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printk changes for 6.3 

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Merge tag 'printk-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Refactor printk code for formatting messages that are shown on
   consoles. This is a preparatory step for introducing atomic consoles
   which could not share the global buffers

 - Prevent memory leak when removing printk index in debugfs

 - Dump also the newest printk message by the sample gdbmacro

 - Fix a compiler warning

* tag 'printk-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printf: fix errname.c list
  kernel/printk/index.c: fix memory leak with using debugfs_lookup()
  printk: Use scnprintf() to print the message about the dropped messages on a console
  printk: adjust string limit macros
  printk: use printk_buffers for devkmsg
  printk: introduce console_prepend_dropped() for dropped messages
  printk: introduce printk_get_next_message() and printk_message
  printk: introduce struct printk_buffers
  console: Document struct console
  console: Use BIT() macros for @flags values
  printk: move size limit macros into internal.h
  docs: gdbmacros: print newest record
This commit is contained in:
Linus Torvalds 2023-02-23 13:49:45 -08:00
parent cd43b50686 392143c9f2
commit d876315445
7 changed files with 314 additions and 169 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/admin-guide/kdump/gdbmacros.txt
View File

@ -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

100
include/linux/console.h
View File

@ -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

2
include/linux/printk.h
View File

@ -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

2
kernel/printk/index.c
View File

@ -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,

45
kernel/printk/internal.h
View File

@ -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;
};

310
kernel/printk/printk.c
View File

@ -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 @@ out:
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, pmsg.seq + 1);
atomic64_set(&user->seq, r->info->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; }
@ -2743,18 +2694,138 @@ static void __console_unlock(void)
up_console_sem();
}
/*
* 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.
*
* @dropped is the dropped count to report in the dropped message.
*
* 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 @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.
*
* @text is a buffer of size CONSOLE_LOG_MAX.
*
* If extended messages should be printed, @ext_text is a buffer of size
* CONSOLE_EXT_LOG_MAX. Otherwise @ext_text must be NULL.
*
* If dropped messages should be printed, @dropped_text is a buffer of size
* DROPPED_TEXT_MAX. Otherwise @dropped_text must be NULL.
*
* @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
* console_lock and the SRCU read lock. Otherwise it is set to false.
@ -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 @@ skip:
*/
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

22
lib/errname.c
View File

@ -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),