diff options
Diffstat (limited to 'drivers/net/netconsole.c')
| -rw-r--r-- | drivers/net/netconsole.c | 386 |
1 files changed, 194 insertions, 192 deletions
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index bb6e03a92956..9cb4dfc242f5 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -50,7 +50,7 @@ MODULE_LICENSE("GPL"); /* The number 3 comes from userdata entry format characters (' ', '=', '\n') */ #define MAX_EXTRADATA_NAME_LEN (MAX_EXTRADATA_ENTRY_LEN - \ MAX_EXTRADATA_VALUE_LEN - 3) -#define MAX_EXTRADATA_ITEMS 16 +#define MAX_USERDATA_ITEMS 256 #define MAX_PRINT_CHUNK 1000 static char config[MAX_PARAM_LENGTH]; @@ -115,6 +115,8 @@ enum sysdata_feature { SYSDATA_RELEASE = BIT(2), /* Include a per-target message ID as part of sysdata */ SYSDATA_MSGID = BIT(3), + /* Sentinel: highest bit position */ + MAX_SYSDATA_ITEMS = 4, }; /** @@ -122,8 +124,9 @@ enum sysdata_feature { * @list: Links this target into the target_list. * @group: Links us into the configfs subsystem hierarchy. * @userdata_group: Links to the userdata configfs hierarchy - * @extradata_complete: Cached, formatted string of append - * @userdata_length: String length of usedata in extradata_complete. + * @userdata: Cached, formatted string of append + * @userdata_length: String length of userdata. + * @sysdata: Cached, formatted string of append * @sysdata_fields: Sysdata features enabled. * @msgcounter: Message sent counter. * @stats: Packet send stats for the target. Used for debugging. @@ -152,8 +155,10 @@ struct netconsole_target { #ifdef CONFIG_NETCONSOLE_DYNAMIC struct config_group group; struct config_group userdata_group; - char extradata_complete[MAX_EXTRADATA_ENTRY_LEN * MAX_EXTRADATA_ITEMS]; + char *userdata; size_t userdata_length; + char sysdata[MAX_EXTRADATA_ENTRY_LEN * MAX_SYSDATA_ITEMS]; + /* bit-wise with sysdata_feature bits */ u32 sysdata_fields; /* protected by target_list_lock */ @@ -802,28 +807,14 @@ out_unlock: return ret; } -/* Count number of entries we have in extradata. - * This is important because the extradata_complete only supports - * MAX_EXTRADATA_ITEMS entries. Before enabling any new {user,sys}data - * feature, number of entries needs to checked for available space. +/* Count number of entries we have in userdata. + * This is important because userdata only supports MAX_USERDATA_ITEMS + * entries. Before enabling any new userdata feature, number of entries needs + * to checked for available space. */ -static size_t count_extradata_entries(struct netconsole_target *nt) +static size_t count_userdata_entries(struct netconsole_target *nt) { - size_t entries; - - /* Userdata entries */ - entries = list_count_nodes(&nt->userdata_group.cg_children); - /* Plus sysdata entries */ - if (nt->sysdata_fields & SYSDATA_CPU_NR) - entries += 1; - if (nt->sysdata_fields & SYSDATA_TASKNAME) - entries += 1; - if (nt->sysdata_fields & SYSDATA_RELEASE) - entries += 1; - if (nt->sysdata_fields & SYSDATA_MSGID) - entries += 1; - - return entries; + return list_count_nodes(&nt->userdata_group.cg_children); } static ssize_t remote_mac_store(struct config_item *item, const char *buf, @@ -884,45 +875,77 @@ static ssize_t userdatum_value_show(struct config_item *item, char *buf) return sysfs_emit(buf, "%s\n", &(to_userdatum(item)->value[0])); } -static void update_userdata(struct netconsole_target *nt) +/* Navigate configfs and calculate the lentgh of the formatted string + * representing userdata. + * Must be called holding netconsole_subsys.su_mutex + */ +static int calc_userdata_len(struct netconsole_target *nt) { + struct userdatum *udm_item; + struct config_item *item; struct list_head *entry; - int child_count = 0; - unsigned long flags; + int len = 0; - spin_lock_irqsave(&target_list_lock, flags); + list_for_each(entry, &nt->userdata_group.cg_children) { + item = container_of(entry, struct config_item, ci_entry); + udm_item = to_userdatum(item); + /* Skip userdata with no value set */ + if (udm_item->value[0]) { + len += snprintf(NULL, 0, " %s=%s\n", item->ci_name, + udm_item->value); + } + } + return len; +} - /* Clear the current string in case the last userdatum was deleted */ - nt->userdata_length = 0; - nt->extradata_complete[0] = 0; +static int update_userdata(struct netconsole_target *nt) +{ + struct userdatum *udm_item; + struct config_item *item; + struct list_head *entry; + char *old_buf = NULL; + char *new_buf = NULL; + unsigned long flags; + int offset = 0; + int len; - list_for_each(entry, &nt->userdata_group.cg_children) { - struct userdatum *udm_item; - struct config_item *item; + /* Calculate required buffer size */ + len = calc_userdata_len(nt); - if (child_count >= MAX_EXTRADATA_ITEMS) { - spin_unlock_irqrestore(&target_list_lock, flags); - WARN_ON_ONCE(1); - return; - } - child_count++; + if (WARN_ON_ONCE(len > MAX_EXTRADATA_ENTRY_LEN * MAX_USERDATA_ITEMS)) + return -ENOSPC; + + /* Allocate new buffer */ + if (len) { + new_buf = kmalloc(len + 1, GFP_KERNEL); + if (!new_buf) + return -ENOMEM; + } + /* Write userdata to new buffer */ + list_for_each(entry, &nt->userdata_group.cg_children) { item = container_of(entry, struct config_item, ci_entry); udm_item = to_userdatum(item); - /* Skip userdata with no value set */ - if (strnlen(udm_item->value, MAX_EXTRADATA_VALUE_LEN) == 0) - continue; - - /* This doesn't overflow extradata_complete since it will write - * one entry length (1/MAX_EXTRADATA_ITEMS long), entry count is - * checked to not exceed MAX items with child_count above - */ - nt->userdata_length += scnprintf(&nt->extradata_complete[nt->userdata_length], - MAX_EXTRADATA_ENTRY_LEN, " %s=%s\n", - item->ci_name, udm_item->value); + if (udm_item->value[0]) { + offset += scnprintf(&new_buf[offset], len + 1 - offset, + " %s=%s\n", item->ci_name, + udm_item->value); + } } + + WARN_ON_ONCE(offset != len); + + /* Switch to new buffer and free old buffer */ + spin_lock_irqsave(&target_list_lock, flags); + old_buf = nt->userdata; + nt->userdata = new_buf; + nt->userdata_length = offset; spin_unlock_irqrestore(&target_list_lock, flags); + + kfree(old_buf); + + return 0; } static ssize_t userdatum_value_store(struct config_item *item, const char *buf, @@ -946,7 +969,9 @@ static ssize_t userdatum_value_store(struct config_item *item, const char *buf, ud = to_userdata(item->ci_parent); nt = userdata_to_target(ud); - update_userdata(nt); + ret = update_userdata(nt); + if (ret < 0) + goto out_unlock; ret = count; out_unlock: mutex_unlock(&dynamic_netconsole_mutex); @@ -962,7 +987,7 @@ static void disable_sysdata_feature(struct netconsole_target *nt, enum sysdata_feature feature) { nt->sysdata_fields &= ~feature; - nt->extradata_complete[nt->userdata_length] = 0; + nt->sysdata[0] = 0; } static ssize_t sysdata_msgid_enabled_store(struct config_item *item, @@ -982,12 +1007,6 @@ static ssize_t sysdata_msgid_enabled_store(struct config_item *item, if (msgid_enabled == curr) goto unlock_ok; - if (msgid_enabled && - count_extradata_entries(nt) >= MAX_EXTRADATA_ITEMS) { - ret = -ENOSPC; - goto unlock; - } - if (msgid_enabled) nt->sysdata_fields |= SYSDATA_MSGID; else @@ -995,7 +1014,6 @@ static ssize_t sysdata_msgid_enabled_store(struct config_item *item, unlock_ok: ret = strnlen(buf, count); -unlock: mutex_unlock(&dynamic_netconsole_mutex); mutex_unlock(&netconsole_subsys.su_mutex); return ret; @@ -1018,12 +1036,6 @@ static ssize_t sysdata_release_enabled_store(struct config_item *item, if (release_enabled == curr) goto unlock_ok; - if (release_enabled && - count_extradata_entries(nt) >= MAX_EXTRADATA_ITEMS) { - ret = -ENOSPC; - goto unlock; - } - if (release_enabled) nt->sysdata_fields |= SYSDATA_RELEASE; else @@ -1031,7 +1043,6 @@ static ssize_t sysdata_release_enabled_store(struct config_item *item, unlock_ok: ret = strnlen(buf, count); -unlock: mutex_unlock(&dynamic_netconsole_mutex); mutex_unlock(&netconsole_subsys.su_mutex); return ret; @@ -1054,12 +1065,6 @@ static ssize_t sysdata_taskname_enabled_store(struct config_item *item, 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 @@ -1067,7 +1072,6 @@ static ssize_t sysdata_taskname_enabled_store(struct config_item *item, unlock_ok: ret = strnlen(buf, count); -unlock: mutex_unlock(&dynamic_netconsole_mutex); mutex_unlock(&netconsole_subsys.su_mutex); return ret; @@ -1092,27 +1096,16 @@ static ssize_t sysdata_cpu_nr_enabled_store(struct config_item *item, /* no change requested */ goto unlock_ok; - if (cpu_nr_enabled && - count_extradata_entries(nt) >= MAX_EXTRADATA_ITEMS) { - /* user wants the new feature, but there is no space in the - * buffer. - */ - ret = -ENOSPC; - goto unlock; - } - if (cpu_nr_enabled) 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. + /* This is special because sysdata might have remaining data + * from previous sysdata, and it needs to be cleaned. */ disable_sysdata_feature(nt, SYSDATA_CPU_NR); unlock_ok: ret = strnlen(buf, count); -unlock: mutex_unlock(&dynamic_netconsole_mutex); mutex_unlock(&netconsole_subsys.su_mutex); return ret; @@ -1156,7 +1149,7 @@ static struct config_item *userdatum_make_item(struct config_group *group, ud = to_userdata(&group->cg_item); nt = userdata_to_target(ud); - if (count_extradata_entries(nt) >= MAX_EXTRADATA_ITEMS) + if (count_userdata_entries(nt) >= MAX_USERDATA_ITEMS) return ERR_PTR(-ENOSPC); udm = kzalloc(sizeof(*udm), GFP_KERNEL); @@ -1234,7 +1227,10 @@ static struct configfs_attribute *netconsole_target_attrs[] = { static void netconsole_target_release(struct config_item *item) { - kfree(to_target(item)); + struct netconsole_target *nt = to_target(item); + + kfree(nt->userdata); + kfree(nt); } static struct configfs_item_operations netconsole_target_item_ops = { @@ -1363,22 +1359,21 @@ static void populate_configfs_item(struct netconsole_target *nt, static int sysdata_append_cpu_nr(struct netconsole_target *nt, int offset) { - /* Append cpu=%d at extradata_complete after userdata str */ - return scnprintf(&nt->extradata_complete[offset], + return scnprintf(&nt->sysdata[offset], MAX_EXTRADATA_ENTRY_LEN, " cpu=%u\n", raw_smp_processor_id()); } static int sysdata_append_taskname(struct netconsole_target *nt, int offset) { - return scnprintf(&nt->extradata_complete[offset], + return scnprintf(&nt->sysdata[offset], MAX_EXTRADATA_ENTRY_LEN, " taskname=%s\n", current->comm); } static int sysdata_append_release(struct netconsole_target *nt, int offset) { - return scnprintf(&nt->extradata_complete[offset], + return scnprintf(&nt->sysdata[offset], MAX_EXTRADATA_ENTRY_LEN, " release=%s\n", init_utsname()->release); } @@ -1386,46 +1381,36 @@ static int sysdata_append_release(struct netconsole_target *nt, int offset) static int sysdata_append_msgid(struct netconsole_target *nt, int offset) { wrapping_assign_add(nt->msgcounter, 1); - return scnprintf(&nt->extradata_complete[offset], + return scnprintf(&nt->sysdata[offset], MAX_EXTRADATA_ENTRY_LEN, " msgid=%u\n", nt->msgcounter); } /* - * prepare_extradata - append sysdata at extradata_complete in runtime + * prepare_sysdata - append sysdata in runtime * @nt: target to send message to */ -static int prepare_extradata(struct netconsole_target *nt) +static int prepare_sysdata(struct netconsole_target *nt) { - int extradata_len; - - /* userdata was appended when configfs write helper was called - * by update_userdata(). - */ - extradata_len = nt->userdata_length; + int sysdata_len = 0; if (!nt->sysdata_fields) goto out; if (nt->sysdata_fields & SYSDATA_CPU_NR) - extradata_len += sysdata_append_cpu_nr(nt, extradata_len); + sysdata_len += sysdata_append_cpu_nr(nt, sysdata_len); if (nt->sysdata_fields & SYSDATA_TASKNAME) - extradata_len += sysdata_append_taskname(nt, extradata_len); + sysdata_len += sysdata_append_taskname(nt, sysdata_len); if (nt->sysdata_fields & SYSDATA_RELEASE) - extradata_len += sysdata_append_release(nt, extradata_len); + sysdata_len += sysdata_append_release(nt, sysdata_len); if (nt->sysdata_fields & SYSDATA_MSGID) - extradata_len += sysdata_append_msgid(nt, extradata_len); + sysdata_len += sysdata_append_msgid(nt, sysdata_len); - WARN_ON_ONCE(extradata_len > - MAX_EXTRADATA_ENTRY_LEN * MAX_EXTRADATA_ITEMS); + WARN_ON_ONCE(sysdata_len > + MAX_EXTRADATA_ENTRY_LEN * MAX_SYSDATA_ITEMS); out: - return extradata_len; -} -#else /* CONFIG_NETCONSOLE_DYNAMIC not set */ -static int prepare_extradata(struct netconsole_target *nt) -{ - return 0; + return sysdata_len; } #endif /* CONFIG_NETCONSOLE_DYNAMIC */ @@ -1527,11 +1512,13 @@ static void send_msg_no_fragmentation(struct netconsole_target *nt, int msg_len, int release_len) { - const char *extradata = NULL; + const char *userdata = NULL; + const char *sysdata = NULL; const char *release; #ifdef CONFIG_NETCONSOLE_DYNAMIC - extradata = nt->extradata_complete; + userdata = nt->userdata; + sysdata = nt->sysdata; #endif if (release_len) { @@ -1543,10 +1530,15 @@ static void send_msg_no_fragmentation(struct netconsole_target *nt, memcpy(nt->buf, msg, msg_len); } - if (extradata) + if (userdata) msg_len += scnprintf(&nt->buf[msg_len], - MAX_PRINT_CHUNK - msg_len, - "%s", extradata); + MAX_PRINT_CHUNK - msg_len, "%s", + userdata); + + if (sysdata) + msg_len += scnprintf(&nt->buf[msg_len], + MAX_PRINT_CHUNK - msg_len, "%s", + sysdata); send_udp(nt, nt->buf, msg_len); } @@ -1560,89 +1552,93 @@ static void append_release(char *buf) } static void send_fragmented_body(struct netconsole_target *nt, - const char *msgbody, int header_len, - int msgbody_len, int extradata_len) + const char *msgbody_ptr, int header_len, + int msgbody_len, int sysdata_len) { - int sent_extradata, preceding_bytes; - const char *extradata = NULL; - int body_len, offset = 0; + const char *userdata_ptr = NULL; + const char *sysdata_ptr = NULL; + int data_len, data_sent = 0; + int userdata_offset = 0; + int sysdata_offset = 0; + int msgbody_offset = 0; + int userdata_len = 0; #ifdef CONFIG_NETCONSOLE_DYNAMIC - extradata = nt->extradata_complete; + userdata_ptr = nt->userdata; + sysdata_ptr = nt->sysdata; + userdata_len = nt->userdata_length; #endif + if (WARN_ON_ONCE(!userdata_ptr && userdata_len != 0)) + return; - /* body_len represents the number of bytes that will be sent. This is + if (WARN_ON_ONCE(!sysdata_ptr && sysdata_len != 0)) + return; + + /* data_len represents the number of bytes that will be sent. This is * bigger than MAX_PRINT_CHUNK, thus, it will be split in multiple * packets */ - body_len = msgbody_len + extradata_len; + data_len = msgbody_len + userdata_len + sysdata_len; /* In each iteration of the while loop below, we send a packet - * containing the header and a portion of the body. The body is - * composed of two parts: msgbody and extradata. We keep track of how - * many bytes have been sent so far using the offset variable, which - * ranges from 0 to the total length of the body. + * containing the header and a portion of the data. The data is + * composed of three parts: msgbody, userdata, and sysdata. + * We keep track of how many bytes have been sent from each part using + * the *_offset variables. + * We keep track of how many bytes have been sent overall using the + * data_sent variable, which ranges from 0 to the total bytes to be + * sent. */ - while (offset < body_len) { - int this_header = header_len; - bool msgbody_written = false; - int this_offset = 0; + while (data_sent < data_len) { + int userdata_left = userdata_len - userdata_offset; + int sysdata_left = sysdata_len - sysdata_offset; + int msgbody_left = msgbody_len - msgbody_offset; + int buf_offset = 0; int this_chunk = 0; - this_header += scnprintf(nt->buf + this_header, - MAX_PRINT_CHUNK - this_header, - ",ncfrag=%d/%d;", offset, - body_len); - - /* Not all msgbody data has been written yet */ - if (offset < msgbody_len) { - this_chunk = min(msgbody_len - offset, - MAX_PRINT_CHUNK - this_header); - if (WARN_ON_ONCE(this_chunk <= 0)) - return; - memcpy(nt->buf + this_header, msgbody + offset, - this_chunk); - this_offset += this_chunk; + /* header is already populated in nt->buf, just append to it */ + buf_offset = header_len; + + buf_offset += scnprintf(nt->buf + buf_offset, + MAX_PRINT_CHUNK - buf_offset, + ",ncfrag=%d/%d;", data_sent, + data_len); + + /* append msgbody first */ + this_chunk = min(msgbody_left, MAX_PRINT_CHUNK - buf_offset); + memcpy(nt->buf + buf_offset, msgbody_ptr + msgbody_offset, + this_chunk); + msgbody_offset += this_chunk; + buf_offset += this_chunk; + data_sent += this_chunk; + + /* after msgbody, append userdata */ + if (userdata_ptr && userdata_left) { + this_chunk = min(userdata_left, + MAX_PRINT_CHUNK - buf_offset); + memcpy(nt->buf + buf_offset, + userdata_ptr + userdata_offset, this_chunk); + userdata_offset += this_chunk; + buf_offset += this_chunk; + data_sent += this_chunk; } - /* msgbody was finally written, either in the previous - * messages and/or in the current buf. Time to write - * the extradata. - */ - msgbody_written |= offset + this_offset >= msgbody_len; - - /* Msg body is fully written and there is pending extradata to - * write, append extradata in this chunk - */ - if (msgbody_written && offset + this_offset < body_len) { - /* Track how much user data was already sent. First - * time here, sent_userdata is zero - */ - sent_extradata = (offset + this_offset) - msgbody_len; - /* offset of bytes used in current buf */ - preceding_bytes = this_chunk + this_header; - - if (WARN_ON_ONCE(sent_extradata < 0)) - return; - - this_chunk = min(extradata_len - sent_extradata, - MAX_PRINT_CHUNK - preceding_bytes); - if (WARN_ON_ONCE(this_chunk < 0)) - /* this_chunk could be zero if all the previous - * message used all the buffer. This is not a - * problem, extradata will be sent in the next - * iteration - */ - return; - - memcpy(nt->buf + this_header + this_offset, - extradata + sent_extradata, - this_chunk); - this_offset += this_chunk; + /* after userdata, append sysdata */ + if (sysdata_ptr && sysdata_left) { + this_chunk = min(sysdata_left, + MAX_PRINT_CHUNK - buf_offset); + memcpy(nt->buf + buf_offset, + sysdata_ptr + sysdata_offset, this_chunk); + sysdata_offset += this_chunk; + buf_offset += this_chunk; + data_sent += this_chunk; } - send_udp(nt, nt->buf, this_header + this_offset); - offset += this_offset; + /* if all is good, send the packet out */ + if (WARN_ON_ONCE(data_sent > data_len)) + return; + + send_udp(nt, nt->buf, buf_offset); } } @@ -1650,7 +1646,7 @@ static void send_msg_fragmented(struct netconsole_target *nt, const char *msg, int msg_len, int release_len, - int extradata_len) + int sysdata_len) { int header_len, msgbody_len; const char *msgbody; @@ -1679,7 +1675,7 @@ static void send_msg_fragmented(struct netconsole_target *nt, * will be replaced */ send_fragmented_body(nt, msgbody, header_len, msgbody_len, - extradata_len); + sysdata_len); } /** @@ -1695,19 +1691,22 @@ static void send_msg_fragmented(struct netconsole_target *nt, static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg, int msg_len) { + int userdata_len = 0; int release_len = 0; - int extradata_len; - - extradata_len = prepare_extradata(nt); + int sysdata_len = 0; +#ifdef CONFIG_NETCONSOLE_DYNAMIC + sysdata_len = prepare_sysdata(nt); + userdata_len = nt->userdata_length; +#endif if (nt->release) release_len = strlen(init_utsname()->release) + 1; - if (msg_len + release_len + extradata_len <= MAX_PRINT_CHUNK) + if (msg_len + release_len + sysdata_len + userdata_len <= MAX_PRINT_CHUNK) return send_msg_no_fragmentation(nt, msg, msg_len, release_len); return send_msg_fragmented(nt, msg, msg_len, release_len, - extradata_len); + sysdata_len); } static void write_ext_msg(struct console *con, const char *msg, @@ -1912,6 +1911,9 @@ fail: static void free_param_target(struct netconsole_target *nt) { netpoll_cleanup(&nt->np); +#ifdef CONFIG_NETCONSOLE_DYNAMIC + kfree(nt->userdata); +#endif kfree(nt); } |