event(struct trace_iterator *iter, int flags) { struct kretprobe_trace_entry *field; struct trace_seq *s = &iter->seq; + struct trace_event *event; + struct trace_probe *tp; int i; field = (struct kretprobe_trace_entry *)iter->ent; + event = ftrace_find_event(field->ent.type); + tp = container_of(event, struct trace_probe, event); if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) goto partial; @@ -916,7 +947,8 @@ print_kretprobe_event(struct trace_iterator *iter, int flags) goto partial; for (i = 0; i < field->nargs; i++) - if (!trace_seq_printf(s, " 0x%lx", field->args[i])) + if (!trace_seq_printf(s, " %s=%lx", + tp->args[i].name, field->args[i])) goto partial; if (!trace_seq_puts(s, "\n")) @@ -972,7 +1004,6 @@ static int kprobe_event_define_fields(struct ftrace_event_call *event_call) { int ret, i; struct kprobe_trace_entry field; - char buf[MAX_ARGSTR_LEN + 1]; struct trace_probe *tp = (struct trace_probe *)event_call->data; ret = trace_define_common_fields(event_call); @@ -981,16 +1012,9 @@ static int kprobe_event_define_fields(struct ftrace_event_call *event_call) DEFINE_FIELD(unsigned long, ip, "ip", 0); DEFINE_FIELD(int, nargs, "nargs", 1); - for (i = 0; i < tp->nr_args; i++) { - /* Set argN as a field */ - sprintf(buf, "arg%d", i); - DEFINE_FIELD(unsigned long, args[i], buf, 0); - /* Set argument string as an alias field */ - ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]); - if (ret < 0) - return ret; - DEFINE_FIELD(unsigned long, args[i], buf, 0); - } + /* Set argument names as fields */ + for (i = 0; i < tp->nr_args; i++) + DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); return 0; } @@ -998,7 +1022,6 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) { int ret, i; struct kretprobe_trace_entry field; - char buf[MAX_ARGSTR_LEN + 1]; struct trace_probe *tp = (struct trace_probe *)event_call->data; ret = trace_define_common_fields(event_call); @@ -1008,16 +1031,9 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) DEFINE_FIELD(unsigned long, func, "func", 0); DEFINE_FIELD(unsigned long, ret_ip, "ret_ip", 0); DEFINE_FIELD(int, nargs, "nargs", 1); - for (i = 0; i < tp->nr_args; i++) { - /* Set argN as a field */ - sprintf(buf, "arg%d", i); - DEFINE_FIELD(unsigned long, args[i], buf, 0); - /* Set argument string as an alias field */ - ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]); - if (ret < 0) - return ret; - DEFINE_FIELD(unsigned long, args[i], buf, 0); - } + /* Set argument names as fields */ + for (i = 0; i < tp->nr_args; i++) + DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); return 0; } @@ -1025,31 +1041,21 @@ static int __probe_event_show_format(struct trace_seq *s, struct trace_probe *tp, const char *fmt, const char *arg) { - int i, ret; - char buf[MAX_ARGSTR_LEN + 1]; + int i; - /* Show aliases */ - for (i = 0; i < tp->nr_args; i++) { - ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i]); - if (ret < 0) - return ret; - if (!trace_seq_printf(s, "\talias: %s;\toriginal: arg%d;\n", - buf, i)) - return 0; - } /* Show format */ if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt)) return 0; for (i = 0; i < tp->nr_args; i++) - if (!trace_seq_puts(s, " 0x%lx")) + if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name)) return 0; if (!trace_seq_printf(s, "\", %s", arg)) return 0; for (i = 0; i < tp->nr_args; i++) - if (!trace_seq_printf(s, ", arg%d", i)) + if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name)) return 0; return trace_seq_puts(s, "\n"); @@ -1071,17 +1077,14 @@ static int kprobe_event_show_format(struct ftrace_event_call *call, { struct kprobe_trace_entry field __attribute__((unused)); int ret, i; - char buf[8]; struct trace_probe *tp = (struct trace_probe *)call->data; SHOW_FIELD(unsigned long, ip, "ip"); SHOW_FIELD(int, nargs, "nargs"); /* Show fields */ - for (i = 0; i < tp->nr_args; i++) { - sprintf(buf, "arg%d", i); - SHOW_FIELD(unsigned long, args[i], buf); - } + for (i = 0; i < tp->nr_args; i++) + SHOW_FIELD(unsigned long, args[i], tp->args[i].name); trace_seq_puts(s, "\n"); return __probe_event_show_format(s, tp, "%lx:", "ip"); @@ -1092,7 +1095,6 @@ static int kretprobe_event_show_format(struct ftrace_event_call *call, { struct kretprobe_trace_entry field __attribute__((unused)); int ret, i; - char buf[8]; struct trace_probe *tp = (struct trace_probe *)call->data; SHOW_FIELD(unsigned long, func, "func"); @@ -1100,10 +1102,8 @@ static int kretprobe_event_show_format(struct ftrace_event_call *call, SHOW_FIELD(int, nargs, "nargs"); /* Show fields */ - for (i = 0; i < tp->nr_args; i++) { - sprintf(buf, "arg%d", i); - SHOW_FIELD(unsigned long, args[i], buf); - } + for (i = 0; i < tp->nr_args; i++) + SHOW_FIELD(unsigned long, args[i], tp->args[i].name); trace_seq_puts(s, "\n"); return __probe_event_show_format(s, tp, "%lx <- %lx:", @@ -1140,7 +1140,7 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp, entry->nargs = tp->nr_args; entry->ip = (unsigned long)kp->addr; for (i = 0; i < tp->nr_args; i++) - entry->args[i] = call_fetch(&tp->args[i], regs); + entry->args[i] = call_fetch(&tp->args[i].fetch, regs); perf_tpcounter_event(call->id, entry->ip, 1, entry, size); } while (0); return 0; @@ -1175,7 +1175,7 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri, entry->func = (unsigned long)tp->rp.kp.addr; entry->ret_ip = (unsigned long)ri->ret_addr; for (i = 0; i < tp->nr_args; i++) - entry->args[i] = call_fetch(&tp->args[i], regs); + entry->args[i] = call_fetch(&tp->args[i].fetch, regs); perf_tpcounter_event(call->id, entry->ret_ip, 1, entry, size); } while (0); return 0; -- cgit v1.2.2