kernel-ark/include/linux/kallsyms.h
Namhyung Kim 0f77a8d378 vsprintf: Introduce %pB format specifier
The %pB format specifier is for stack backtrace. Its handler
sprint_backtrace() does symbol lookup using (address-1) to
ensure the address will not point outside of the function.

If there is a tail-call to the function marked "noreturn",
gcc optimized out the code after the call then causes saved
return address points outside of the function (i.e. the start
of the next function), so pollutes call trace somewhat.

This patch adds the %pB printk mechanism that allows architecture
call-trace printout functions to improve backtrace printouts.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
LKML-Reference: <1300934550-21394-1-git-send-email-namhyung@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-24 08:36:10 +01:00

123 lines
3.3 KiB
C

/* Rewritten and vastly simplified by Rusty Russell for in-kernel
* module loader:
* Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
*/
#ifndef _LINUX_KALLSYMS_H
#define _LINUX_KALLSYMS_H
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#define KSYM_NAME_LEN 128
#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \
2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1)
struct module;
#ifdef CONFIG_KALLSYMS
/* Lookup the address for a symbol. Returns 0 if not found. */
unsigned long kallsyms_lookup_name(const char *name);
/* Call a function on each kallsyms symbol in the core kernel */
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
unsigned long),
void *data);
extern int kallsyms_lookup_size_offset(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset);
/* Lookup an address. modname is set to NULL if it's in the kernel. */
const char *kallsyms_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
char **modname, char *namebuf);
/* Look up a kernel symbol and return it in a text buffer. */
extern int sprint_symbol(char *buffer, unsigned long address);
extern int sprint_backtrace(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);
int lookup_symbol_name(unsigned long addr, char *symname);
int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
#else /* !CONFIG_KALLSYMS */
static inline unsigned long kallsyms_lookup_name(const char *name)
{
return 0;
}
static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *,
struct module *,
unsigned long),
void *data)
{
return 0;
}
static inline int kallsyms_lookup_size_offset(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset)
{
return 0;
}
static inline const char *kallsyms_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
char **modname, char *namebuf)
{
return NULL;
}
static inline int sprint_symbol(char *buffer, unsigned long addr)
{
*buffer = '\0';
return 0;
}
static inline int sprint_backtrace(char *buffer, unsigned long addr)
{
*buffer = '\0';
return 0;
}
static inline int lookup_symbol_name(unsigned long addr, char *symname)
{
return -ERANGE;
}
static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
{
return -ERANGE;
}
/* Stupid that this does nothing, but I didn't create this mess. */
#define __print_symbol(fmt, addr)
#endif /*CONFIG_KALLSYMS*/
/* This macro allows us to keep printk typechecking */
static void __check_printsym_format(const char *fmt, ...)
__attribute__((format(printf,1,2)));
static inline void __check_printsym_format(const char *fmt, ...)
{
}
static inline void print_symbol(const char *fmt, unsigned long addr)
{
__check_printsym_format(fmt, "");
__print_symbol(fmt, (unsigned long)
__builtin_extract_return_addr((void *)addr));
}
static inline void print_ip_sym(unsigned long ip)
{
printk("[<%p>] %pS\n", (void *) ip, (void *) ip);
}
#endif /*_LINUX_KALLSYMS_H*/