diff --git a/Documentation/admin-guide/kdump/gdbmacros.txt b/Documentation/admin-guide/kdump/gdbmacros.txt
index 82aecdcae8a6c182d0bebea90492b79a199510a8..030de95e3e6b2464f130ecd2f2e93f8ce804d151 100644
--- a/Documentation/admin-guide/kdump/gdbmacros.txt
+++ b/Documentation/admin-guide/kdump/gdbmacros.txt
@@ -312,10 +312,10 @@ define dmesg
set var $prev_flags = $info->flags
end
- set var $id = ($id + 1) & $id_mask
if ($id == $end_id)
loop_break
end
+ set var $id = ($id + 1) & $id_mask
end
end
document dmesg
diff --git a/include/linux/console.h b/include/linux/console.h
index 9cea254b34b8eac4420532eba870ce24cfee6937..1e36958aa656af785a0a36c6e4eded296a44c36a 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -15,6 +15,7 @@
#define _LINUX_CONSOLE_H_ 1
#include <linux/atomic.h>
+#include <linux/bits.h>
#include <linux/rculist.h>
#include <linux/types.h>
@@ -125,37 +126,82 @@ static inline int con_debug_leave(void)
/*
* The interface for a console, or any other device that wants to capture
* console messages (printer driver?)
- *
- * If a console driver is marked CON_BOOT then it will be auto-unregistered
- * when the first real console is registered. This is for early-printk drivers.
*/
-#define CON_PRINTBUFFER (1)
-#define CON_CONSDEV (2) /* Preferred console, /dev/console */
-#define CON_ENABLED (4)
-#define CON_BOOT (8)
-#define CON_ANYTIME (16) /* Safe to call when cpu is offline */
-#define CON_BRL (32) /* Used for a braille device */
-#define CON_EXTENDED (64) /* Use the extended output format a la /dev/kmsg */
+/**
+ * cons_flags - General console flags
+ * @CON_PRINTBUFFER: Used by newly registered consoles to avoid duplicate
+ * output of messages that were already shown by boot
+ * consoles or read by userspace via syslog() syscall.
+ * @CON_CONSDEV: Indicates that the console driver is backing
+ * /dev/console.
+ * @CON_ENABLED: Indicates if a console is allowed to print records. If
+ * false, the console also will not advance to later
+ * records.
+ * @CON_BOOT: Marks the console driver as early console driver which
+ * is used during boot before the real driver becomes
+ * available. It will be automatically unregistered
+ * when the real console driver is registered unless
+ * "keep_bootcon" parameter is used.
+ * @CON_ANYTIME: A misnomed historical flag which tells the core code
+ * that the legacy @console::write callback can be invoked
+ * on a CPU which is marked OFFLINE. That is misleading as
+ * it suggests that there is no contextual limit for
+ * invoking the callback. The original motivation was
+ * readiness of the per-CPU areas.
+ * @CON_BRL: Indicates a braille device which is exempt from
+ * receiving the printk spam for obvious reasons.
+ * @CON_EXTENDED: The console supports the extended output format of
+ * /dev/kmesg which requires a larger output buffer.
+ */
+enum cons_flags {
+ CON_PRINTBUFFER = BIT(0),
+ CON_CONSDEV = BIT(1),
+ CON_ENABLED = BIT(2),
+ CON_BOOT = BIT(3),
+ CON_ANYTIME = BIT(4),
+ CON_BRL = BIT(5),
+ CON_EXTENDED = BIT(6),
+};
+/**
+ * struct console - The console descriptor structure
+ * @name: The name of the console driver
+ * @write: Write callback to output messages (Optional)
+ * @read: Read callback for console input (Optional)
+ * @device: The underlying TTY device driver (Optional)
+ * @unblank: Callback to unblank the console (Optional)
+ * @setup: Callback for initializing the console (Optional)
+ * @exit: Callback for teardown of the console (Optional)
+ * @match: Callback for matching a console (Optional)
+ * @flags: Console flags. See enum cons_flags
+ * @index: Console index, e.g. port number
+ * @cflag: TTY control mode flags
+ * @ispeed: TTY input speed
+ * @ospeed: TTY output speed
+ * @seq: Sequence number of the next ringbuffer record to print
+ * @dropped: Number of unreported dropped ringbuffer records
+ * @data: Driver private data
+ * @node: hlist node for the console list
+ */
struct console {
- char name[16];
- void (*write)(struct console *, const char *, unsigned);
- int (*read)(struct console *, char *, unsigned);
- struct tty_driver *(*device)(struct console *, int *);
- void (*unblank)(void);
- int (*setup)(struct console *, char *);
- int (*exit)(struct console *);
- int (*match)(struct console *, char *name, int idx, char *options);
- short flags;
- short index;
- int cflag;
- uint ispeed;
- uint ospeed;
- u64 seq;
- unsigned long dropped;
- void *data;
- struct hlist_node node;
+ char name[16];
+ void (*write)(struct console *co, const char *s, unsigned int count);
+ int (*read)(struct console *co, char *s, unsigned int count);
+ struct tty_driver *(*device)(struct console *co, int *index);
+ void (*unblank)(void);
+ int (*setup)(struct console *co, char *options);
+ int (*exit)(struct console *co);
+ int (*match)(struct console *co, char *name, int idx, char *options);
+ short flags;
+ short index;
+ int cflag;
+ uint ispeed;
+ uint ospeed;
+ u64 seq;
+ unsigned long dropped;
+ void *data;
+ struct hlist_node node;
};
#ifdef CONFIG_LOCKDEP
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 8c81806c2e99f906184269505fcc2a549dd25a28..8ef499ab3c1ed2ec98946c9fd55329f876e47295 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -44,8 +44,6 @@ static inline const char *printk_skip_headers(const char *buffer)
return buffer;
}
-#define CONSOLE_EXT_LOG_MAX 8192
-
/* printk's without a loglevel use this.. */
#define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT
diff --git a/kernel/printk/index.c b/kernel/printk/index.c
index c85be186a7832c4431ea2fcffd2800a2b5215e3a..a6b27526baaf6f1eedde94858ec50e52dc2ac060 100644
--- a/kernel/printk/index.c
+++ b/kernel/printk/index.c
@@ -145,7 +145,7 @@ static void pi_create_file(struct module *mod)
#ifdef CONFIG_MODULES
static void pi_remove_file(struct module *mod)
{
- debugfs_remove(debugfs_lookup(pi_get_module_name(mod), dfs_index));
+ debugfs_lookup_and_remove(pi_get_module_name(mod), dfs_index);
}
static int pi_module_notify(struct notifier_block *nb, unsigned long op,
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h
index d947ca6c84f997d3e4e657bc2010f0e22367efe2..2a17704136f1dbbb3394a73813a4de40873d684b 100644
--- a/kernel/printk/internal.h
+++ b/kernel/printk/internal.h
@@ -14,6 +14,21 @@ int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write,
#ifdef CONFIG_PRINTK
+#ifdef CONFIG_PRINTK_CALLER
+#define PRINTK_PREFIX_MAX 48
+#else
+#define PRINTK_PREFIX_MAX 32
+#endif
+
+/*
+ * the maximum size of a formatted record (i.e. with prefix added
+ * per line and dropped messages or in extended message format)
+ */
+#define PRINTK_MESSAGE_MAX 2048
+
+/* the maximum size allowed to be reserved for a record */
+#define PRINTKRB_RECORD_MAX 1024
+
/* Flags for a single printk record. */
enum printk_info_flags {
LOG_NEWLINE = 2, /* text ended with a newline */
@@ -48,6 +63,10 @@ u16 printk_parse_prefix(const char *text, int *level,
enum printk_info_flags *flags);
#else
+#define PRINTK_PREFIX_MAX 0
+#define PRINTK_MESSAGE_MAX 0
+#define PRINTKRB_RECORD_MAX 0
+
/*
* In !PRINTK builds we still export console_sem
* semaphore and some of console functions (console_unlock()/etc.), so
@@ -58,3 +77,29 @@ u16 printk_parse_prefix(const char *text, int *level,
static inline bool printk_percpu_data_ready(void) { return false; }
#endif /* CONFIG_PRINTK */
+
+/**
+ * struct printk_buffers - Buffers to read/format/output printk messages.
+ * @outbuf: After formatting, contains text to output.
+ * @scratchbuf: Used as temporary ringbuffer reading and string-print space.
+ */
+struct printk_buffers {
+ char outbuf[PRINTK_MESSAGE_MAX];
+ char scratchbuf[PRINTKRB_RECORD_MAX];
+};
+
+/**
+ * struct printk_message - Container for a prepared printk message.
+ * @pbufs: printk buffers used to prepare the message.
+ * @outbuf_len: The length of prepared text in @pbufs->outbuf to output. This
+ * does not count the terminator. A value of 0 means there is
+ * nothing to output and this record should be skipped.
+ * @seq: The sequence number of the record used for @pbufs->outbuf.
+ * @dropped: The number of dropped records from reading @seq.
+ */
+struct printk_message {
+ struct printk_buffers *pbufs;
+ unsigned int outbuf_len;
+ u64 seq;
+ unsigned long dropped;
+};
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 94f136b25f6ae1f107e9dc992a25ee493928262d..fd0c9f913940acf3675cae278465b70ec76c4a87 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -466,21 +466,6 @@ static struct latched_seq clear_seq = {
.val[1] = 0,
};
-#ifdef CONFIG_PRINTK_CALLER
-#define PREFIX_MAX 48
-#else
-#define PREFIX_MAX 32
-#endif
-
-/* the maximum size of a formatted record (i.e. with prefix added per line) */
-#define CONSOLE_LOG_MAX 1024
-
-/* the maximum size for a dropped text message */
-#define DROPPED_TEXT_MAX 64
-
-/* the maximum size allowed to be reserved for a record */
-#define LOG_LINE_MAX (CONSOLE_LOG_MAX - PREFIX_MAX)
-
#define LOG_LEVEL(v) ((v) & 0x07)
#define LOG_FACILITY(v) ((v) >> 3 & 0xff)
@@ -711,16 +696,15 @@ static ssize_t msg_print_ext_body(char *buf, size_t size,
return len;
}
+static bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
+ bool is_extended, bool may_supress);
+
/* /dev/kmsg - userspace message inject/listen interface */
struct devkmsg_user {
atomic64_t seq;
struct ratelimit_state rs;
struct mutex lock;
- char buf[CONSOLE_EXT_LOG_MAX];
-
- struct printk_info info;
- char text_buf[CONSOLE_EXT_LOG_MAX];
- struct printk_record record;
+ struct printk_buffers pbufs;
};
static __printf(3, 4) __cold
@@ -746,7 +730,7 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from)
size_t len = iov_iter_count(from);
ssize_t ret = len;
- if (!user || len > LOG_LINE_MAX)
+ if (!user || len > PRINTKRB_RECORD_MAX)
return -EINVAL;
/* Ignore when user logging is disabled. */
@@ -802,8 +786,10 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct devkmsg_user *user = file->private_data;
- struct printk_record *r = &user->record;
- size_t len;
+ char *outbuf = &user->pbufs.outbuf[0];
+ struct printk_message pmsg = {
+ .pbufs = &user->pbufs,
+ };
ssize_t ret;
if (!user)
@@ -813,7 +799,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
if (ret)
return ret;
- if (!prb_read_valid(prb, atomic64_read(&user->seq), r)) {
+ if (!printk_get_next_message(&pmsg, atomic64_read(&user->seq), true, false)) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
goto out;
@@ -830,36 +816,31 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
* This pairs with __wake_up_klogd:A.
*/
ret = wait_event_interruptible(log_wait,
- prb_read_valid(prb,
- atomic64_read(&user->seq), r)); /* LMM(devkmsg_read:A) */
+ printk_get_next_message(&pmsg, atomic64_read(&user->seq), true,
+ false)); /* LMM(devkmsg_read:A) */
if (ret)
goto out;
}
- if (r->info->seq != atomic64_read(&user->seq)) {
+ if (pmsg.dropped) {
/* our last seen message is gone, return error and reset */
- atomic64_set(&user->seq, r->info->seq);
+ atomic64_set(&user->seq, pmsg.seq);
ret = -EPIPE;
goto out;
}
- len = info_print_ext_header(user->buf, sizeof(user->buf), r->info);
- len += msg_print_ext_body(user->buf + len, sizeof(user->buf) - len,
- &r->text_buf[0], r->info->text_len,
- &r->info->dev_info);
-
- atomic64_set(&user->seq, r->info->seq + 1);
+ atomic64_set(&user->seq, pmsg.seq + 1);
- if (len > count) {
+ if (pmsg.outbuf_len > count) {
ret = -EINVAL;
goto out;
}
- if (copy_to_user(buf, user->buf, len)) {
+ if (copy_to_user(buf, outbuf, pmsg.outbuf_len)) {
ret = -EFAULT;
goto out;
}
- ret = len;
+ ret = pmsg.outbuf_len;
out:
mutex_unlock(&user->lock);
return ret;
@@ -953,9 +934,6 @@ static int devkmsg_open(struct inode *inode, struct file *file)
mutex_init(&user->lock);
- prb_rec_init_rd(&user->record, &user->info,
- &user->text_buf[0], sizeof(user->text_buf));
-
atomic64_set(&user->seq, prb_first_valid_seq(prb));
file->private_data = user;
@@ -1150,7 +1128,7 @@ static unsigned int __init add_to_rb(struct printk_ringbuffer *rb,
return prb_record_text_space(&e);
}
-static char setup_text_buf[LOG_LINE_MAX] __initdata;
+static char setup_text_buf[PRINTKRB_RECORD_MAX] __initdata;
void __init setup_log_buf(int early)
{
@@ -1416,7 +1394,7 @@ static size_t record_print_text(struct printk_record *r, bool syslog,
size_t text_len = r->info->text_len;
size_t buf_size = r->text_buf_size;
char *text = r->text_buf;
- char prefix[PREFIX_MAX];
+ char prefix[PRINTK_PREFIX_MAX];
bool truncated = false;
size_t prefix_len;
size_t line_len;
@@ -1515,7 +1493,7 @@ static size_t get_record_print_text_size(struct printk_info *info,
unsigned int line_count,
bool syslog, bool time)
{
- char prefix[PREFIX_MAX];
+ char prefix[PRINTK_PREFIX_MAX];
size_t prefix_len;
prefix_len = info_print_prefix(info, syslog, time, prefix);
@@ -1581,11 +1559,11 @@ static int syslog_print(char __user *buf, int size)
int len = 0;
u64 seq;
- text = kmalloc(CONSOLE_LOG_MAX, GFP_KERNEL);
+ text = kmalloc(PRINTK_MESSAGE_MAX, GFP_KERNEL);
if (!text)
return -ENOMEM;
- prb_rec_init_rd(&r, &info, text, CONSOLE_LOG_MAX);
+ prb_rec_init_rd(&r, &info, text, PRINTK_MESSAGE_MAX);
mutex_lock(&syslog_lock);
@@ -1686,7 +1664,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
u64 seq;
bool time;
- text = kmalloc(CONSOLE_LOG_MAX, GFP_KERNEL);
+ text = kmalloc(PRINTK_MESSAGE_MAX, GFP_KERNEL);
if (!text)
return -ENOMEM;
@@ -1698,7 +1676,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
seq = find_first_fitting_seq(latched_seq_read_nolock(&clear_seq), -1,
size, true, time);
- prb_rec_init_rd(&r, &info, text, CONSOLE_LOG_MAX);
+ prb_rec_init_rd(&r, &info, text, PRINTK_MESSAGE_MAX);
len = 0;
prb_for_each_record(seq, prb, seq, &r) {
@@ -2012,27 +1990,6 @@ static int console_trylock_spinning(void)
return 1;
}
-/*
- * Call the specified console driver, asking it to write out the specified
- * text and length. If @dropped_text is non-NULL and any records have been
- * dropped, a dropped message will be written out first.
- */
-static void call_console_driver(struct console *con, const char *text, size_t len,
- char *dropped_text)
-{
- size_t dropped_len;
-
- if (con->dropped && dropped_text) {
- dropped_len = snprintf(dropped_text, DROPPED_TEXT_MAX,
- "** %lu printk messages dropped **\n",
- con->dropped);
- con->dropped = 0;
- con->write(con, dropped_text, dropped_len);
- }
-
- con->write(con, text, len);
-}
-
/*
* Recursion is tracked separately on each CPU. If NMIs are supported, an
* additional NMI context per CPU is also separately tracked. Until per-CPU
@@ -2243,8 +2200,8 @@ int vprintk_store(int facility, int level,
reserve_size = vsnprintf(&prefix_buf[0], sizeof(prefix_buf), fmt, args2) + 1;
va_end(args2);
- if (reserve_size > LOG_LINE_MAX)
- reserve_size = LOG_LINE_MAX;
+ if (reserve_size > PRINTKRB_RECORD_MAX)
+ reserve_size = PRINTKRB_RECORD_MAX;
/* Extract log level or control flags. */
if (facility == 0)
@@ -2258,7 +2215,7 @@ int vprintk_store(int facility, int level,
if (flags & LOG_CONT) {
prb_rec_init_wr(&r, reserve_size);
- if (prb_reserve_in_last(&e, prb, &r, caller_id, LOG_LINE_MAX)) {
+ if (prb_reserve_in_last(&e, prb, &r, caller_id, PRINTKRB_RECORD_MAX)) {
text_len = printk_sprint(&r.text_buf[r.info->text_len], reserve_size,
facility, &flags, fmt, args);
r.info->text_len += text_len;
@@ -2389,8 +2346,6 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre
#else /* CONFIG_PRINTK */
-#define CONSOLE_LOG_MAX 0
-#define DROPPED_TEXT_MAX 0
#define printk_time false
#define prb_read_valid(rb, seq, r) false
@@ -2414,10 +2369,6 @@ static ssize_t msg_print_ext_body(char *buf, size_t size,
struct dev_printk_info *dev_info) { return 0; }
static void console_lock_spinning_enable(void) { }
static int console_lock_spinning_disable_and_check(int cookie) { return 0; }
-static void call_console_driver(struct console *con, const char *text, size_t len,
- char *dropped_text)
-{
-}
static bool suppress_message_printing(int level) { return false; }
static bool pr_flush(int timeout_ms, bool reset_on_progress) { return true; }
static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progress) { return true; }
@@ -2744,16 +2695,136 @@ static void __console_unlock(void)
}
/*
- * Print one record for the given console. The record printed is whatever
- * record is the next available record for the given console.
+ * Prepend the message in @pmsg->pbufs->outbuf with a "dropped message". This
+ * is achieved by shifting the existing message over and inserting the dropped
+ * message.
+ *
+ * @pmsg is the printk message to prepend.
*
- * @text is a buffer of size CONSOLE_LOG_MAX.
+ * @dropped is the dropped count to report in the dropped message.
*
- * If extended messages should be printed, @ext_text is a buffer of size
- * CONSOLE_EXT_LOG_MAX. Otherwise @ext_text must be NULL.
+ * If the message text in @pmsg->pbufs->outbuf does not have enough space for
+ * the dropped message, the message text will be sufficiently truncated.
*
- * If dropped messages should be printed, @dropped_text is a buffer of size
- * DROPPED_TEXT_MAX. Otherwise @dropped_text must be NULL.
+ * If @pmsg->pbufs->outbuf is modified, @pmsg->outbuf_len is updated.
+ */
+#ifdef CONFIG_PRINTK
+static void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped)
+{
+ struct printk_buffers *pbufs = pmsg->pbufs;
+ const size_t scratchbuf_sz = sizeof(pbufs->scratchbuf);
+ const size_t outbuf_sz = sizeof(pbufs->outbuf);
+ char *scratchbuf = &pbufs->scratchbuf[0];
+ char *outbuf = &pbufs->outbuf[0];
+ size_t len;
+
+ len = scnprintf(scratchbuf, scratchbuf_sz,
+ "** %lu printk messages dropped **\n", dropped);
+
+ /*
+ * Make sure outbuf is sufficiently large before prepending.
+ * Keep at least the prefix when the message must be truncated.
+ * It is a rather theoretical problem when someone tries to
+ * use a minimalist buffer.
+ */
+ if (WARN_ON_ONCE(len + PRINTK_PREFIX_MAX >= outbuf_sz))
+ return;
+
+ if (pmsg->outbuf_len + len >= outbuf_sz) {
+ /* Truncate the message, but keep it terminated. */
+ pmsg->outbuf_len = outbuf_sz - (len + 1);
+ outbuf[pmsg->outbuf_len] = 0;
+ }
+
+ memmove(outbuf + len, outbuf, pmsg->outbuf_len + 1);
+ memcpy(outbuf, scratchbuf, len);
+ pmsg->outbuf_len += len;
+}
+#else
+#define console_prepend_dropped(pmsg, dropped)
+#endif /* CONFIG_PRINTK */
+
+/*
+ * Read and format the specified record (or a later record if the specified
+ * record is not available).
+ *
+ * @pmsg will contain the formatted result. @pmsg->pbufs must point to a
+ * struct printk_buffers.
+ *
+ * @seq is the record to read and format. If it is not available, the next
+ * valid record is read.
+ *
+ * @is_extended specifies if the message should be formatted for extended
+ * console output.
+ *
+ * @may_supress specifies if records may be skipped based on loglevel.
+ *
+ * Returns false if no record is available. Otherwise true and all fields
+ * of @pmsg are valid. (See the documentation of struct printk_message
+ * for information about the @pmsg fields.)
+ */
+static bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
+ bool is_extended, bool may_suppress)
+{
+ static int panic_console_dropped;
+
+ struct printk_buffers *pbufs = pmsg->pbufs;
+ const size_t scratchbuf_sz = sizeof(pbufs->scratchbuf);
+ const size_t outbuf_sz = sizeof(pbufs->outbuf);
+ char *scratchbuf = &pbufs->scratchbuf[0];
+ char *outbuf = &pbufs->outbuf[0];
+ struct printk_info info;
+ struct printk_record r;
+ size_t len = 0;
+
+ /*
+ * Formatting extended messages requires a separate buffer, so use the
+ * scratch buffer to read in the ringbuffer text.
+ *
+ * Formatting normal messages is done in-place, so read the ringbuffer
+ * text directly into the output buffer.
+ */
+ if (is_extended)
+ prb_rec_init_rd(&r, &info, scratchbuf, scratchbuf_sz);
+ else
+ prb_rec_init_rd(&r, &info, outbuf, outbuf_sz);
+
+ if (!prb_read_valid(prb, seq, &r))
+ return false;
+
+ pmsg->seq = r.info->seq;
+ pmsg->dropped = r.info->seq - seq;
+
+ /*
+ * Check for dropped messages in panic here so that printk
+ * suppression can occur as early as possible if necessary.
+ */
+ if (pmsg->dropped &&
+ panic_in_progress() &&
+ panic_console_dropped++ > 10) {
+ suppress_panic_printk = 1;
+ pr_warn_once("Too many dropped messages. Suppress messages on non-panic CPUs to prevent livelock.\n");
+ }
+
+ /* Skip record that has level above the console loglevel. */
+ if (may_suppress && suppress_message_printing(r.info->level))
+ goto out;
+
+ if (is_extended) {
+ len = info_print_ext_header(outbuf, outbuf_sz, r.info);
+ len += msg_print_ext_body(outbuf + len, outbuf_sz - len,
+ &r.text_buf[0], r.info->text_len, &r.info->dev_info);
+ } else {
+ len = record_print_text(&r, console_msg_format & MSG_FORMAT_SYSLOG, printk_time);
+ }
+out:
+ pmsg->outbuf_len = len;
+ return true;
+}
+
+/*
+ * Print one record for the given console. The record printed is whatever
+ * record is the next available record for the given console.
*
* @handover will be set to true if a printk waiter has taken over the
* console_lock, in which case the caller is no longer holding both the
@@ -2766,46 +2837,33 @@ static void __console_unlock(void)
*
* Requires the console_lock and the SRCU read lock.
*/
-static bool console_emit_next_record(struct console *con, char *text, char *ext_text,
- char *dropped_text, bool *handover, int cookie)
+static bool console_emit_next_record(struct console *con, bool *handover, int cookie)
{
- static int panic_console_dropped;
- struct printk_info info;
- struct printk_record r;
- unsigned long flags;
- char *write_text;
- size_t len;
+ static struct printk_buffers pbufs;
- prb_rec_init_rd(&r, &info, text, CONSOLE_LOG_MAX);
+ bool is_extended = console_srcu_read_flags(con) & CON_EXTENDED;
+ char *outbuf = &pbufs.outbuf[0];
+ struct printk_message pmsg = {
+ .pbufs = &pbufs,
+ };
+ unsigned long flags;
*handover = false;
- if (!prb_read_valid(prb, con->seq, &r))
+ if (!printk_get_next_message(&pmsg, con->seq, is_extended, true))
return false;
- if (con->seq != r.info->seq) {
- con->dropped += r.info->seq - con->seq;
- con->seq = r.info->seq;
- if (panic_in_progress() && panic_console_dropped++ > 10) {
- suppress_panic_printk = 1;
- pr_warn_once("Too many dropped messages. Suppress messages on non-panic CPUs to prevent livelock.\n");
- }
- }
+ con->dropped += pmsg.dropped;
- /* Skip record that has level above the console loglevel. */
- if (suppress_message_printing(r.info->level)) {
- con->seq++;
+ /* Skip messages of formatted length 0. */
+ if (pmsg.outbuf_len == 0) {
+ con->seq = pmsg.seq + 1;
goto skip;
}
- if (ext_text) {
- write_text = ext_text;
- len = info_print_ext_header(ext_text, CONSOLE_EXT_LOG_MAX, r.info);
- len += msg_print_ext_body(ext_text + len, CONSOLE_EXT_LOG_MAX - len,
- &r.text_buf[0], r.info->text_len, &r.info->dev_info);
- } else {
- write_text = text;
- len = record_print_text(&r, console_msg_format & MSG_FORMAT_SYSLOG, printk_time);
+ if (con->dropped && !is_extended) {
+ console_prepend_dropped(&pmsg, con->dropped);
+ con->dropped = 0;
}
/*
@@ -2821,11 +2879,15 @@ static bool console_emit_next_record(struct console *con, char *text, char *ext_
printk_safe_enter_irqsave(flags);
console_lock_spinning_enable();
- stop_critical_timings(); /* don't trace print latency */
- call_console_driver(con, write_text, len, dropped_text);
+ /* Do not trace print latency. */
+ stop_critical_timings();
+
+ /* Write everything out to the hardware. */
+ con->write(con, outbuf, pmsg.outbuf_len);
+
start_critical_timings();
- con->seq++;
+ con->seq = pmsg.seq + 1;
*handover = console_lock_spinning_disable_and_check(cookie);
printk_safe_exit_irqrestore(flags);
@@ -2858,9 +2920,6 @@ static bool console_emit_next_record(struct console *con, char *text, char *ext_
*/
static bool console_flush_all(bool do_cond_resched, u64 *next_seq, bool *handover)
{
- static char dropped_text[DROPPED_TEXT_MAX];
- static char ext_text[CONSOLE_EXT_LOG_MAX];
- static char text[CONSOLE_LOG_MAX];
bool any_usable = false;
struct console *con;
bool any_progress;
@@ -2880,16 +2939,7 @@ static bool console_flush_all(bool do_cond_resched, u64 *next_seq, bool *handove
continue;
any_usable = true;
- if (console_srcu_read_flags(con) & CON_EXTENDED) {
- /* Extended consoles do not print "dropped messages". */
- progress = console_emit_next_record(con, &text[0],
- &ext_text[0], NULL,
- handover, cookie);
- } else {
- progress = console_emit_next_record(con, &text[0],
- NULL, &dropped_text[0],
- handover, cookie);
- }
+ progress = console_emit_next_record(con, handover, cookie);
/*
* If a handover has occurred, the SRCU read lock
diff --git a/lib/errname.c b/lib/errname.c
index 05cbf731545f07b1984cd5ef3f8a5b15535aa041..67739b174a8cc481216c33a8db7a2569544f41ff 100644
--- a/lib/errname.c
+++ b/lib/errname.c
@@ -21,6 +21,7 @@ static const char *names_0[] = {
E(EADDRNOTAVAIL),
E(EADV),
E(EAFNOSUPPORT),
+ E(EAGAIN), /* EWOULDBLOCK */
E(EALREADY),
E(EBADE),
E(EBADF),
@@ -31,15 +32,17 @@ static const char *names_0[] = {
E(EBADSLT),
E(EBFONT),
E(EBUSY),
-#ifdef ECANCELLED
- E(ECANCELLED),
-#endif
+ E(ECANCELED), /* ECANCELLED */
E(ECHILD),
E(ECHRNG),
E(ECOMM),
E(ECONNABORTED),
+ E(ECONNREFUSED), /* EREFUSED */
E(ECONNRESET),
+ E(EDEADLK), /* EDEADLOCK */
+#if EDEADLK != EDEADLOCK /* mips, sparc, powerpc */
E(EDEADLOCK),
+#endif
E(EDESTADDRREQ),
E(EDOM),
E(EDOTDOT),
@@ -166,14 +169,17 @@ static const char *names_0[] = {
E(EUSERS),
E(EXDEV),
E(EXFULL),
-
- E(ECANCELED), /* ECANCELLED */
- E(EAGAIN), /* EWOULDBLOCK */
- E(ECONNREFUSED), /* EREFUSED */
- E(EDEADLK), /* EDEADLOCK */
};
#undef E
+#ifdef EREFUSED /* parisc */
+static_assert(EREFUSED == ECONNREFUSED);
+#endif
+#ifdef ECANCELLED /* parisc */
+static_assert(ECANCELLED == ECANCELED);
+#endif
+static_assert(EAGAIN == EWOULDBLOCK); /* everywhere */
+
#define E(err) [err - 512 + BUILD_BUG_ON_ZERO(err < 512 || err > 550)] = "-" #err
static const char *names_512[] = {
E(ERESTARTSYS),