X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.cpp;h=5b4fc086bde52ce333f8cf72cf9f3d627b0cc000;hp=2914475d55f2af0ba9052844095db1f372939214;hb=HEAD;hpb=0038180de36c422cfaeade1145fa9fbc9436b8ad diff --git a/src/bin/lttng-sessiond/kernel.cpp b/src/bin/lttng-sessiond/kernel.cpp index 2914475d5..4cc51a279 100644 --- a/src/bin/lttng-sessiond/kernel.cpp +++ b/src/bin/lttng-sessiond/kernel.cpp @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -49,20 +50,47 @@ #include #include +namespace { /* * Key used to reference a channel between the sessiond and the consumer. This * is only read and updated with the session_list lock held. */ -static uint64_t next_kernel_channel_key; +uint64_t next_kernel_channel_key; -static const char *module_proc_lttng = "/proc/lttng"; +const char *module_proc_lttng = "/proc/lttng"; -static int kernel_tracer_fd = -1; -static int kernel_tracer_event_notifier_group_fd = -1; -static int kernel_tracer_event_notifier_group_notification_fd = -1; -static struct cds_lfht *kernel_token_to_event_notifier_rule_ht; +int kernel_tracer_fd = -1; +nonstd::optional kernel_tracer_status = nonstd::nullopt; +int kernel_tracer_event_notifier_group_fd = -1; +int kernel_tracer_event_notifier_group_notification_fd = -1; +struct cds_lfht *kernel_token_to_event_notifier_rule_ht; + +const char *kernel_tracer_status_to_str(lttng_kernel_tracer_status status) +{ + switch (status) { + case LTTNG_KERNEL_TRACER_STATUS_INITIALIZED: + return "LTTNG_KERNEL_TRACER_STATUS_INITIALIZED"; + case LTTNG_KERNEL_TRACER_STATUS_ERR_UNKNOWN: + return "LTTNG_KERNEL_TRACER_STATUS_ERR_UNKNOWN"; + case LTTNG_KERNEL_TRACER_STATUS_ERR_NEED_ROOT: + return "LTTNG_KERNEL_TRACER_STATUS_ERR_NEED_ROOT"; + case LTTNG_KERNEL_TRACER_STATUS_ERR_NOTIFIER: + return "LTTNG_KERNEL_TRACER_STATUS_ERR_NOTIFIER"; + case LTTNG_KERNEL_TRACER_STATUS_ERR_OPEN_PROC_LTTNG: + return "LTTNG_KERNEL_TRACER_STATUS_ERR_OPEN_PROC_LTTNG"; + case LTTNG_KERNEL_TRACER_STATUS_ERR_VERSION_MISMATCH: + return "LTTNG_KERNEL_TRACER_STATUS_ERR_VERSION_MISMATCH"; + case LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_UNKNOWN: + return "LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_UNKNOWN"; + case LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_MISSING: + return "LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_MISSING"; + case LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_SIGNATURE: + return "LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_SIGNATURE"; + } + + abort(); +} -namespace { /* * On some architectures, calling convention details are embedded in the symbol * addresses. Uprobe requires a "clean" symbol offset (or at least, an address @@ -86,7 +114,7 @@ static inline uint64_t sanitize_uprobe_offset(uint64_t raw_offset) return raw_offset; } #endif -} +} /* namespace */ /* * Add context on a kernel channel. @@ -1949,6 +1977,48 @@ error: return ret; } +/* + * Get current kernel tracer status + */ +enum lttng_kernel_tracer_status get_kernel_tracer_status() +{ + if (!kernel_tracer_status) { + return LTTNG_KERNEL_TRACER_STATUS_ERR_UNKNOWN; + } + + return *kernel_tracer_status; +} + +/* + * Sets the kernel tracer status based on the positive errno code + */ +void set_kernel_tracer_status_from_modules_ret(int code) +{ + switch (code) { + case ENOENT: + { + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_MISSING); + break; + } + case ENOKEY: + case EKEYEXPIRED: + case EKEYREVOKED: + case EKEYREJECTED: + { + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_SIGNATURE); + break; + } + default: + { + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_MODULES_UNKNOWN); + break; + } + } +} + /* * Setup necessary data for kernel tracer action. */ @@ -1957,9 +2027,15 @@ int init_kernel_tracer() int ret; bool is_root = !getuid(); + const auto log_status_on_exit = lttng::make_scope_exit([]() noexcept { + DBG_FMT("Kernel tracer status set to `{}`", + kernel_tracer_status_to_str(*kernel_tracer_status)); + }); + /* Modprobe lttng kernel modules */ ret = modprobe_lttng_control(); if (ret < 0) { + set_kernel_tracer_status_from_modules_ret(-ret); goto error; } @@ -1967,17 +2043,22 @@ int init_kernel_tracer() kernel_tracer_fd = open(module_proc_lttng, O_RDWR); if (kernel_tracer_fd < 0) { DBG("Failed to open %s", module_proc_lttng); + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_OPEN_PROC_LTTNG); goto error_open; } /* Validate kernel version */ ret = kernel_validate_version(&the_kernel_tracer_version, &the_kernel_tracer_abi_version); if (ret < 0) { + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_VERSION_MISMATCH); goto error_version; } ret = modprobe_lttng_data(); if (ret < 0) { + set_kernel_tracer_status_from_modules_ret(-ret); goto error_modules; } @@ -1994,6 +2075,8 @@ int init_kernel_tracer() ret = kernel_supports_event_notifiers(); if (ret < 0) { ERR("Failed to check for kernel tracer event notifier support"); + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_NOTIFIER); goto error_modules; } ret = kernel_create_event_notifier_group(&kernel_tracer_event_notifier_group_fd); @@ -2008,6 +2091,8 @@ int init_kernel_tracer() &kernel_tracer_event_notifier_group_notification_fd); if (error_code_ret != LTTNG_OK) { + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_NOTIFIER); goto error_modules; } @@ -2016,12 +2101,16 @@ int init_kernel_tracer() if (error_accounting_status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) { ERR("Failed to initialize event notifier error accounting for kernel tracer"); error_code_ret = LTTNG_ERR_EVENT_NOTIFIER_ERROR_ACCOUNTING; + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_NOTIFIER); goto error_modules; } kernel_token_to_event_notifier_rule_ht = cds_lfht_new( DEFAULT_HT_SIZE, 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, nullptr); if (!kernel_token_to_event_notifier_rule_ht) { + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_NOTIFIER); goto error_token_ht; } } @@ -2037,6 +2126,8 @@ int init_kernel_tracer() "work for this session daemon."); } + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_INITIALIZED); return 0; error_version: @@ -2081,6 +2172,8 @@ error: WARN("No kernel tracer available"); kernel_tracer_fd = -1; if (!is_root) { + kernel_tracer_status = nonstd::optional( + LTTNG_KERNEL_TRACER_STATUS_ERR_NEED_ROOT); return LTTNG_ERR_NEED_ROOT_SESSIOND; } else { return LTTNG_ERR_KERN_NA; @@ -2136,6 +2229,7 @@ void cleanup_kernel_tracer() kernel_tracer_fd = -1; } + kernel_tracer_status = nonstd::nullopt; free(syscall_table); }