[ltt-dev] [lttng-tools PATCH] Add kretprobe support (new --function implementation)
David Goulet
david.goulet at polymtl.ca
Fri Jul 29 11:25:17 EDT 2011
Merged! Thanks
FIN
David
On 11-07-28 06:45 PM, Mathieu Desnoyers wrote:
> Add kretprobe support (new --function implementation)
>
> Also support probe "symbol" (without +offset) by checking first
> character with isalpha().
>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> ---
> include/lttng-kernel.h | 9 ++++++
> include/lttng/lttng.h | 1
> ltt-sessiond/ltt-sessiond.h | 1
> ltt-sessiond/trace.c | 8 +++++
> lttng/commands/enable_events.c | 58 +++++++++++++++++++++++++++++++++--------
> 5 files changed, 66 insertions(+), 11 deletions(-)
>
> Index: lttng-tools/include/lttng-kernel.h
> ===================================================================
> --- lttng-tools.orig/include/lttng-kernel.h
> +++ lttng-tools/include/lttng-kernel.h
> @@ -35,6 +35,7 @@ enum lttng_kernel_instrumentation {
> LTTNG_KERNEL_TRACEPOINT = 0,
> LTTNG_KERNEL_KPROBE = 1,
> LTTNG_KERNEL_FUNCTION = 2,
> + LTTNG_KERNEL_KRETPROBE = 3,
> };
>
> enum lttng_kernel_context_type {
> @@ -65,6 +66,13 @@ struct lttng_kernel_context {
> } u;
> };
>
> +struct lttng_kernel_kretprobe {
> + uint64_t addr;
> +
> + uint64_t offset;
> + char symbol_name[LTTNG_SYM_NAME_LEN];
> +};
> +
> /*
> * Either addr is used, or symbol_name and offset.
> */
> @@ -85,6 +93,7 @@ struct lttng_kernel_event {
> enum lttng_kernel_instrumentation instrumentation;
> /* Per instrumentation type configuration */
> union {
> + struct lttng_kernel_kretprobe kretprobe;
> struct lttng_kernel_kprobe kprobe;
> struct lttng_kernel_function ftrace;
> } u;
> Index: lttng-tools/include/lttng/lttng.h
> ===================================================================
> --- lttng-tools.orig/include/lttng/lttng.h
> +++ lttng-tools/include/lttng/lttng.h
> @@ -73,6 +73,7 @@ enum lttng_event_type {
> LTTNG_EVENT_TRACEPOINT,
> LTTNG_EVENT_PROBE,
> LTTNG_EVENT_FUNCTION,
> + LTTNG_EVENT_FUNCTION_ENTRY,
> };
>
> /*
> Index: lttng-tools/ltt-sessiond/ltt-sessiond.h
> ===================================================================
> --- lttng-tools.orig/ltt-sessiond/ltt-sessiond.h
> +++ lttng-tools/ltt-sessiond/ltt-sessiond.h
> @@ -36,6 +36,7 @@ const char *kernel_modules_list[] = {
> "ltt-ring-buffer-metadata-mmap-client",
> "lttng-ftrace",
> "lttng-kprobes",
> + "lttng-kretprobes",
> "lttng-probe-block",
> "lttng-probe-irq",
> "lttng-probe-kvm",
> Index: lttng-tools/ltt-sessiond/trace.c
> ===================================================================
> --- lttng-tools.orig/ltt-sessiond/trace.c
> +++ lttng-tools/ltt-sessiond/trace.c
> @@ -185,6 +185,14 @@ struct ltt_kernel_event *trace_create_ke
> ev->attr.probe.symbol_name, LTTNG_SYM_NAME_LEN);
> break;
> case LTTNG_EVENT_FUNCTION:
> + attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
> + attr->u.kretprobe.addr = ev->attr.probe.addr;
> + attr->u.kretprobe.offset = ev->attr.probe.offset;
> + attr->u.kretprobe.offset = ev->attr.probe.offset;
> + strncpy(attr->u.kretprobe.symbol_name,
> + ev->attr.probe.symbol_name, LTTNG_SYM_NAME_LEN);
> + break;
> + case LTTNG_EVENT_FUNCTION_ENTRY:
> attr->instrumentation = LTTNG_KERNEL_FUNCTION;
> strncpy(attr->u.ftrace.symbol_name,
> ev->attr.ftrace.symbol_name, LTTNG_SYM_NAME_LEN);
> Index: lttng-tools/lttng/commands/enable_events.c
> ===================================================================
> --- lttng-tools.orig/lttng/commands/enable_events.c
> +++ lttng-tools/lttng/commands/enable_events.c
> @@ -25,6 +25,7 @@
> #include <sys/types.h>
> #include <unistd.h>
> #include <inttypes.h>
> +#include <ctype.h>
>
> #include "../cmd.h"
> #include "../conf.h"
> @@ -40,7 +41,8 @@ static int opt_userspace;
> static int opt_enable_all;
> static pid_t opt_pid;
> static char *opt_probe;
> -static char *opt_function_symbol;
> +static char *opt_function;
> +static char *opt_function_entry_symbol;
> static char *opt_channel_name;
>
> enum {
> @@ -50,6 +52,7 @@ enum {
> OPT_MARKER,
> OPT_PROBE,
> OPT_FUNCTION,
> + OPT_FUNCTION_ENTRY,
> };
>
> static struct poptOption long_options[] = {
> @@ -66,6 +69,7 @@ static struct poptOption long_options[]
> {"marker", 0, POPT_ARG_NONE, 0, OPT_MARKER, 0, 0},
> {"probe", 0, POPT_ARG_STRING, 0, OPT_PROBE, 0, 0},
> {"function", 0, POPT_ARG_STRING, 0, OPT_FUNCTION, 0, 0},
> + {"function:entry", 0, POPT_ARG_STRING, 0, OPT_FUNCTION_ENTRY, 0, 0},
> {0, 0, 0, 0, 0, 0, 0}
> };
>
> @@ -87,11 +91,16 @@ static void usage(FILE *ofp)
> fprintf(ofp, "\n");
> fprintf(ofp, "Event options:\n");
> fprintf(ofp, " --tracepoint Tracepoint event (default)\n");
> - fprintf(ofp, " --probe [addr | symbol+offset]\n");
> + fprintf(ofp, " --probe [addr | symbol | symbol+offset]\n");
> 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, " --function SYMBOL Function tracer event\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");
> + fprintf(ofp, " decimal (NNN...) or hexadecimal (0xNNN...)\n");
> + fprintf(ofp, " --function:entry symbol\n");
> + fprintf(ofp, " Function tracer event\n");
> fprintf(ofp, " --marker User-space marker (deprecated)\n");
> fprintf(ofp, "\n");
> }
> @@ -109,7 +118,7 @@ static int parse_probe_opts(struct lttng
>
> if (opt == NULL) {
> ret = -1;
> - goto error;
> + goto end;
> }
>
> /* Check for symbol+offset */
> @@ -120,12 +129,25 @@ static int parse_probe_opts(struct lttng
> if (strlen(s_hex) == 0) {
> ERR("Invalid probe offset %s", s_hex);
> ret = -1;
> - goto error;
> + goto end;
> }
> ev->attr.probe.offset = strtoul(s_hex, NULL, 0);
> DBG("probe offset %" PRIu64, ev->attr.probe.offset);
> ev->attr.probe.addr = 0;
> - goto error;
> + goto end;
> + }
> +
> + /* Check for symbol */
> + if (isalpha(name[0])) {
> + ret = sscanf(opt, "%s", name);
> + if (ret == 1) {
> + strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
> + DBG("probe symbol %s", ev->attr.probe.symbol_name);
> + ev->attr.probe.offset = 0;
> + DBG("probe offset %" PRIu64, ev->attr.probe.offset);
> + ev->attr.probe.addr = 0;
> + goto end;
> + }
> }
>
> /* Check for address */
> @@ -134,19 +156,19 @@ static int parse_probe_opts(struct lttng
> if (strlen(s_hex) == 0) {
> ERR("Invalid probe address %s", s_hex);
> ret = -1;
> - goto error;
> + goto end;
> }
> ev->attr.probe.addr = strtoul(s_hex, NULL, 0);
> DBG("probe addr %" PRIu64, ev->attr.probe.addr);
> ev->attr.probe.offset = 0;
> memset(ev->attr.probe.symbol_name, 0, LTTNG_SYMBOL_NAME_LEN);
> - goto error;
> + goto end;
> }
>
> /* No match */
> ret = -1;
>
> -error:
> +end:
> return ret;
> }
>
> @@ -217,7 +239,17 @@ static int enable_events(void)
> }
> break;
> case LTTNG_EVENT_FUNCTION:
> - strncpy(ev.attr.ftrace.symbol_name, opt_function_symbol, LTTNG_SYMBOL_NAME_LEN);
> + ret = parse_probe_opts(&ev, opt_function);
> + if (ret < 0) {
> + ERR("Unable to parse function probe options");
> + ret = 0;
> + goto error;
> + }
> + break;
> + case LTTNG_EVENT_FUNCTION_ENTRY:
> + strncpy(ev.attr.ftrace.symbol_name,
> + opt_function_entry_symbol,
> + LTTNG_SYMBOL_NAME_LEN);
> break;
> default:
> ret = CMD_NOT_IMPLEMENTED;
> @@ -291,7 +323,11 @@ int cmd_enable_events(int argc, const ch
> break;
> case OPT_FUNCTION:
> opt_event_type = LTTNG_EVENT_FUNCTION;
> - opt_function_symbol = poptGetOptArg(pc);
> + opt_function = poptGetOptArg(pc);
> + break;
> + case OPT_FUNCTION_ENTRY:
> + opt_event_type = LTTNG_EVENT_FUNCTION_ENTRY;
> + opt_function_entry_symbol = poptGetOptArg(pc);
> break;
> default:
> usage(stderr);
>
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