From cf5b0208fda4602d0ef383a86e942fb3dcb8852b Mon Sep 17 00:00:00 2001 From: John Ogness Date: Wed, 3 Mar 2021 11:15:20 +0100 Subject: printk: introduce CONSOLE_LOG_MAX Instead of using "LOG_LINE_MAX + PREFIX_MAX" for temporary buffer sizes, introduce CONSOLE_LOG_MAX. This represents the maximum size that is allowed to be printed to the console for a single record. Signed-off-by: John Ogness Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210303101528.29901-8-john.ogness@linutronix.de --- kernel/printk/printk.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'kernel/printk') diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 9a5f9ccc46ea..2c8873fa2f29 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -410,7 +410,12 @@ static u64 clear_seq; #else #define PREFIX_MAX 32 #endif -#define LOG_LINE_MAX (1024 - PREFIX_MAX) + +/* the maximum size of a formatted record (i.e. with prefix added per line) */ +#define CONSOLE_LOG_MAX 1024 + +/* 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) @@ -1472,11 +1477,11 @@ static int syslog_print(char __user *buf, int size) char *text; int len = 0; - text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL); + text = kmalloc(CONSOLE_LOG_MAX, GFP_KERNEL); if (!text) return -ENOMEM; - prb_rec_init_rd(&r, &info, text, LOG_LINE_MAX + PREFIX_MAX); + prb_rec_init_rd(&r, &info, text, CONSOLE_LOG_MAX); while (size > 0) { size_t n; @@ -1542,7 +1547,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear) u64 seq; bool time; - text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL); + text = kmalloc(CONSOLE_LOG_MAX, GFP_KERNEL); if (!text) return -ENOMEM; @@ -1554,7 +1559,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear) */ seq = find_first_fitting_seq(clear_seq, -1, size, true, time); - prb_rec_init_rd(&r, &info, text, LOG_LINE_MAX + PREFIX_MAX); + prb_rec_init_rd(&r, &info, text, CONSOLE_LOG_MAX); len = 0; prb_for_each_record(seq, prb, seq, &r) { @@ -2187,8 +2192,7 @@ EXPORT_SYMBOL(printk); #else /* CONFIG_PRINTK */ -#define LOG_LINE_MAX 0 -#define PREFIX_MAX 0 +#define CONSOLE_LOG_MAX 0 #define printk_time false #define prb_read_valid(rb, seq, r) false @@ -2506,7 +2510,7 @@ static inline int can_use_console(void) void console_unlock(void) { static char ext_text[CONSOLE_EXT_LOG_MAX]; - static char text[LOG_LINE_MAX + PREFIX_MAX]; + static char text[CONSOLE_LOG_MAX]; unsigned long flags; bool do_cond_resched, retry; struct printk_info info; -- cgit v1.2.3