The following commit has been merged into the sched/rt branch of tip: Commit-ID: 75d430372abba5210fbc56a813d2515c001a4f45 Gitweb: https://git.kernel.org/tip/75d430372abba5210fbc56a813d2515c001a4f45 Author: John Ogness <john.ogness@xxxxxxxxxxxxx> AuthorDate: Wed, 04 Sep 2024 14:11:29 +02:06 Committer: Petr Mladek <pmladek@xxxxxxxx> CommitterDate: Wed, 04 Sep 2024 15:56:32 +02:00 printk: Provide helper for message prepending In order to support prepending different texts to printk messages, split out the prepending code into a helper function. Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx> Link: https://lore.kernel.org/r/20240904120536.115780-11-john.ogness@xxxxxxxxxxxxx Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> --- kernel/printk/printk.c | 36 +++++++++++++++++++++++++----------- 1 file changed, 25 insertions(+), 11 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 149c3e0..e945856 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2843,30 +2843,31 @@ static void __console_unlock(void) #ifdef CONFIG_PRINTK /* - * 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. + * Prepend the message in @pmsg->pbufs->outbuf. This is achieved by shifting + * the existing message over and inserting the scratchbuf message. * - * @pmsg is the printk message to prepend. - * - * @dropped is the dropped count to report in the dropped message. + * @pmsg is the original printk message. + * @fmt is the printf format of the message which will prepend the existing one. * - * 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 there is not enough space in @pmsg->pbufs->outbuf, the existing + * message text will be sufficiently truncated. * * If @pmsg->pbufs->outbuf is modified, @pmsg->outbuf_len is updated. */ -void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped) +__printf(2, 3) +static void console_prepend_message(struct printk_message *pmsg, const char *fmt, ...) { 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]; + va_list args; size_t len; - len = scnprintf(scratchbuf, scratchbuf_sz, - "** %lu printk messages dropped **\n", dropped); + va_start(args, fmt); + len = vscnprintf(scratchbuf, scratchbuf_sz, fmt, args); + va_end(args); /* * Make sure outbuf is sufficiently large before prepending. @@ -2889,6 +2890,19 @@ void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped) } /* + * Prepend the message in @pmsg->pbufs->outbuf with a "dropped message". + * @pmsg->outbuf_len is updated appropriately. + * + * @pmsg is the printk message to prepend. + * + * @dropped is the dropped count to report in the dropped message. + */ +void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped) +{ + console_prepend_message(pmsg, "** %lu printk messages dropped **\n", dropped); +} + +/* * Read and format the specified record (or a later record if the specified * record is not available). *