diff options
| -rw-r--r-- | Documentation/networking/netconsole.rst | 28 | ||||
| -rw-r--r-- | drivers/net/netconsole.c | 95 | ||||
| -rwxr-xr-x | tools/testing/selftests/drivers/net/netcons_sysdata.sh | 51 |
3 files changed, 153 insertions, 21 deletions
diff --git a/Documentation/networking/netconsole.rst b/Documentation/networking/netconsole.rst index 84803c59968a..ae82a6337a8d 100644 --- a/Documentation/networking/netconsole.rst +++ b/Documentation/networking/netconsole.rst @@ -240,6 +240,34 @@ Delete `userdata` entries with `rmdir`:: It is recommended to not write user data values with newlines. +Task name auto population in userdata +------------------------------------- + +Inside the netconsole configfs hierarchy, there is a file called +`taskname_enabled` under the `userdata` directory. This file is used to enable +or disable the automatic task name population feature. This feature +automatically populates the current task name that is scheduled in the CPU +sneding the message. + +To enable task name auto-population:: + + echo 1 > /sys/kernel/config/netconsole/target1/userdata/taskname_enabled + +When this option is enabled, the netconsole messages will include an additional +line in the userdata field with the format `taskname=<task name>`. This allows +the receiver of the netconsole messages to easily find which application was +currently scheduled when that message was generated, providing extra context +for kernel messages and helping to categorize them. + +Example:: + + echo "This is a message" > /dev/kmsg + 12,607,22085407756,-;This is a message + taskname=echo + +In this example, the message was generated while "echo" was the current +scheduled process. + CPU number auto population in userdata -------------------------------------- diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index f77eddf22185..098ea9eb0237 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -103,7 +103,9 @@ struct netconsole_target_stats { */ enum sysdata_feature { /* Populate the CPU that sends the message */ - CPU_NR = BIT(0), + SYSDATA_CPU_NR = BIT(0), + /* Populate the task name (as in current->comm) in sysdata */ + SYSDATA_TASKNAME = BIT(1), }; /** @@ -418,12 +420,26 @@ static ssize_t sysdata_cpu_nr_enabled_show(struct config_item *item, char *buf) bool cpu_nr_enabled; mutex_lock(&dynamic_netconsole_mutex); - cpu_nr_enabled = !!(nt->sysdata_fields & CPU_NR); + cpu_nr_enabled = !!(nt->sysdata_fields & SYSDATA_CPU_NR); mutex_unlock(&dynamic_netconsole_mutex); return sysfs_emit(buf, "%d\n", cpu_nr_enabled); } +/* configfs helper to display if taskname sysdata feature is enabled */ +static ssize_t sysdata_taskname_enabled_show(struct config_item *item, + char *buf) +{ + struct netconsole_target *nt = to_target(item->ci_parent); + bool taskname_enabled; + + mutex_lock(&dynamic_netconsole_mutex); + taskname_enabled = !!(nt->sysdata_fields & SYSDATA_TASKNAME); + mutex_unlock(&dynamic_netconsole_mutex); + + return sysfs_emit(buf, "%d\n", taskname_enabled); +} + /* * This one is special -- targets created through the configfs interface * are not enabled (and the corresponding netpoll activated) by default. @@ -699,7 +715,9 @@ static size_t count_extradata_entries(struct netconsole_target *nt) /* Userdata entries */ entries = list_count_nodes(&nt->userdata_group.cg_children); /* Plus sysdata entries */ - if (nt->sysdata_fields & CPU_NR) + if (nt->sysdata_fields & SYSDATA_CPU_NR) + entries += 1; + if (nt->sysdata_fields & SYSDATA_TASKNAME) entries += 1; return entries; @@ -837,6 +855,40 @@ static void disable_sysdata_feature(struct netconsole_target *nt, nt->extradata_complete[nt->userdata_length] = 0; } +static ssize_t sysdata_taskname_enabled_store(struct config_item *item, + const char *buf, size_t count) +{ + struct netconsole_target *nt = to_target(item->ci_parent); + bool taskname_enabled, curr; + ssize_t ret; + + ret = kstrtobool(buf, &taskname_enabled); + if (ret) + return ret; + + mutex_lock(&dynamic_netconsole_mutex); + curr = !!(nt->sysdata_fields & SYSDATA_TASKNAME); + if (taskname_enabled == curr) + goto unlock_ok; + + if (taskname_enabled && + count_extradata_entries(nt) >= MAX_EXTRADATA_ITEMS) { + ret = -ENOSPC; + goto unlock; + } + + if (taskname_enabled) + nt->sysdata_fields |= SYSDATA_TASKNAME; + else + disable_sysdata_feature(nt, SYSDATA_TASKNAME); + +unlock_ok: + ret = strnlen(buf, count); +unlock: + mutex_unlock(&dynamic_netconsole_mutex); + return ret; +} + /* configfs helper to sysdata cpu_nr feature */ static ssize_t sysdata_cpu_nr_enabled_store(struct config_item *item, const char *buf, size_t count) @@ -850,7 +902,7 @@ static ssize_t sysdata_cpu_nr_enabled_store(struct config_item *item, return ret; mutex_lock(&dynamic_netconsole_mutex); - curr = nt->sysdata_fields & CPU_NR; + curr = !!(nt->sysdata_fields & SYSDATA_CPU_NR); if (cpu_nr_enabled == curr) /* no change requested */ goto unlock_ok; @@ -865,13 +917,13 @@ static ssize_t sysdata_cpu_nr_enabled_store(struct config_item *item, } if (cpu_nr_enabled) - nt->sysdata_fields |= CPU_NR; + nt->sysdata_fields |= SYSDATA_CPU_NR; else /* This is special because extradata_complete might have * remaining data from previous sysdata, and it needs to be * cleaned. */ - disable_sysdata_feature(nt, CPU_NR); + disable_sysdata_feature(nt, SYSDATA_CPU_NR); unlock_ok: ret = strnlen(buf, count); @@ -882,6 +934,7 @@ unlock: CONFIGFS_ATTR(userdatum_, value); CONFIGFS_ATTR(sysdata_, cpu_nr_enabled); +CONFIGFS_ATTR(sysdata_, taskname_enabled); static struct configfs_attribute *userdatum_attrs[] = { &userdatum_attr_value, @@ -942,6 +995,7 @@ static void userdatum_drop(struct config_group *group, struct config_item *item) static struct configfs_attribute *userdata_attrs[] = { &sysdata_attr_cpu_nr_enabled, + &sysdata_attr_taskname_enabled, NULL, }; @@ -1117,28 +1171,41 @@ static void populate_configfs_item(struct netconsole_target *nt, init_target_config_group(nt, target_name); } +static int append_cpu_nr(struct netconsole_target *nt, int offset) +{ + /* Append cpu=%d at extradata_complete after userdata str */ + return scnprintf(&nt->extradata_complete[offset], + MAX_EXTRADATA_ENTRY_LEN, " cpu=%u\n", + raw_smp_processor_id()); +} + +static int append_taskname(struct netconsole_target *nt, int offset) +{ + return scnprintf(&nt->extradata_complete[offset], + MAX_EXTRADATA_ENTRY_LEN, " taskname=%s\n", + current->comm); +} /* * prepare_extradata - append sysdata at extradata_complete in runtime * @nt: target to send message to */ static int prepare_extradata(struct netconsole_target *nt) { - int sysdata_len, extradata_len; + u32 fields = SYSDATA_CPU_NR | SYSDATA_TASKNAME; + int extradata_len; /* userdata was appended when configfs write helper was called * by update_userdata(). */ extradata_len = nt->userdata_length; - if (!(nt->sysdata_fields & CPU_NR)) + if (!(nt->sysdata_fields & fields)) goto out; - /* Append cpu=%d at extradata_complete after userdata str */ - sysdata_len = scnprintf(&nt->extradata_complete[nt->userdata_length], - MAX_EXTRADATA_ENTRY_LEN, " cpu=%u\n", - raw_smp_processor_id()); - - extradata_len += sysdata_len; + if (nt->sysdata_fields & SYSDATA_CPU_NR) + extradata_len += append_cpu_nr(nt, extradata_len); + if (nt->sysdata_fields & SYSDATA_TASKNAME) + extradata_len += append_taskname(nt, extradata_len); WARN_ON_ONCE(extradata_len > MAX_EXTRADATA_ENTRY_LEN * MAX_EXTRADATA_ITEMS); diff --git a/tools/testing/selftests/drivers/net/netcons_sysdata.sh b/tools/testing/selftests/drivers/net/netcons_sysdata.sh index 2b78fd1f5982..f351206ed1bd 100755 --- a/tools/testing/selftests/drivers/net/netcons_sysdata.sh +++ b/tools/testing/selftests/drivers/net/netcons_sysdata.sh @@ -31,17 +31,38 @@ function set_cpu_nr() { echo 1 > "${NETCONS_PATH}/userdata/cpu_nr_enabled" } +# Enable the taskname to be appended to sysdata +function set_taskname() { + if [[ ! -f "${NETCONS_PATH}/userdata/taskname_enabled" ]] + then + echo "Not able to enable taskname sysdata append. Configfs not available in ${NETCONS_PATH}/userdata/taskname_enabled" >&2 + exit "${ksft_skip}" + fi + + echo 1 > "${NETCONS_PATH}/userdata/taskname_enabled" +} + # Disable the sysdata cpu_nr feature function unset_cpu_nr() { echo 0 > "${NETCONS_PATH}/userdata/cpu_nr_enabled" } -# Test if MSG content and `cpu=${CPU}` exists in OUTPUT_FILE -function validate_sysdata_cpu_exists() { +# Once called, taskname=<..> will not be appended anymore +function unset_taskname() { + echo 0 > "${NETCONS_PATH}/userdata/taskname_enabled" +} + +# Test if MSG contains sysdata +function validate_sysdata() { # OUTPUT_FILE will contain something like: # 6.11.1-0_fbk0_rc13_509_g30d75cea12f7,13,1822,115075213798,-;netconsole selftest: netcons_gtJHM # userdatakey=userdatavalue # cpu=X + # taskname=<taskname> + + # Echo is what this test uses to create the message. See runtest() + # function + SENDER="echo" if [ ! -f "$OUTPUT_FILE" ]; then echo "FAIL: File was not generated." >&2 @@ -62,12 +83,19 @@ function validate_sysdata_cpu_exists() { exit "${ksft_fail}" fi + if ! grep -q "taskname=${SENDER}" "${OUTPUT_FILE}"; then + echo "FAIL: 'taskname=echo' not found in ${OUTPUT_FILE}" >&2 + cat "${OUTPUT_FILE}" >&2 + exit "${ksft_fail}" + fi + rm "${OUTPUT_FILE}" pkill_socat } -# Test if MSG content exists in OUTPUT_FILE but no `cpu=` string -function validate_sysdata_no_cpu() { +# Test if MSG content exists in OUTPUT_FILE but no `cpu=` and `taskname=` +# strings +function validate_no_sysdata() { if [ ! -f "$OUTPUT_FILE" ]; then echo "FAIL: File was not generated." >&2 exit "${ksft_fail}" @@ -85,6 +113,12 @@ function validate_sysdata_no_cpu() { exit "${ksft_fail}" fi + if grep -q "taskname=" "${OUTPUT_FILE}"; then + echo "FAIL: 'taskname= found in ${OUTPUT_FILE}" >&2 + cat "${OUTPUT_FILE}" >&2 + exit "${ksft_fail}" + fi + rm "${OUTPUT_FILE}" } @@ -133,10 +167,12 @@ OUTPUT_FILE="/tmp/${TARGET}_1" MSG="Test #1 from CPU${CPU}" # Enable the auto population of cpu_nr set_cpu_nr +# Enable taskname to be appended to sysdata +set_taskname runtest # Make sure the message was received in the dst part # and exit -validate_sysdata_cpu_exists +validate_sysdata #==================================================== # TEST #2 @@ -148,7 +184,7 @@ OUTPUT_FILE="/tmp/${TARGET}_2" MSG="Test #2 from CPU${CPU}" set_user_data runtest -validate_sysdata_cpu_exists +validate_sysdata # =================================================== # TEST #3 @@ -160,8 +196,9 @@ OUTPUT_FILE="/tmp/${TARGET}_3" MSG="Test #3 from CPU${CPU}" # Enable the auto population of cpu_nr unset_cpu_nr +unset_taskname runtest # At this time, cpu= shouldn't be present in the msg -validate_sysdata_no_cpu +validate_no_sysdata exit "${ksft_pass}" |