From d59745ce3e7aa13856bca16d3bcbb95041775ff6 Mon Sep 17 00:00:00 2001 From: Matt Mackall Date: Sun, 1 May 2005 08:59:02 -0700 Subject: [PATCH] [PATCH] clean up kernel messages Arrange for all kernel printks to be no-ops. Only available if CONFIG_EMBEDDED. This patch saves about 375k on my laptop config and nearly 100k on minimal configs. Signed-off-by: Matt Mackall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/head.S | 2 ++ include/linux/kernel.h | 9 +++++++++ init/Kconfig | 11 +++++++++++ kernel/printk.c | 27 +++++++++++++++++++++------ 4 files changed, 43 insertions(+), 6 deletions(-) diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S index d273fd746192..e966fc8c44c4 100644 --- a/arch/i386/kernel/head.S +++ b/arch/i386/kernel/head.S @@ -380,6 +380,7 @@ rp_sidt: ALIGN ignore_int: cld +#ifdef CONFIG_PRINTK pushl %eax pushl %ecx pushl %edx @@ -400,6 +401,7 @@ ignore_int: popl %edx popl %ecx popl %eax +#endif iret /* diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 7c1cba4a5278..e25b97062ce1 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -115,10 +115,19 @@ extern int __kernel_text_address(unsigned long addr); extern int kernel_text_address(unsigned long addr); extern int session_of_pgrp(int pgrp); +#ifdef CONFIG_PRINTK asmlinkage int vprintk(const char *fmt, va_list args) __attribute__ ((format (printf, 1, 0))); asmlinkage int printk(const char * fmt, ...) __attribute__ ((format (printf, 1, 2))); +#else +static inline int vprintk(const char *s, va_list args) + __attribute__ ((format (printf, 1, 0))); +static inline int vprintk(const char *s, va_list args) { return 0; } +static inline int printk(const char *s, ...) + __attribute__ ((format (printf, 1, 2))); +static inline int printk(const char *s, ...) { return 0; } +#endif unsigned long int_sqrt(unsigned long); diff --git a/init/Kconfig b/init/Kconfig index 42dca393b94e..40d286d1d118 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -275,6 +275,17 @@ config KALLSYMS_EXTRA_PASS reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while you wait for kallsyms to be fixed. + +config PRINTK + default y + bool "Enable support for printk" if EMBEDDED + help + This option enables normal printk support. Removing it + eliminates most of the message strings from the kernel image + and makes the kernel more or less silent. As this makes it + very difficult to diagnose system problems, saying N here is + strongly discouraged. + config BUG bool "BUG() support" if EMBEDDED default y diff --git a/kernel/printk.c b/kernel/printk.c index 1498689548d1..290a07ce2c8a 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -85,10 +85,6 @@ static int console_locked; */ static DEFINE_SPINLOCK(logbuf_lock); -static char __log_buf[__LOG_BUF_LEN]; -static char *log_buf = __log_buf; -static int log_buf_len = __LOG_BUF_LEN; - #define LOG_BUF_MASK (log_buf_len-1) #define LOG_BUF(idx) (log_buf[(idx) & LOG_BUF_MASK]) @@ -99,7 +95,6 @@ static int log_buf_len = __LOG_BUF_LEN; static unsigned long log_start; /* Index into log_buf: next char to be read by syslog() */ static unsigned long con_start; /* Index into log_buf: next char to be sent to consoles */ static unsigned long log_end; /* Index into log_buf: most-recently-written-char + 1 */ -static unsigned long logged_chars; /* Number of chars produced since last read+clear operation */ /* * Array of consoles built from command line options (console=) @@ -120,6 +115,13 @@ static int preferred_console = -1; /* Flag: console code may call schedule() */ static int console_may_schedule; +#ifdef CONFIG_PRINTK + +static char __log_buf[__LOG_BUF_LEN]; +static char *log_buf = __log_buf; +static int log_buf_len = __LOG_BUF_LEN; +static unsigned long logged_chars; /* Number of chars produced since last read+clear operation */ + /* * Setup a list of consoles. Called from init/main.c */ @@ -535,6 +537,7 @@ __setup("time", printk_time_setup); * then changes console_loglevel may break. This is because console_loglevel * is inspected when the actual printing occurs. */ + asmlinkage int printk(const char *fmt, ...) { va_list args; @@ -655,6 +658,18 @@ asmlinkage int vprintk(const char *fmt, va_list args) EXPORT_SYMBOL(printk); EXPORT_SYMBOL(vprintk); +#else + +asmlinkage long sys_syslog(int type, char __user * buf, int len) +{ + return 0; +} + +int do_syslog(int type, char __user * buf, int len) { return 0; } +static void call_console_drivers(unsigned long start, unsigned long end) {} + +#endif + /** * acquire_console_sem - lock the console system for exclusive use. * @@ -931,7 +946,7 @@ int unregister_console(struct console * console) return res; } EXPORT_SYMBOL(unregister_console); - + /** * tty_write_message - write a message to a certain tty, not just the console. * -- GitLab