[lttng-dev] [lttng-tools PATCH] Add support for kernel uprobes
Yannick Brosseau
yannick.brosseau at gmail.com
Sun Jan 13 22:03:37 EST 2013
Inspired by the k*probe support.
It add a new option to enable-event --uprobe which require a path name
and an offset in the specified file.
(The file Documentation/trace/uprobetracer.txt in the kernel source provides
and example on how to extract the offset for a symbol in a program)
Signed-off-by: Yannick Brosseau <yannick.brosseau at gmail.com>
---
include/lttng/lttng.h | 15 +++++++++
src/bin/lttng-sessiond/cmd.c | 5 +++
src/bin/lttng-sessiond/modprobe.c | 1 +
src/bin/lttng-sessiond/trace-kernel.c | 7 ++++
src/bin/lttng/commands/enable_events.c | 55 ++++++++++++++++++++++++++++++++
src/bin/lttng/commands/list.c | 8 +++++
src/common/lttng-kernel.h | 7 ++++
7 files changed, 98 insertions(+)
diff --git a/include/lttng/lttng.h b/include/lttng/lttng.h
index e21b479..c790e7b 100644
--- a/include/lttng/lttng.h
+++ b/include/lttng/lttng.h
@@ -72,6 +72,7 @@ enum lttng_event_type {
LTTNG_EVENT_FUNCTION_ENTRY = 3,
LTTNG_EVENT_NOOP = 4,
LTTNG_EVENT_SYSCALL = 5,
+ LTTNG_EVENT_UPROBE = 6,
};
/*
@@ -219,6 +220,19 @@ struct lttng_event_function_attr {
};
/*
+ * Event uprobe.
+ *
+ * The structures should be initialized to zero before use.
+ */
+#define LTTNG_EVENT_UPROBE_PADDING1 24
+struct lttng_event_uprobe_attr {
+ char path[LTTNG_SYMBOL_NAME_LEN];
+ uint64_t offset;
+
+ char padding[LTTNG_EVENT_UPROBE_PADDING1];
+};
+
+/*
* Generic lttng event
*
* The structures should be initialized to zero before use.
@@ -242,6 +256,7 @@ struct lttng_event {
union {
struct lttng_event_probe_attr probe;
struct lttng_event_function_attr ftrace;
+ struct lttng_event_uprobe_attr uprobe;
char padding[LTTNG_EVENT_PADDING2];
} attr;
diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 491acde..d7fee70 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -315,6 +315,11 @@ static int list_lttng_kernel_events(char *channel_name,
memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
sizeof(struct lttng_kernel_function));
break;
+ case LTTNG_KERNEL_UPROBE:
+ (*events)[i].type = LTTNG_EVENT_UPROBE;
+ memcpy(&(*events)[i].attr.uprobe, &event->event->u.uprobe,
+ sizeof(struct lttng_kernel_uprobe));
+ break;
case LTTNG_KERNEL_NOOP:
(*events)[i].type = LTTNG_EVENT_NOOP;
break;
diff --git a/src/bin/lttng-sessiond/modprobe.c b/src/bin/lttng-sessiond/modprobe.c
index 1a5a1b7..805e127 100644
--- a/src/bin/lttng-sessiond/modprobe.c
+++ b/src/bin/lttng-sessiond/modprobe.c
@@ -35,6 +35,7 @@ const struct kern_modules_param kern_modules_list[] = {
{ "lttng-ftrace", 0 },
{ "lttng-kprobes", 0 },
{ "lttng-kretprobes", 0 },
+ { "lttng-uprobes", 0 },
{ "lttng-lib-ring-buffer", 1 },
{ "lttng-ring-buffer-client-discard", 1 },
{ "lttng-ring-buffer-client-overwrite", 1 },
diff --git a/src/bin/lttng-sessiond/trace-kernel.c b/src/bin/lttng-sessiond/trace-kernel.c
index f38cf3d..24f33f9 100644
--- a/src/bin/lttng-sessiond/trace-kernel.c
+++ b/src/bin/lttng-sessiond/trace-kernel.c
@@ -207,6 +207,13 @@ struct ltt_kernel_event *trace_kernel_create_event(struct lttng_event *ev)
ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
attr->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
break;
+ case LTTNG_EVENT_UPROBE:
+ attr->instrumentation = LTTNG_KERNEL_UPROBE;
+ attr->u.uprobe.offset = ev->attr.uprobe.offset;
+ strncpy(attr->u.uprobe.path,
+ ev->attr.uprobe.path, LTTNG_KERNEL_SYM_NAME_LEN);
+ attr->u.uprobe.path[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
+ break;
case LTTNG_EVENT_FUNCTION:
attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
attr->u.kretprobe.addr = ev->attr.probe.addr;
diff --git a/src/bin/lttng/commands/enable_events.c b/src/bin/lttng/commands/enable_events.c
index b6c18e1..61cb15b 100644
--- a/src/bin/lttng/commands/enable_events.c
+++ b/src/bin/lttng/commands/enable_events.c
@@ -38,6 +38,7 @@ static char *opt_session_name;
static int opt_userspace;
static int opt_enable_all;
static char *opt_probe;
+static char *opt_uprobe;
static char *opt_function;
static char *opt_function_entry_symbol;
static char *opt_channel_name;
@@ -52,6 +53,7 @@ enum {
OPT_HELP = 1,
OPT_TRACEPOINT,
OPT_PROBE,
+ OPT_UPROBE,
OPT_FUNCTION,
OPT_FUNCTION_ENTRY,
OPT_SYSCALL,
@@ -74,6 +76,7 @@ static struct poptOption long_options[] = {
{"userspace", 'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
{"tracepoint", 0, POPT_ARG_NONE, 0, OPT_TRACEPOINT, 0, 0},
{"probe", 0, POPT_ARG_STRING, &opt_probe, OPT_PROBE, 0, 0},
+ {"uprobe", 0, POPT_ARG_STRING, &opt_uprobe, OPT_UPROBE, 0, 0},
{"function", 0, POPT_ARG_STRING, &opt_function, OPT_FUNCTION, 0, 0},
#if 0
/*
@@ -117,6 +120,10 @@ static void usage(FILE *ofp)
fprintf(ofp, " Dynamic probe.\n");
fprintf(ofp, " Addr and offset can be octal (0NNN...),\n");
fprintf(ofp, " decimal (NNN...) or hexadecimal (0xNNN...)\n");
+ fprintf(ofp, " --uprobe [path+offset]\n");
+ fprintf(ofp, " Dynamic uprobe.\n");
+ fprintf(ofp, " offset can be octal (0NNN...),\n");
+ fprintf(ofp, " decimal (NNN...) or hexadecimal (0xNNN...)\n");
fprintf(ofp, " --function [addr | symbol | symbol+offset]\n");
fprintf(ofp, " Dynamic function entry/return probe.\n");
fprintf(ofp, " Addr and offset can be octal (0NNN...),\n");
@@ -245,6 +252,42 @@ static int parse_probe_opts(struct lttng_event *ev, char *opt)
end:
return ret;
}
+/*
+ * Parse uprobe options.
+ */
+static int parse_uprobe_opts(struct lttng_event *ev, char *opt)
+{
+ int ret;
+ char s_hex[19];
+ char name[LTTNG_SYMBOL_NAME_LEN];
+
+ if (opt == NULL) {
+ ret = -1;
+ goto end;
+ }
+
+ /* Check for path+offset */
+ ret = sscanf(opt, "%[^'+']+%s", name, s_hex);
+ if (ret == 2) {
+ strncpy(ev->attr.uprobe.path, name, LTTNG_SYMBOL_NAME_LEN);
+ ev->attr.uprobe.path[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
+ DBG("probe path %s", ev->attr.uprobe.path);
+ if (strlen(s_hex) == 0) {
+ ERR("Invalid uprobe offset %s", s_hex);
+ ret = -1;
+ goto end;
+ }
+ ev->attr.uprobe.offset = strtoul(s_hex, NULL, 0);
+ DBG("uprobe offset %" PRIu64, ev->attr.uprobe.offset);
+ goto end;
+ }
+
+ /* No match */
+ ret = -1;
+
+end:
+ return ret;
+}
/*
* Maps loglevel from string to value
@@ -471,6 +514,14 @@ static int enable_events(char *session_name)
goto error;
}
break;
+ case LTTNG_EVENT_UPROBE:
+ ret = parse_uprobe_opts(&ev, opt_uprobe);
+ if (ret < 0) {
+ ERR("Unable to parse uprobe options");
+ ret = 0;
+ goto error;
+ }
+ break;
case LTTNG_EVENT_FUNCTION:
ret = parse_probe_opts(&ev, opt_function);
if (ret < 0) {
@@ -522,6 +573,7 @@ static int enable_events(char *session_name)
ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
break;
case LTTNG_EVENT_PROBE:
+ case LTTNG_EVENT_UPROBE:
case LTTNG_EVENT_FUNCTION:
case LTTNG_EVENT_FUNCTION_ENTRY:
case LTTNG_EVENT_SYSCALL:
@@ -636,6 +688,9 @@ int cmd_enable_events(int argc, const char **argv)
case OPT_PROBE:
opt_event_type = LTTNG_EVENT_PROBE;
break;
+ case OPT_UPROBE:
+ opt_event_type = LTTNG_EVENT_UPROBE;
+ break;
case OPT_FUNCTION:
opt_event_type = LTTNG_EVENT_FUNCTION;
break;
diff --git a/src/bin/lttng/commands/list.c b/src/bin/lttng/commands/list.c
index a6ea6b8..ffae239 100644
--- a/src/bin/lttng/commands/list.c
+++ b/src/bin/lttng/commands/list.c
@@ -231,6 +231,14 @@ static void print_events(struct lttng_event *event)
MSG("%ssymbol: %s", indent8, event->attr.probe.symbol_name);
}
break;
+ case LTTNG_EVENT_UPROBE:
+ MSG("%s%s (type: uprobe)%s%s", indent6,
+ event->name, enabled_string(event->enabled),
+ filter_string(event->filter));
+
+ MSG("%spath: %s", indent8, event->attr.uprobe.path);
+ MSG("%soffset: 0x%" PRIx64, indent8, event->attr.uprobe.offset);
+ break;
case LTTNG_EVENT_FUNCTION:
case LTTNG_EVENT_FUNCTION_ENTRY:
MSG("%s%s (type: function)%s%s", indent6,
diff --git a/src/common/lttng-kernel.h b/src/common/lttng-kernel.h
index fa8ba61..a43b956 100644
--- a/src/common/lttng-kernel.h
+++ b/src/common/lttng-kernel.h
@@ -38,6 +38,7 @@ enum lttng_kernel_instrumentation {
LTTNG_KERNEL_KRETPROBE = 3,
LTTNG_KERNEL_NOOP = 4, /* not hooked */
LTTNG_KERNEL_SYSCALL = 5,
+ LTTNG_KERNEL_UPROBE = 6,
};
enum lttng_kernel_context_type {
@@ -96,6 +97,11 @@ struct lttng_kernel_function {
char symbol_name[LTTNG_KERNEL_SYM_NAME_LEN];
}__attribute__((packed));
+struct lttng_kernel_uprobe {
+ char path[LTTNG_KERNEL_SYM_NAME_LEN];
+ uint64_t offset;
+}__attribute__((packed));
+
#define LTTNG_KERNEL_EVENT_PADDING1 16
#define LTTNG_KERNEL_EVENT_PADDING2 LTTNG_KERNEL_SYM_NAME_LEN + 32
struct lttng_kernel_event {
@@ -108,6 +114,7 @@ struct lttng_kernel_event {
struct lttng_kernel_kretprobe kretprobe;
struct lttng_kernel_kprobe kprobe;
struct lttng_kernel_function ftrace;
+ struct lttng_kernel_uprobe uprobe;
char padding[LTTNG_KERNEL_EVENT_PADDING2];
} u;
}__attribute__((packed));
--
1.7.10.4
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