diff options
| -rw-r--r-- | kernel/printk/internal.h | 10 | ||||
| -rw-r--r-- | kernel/printk/printk.c | 57 |
2 files changed, 36 insertions, 31 deletions
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index f394332410c9..6080d289a342 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -82,3 +82,13 @@ 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[CONSOLE_EXT_LOG_MAX]; + char scratchbuf[LOG_LINE_MAX]; +}; diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 55bb065de65f..bc5d4574c459 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2728,14 +2728,6 @@ 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. * - * @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. @@ -2747,17 +2739,33 @@ 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 char dropped_text[DROPPED_TEXT_MAX]; + static struct printk_buffers pbufs; static int panic_console_dropped; + + bool is_extended = console_srcu_read_flags(con) & CON_EXTENDED; + 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; unsigned long flags; - char *write_text; size_t len; - prb_rec_init_rd(&r, &info, text, CONSOLE_LOG_MAX); + /* + * 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); *handover = false; @@ -2779,13 +2787,11 @@ static bool console_emit_next_record(struct console *con, char *text, char *ext_ 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, + 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 { - write_text = text; len = record_print_text(&r, console_msg_format & MSG_FORMAT_SYSLOG, printk_time); } @@ -2803,7 +2809,8 @@ static bool console_emit_next_record(struct console *con, char *text, char *ext_ console_lock_spinning_enable(); stop_critical_timings(); /* don't trace print latency */ - call_console_driver(con, write_text, len, dropped_text); + call_console_driver(con, outbuf, len, + is_extended ? NULL : dropped_text); start_critical_timings(); con->seq++; @@ -2839,9 +2846,6 @@ 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; @@ -2861,16 +2865,7 @@ 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 |