diff options
| -rw-r--r-- | kernel/printk/printk.c | 138 |
1 files changed, 98 insertions, 40 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 150bfde41ba1..c8847ee571f0 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1126,7 +1126,7 @@ void __init setup_log_buf(int early) new_descs, ilog2(new_descs_count), new_infos); - logbuf_lock_irqsave(flags); + printk_safe_enter_irqsave(flags); log_buf_len = new_log_buf_len; log_buf = new_log_buf; @@ -1143,7 +1143,7 @@ void __init setup_log_buf(int early) */ prb = &printk_rb_dynamic; - logbuf_unlock_irqrestore(flags); + printk_safe_exit_irqrestore(flags); if (seq != prb_next_seq(&printk_rb_static)) { pr_err("dropped %llu messages\n", @@ -1861,18 +1861,90 @@ static inline u32 printk_caller_id(void) 0x80000000 + raw_smp_processor_id(); } -/* Must be called under logbuf_lock. */ +/** + * parse_prefix - Parse level and control flags. + * + * @text: The terminated text message. + * @level: A pointer to the current level value, will be updated. + * @lflags: A pointer to the current log flags, will be updated. + * + * @level may be NULL if the caller is not interested in the parsed value. + * Otherwise the variable pointed to by @level must be set to + * LOGLEVEL_DEFAULT in order to be updated with the parsed value. + * + * @lflags may be NULL if the caller is not interested in the parsed value. + * Otherwise the variable pointed to by @lflags will be OR'd with the parsed + * value. + * + * Return: The length of the parsed level and control flags. + */ +static u16 parse_prefix(char *text, int *level, enum log_flags *lflags) +{ + u16 prefix_len = 0; + int kern_level; + + while (*text) { + kern_level = printk_get_level(text); + if (!kern_level) + break; + + switch (kern_level) { + case '0' ... '7': + if (level && *level == LOGLEVEL_DEFAULT) + *level = kern_level - '0'; + break; + case 'c': /* KERN_CONT */ + if (lflags) + *lflags |= LOG_CONT; + } + + prefix_len += 2; + text += 2; + } + + return prefix_len; +} + +static u16 printk_sprint(char *text, u16 size, int facility, enum log_flags *lflags, + const char *fmt, va_list args) +{ + u16 text_len; + + text_len = vscnprintf(text, size, fmt, args); + + /* Mark and strip a trailing newline. */ + if (text_len && text[text_len - 1] == '\n') { + text_len--; + *lflags |= LOG_NEWLINE; + } + + /* Strip log level and control flags. */ + if (facility == 0) { + u16 prefix_len; + + prefix_len = parse_prefix(text, NULL, NULL); + if (prefix_len) { + text_len -= prefix_len; + memmove(text, text + prefix_len, text_len); + } + } + + return text_len; +} + +__printf(4, 0) int vprintk_store(int facility, int level, const struct dev_printk_info *dev_info, const char *fmt, va_list args) { const u32 caller_id = printk_caller_id(); - static char textbuf[LOG_LINE_MAX]; struct prb_reserved_entry e; enum log_flags lflags = 0; struct printk_record r; u16 trunc_msg_len = 0; - char *text = textbuf; + char prefix_buf[8]; + u16 reserve_size; + va_list args2; u16 text_len; u64 ts_nsec; @@ -1885,35 +1957,21 @@ int vprintk_store(int facility, int level, ts_nsec = local_clock(); /* - * The printf needs to come first; we need the syslog - * prefix which might be passed-in as a parameter. + * The sprintf needs to come first since the syslog prefix might be + * passed in as a parameter. An extra byte must be reserved so that + * later the vscnprintf() into the reserved buffer has room for the + * terminating '\0', which is not counted by vsnprintf(). */ - text_len = vscnprintf(text, sizeof(textbuf), fmt, args); - - /* mark and strip a trailing newline */ - if (text_len && text[text_len-1] == '\n') { - text_len--; - lflags |= LOG_NEWLINE; - } - - /* strip kernel syslog prefix and extract log level or control flags */ - if (facility == 0) { - int kern_level; + va_copy(args2, args); + reserve_size = vsnprintf(&prefix_buf[0], sizeof(prefix_buf), fmt, args2) + 1; + va_end(args2); - while ((kern_level = printk_get_level(text)) != 0) { - switch (kern_level) { - case '0' ... '7': - if (level == LOGLEVEL_DEFAULT) - level = kern_level - '0'; - break; - case 'c': /* KERN_CONT */ - lflags |= LOG_CONT; - } + if (reserve_size > LOG_LINE_MAX) + reserve_size = LOG_LINE_MAX; - text_len -= 2; - text += 2; - } - } + /* Extract log level or control flags. */ + if (facility == 0) + parse_prefix(&prefix_buf[0], &level, &lflags); if (level == LOGLEVEL_DEFAULT) level = default_message_loglevel; @@ -1922,9 +1980,10 @@ int vprintk_store(int facility, int level, lflags |= LOG_NEWLINE; if (lflags & LOG_CONT) { - prb_rec_init_wr(&r, text_len); + prb_rec_init_wr(&r, reserve_size); if (prb_reserve_in_last(&e, prb, &r, caller_id, LOG_LINE_MAX)) { - memcpy(&r.text_buf[r.info->text_len], text, text_len); + text_len = printk_sprint(&r.text_buf[r.info->text_len], reserve_size, + facility, &lflags, fmt, args); r.info->text_len += text_len; if (lflags & LOG_NEWLINE) { @@ -1943,18 +2002,18 @@ int vprintk_store(int facility, int level, * prb_reserve_in_last() and prb_reserve() purposely invalidate the * structure when they fail. */ - prb_rec_init_wr(&r, text_len); + prb_rec_init_wr(&r, reserve_size); if (!prb_reserve(&e, prb, &r)) { /* truncate the message if it is too long for empty buffer */ - truncate_msg(&text_len, &trunc_msg_len); + truncate_msg(&reserve_size, &trunc_msg_len); - prb_rec_init_wr(&r, text_len + trunc_msg_len); + prb_rec_init_wr(&r, reserve_size + trunc_msg_len); if (!prb_reserve(&e, prb, &r)) return 0; } /* fill message */ - memcpy(&r.text_buf[0], text, text_len); + text_len = printk_sprint(&r.text_buf[0], reserve_size, facility, &lflags, fmt, args); if (trunc_msg_len) memcpy(&r.text_buf[text_len], trunc_msg, trunc_msg_len); r.info->text_len = text_len + trunc_msg_len; @@ -1995,10 +2054,9 @@ asmlinkage int vprintk_emit(int facility, int level, boot_delay_msec(level); printk_delay(); - /* This stops the holder of console_sem just where we want him */ - logbuf_lock_irqsave(flags); + printk_safe_enter_irqsave(flags); printed_len = vprintk_store(facility, level, dev_info, fmt, args); - logbuf_unlock_irqrestore(flags); + printk_safe_exit_irqrestore(flags); /* If called from the scheduler, we can not call up(). */ if (!in_sched) { |