From acc8fa41ad31c576cdbc569cc3e0e443b1b98b44 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Mon, 30 Jul 2012 14:40:09 -0700 Subject: [PATCH] printk: add generic functions to find KERN_ headers The current form of a KERN_ is "<.>". Add printk_get_level and printk_skip_level functions to handle these formats. These functions centralize tests of KERN_ so a future modification can change the KERN_ style and shorten the number of bytes consumed by these headers. [akpm@linux-foundation.org: fix build error and warning] Signed-off-by: Joe Perches Cc: Kay Sievers Cc: Wu Fengguang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/printk.h | 26 ++++++++++++++++++++++++++ kernel/printk.c | 14 +++++++++----- 2 files changed, 35 insertions(+), 5 deletions(-) diff --git a/include/linux/printk.h b/include/linux/printk.h index 1bec2f7a2d42..6e12e1f09047 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -24,6 +24,32 @@ extern const char linux_proc_banner[]; */ #define KERN_CONT "" +static inline int printk_get_level(const char *buffer) +{ + if (buffer[0] == '<' && buffer[1] && buffer[2] == '>') { + switch (buffer[1]) { + case '0' ... '7': + case 'd': /* KERN_DEFAULT */ + case 'c': /* KERN_CONT */ + return buffer[1]; + } + } + return 0; +} + +static inline const char *printk_skip_level(const char *buffer) +{ + if (printk_get_level(buffer)) { + switch (buffer[1]) { + case '0' ... '7': + case 'd': /* KERN_DEFAULT */ + case 'c': /* KERN_CONT */ + return buffer + 3; + } + } + return buffer; +} + extern int console_printk[]; #define console_loglevel (console_printk[0]) diff --git a/kernel/printk.c b/kernel/printk.c index 852269adad25..0d882a2f231e 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1487,6 +1487,7 @@ asmlinkage int vprintk_emit(int facility, int level, size_t text_len; enum log_flags lflags = 0; unsigned long flags; + int kern_level; int this_cpu; int printed_len = 0; @@ -1543,17 +1544,20 @@ asmlinkage int vprintk_emit(int facility, int level, } /* strip syslog prefix and extract log level or control flags */ - if (text[0] == '<' && text[1] && text[2] == '>') { - switch (text[1]) { + kern_level = printk_get_level(text); + if (kern_level) { + const char *end_of_header = printk_skip_level(text); + switch (kern_level) { case '0' ... '7': if (level == -1) - level = text[1] - '0'; + level = kern_level - '0'; case 'd': /* KERN_DEFAULT */ lflags |= LOG_PREFIX; case 'c': /* KERN_CONT */ - text += 3; - text_len -= 3; + break; } + text_len -= end_of_header - text; + text = (char *)end_of_header; } if (level == -1)