From: Robert Peterson Today's print_symbol function dumps a kernel symbol with printk. This patch extends the functionality of kallsyms.c so that the symbol lookup function may be used without the printk. This is useful for modules that want to dump symbols elsewhere, for example, to debugfs. I intend to use the new function call in the GFS2 file system (which will be a separate patch). Signed-off-by: Robert Peterson Cc: Rusty Russell Cc: Roman Zippel Cc: "Randy.Dunlap" Cc: Sam Ravnborg Acked-by: Paulo Marques Signed-off-by: Andrew Morton --- include/linux/kallsyms.h | 13 ++++++++++++- kernel/kallsyms.c | 17 ++++++++++++----- 2 files changed, 24 insertions(+), 6 deletions(-) diff -puN include/linux/kallsyms.h~extend-print_symbol-capability include/linux/kallsyms.h --- a/include/linux/kallsyms.h~extend-print_symbol-capability +++ a/include/linux/kallsyms.h @@ -7,6 +7,8 @@ #define KSYM_NAME_LEN 127 +#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + KSYM_NAME_LEN + \ + 2*(BITS_PER_LONG*3/10) + MODULE_NAME_LEN + 1) #ifdef CONFIG_KALLSYMS /* Lookup the address for a symbol. Returns 0 if not found. */ @@ -22,7 +24,10 @@ const char *kallsyms_lookup(unsigned lon unsigned long *offset, char **modname, char *namebuf); -/* Replace "%s" in format with address, if found */ +/* Look up a kernel symbol and return it in a text buffer. */ +extern void sprint_symbol(char *buffer, unsigned long address); + +/* Look up a kernel symbol and print it to the kernel messages. */ extern void __print_symbol(const char *fmt, unsigned long address); #else /* !CONFIG_KALLSYMS */ @@ -47,6 +52,12 @@ static inline const char *kallsyms_looku return NULL; } +static inline void sprint_symbol(char *buffer, unsigned long addr) +{ + *buffer = '\0'; + return; +} + /* Stupid that this does nothing, but I didn't create this mess. */ #define __print_symbol(fmt, addr) #endif /*CONFIG_KALLSYMS*/ diff -puN kernel/kallsyms.c~extend-print_symbol-capability kernel/kallsyms.c --- a/kernel/kallsyms.c~extend-print_symbol-capability +++ a/kernel/kallsyms.c @@ -267,18 +267,15 @@ const char *kallsyms_lookup(unsigned lon return NULL; } -/* Replace "%s" in format with address, or returns -errno. */ -void __print_symbol(const char *fmt, unsigned long address) +/* Look up a kernel symbol and return it in a text buffer. */ +void sprint_symbol(char *buffer, unsigned long address) { char *modname; const char *name; unsigned long offset, size; char namebuf[KSYM_NAME_LEN+1]; - char buffer[sizeof("%s+%#lx/%#lx [%s]") + KSYM_NAME_LEN + - 2*(BITS_PER_LONG*3/10) + MODULE_NAME_LEN + 1]; name = kallsyms_lookup(address, &size, &offset, &modname, namebuf); - if (!name) sprintf(buffer, "0x%lx", address); else { @@ -288,6 +285,15 @@ void __print_symbol(const char *fmt, uns else sprintf(buffer, "%s+%#lx/%#lx", name, offset, size); } +} + +/* Look up a kernel symbol and print it to the kernel messages. */ +void __print_symbol(const char *fmt, unsigned long address) +{ + char buffer[KSYM_SYMBOL_LEN]; + + sprint_symbol(buffer, address); + printk(fmt, buffer); } @@ -452,3 +458,4 @@ static int __init kallsyms_init(void) __initcall(kallsyms_init); EXPORT_SYMBOL(__print_symbol); +EXPORT_SYMBOL_GPL(sprint_symbol); _