e9b4b72567
[ Upstream commit 4dc533e0f2c04174e1ae4aa98e7cffc1c04b9998 ] Function kallsyms_on_each_symbol() traverses all symbols and submits each symbol to the hook 'fn' for judgment and processing. For some cases, the hook actually only handles the matched symbol, such as livepatch. Because all symbols are currently sorted by name, all the symbols with the same name are clustered together. Function kallsyms_lookup_names() gets the start and end positions of the set corresponding to the specified name. So we can easily and quickly traverse all the matches. The test results are as follows (twice): (x86) kallsyms_on_each_match_symbol: 7454, 7984 kallsyms_on_each_symbol : 11733809, 11785803 kallsyms_on_each_match_symbol() consumes only 0.066% of kallsyms_on_each_symbol()'s time. In other words, 1523x better performance. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Stable-dep-of: b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols") Signed-off-by: Sasha Levin <sashal@kernel.org>
187 lines
4.6 KiB
C
187 lines
4.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Rewritten and vastly simplified by Rusty Russell for in-kernel
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* module loader:
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* Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
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*/
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#ifndef _LINUX_KALLSYMS_H
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#define _LINUX_KALLSYMS_H
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#include <linux/errno.h>
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#include <linux/buildid.h>
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#include <linux/kernel.h>
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#include <linux/stddef.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <asm/sections.h>
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#define KSYM_NAME_LEN 512
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#define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s %s]") + \
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(KSYM_NAME_LEN - 1) + \
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2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + \
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(BUILD_ID_SIZE_MAX * 2) + 1)
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struct cred;
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struct module;
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static inline int is_kernel_text(unsigned long addr)
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{
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if (__is_kernel_text(addr))
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return 1;
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return in_gate_area_no_mm(addr);
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}
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static inline int is_kernel(unsigned long addr)
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{
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if (__is_kernel(addr))
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return 1;
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return in_gate_area_no_mm(addr);
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}
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static inline int is_ksym_addr(unsigned long addr)
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{
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if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
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return is_kernel(addr);
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return is_kernel_text(addr) || is_kernel_inittext(addr);
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}
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static inline void *dereference_symbol_descriptor(void *ptr)
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{
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#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
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struct module *mod;
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ptr = dereference_kernel_function_descriptor(ptr);
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if (is_ksym_addr((unsigned long)ptr))
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return ptr;
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preempt_disable();
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mod = __module_address((unsigned long)ptr);
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preempt_enable();
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if (mod)
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ptr = dereference_module_function_descriptor(mod, ptr);
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#endif
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return ptr;
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}
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#ifdef CONFIG_KALLSYMS
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int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
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unsigned long),
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void *data);
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int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
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const char *name, void *data);
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/* Lookup the address for a symbol. Returns 0 if not found. */
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unsigned long kallsyms_lookup_name(const char *name);
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extern int kallsyms_lookup_size_offset(unsigned long addr,
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unsigned long *symbolsize,
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unsigned long *offset);
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/* Lookup an address. modname is set to NULL if it's in the kernel. */
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const char *kallsyms_lookup(unsigned long addr,
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unsigned long *symbolsize,
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unsigned long *offset,
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char **modname, char *namebuf);
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/* Look up a kernel symbol and return it in a text buffer. */
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extern int sprint_symbol(char *buffer, unsigned long address);
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extern int sprint_symbol_build_id(char *buffer, unsigned long address);
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extern int sprint_symbol_no_offset(char *buffer, unsigned long address);
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extern int sprint_backtrace(char *buffer, unsigned long address);
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extern int sprint_backtrace_build_id(char *buffer, unsigned long address);
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int lookup_symbol_name(unsigned long addr, char *symname);
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int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
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/* How and when do we show kallsyms values? */
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extern bool kallsyms_show_value(const struct cred *cred);
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#else /* !CONFIG_KALLSYMS */
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static inline unsigned long kallsyms_lookup_name(const char *name)
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{
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return 0;
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}
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static inline int kallsyms_lookup_size_offset(unsigned long addr,
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unsigned long *symbolsize,
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unsigned long *offset)
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{
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return 0;
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}
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static inline const char *kallsyms_lookup(unsigned long addr,
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unsigned long *symbolsize,
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unsigned long *offset,
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char **modname, char *namebuf)
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{
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return NULL;
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}
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static inline int sprint_symbol(char *buffer, unsigned long addr)
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{
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*buffer = '\0';
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return 0;
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}
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static inline int sprint_symbol_build_id(char *buffer, unsigned long address)
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{
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*buffer = '\0';
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return 0;
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}
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static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr)
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{
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*buffer = '\0';
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return 0;
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}
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static inline int sprint_backtrace(char *buffer, unsigned long addr)
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{
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*buffer = '\0';
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return 0;
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}
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static inline int sprint_backtrace_build_id(char *buffer, unsigned long addr)
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{
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*buffer = '\0';
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return 0;
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}
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static inline int lookup_symbol_name(unsigned long addr, char *symname)
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{
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return -ERANGE;
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}
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static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
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{
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return -ERANGE;
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}
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static inline bool kallsyms_show_value(const struct cred *cred)
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{
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return false;
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}
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static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
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unsigned long), void *data)
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{
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return -EOPNOTSUPP;
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}
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static inline int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long),
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const char *name, void *data)
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{
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return -EOPNOTSUPP;
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}
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#endif /*CONFIG_KALLSYMS*/
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static inline void print_ip_sym(const char *loglvl, unsigned long ip)
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{
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printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip);
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}
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#endif /*_LINUX_KALLSYMS_H*/
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