X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fcommands%2Fenable_events.c;h=3d32cbf813bc2615b211888748018fbebb77b5d8;hp=62f99a1fcfc760e659a3ab1c3a0e775fc79dccec;hb=54185c70692f8a6d9c667214743e0ffd07a0afa3;hpb=dcabc1905756b2999886313ec33705f7571a3fb9 diff --git a/src/bin/lttng/commands/enable_events.c b/src/bin/lttng/commands/enable_events.c index 62f99a1fc..3d32cbf81 100644 --- a/src/bin/lttng/commands/enable_events.c +++ b/src/bin/lttng/commands/enable_events.c @@ -290,6 +290,65 @@ end: return ret; } +/* + * Check if the symbol field passed by the user is in fact an address or an + * offset from a symbol. Those two instrumentation types are not supported yet. + * It's expected to be a common mistake because of the existing --probe option + * that does support these formats. + * + * Here are examples of these unsupported formats for the --userspace-probe + * option: + * elf:/path/to/binary:0x400430 + * elf:/path/to/binary:4194364 + * elf:/path/to/binary:my_symbol+0x323 + * elf:/path/to/binary:my_symbol+43 + */ +static int warn_userspace_probe_syntax(const char *symbol) +{ + int ret; + + /* Check if the symbol field is an hex address. */ + ret = sscanf(symbol, "0x%*x"); + if (ret > 0) { + /* If there is a match, print a warning and return an error. */ + ERR("Userspace probe on address not supported yet."); + ret = CMD_UNSUPPORTED; + goto error; + } + + /* Check if the symbol field is an decimal address. */ + ret = sscanf(symbol, "%*u"); + if (ret > 0) { + /* If there is a match, print a warning and return an error. */ + ERR("Userspace probe on address not supported yet."); + ret = CMD_UNSUPPORTED; + goto error; + } + + /* Check if the symbol field is symbol+hex_offset. */ + ret = sscanf(symbol, "%*[^+]+0x%*x"); + if (ret > 0) { + /* If there is a match, print a warning and return an error. */ + ERR("Userspace probe on symbol+offset not supported yet."); + ret = CMD_UNSUPPORTED; + goto error; + } + + /* Check if the symbol field is symbol+decimal_offset. */ + ret = sscanf(symbol, "%*[^+]+%*u"); + if (ret > 0) { + /* If there is a match, print a warning and return an error. */ + ERR("Userspace probe on symbol+offset not supported yet."); + ret = CMD_UNSUPPORTED; + goto error; + } + + ret = 0; + +error: + return ret; +} + /* * Parse userspace probe options * Set the userspace probe fields in the lttng_event struct and set the @@ -313,6 +372,13 @@ static int parse_userspace_probe_opts(struct lttng_event *ev, char *opt) goto end; } + switch (ev->type) { + case LTTNG_EVENT_USERSPACE_PROBE: + break; + default: + assert(0); + } + /* * userspace probe fields are separated by ':'. */ @@ -382,53 +448,63 @@ static int parse_userspace_probe_opts(struct lttng_event *ev, char *opt) /* strutils_unescape_string allocates a new char *. */ unescaped_target_path = strutils_unescape_string(target_path, 0); if (!unescaped_target_path) { - ret = -LTTNG_ERR_INVALID; - goto end_string; + ret = CMD_ERROR; + goto end_destroy_lookup_method; } /* * If there is not forward slash in the path. Walk the $PATH else * expand. */ - if (strchr(target_path, '/') == NULL) { + if (strchr(unescaped_target_path, '/') == NULL) { /* Walk the $PATH variable to find the targeted binary. */ real_target_path = zmalloc(LTTNG_PATH_MAX * sizeof(char)); if (!real_target_path) { PERROR("Error allocating path buffer"); ret = CMD_ERROR; - goto end_unescaped_string; + goto end_destroy_lookup_method; } - ret = walk_command_search_path(target_path, real_target_path); + ret = walk_command_search_path(unescaped_target_path, real_target_path); if (ret) { ERR("Binary not found."); ret = CMD_ERROR; - goto end_free_path; + goto end_destroy_lookup_method; } } else { /* * Expand references to `/./` and `/../`. This function does not check - * if the file exists. + * if the file exists. This call returns an allocated buffer on + * success. */ - real_target_path = utils_expand_path_keep_symlink(target_path); + real_target_path = utils_expand_path_keep_symlink(unescaped_target_path); if (!real_target_path) { ERR("Error expanding the path to binary."); ret = CMD_ERROR; - goto end_free_path; + goto end_destroy_lookup_method; } /* - * Check if the file exists using access(2). If it does not, walk the - * $PATH. + * Check if the file exists using access(2), If it does not, + * return an error. */ ret = access(real_target_path, F_OK); if (ret) { + ERR("Cannot find binary at path: %s.", real_target_path); ret = CMD_ERROR; - goto end_free_path; + goto end_destroy_lookup_method; } } switch (lttng_userspace_probe_location_lookup_method_get_type(lookup_method)) { case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF: + /* + * Check for common mistakes in userspace probe description syntax. + */ + ret = warn_userspace_probe_syntax(symbol_name); + if (ret) { + goto end_destroy_lookup_method; + } + probe_location = lttng_userspace_probe_location_function_create( real_target_path, symbol_name, lookup_method); if (!probe_location) { @@ -468,32 +544,24 @@ static int parse_userspace_probe_opts(struct lttng_event *ev, char *opt) break; default: ret = CMD_ERROR; - goto end_string; + goto end_destroy_lookup_method; } - switch (ev->type) { - case LTTNG_EVENT_USERSPACE_PROBE: - break; - default: - assert(0); - } - - goto end; + /* Successful parsing, now clean up everything and return. */ + goto end_string; end_destroy_location: lttng_userspace_probe_location_destroy(probe_location); end_destroy_lookup_method: lttng_userspace_probe_location_lookup_method_destroy(lookup_method); -end_free_path: +end_string: + strutils_free_null_terminated_array_of_strings(tokens); /* - * Free path that was allocated by the call to realpath() or when walking - * the PATH. + * Freeing both char * here makes the error handling simplier. free() + * performs not action if the pointer is NULL. */ free(real_target_path); -end_unescaped_string: free(unescaped_target_path); -end_string: - strutils_free_null_terminated_array_of_strings(tokens); end: return ret; } @@ -737,7 +805,7 @@ char *print_exclusions(char **names) { int length = 0; int i; - const char *preamble = " excluding "; + const char preamble[] = " excluding "; char *ret; int count = names ? strutils_array_of_strings_len(names) : 0; @@ -750,9 +818,8 @@ char *print_exclusions(char **names) length += strlen(names[i]) + 4; } - /* add length of preamble + one for NUL - one for last (missing) comma */ - length += strlen(preamble); - ret = zmalloc(length + 1); + length += sizeof(preamble); + ret = zmalloc(length); if (!ret) { return NULL; } @@ -965,6 +1032,30 @@ static int enable_events(char *session_name) } } + /* + * Adding a filter to a probe, function or userspace-probe would be + * denied by the kernel tracer as it's not supported at the moment. We + * do an early check here to warn the user. + */ + if (opt_filter && opt_kernel) { + switch (opt_event_type) { + case LTTNG_EVENT_ALL: + case LTTNG_EVENT_TRACEPOINT: + case LTTNG_EVENT_SYSCALL: + break; + case LTTNG_EVENT_PROBE: + case LTTNG_EVENT_USERSPACE_PROBE: + case LTTNG_EVENT_FUNCTION: + ERR("Filter expressions are not supported for %s events", + get_event_type_str(opt_event_type)); + ret = CMD_ERROR; + goto error; + default: + ret = CMD_UNDEFINED; + goto error; + } + } + channel_name = opt_channel_name; handle = lttng_create_handle(session_name, &dom); @@ -1272,8 +1363,19 @@ static int enable_events(char *session_name) case LTTNG_EVENT_USERSPACE_PROBE: ret = parse_userspace_probe_opts(ev, opt_userspace_probe); if (ret) { - ERR("Unable to parse userspace probe options"); - ret = CMD_ERROR; + switch (ret) { + case CMD_UNSUPPORTED: + /* + * Error message describing + * what is not supported was + * printed in the function. + */ + break; + case CMD_ERROR: + default: + ERR("Unable to parse userspace probe options"); + break; + } goto error; } break;