From a703d946e883d8e447d0597de556e2effd110372 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 7 Oct 2009 18:28:07 -0400 Subject: [PATCH] tracing/kprobes: Avoid field name confliction Check whether the argument name is in conflict with other field names while creating a kprobe through the debugfs interface. Changes in v3: - Check strcmp() == 0 instead of !strcmp(). Changes in v2: - Add common_lock_depth to reserved name list. Signed-off-by: Masami Hiramatsu Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Arnaldo Carvalho de Melo Cc: Steven Rostedt Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Christoph Hellwig Cc: Ananth N Mavinakayanahalli Cc: Jim Keniston Cc: Frank Ch. Eigler LKML-Reference: <20091007222807.1684.26880.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker --- kernel/trace/trace_kprobe.c | 65 ++++++++++++++++++++++++++++++------- 1 file changed, 53 insertions(+), 12 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 3313fa74ce5f..bb6cb2bc6fae 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -38,6 +38,25 @@ #define MAX_EVENT_NAME_LEN 64 #define KPROBE_EVENT_SYSTEM "kprobes" +/* Reserved field names */ +#define FIELD_STRING_IP "ip" +#define FIELD_STRING_NARGS "nargs" +#define FIELD_STRING_RETIP "ret_ip" +#define FIELD_STRING_FUNC "func" + +const char *reserved_field_names[] = { + "common_type", + "common_flags", + "common_preempt_count", + "common_pid", + "common_tgid", + "common_lock_depth", + FIELD_STRING_IP, + FIELD_STRING_NARGS, + FIELD_STRING_RETIP, + FIELD_STRING_FUNC, +}; + /* currently, trace_kprobe only supports X86. */ struct fetch_func { @@ -537,6 +556,20 @@ static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return) return ret; } +/* Return 1 if name is reserved or already used by another argument */ +static int conflict_field_name(const char *name, + struct probe_arg *args, int narg) +{ + int i; + for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) + if (strcmp(reserved_field_names[i], name) == 0) + return 1; + for (i = 0; i < narg; i++) + if (strcmp(args[i].name, name) == 0) + return 1; + return 0; +} + static int create_trace_probe(int argc, char **argv) { /* @@ -637,6 +670,12 @@ static int create_trace_probe(int argc, char **argv) *arg++ = '\0'; else arg = argv[i]; + + if (conflict_field_name(argv[i], tp->args, i)) { + ret = -EINVAL; + goto error; + } + tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); /* Parse fetch argument */ @@ -1039,8 +1078,8 @@ static int kprobe_event_define_fields(struct ftrace_event_call *event_call) if (!ret) return ret; - DEFINE_FIELD(unsigned long, ip, "ip", 0); - DEFINE_FIELD(int, nargs, "nargs", 1); + DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); + DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1); /* Set argument names as fields */ for (i = 0; i < tp->nr_args; i++) DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); @@ -1057,9 +1096,9 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) if (!ret) return ret; - DEFINE_FIELD(unsigned long, func, "func", 0); - DEFINE_FIELD(unsigned long, ret_ip, "ret_ip", 0); - DEFINE_FIELD(int, nargs, "nargs", 1); + DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); + DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); + DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1); /* Set argument names as fields */ for (i = 0; i < tp->nr_args; i++) DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); @@ -1108,15 +1147,16 @@ static int kprobe_event_show_format(struct ftrace_event_call *call, int ret, i; struct trace_probe *tp = (struct trace_probe *)call->data; - SHOW_FIELD(unsigned long, ip, "ip"); - SHOW_FIELD(int, nargs, "nargs"); + SHOW_FIELD(unsigned long, ip, FIELD_STRING_IP); + SHOW_FIELD(int, nargs, FIELD_STRING_NARGS); /* Show fields */ 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)", "REC->ip"); + return __probe_event_show_format(s, tp, "(%lx)", + "REC->" FIELD_STRING_IP); } static int kretprobe_event_show_format(struct ftrace_event_call *call, @@ -1126,9 +1166,9 @@ static int kretprobe_event_show_format(struct ftrace_event_call *call, int ret, i; struct trace_probe *tp = (struct trace_probe *)call->data; - SHOW_FIELD(unsigned long, func, "func"); - SHOW_FIELD(unsigned long, ret_ip, "ret_ip"); - SHOW_FIELD(int, nargs, "nargs"); + SHOW_FIELD(unsigned long, func, FIELD_STRING_FUNC); + SHOW_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP); + SHOW_FIELD(int, nargs, FIELD_STRING_NARGS); /* Show fields */ for (i = 0; i < tp->nr_args; i++) @@ -1136,7 +1176,8 @@ static int kretprobe_event_show_format(struct ftrace_event_call *call, trace_seq_puts(s, "\n"); return __probe_event_show_format(s, tp, "(%lx <- %lx)", - "REC->func, REC->ret_ip"); + "REC->" FIELD_STRING_FUNC + ", REC->" FIELD_STRING_RETIP); } #ifdef CONFIG_EVENT_PROFILE -- 2.20.1