module: Move kallsyms support into a separate file
No functional change. This patch migrates kallsyms code out of core module code kernel/module/kallsyms.c Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
This commit is contained in:
Aaron Tomlin
Luis Chamberlain
parent
473c84d185
commit
91fb02f315
@ -14,3 +14,4 @@ obj-$(CONFIG_LIVEPATCH) += livepatch.o
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obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
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obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
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obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
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obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
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obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
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obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
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obj-$(CONFIG_KALLSYMS) += kallsyms.o
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@ -68,6 +68,19 @@ struct load_info {
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};
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};
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int mod_verify_sig(const void *mod, struct load_info *info);
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int mod_verify_sig(const void *mod, struct load_info *info);
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struct module *find_module_all(const char *name, size_t len, bool even_unformed);
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int cmp_name(const void *name, const void *sym);
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long module_get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr,
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unsigned int section);
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static inline unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
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{
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#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
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return (unsigned long)offset_to_ptr(&sym->value_offset);
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#else
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return sym->value;
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#endif
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}
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#ifdef CONFIG_LIVEPATCH
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#ifdef CONFIG_LIVEPATCH
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int copy_module_elf(struct module *mod, struct load_info *info);
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int copy_module_elf(struct module *mod, struct load_info *info);
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@ -174,3 +187,19 @@ void kmemleak_load_module(const struct module *mod, const struct load_info *info
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static inline void kmemleak_load_module(const struct module *mod,
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static inline void kmemleak_load_module(const struct module *mod,
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const struct load_info *info) { }
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const struct load_info *info) { }
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#endif /* CONFIG_DEBUG_KMEMLEAK */
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#endif /* CONFIG_DEBUG_KMEMLEAK */
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#ifdef CONFIG_KALLSYMS
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void init_build_id(struct module *mod, const struct load_info *info);
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void layout_symtab(struct module *mod, struct load_info *info);
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void add_kallsyms(struct module *mod, const struct load_info *info);
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unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
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static inline bool sect_empty(const Elf_Shdr *sect)
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{
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return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
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}
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#else /* !CONFIG_KALLSYMS */
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static inline void init_build_id(struct module *mod, const struct load_info *info) { }
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static inline void layout_symtab(struct module *mod, struct load_info *info) { }
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static inline void add_kallsyms(struct module *mod, const struct load_info *info) { }
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#endif /* CONFIG_KALLSYMS */
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502
kernel/module/kallsyms.c
Normal file
502
kernel/module/kallsyms.c
Normal file
@ -0,0 +1,502 @@
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Module kallsyms support
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*
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* Copyright (C) 2010 Rusty Russell
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*/
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#include <linux/module.h>
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#include <linux/kallsyms.h>
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#include <linux/buildid.h>
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#include <linux/bsearch.h>
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#include "internal.h"
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/* Lookup exported symbol in given range of kernel_symbols */
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static const struct kernel_symbol *lookup_exported_symbol(const char *name,
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const struct kernel_symbol *start,
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const struct kernel_symbol *stop)
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{
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return bsearch(name, start, stop - start,
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sizeof(struct kernel_symbol), cmp_name);
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}
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static int is_exported(const char *name, unsigned long value,
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const struct module *mod)
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{
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const struct kernel_symbol *ks;
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if (!mod)
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ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
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else
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ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
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return ks && kernel_symbol_value(ks) == value;
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}
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/* As per nm */
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static char elf_type(const Elf_Sym *sym, const struct load_info *info)
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{
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const Elf_Shdr *sechdrs = info->sechdrs;
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if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
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if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
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return 'v';
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else
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return 'w';
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}
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if (sym->st_shndx == SHN_UNDEF)
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return 'U';
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if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
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return 'a';
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if (sym->st_shndx >= SHN_LORESERVE)
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return '?';
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if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
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return 't';
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if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC &&
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sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
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if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
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return 'r';
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else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
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return 'g';
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else
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return 'd';
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}
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if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
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if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
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return 's';
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else
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return 'b';
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}
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if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
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".debug")) {
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return 'n';
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}
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return '?';
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}
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static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
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unsigned int shnum, unsigned int pcpundx)
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{
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const Elf_Shdr *sec;
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if (src->st_shndx == SHN_UNDEF ||
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src->st_shndx >= shnum ||
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!src->st_name)
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return false;
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#ifdef CONFIG_KALLSYMS_ALL
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if (src->st_shndx == pcpundx)
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return true;
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#endif
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sec = sechdrs + src->st_shndx;
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if (!(sec->sh_flags & SHF_ALLOC)
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#ifndef CONFIG_KALLSYMS_ALL
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|| !(sec->sh_flags & SHF_EXECINSTR)
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#endif
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|| (sec->sh_entsize & INIT_OFFSET_MASK))
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return false;
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return true;
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}
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/*
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* We only allocate and copy the strings needed by the parts of symtab
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* we keep. This is simple, but has the effect of making multiple
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* copies of duplicates. We could be more sophisticated, see
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* linux-kernel thread starting with
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* <73defb5e4bca04a6431392cc341112b1@localhost>.
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*/
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void layout_symtab(struct module *mod, struct load_info *info)
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{
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Elf_Shdr *symsect = info->sechdrs + info->index.sym;
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Elf_Shdr *strsect = info->sechdrs + info->index.str;
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const Elf_Sym *src;
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unsigned int i, nsrc, ndst, strtab_size = 0;
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/* Put symbol section at end of init part of module. */
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symsect->sh_flags |= SHF_ALLOC;
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symsect->sh_entsize = module_get_offset(mod, &mod->init_layout.size, symsect,
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info->index.sym) | INIT_OFFSET_MASK;
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pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
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src = (void *)info->hdr + symsect->sh_offset;
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nsrc = symsect->sh_size / sizeof(*src);
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/* Compute total space required for the core symbols' strtab. */
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for (ndst = i = 0; i < nsrc; i++) {
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if (i == 0 || is_livepatch_module(mod) ||
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is_core_symbol(src + i, info->sechdrs, info->hdr->e_shnum,
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info->index.pcpu)) {
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strtab_size += strlen(&info->strtab[src[i].st_name]) + 1;
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ndst++;
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}
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}
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/* Append room for core symbols at end of core part. */
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info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
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info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
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mod->core_layout.size += strtab_size;
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info->core_typeoffs = mod->core_layout.size;
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mod->core_layout.size += ndst * sizeof(char);
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mod->core_layout.size = debug_align(mod->core_layout.size);
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/* Put string table section at end of init part of module. */
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strsect->sh_flags |= SHF_ALLOC;
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strsect->sh_entsize = module_get_offset(mod, &mod->init_layout.size, strsect,
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info->index.str) | INIT_OFFSET_MASK;
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pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
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/* We'll tack temporary mod_kallsyms on the end. */
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mod->init_layout.size = ALIGN(mod->init_layout.size,
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__alignof__(struct mod_kallsyms));
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info->mod_kallsyms_init_off = mod->init_layout.size;
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mod->init_layout.size += sizeof(struct mod_kallsyms);
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info->init_typeoffs = mod->init_layout.size;
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mod->init_layout.size += nsrc * sizeof(char);
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mod->init_layout.size = debug_align(mod->init_layout.size);
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}
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/*
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* We use the full symtab and strtab which layout_symtab arranged to
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* be appended to the init section. Later we switch to the cut-down
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* core-only ones.
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*/
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void add_kallsyms(struct module *mod, const struct load_info *info)
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{
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unsigned int i, ndst;
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const Elf_Sym *src;
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Elf_Sym *dst;
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char *s;
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Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
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/* Set up to point into init section. */
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mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
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/* The following is safe since this pointer cannot change */
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mod->kallsyms->symtab = (void *)symsec->sh_addr;
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mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
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/* Make sure we get permanent strtab: don't use info->strtab. */
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mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
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mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
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/*
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* Now populate the cut down core kallsyms for after init
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* and set types up while we still have access to sections.
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*/
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mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
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mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
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mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
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src = mod->kallsyms->symtab;
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for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
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mod->kallsyms->typetab[i] = elf_type(src + i, info);
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if (i == 0 || is_livepatch_module(mod) ||
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is_core_symbol(src + i, info->sechdrs, info->hdr->e_shnum,
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info->index.pcpu)) {
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mod->core_kallsyms.typetab[ndst] =
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mod->kallsyms->typetab[i];
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dst[ndst] = src[i];
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dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
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s += strscpy(s, &mod->kallsyms->strtab[src[i].st_name],
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KSYM_NAME_LEN) + 1;
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}
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}
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mod->core_kallsyms.num_symtab = ndst;
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}
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#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
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void init_build_id(struct module *mod, const struct load_info *info)
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{
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const Elf_Shdr *sechdr;
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unsigned int i;
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for (i = 0; i < info->hdr->e_shnum; i++) {
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sechdr = &info->sechdrs[i];
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if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
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!build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
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sechdr->sh_size))
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break;
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}
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}
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#else
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void init_build_id(struct module *mod, const struct load_info *info)
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{
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}
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#endif
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/*
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* This ignores the intensely annoying "mapping symbols" found
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* in ARM ELF files: $a, $t and $d.
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*/
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static inline int is_arm_mapping_symbol(const char *str)
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{
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if (str[0] == '.' && str[1] == 'L')
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return true;
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return str[0] == '$' && strchr("axtd", str[1]) &&
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(str[2] == '\0' || str[2] == '.');
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}
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static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
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{
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return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
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}
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/*
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* Given a module and address, find the corresponding symbol and return its name
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* while providing its size and offset if needed.
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*/
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static const char *find_kallsyms_symbol(struct module *mod,
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unsigned long addr,
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unsigned long *size,
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unsigned long *offset)
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{
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unsigned int i, best = 0;
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unsigned long nextval, bestval;
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struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
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/* At worse, next value is at end of module */
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if (within_module_init(addr, mod))
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nextval = (unsigned long)mod->init_layout.base + mod->init_layout.text_size;
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else
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nextval = (unsigned long)mod->core_layout.base + mod->core_layout.text_size;
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bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
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/*
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* Scan for closest preceding symbol, and next symbol. (ELF
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* starts real symbols at 1).
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*/
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for (i = 1; i < kallsyms->num_symtab; i++) {
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const Elf_Sym *sym = &kallsyms->symtab[i];
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unsigned long thisval = kallsyms_symbol_value(sym);
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if (sym->st_shndx == SHN_UNDEF)
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continue;
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/*
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* We ignore unnamed symbols: they're uninformative
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* and inserted at a whim.
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*/
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if (*kallsyms_symbol_name(kallsyms, i) == '\0' ||
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is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
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continue;
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if (thisval <= addr && thisval > bestval) {
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best = i;
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bestval = thisval;
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||||||
|
}
|
||||||
|
if (thisval > addr && thisval < nextval)
|
||||||
|
nextval = thisval;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (!best)
|
||||||
|
return NULL;
|
||||||
|
|
||||||
|
if (size)
|
||||||
|
*size = nextval - bestval;
|
||||||
|
if (offset)
|
||||||
|
*offset = addr - bestval;
|
||||||
|
|
||||||
|
return kallsyms_symbol_name(kallsyms, best);
|
||||||
|
}
|
||||||
|
|
||||||
|
void * __weak dereference_module_function_descriptor(struct module *mod,
|
||||||
|
void *ptr)
|
||||||
|
{
|
||||||
|
return ptr;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* For kallsyms to ask for address resolution. NULL means not found. Careful
|
||||||
|
* not to lock to avoid deadlock on oopses, simply disable preemption.
|
||||||
|
*/
|
||||||
|
const char *module_address_lookup(unsigned long addr,
|
||||||
|
unsigned long *size,
|
||||||
|
unsigned long *offset,
|
||||||
|
char **modname,
|
||||||
|
const unsigned char **modbuildid,
|
||||||
|
char *namebuf)
|
||||||
|
{
|
||||||
|
const char *ret = NULL;
|
||||||
|
struct module *mod;
|
||||||
|
|
||||||
|
preempt_disable();
|
||||||
|
mod = __module_address(addr);
|
||||||
|
if (mod) {
|
||||||
|
if (modname)
|
||||||
|
*modname = mod->name;
|
||||||
|
if (modbuildid) {
|
||||||
|
#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
|
||||||
|
*modbuildid = mod->build_id;
|
||||||
|
#else
|
||||||
|
*modbuildid = NULL;
|
||||||
|
#endif
|
||||||
|
}
|
||||||
|
|
||||||
|
ret = find_kallsyms_symbol(mod, addr, size, offset);
|
||||||
|
}
|
||||||
|
/* Make a copy in here where it's safe */
|
||||||
|
if (ret) {
|
||||||
|
strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
|
||||||
|
ret = namebuf;
|
||||||
|
}
|
||||||
|
preempt_enable();
|
||||||
|
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
int lookup_module_symbol_name(unsigned long addr, char *symname)
|
||||||
|
{
|
||||||
|
struct module *mod;
|
||||||
|
|
||||||
|
preempt_disable();
|
||||||
|
list_for_each_entry_rcu(mod, &modules, list) {
|
||||||
|
if (mod->state == MODULE_STATE_UNFORMED)
|
||||||
|
continue;
|
||||||
|
if (within_module(addr, mod)) {
|
||||||
|
const char *sym;
|
||||||
|
|
||||||
|
sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
|
||||||
|
if (!sym)
|
||||||
|
goto out;
|
||||||
|
|
||||||
|
strscpy(symname, sym, KSYM_NAME_LEN);
|
||||||
|
preempt_enable();
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
out:
|
||||||
|
preempt_enable();
|
||||||
|
return -ERANGE;
|
||||||
|
}
|
||||||
|
|
||||||
|
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
|
||||||
|
unsigned long *offset, char *modname, char *name)
|
||||||
|
{
|
||||||
|
struct module *mod;
|
||||||
|
|
||||||
|
preempt_disable();
|
||||||
|
list_for_each_entry_rcu(mod, &modules, list) {
|
||||||
|
if (mod->state == MODULE_STATE_UNFORMED)
|
||||||
|
continue;
|
||||||
|
if (within_module(addr, mod)) {
|
||||||
|
const char *sym;
|
||||||
|
|
||||||
|
sym = find_kallsyms_symbol(mod, addr, size, offset);
|
||||||
|
if (!sym)
|
||||||
|
goto out;
|
||||||
|
if (modname)
|
||||||
|
strscpy(modname, mod->name, MODULE_NAME_LEN);
|
||||||
|
if (name)
|
||||||
|
strscpy(name, sym, KSYM_NAME_LEN);
|
||||||
|
preempt_enable();
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
out:
|
||||||
|
preempt_enable();
|
||||||
|
return -ERANGE;
|
||||||
|
}
|
||||||
|
|
||||||
|
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
|
||||||
|
char *name, char *module_name, int *exported)
|
||||||
|
{
|
||||||
|
struct module *mod;
|
||||||
|
|
||||||
|
preempt_disable();
|
||||||
|
list_for_each_entry_rcu(mod, &modules, list) {
|
||||||
|
struct mod_kallsyms *kallsyms;
|
||||||
|
|
||||||
|
if (mod->state == MODULE_STATE_UNFORMED)
|
||||||
|
continue;
|
||||||
|
kallsyms = rcu_dereference_sched(mod->kallsyms);
|
||||||
|
if (symnum < kallsyms->num_symtab) {
|
||||||
|
const Elf_Sym *sym = &kallsyms->symtab[symnum];
|
||||||
|
|
||||||
|
*value = kallsyms_symbol_value(sym);
|
||||||
|
*type = kallsyms->typetab[symnum];
|
||||||
|
strscpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
|
||||||
|
strscpy(module_name, mod->name, MODULE_NAME_LEN);
|
||||||
|
*exported = is_exported(name, *value, mod);
|
||||||
|
preempt_enable();
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
symnum -= kallsyms->num_symtab;
|
||||||
|
}
|
||||||
|
preempt_enable();
|
||||||
|
return -ERANGE;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Given a module and name of symbol, find and return the symbol's value */
|
||||||
|
unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
|
||||||
|
{
|
||||||
|
unsigned int i;
|
||||||
|
struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
|
||||||
|
|
||||||
|
for (i = 0; i < kallsyms->num_symtab; i++) {
|
||||||
|
const Elf_Sym *sym = &kallsyms->symtab[i];
|
||||||
|
|
||||||
|
if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
|
||||||
|
sym->st_shndx != SHN_UNDEF)
|
||||||
|
return kallsyms_symbol_value(sym);
|
||||||
|
}
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Look for this name: can be of form module:name. */
|
||||||
|
unsigned long module_kallsyms_lookup_name(const char *name)
|
||||||
|
{
|
||||||
|
struct module *mod;
|
||||||
|
char *colon;
|
||||||
|
unsigned long ret = 0;
|
||||||
|
|
||||||
|
/* Don't lock: we're in enough trouble already. */
|
||||||
|
preempt_disable();
|
||||||
|
if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
|
||||||
|
if ((mod = find_module_all(name, colon - name, false)) != NULL)
|
||||||
|
ret = find_kallsyms_symbol_value(mod, colon + 1);
|
||||||
|
} else {
|
||||||
|
list_for_each_entry_rcu(mod, &modules, list) {
|
||||||
|
if (mod->state == MODULE_STATE_UNFORMED)
|
||||||
|
continue;
|
||||||
|
if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
|
||||||
|
break;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
preempt_enable();
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
#ifdef CONFIG_LIVEPATCH
|
||||||
|
int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
|
||||||
|
struct module *, unsigned long),
|
||||||
|
void *data)
|
||||||
|
{
|
||||||
|
struct module *mod;
|
||||||
|
unsigned int i;
|
||||||
|
int ret = 0;
|
||||||
|
|
||||||
|
mutex_lock(&module_mutex);
|
||||||
|
list_for_each_entry(mod, &modules, list) {
|
||||||
|
/* We hold module_mutex: no need for rcu_dereference_sched */
|
||||||
|
struct mod_kallsyms *kallsyms = mod->kallsyms;
|
||||||
|
|
||||||
|
if (mod->state == MODULE_STATE_UNFORMED)
|
||||||
|
continue;
|
||||||
|
for (i = 0; i < kallsyms->num_symtab; i++) {
|
||||||
|
const Elf_Sym *sym = &kallsyms->symtab[i];
|
||||||
|
|
||||||
|
if (sym->st_shndx == SHN_UNDEF)
|
||||||
|
continue;
|
||||||
|
|
||||||
|
ret = fn(data, kallsyms_symbol_name(kallsyms, i),
|
||||||
|
mod, kallsyms_symbol_value(sym));
|
||||||
|
if (ret != 0)
|
||||||
|
goto out;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
out:
|
||||||
|
mutex_unlock(&module_mutex);
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
#endif /* CONFIG_LIVEPATCH */
|
||||||
@ -288,15 +288,6 @@ static bool check_exported_symbol(const struct symsearch *syms,
|
|||||||
return true;
|
return true;
|
||||||
}
|
}
|
||||||
|
|
||||||
static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
|
|
||||||
{
|
|
||||||
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
|
|
||||||
return (unsigned long)offset_to_ptr(&sym->value_offset);
|
|
||||||
#else
|
|
||||||
return sym->value;
|
|
||||||
#endif
|
|
||||||
}
|
|
||||||
|
|
||||||
static const char *kernel_symbol_name(const struct kernel_symbol *sym)
|
static const char *kernel_symbol_name(const struct kernel_symbol *sym)
|
||||||
{
|
{
|
||||||
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
|
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
|
||||||
@ -317,7 +308,7 @@ static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
|
|||||||
#endif
|
#endif
|
||||||
}
|
}
|
||||||
|
|
||||||
static int cmp_name(const void *name, const void *sym)
|
int cmp_name(const void *name, const void *sym)
|
||||||
{
|
{
|
||||||
return strcmp(name, kernel_symbol_name(sym));
|
return strcmp(name, kernel_symbol_name(sym));
|
||||||
}
|
}
|
||||||
@ -387,8 +378,8 @@ static bool find_symbol(struct find_symbol_arg *fsa)
|
|||||||
* Search for module by name: must hold module_mutex (or preempt disabled
|
* Search for module by name: must hold module_mutex (or preempt disabled
|
||||||
* for read-only access).
|
* for read-only access).
|
||||||
*/
|
*/
|
||||||
static struct module *find_module_all(const char *name, size_t len,
|
struct module *find_module_all(const char *name, size_t len,
|
||||||
bool even_unformed)
|
bool even_unformed)
|
||||||
{
|
{
|
||||||
struct module *mod;
|
struct module *mod;
|
||||||
|
|
||||||
@ -1294,13 +1285,6 @@ resolve_symbol_wait(struct module *mod,
|
|||||||
return ksym;
|
return ksym;
|
||||||
}
|
}
|
||||||
|
|
||||||
#ifdef CONFIG_KALLSYMS
|
|
||||||
static inline bool sect_empty(const Elf_Shdr *sect)
|
|
||||||
{
|
|
||||||
return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
|
|
||||||
}
|
|
||||||
#endif
|
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* /sys/module/foo/sections stuff
|
* /sys/module/foo/sections stuff
|
||||||
* J. Corbet <corbet@lwn.net>
|
* J. Corbet <corbet@lwn.net>
|
||||||
@ -2065,7 +2049,7 @@ unsigned int __weak arch_mod_section_prepend(struct module *mod,
|
|||||||
}
|
}
|
||||||
|
|
||||||
/* Update size with this section: return offset. */
|
/* Update size with this section: return offset. */
|
||||||
static long get_offset(struct module *mod, unsigned int *size,
|
long module_get_offset(struct module *mod, unsigned int *size,
|
||||||
Elf_Shdr *sechdr, unsigned int section)
|
Elf_Shdr *sechdr, unsigned int section)
|
||||||
{
|
{
|
||||||
long ret;
|
long ret;
|
||||||
@ -2121,7 +2105,7 @@ static void layout_sections(struct module *mod, struct load_info *info)
|
|||||||
|| s->sh_entsize != ~0UL
|
|| s->sh_entsize != ~0UL
|
||||||
|| module_init_layout_section(sname))
|
|| module_init_layout_section(sname))
|
||||||
continue;
|
continue;
|
||||||
s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
|
s->sh_entsize = module_get_offset(mod, &mod->core_layout.size, s, i);
|
||||||
pr_debug("\t%s\n", sname);
|
pr_debug("\t%s\n", sname);
|
||||||
}
|
}
|
||||||
switch (m) {
|
switch (m) {
|
||||||
@ -2154,7 +2138,7 @@ static void layout_sections(struct module *mod, struct load_info *info)
|
|||||||
|| s->sh_entsize != ~0UL
|
|| s->sh_entsize != ~0UL
|
||||||
|| !module_init_layout_section(sname))
|
|| !module_init_layout_section(sname))
|
||||||
continue;
|
continue;
|
||||||
s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
|
s->sh_entsize = (module_get_offset(mod, &mod->init_layout.size, s, i)
|
||||||
| INIT_OFFSET_MASK);
|
| INIT_OFFSET_MASK);
|
||||||
pr_debug("\t%s\n", sname);
|
pr_debug("\t%s\n", sname);
|
||||||
}
|
}
|
||||||
@ -2267,228 +2251,6 @@ static void free_modinfo(struct module *mod)
|
|||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
#ifdef CONFIG_KALLSYMS
|
|
||||||
|
|
||||||
/* Lookup exported symbol in given range of kernel_symbols */
|
|
||||||
static const struct kernel_symbol *lookup_exported_symbol(const char *name,
|
|
||||||
const struct kernel_symbol *start,
|
|
||||||
const struct kernel_symbol *stop)
|
|
||||||
{
|
|
||||||
return bsearch(name, start, stop - start,
|
|
||||||
sizeof(struct kernel_symbol), cmp_name);
|
|
||||||
}
|
|
||||||
|
|
||||||
static int is_exported(const char *name, unsigned long value,
|
|
||||||
const struct module *mod)
|
|
||||||
{
|
|
||||||
const struct kernel_symbol *ks;
|
|
||||||
if (!mod)
|
|
||||||
ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
|
|
||||||
else
|
|
||||||
ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
|
|
||||||
|
|
||||||
return ks != NULL && kernel_symbol_value(ks) == value;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* As per nm */
|
|
||||||
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
|
|
||||||
{
|
|
||||||
const Elf_Shdr *sechdrs = info->sechdrs;
|
|
||||||
|
|
||||||
if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
|
|
||||||
if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
|
|
||||||
return 'v';
|
|
||||||
else
|
|
||||||
return 'w';
|
|
||||||
}
|
|
||||||
if (sym->st_shndx == SHN_UNDEF)
|
|
||||||
return 'U';
|
|
||||||
if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
|
|
||||||
return 'a';
|
|
||||||
if (sym->st_shndx >= SHN_LORESERVE)
|
|
||||||
return '?';
|
|
||||||
if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
|
|
||||||
return 't';
|
|
||||||
if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
|
|
||||||
&& sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
|
|
||||||
if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
|
|
||||||
return 'r';
|
|
||||||
else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
|
|
||||||
return 'g';
|
|
||||||
else
|
|
||||||
return 'd';
|
|
||||||
}
|
|
||||||
if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
|
|
||||||
if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
|
|
||||||
return 's';
|
|
||||||
else
|
|
||||||
return 'b';
|
|
||||||
}
|
|
||||||
if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
|
|
||||||
".debug")) {
|
|
||||||
return 'n';
|
|
||||||
}
|
|
||||||
return '?';
|
|
||||||
}
|
|
||||||
|
|
||||||
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
|
|
||||||
unsigned int shnum, unsigned int pcpundx)
|
|
||||||
{
|
|
||||||
const Elf_Shdr *sec;
|
|
||||||
|
|
||||||
if (src->st_shndx == SHN_UNDEF
|
|
||||||
|| src->st_shndx >= shnum
|
|
||||||
|| !src->st_name)
|
|
||||||
return false;
|
|
||||||
|
|
||||||
#ifdef CONFIG_KALLSYMS_ALL
|
|
||||||
if (src->st_shndx == pcpundx)
|
|
||||||
return true;
|
|
||||||
#endif
|
|
||||||
|
|
||||||
sec = sechdrs + src->st_shndx;
|
|
||||||
if (!(sec->sh_flags & SHF_ALLOC)
|
|
||||||
#ifndef CONFIG_KALLSYMS_ALL
|
|
||||||
|| !(sec->sh_flags & SHF_EXECINSTR)
|
|
||||||
#endif
|
|
||||||
|| (sec->sh_entsize & INIT_OFFSET_MASK))
|
|
||||||
return false;
|
|
||||||
|
|
||||||
return true;
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
|
||||||
* We only allocate and copy the strings needed by the parts of symtab
|
|
||||||
* we keep. This is simple, but has the effect of making multiple
|
|
||||||
* copies of duplicates. We could be more sophisticated, see
|
|
||||||
* linux-kernel thread starting with
|
|
||||||
* <73defb5e4bca04a6431392cc341112b1@localhost>.
|
|
||||||
*/
|
|
||||||
static void layout_symtab(struct module *mod, struct load_info *info)
|
|
||||||
{
|
|
||||||
Elf_Shdr *symsect = info->sechdrs + info->index.sym;
|
|
||||||
Elf_Shdr *strsect = info->sechdrs + info->index.str;
|
|
||||||
const Elf_Sym *src;
|
|
||||||
unsigned int i, nsrc, ndst, strtab_size = 0;
|
|
||||||
|
|
||||||
/* Put symbol section at end of init part of module. */
|
|
||||||
symsect->sh_flags |= SHF_ALLOC;
|
|
||||||
symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
|
|
||||||
info->index.sym) | INIT_OFFSET_MASK;
|
|
||||||
pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
|
|
||||||
|
|
||||||
src = (void *)info->hdr + symsect->sh_offset;
|
|
||||||
nsrc = symsect->sh_size / sizeof(*src);
|
|
||||||
|
|
||||||
/* Compute total space required for the core symbols' strtab. */
|
|
||||||
for (ndst = i = 0; i < nsrc; i++) {
|
|
||||||
if (i == 0 || is_livepatch_module(mod) ||
|
|
||||||
is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
|
|
||||||
info->index.pcpu)) {
|
|
||||||
strtab_size += strlen(&info->strtab[src[i].st_name])+1;
|
|
||||||
ndst++;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Append room for core symbols at end of core part. */
|
|
||||||
info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
|
|
||||||
info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
|
|
||||||
mod->core_layout.size += strtab_size;
|
|
||||||
info->core_typeoffs = mod->core_layout.size;
|
|
||||||
mod->core_layout.size += ndst * sizeof(char);
|
|
||||||
mod->core_layout.size = debug_align(mod->core_layout.size);
|
|
||||||
|
|
||||||
/* Put string table section at end of init part of module. */
|
|
||||||
strsect->sh_flags |= SHF_ALLOC;
|
|
||||||
strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
|
|
||||||
info->index.str) | INIT_OFFSET_MASK;
|
|
||||||
pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
|
|
||||||
|
|
||||||
/* We'll tack temporary mod_kallsyms on the end. */
|
|
||||||
mod->init_layout.size = ALIGN(mod->init_layout.size,
|
|
||||||
__alignof__(struct mod_kallsyms));
|
|
||||||
info->mod_kallsyms_init_off = mod->init_layout.size;
|
|
||||||
mod->init_layout.size += sizeof(struct mod_kallsyms);
|
|
||||||
info->init_typeoffs = mod->init_layout.size;
|
|
||||||
mod->init_layout.size += nsrc * sizeof(char);
|
|
||||||
mod->init_layout.size = debug_align(mod->init_layout.size);
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
|
||||||
* We use the full symtab and strtab which layout_symtab arranged to
|
|
||||||
* be appended to the init section. Later we switch to the cut-down
|
|
||||||
* core-only ones.
|
|
||||||
*/
|
|
||||||
static void add_kallsyms(struct module *mod, const struct load_info *info)
|
|
||||||
{
|
|
||||||
unsigned int i, ndst;
|
|
||||||
const Elf_Sym *src;
|
|
||||||
Elf_Sym *dst;
|
|
||||||
char *s;
|
|
||||||
Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
|
|
||||||
|
|
||||||
/* Set up to point into init section. */
|
|
||||||
mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
|
|
||||||
|
|
||||||
mod->kallsyms->symtab = (void *)symsec->sh_addr;
|
|
||||||
mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
|
|
||||||
/* Make sure we get permanent strtab: don't use info->strtab. */
|
|
||||||
mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
|
|
||||||
mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Now populate the cut down core kallsyms for after init
|
|
||||||
* and set types up while we still have access to sections.
|
|
||||||
*/
|
|
||||||
mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
|
|
||||||
mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
|
|
||||||
mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
|
|
||||||
src = mod->kallsyms->symtab;
|
|
||||||
for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
|
|
||||||
mod->kallsyms->typetab[i] = elf_type(src + i, info);
|
|
||||||
if (i == 0 || is_livepatch_module(mod) ||
|
|
||||||
is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
|
|
||||||
info->index.pcpu)) {
|
|
||||||
mod->core_kallsyms.typetab[ndst] =
|
|
||||||
mod->kallsyms->typetab[i];
|
|
||||||
dst[ndst] = src[i];
|
|
||||||
dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
|
|
||||||
s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
|
|
||||||
KSYM_NAME_LEN) + 1;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
mod->core_kallsyms.num_symtab = ndst;
|
|
||||||
}
|
|
||||||
#else
|
|
||||||
static inline void layout_symtab(struct module *mod, struct load_info *info)
|
|
||||||
{
|
|
||||||
}
|
|
||||||
|
|
||||||
static void add_kallsyms(struct module *mod, const struct load_info *info)
|
|
||||||
{
|
|
||||||
}
|
|
||||||
#endif /* CONFIG_KALLSYMS */
|
|
||||||
|
|
||||||
#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
|
|
||||||
static void init_build_id(struct module *mod, const struct load_info *info)
|
|
||||||
{
|
|
||||||
const Elf_Shdr *sechdr;
|
|
||||||
unsigned int i;
|
|
||||||
|
|
||||||
for (i = 0; i < info->hdr->e_shnum; i++) {
|
|
||||||
sechdr = &info->sechdrs[i];
|
|
||||||
if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
|
|
||||||
!build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
|
|
||||||
sechdr->sh_size))
|
|
||||||
break;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
#else
|
|
||||||
static void init_build_id(struct module *mod, const struct load_info *info)
|
|
||||||
{
|
|
||||||
}
|
|
||||||
#endif
|
|
||||||
|
|
||||||
static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
|
static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
|
||||||
{
|
{
|
||||||
if (!debug)
|
if (!debug)
|
||||||
@ -3799,287 +3561,6 @@ static inline int within(unsigned long addr, void *start, unsigned long size)
|
|||||||
return ((void *)addr >= start && (void *)addr < start + size);
|
return ((void *)addr >= start && (void *)addr < start + size);
|
||||||
}
|
}
|
||||||
|
|
||||||
#ifdef CONFIG_KALLSYMS
|
|
||||||
/*
|
|
||||||
* This ignores the intensely annoying "mapping symbols" found
|
|
||||||
* in ARM ELF files: $a, $t and $d.
|
|
||||||
*/
|
|
||||||
static inline int is_arm_mapping_symbol(const char *str)
|
|
||||||
{
|
|
||||||
if (str[0] == '.' && str[1] == 'L')
|
|
||||||
return true;
|
|
||||||
return str[0] == '$' && strchr("axtd", str[1])
|
|
||||||
&& (str[2] == '\0' || str[2] == '.');
|
|
||||||
}
|
|
||||||
|
|
||||||
static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
|
|
||||||
{
|
|
||||||
return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Given a module and address, find the corresponding symbol and return its name
|
|
||||||
* while providing its size and offset if needed.
|
|
||||||
*/
|
|
||||||
static const char *find_kallsyms_symbol(struct module *mod,
|
|
||||||
unsigned long addr,
|
|
||||||
unsigned long *size,
|
|
||||||
unsigned long *offset)
|
|
||||||
{
|
|
||||||
unsigned int i, best = 0;
|
|
||||||
unsigned long nextval, bestval;
|
|
||||||
struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
|
|
||||||
|
|
||||||
/* At worse, next value is at end of module */
|
|
||||||
if (within_module_init(addr, mod))
|
|
||||||
nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
|
|
||||||
else
|
|
||||||
nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
|
|
||||||
|
|
||||||
bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Scan for closest preceding symbol, and next symbol. (ELF
|
|
||||||
* starts real symbols at 1).
|
|
||||||
*/
|
|
||||||
for (i = 1; i < kallsyms->num_symtab; i++) {
|
|
||||||
const Elf_Sym *sym = &kallsyms->symtab[i];
|
|
||||||
unsigned long thisval = kallsyms_symbol_value(sym);
|
|
||||||
|
|
||||||
if (sym->st_shndx == SHN_UNDEF)
|
|
||||||
continue;
|
|
||||||
|
|
||||||
/*
|
|
||||||
* We ignore unnamed symbols: they're uninformative
|
|
||||||
* and inserted at a whim.
|
|
||||||
*/
|
|
||||||
if (*kallsyms_symbol_name(kallsyms, i) == '\0'
|
|
||||||
|| is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
|
|
||||||
continue;
|
|
||||||
|
|
||||||
if (thisval <= addr && thisval > bestval) {
|
|
||||||
best = i;
|
|
||||||
bestval = thisval;
|
|
||||||
}
|
|
||||||
if (thisval > addr && thisval < nextval)
|
|
||||||
nextval = thisval;
|
|
||||||
}
|
|
||||||
|
|
||||||
if (!best)
|
|
||||||
return NULL;
|
|
||||||
|
|
||||||
if (size)
|
|
||||||
*size = nextval - bestval;
|
|
||||||
if (offset)
|
|
||||||
*offset = addr - bestval;
|
|
||||||
|
|
||||||
return kallsyms_symbol_name(kallsyms, best);
|
|
||||||
}
|
|
||||||
|
|
||||||
void * __weak dereference_module_function_descriptor(struct module *mod,
|
|
||||||
void *ptr)
|
|
||||||
{
|
|
||||||
return ptr;
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
|
||||||
* For kallsyms to ask for address resolution. NULL means not found. Careful
|
|
||||||
* not to lock to avoid deadlock on oopses, simply disable preemption.
|
|
||||||
*/
|
|
||||||
const char *module_address_lookup(unsigned long addr,
|
|
||||||
unsigned long *size,
|
|
||||||
unsigned long *offset,
|
|
||||||
char **modname,
|
|
||||||
const unsigned char **modbuildid,
|
|
||||||
char *namebuf)
|
|
||||||
{
|
|
||||||
const char *ret = NULL;
|
|
||||||
struct module *mod;
|
|
||||||
|
|
||||||
preempt_disable();
|
|
||||||
mod = __module_address(addr);
|
|
||||||
if (mod) {
|
|
||||||
if (modname)
|
|
||||||
*modname = mod->name;
|
|
||||||
if (modbuildid) {
|
|
||||||
#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
|
|
||||||
*modbuildid = mod->build_id;
|
|
||||||
#else
|
|
||||||
*modbuildid = NULL;
|
|
||||||
#endif
|
|
||||||
}
|
|
||||||
|
|
||||||
ret = find_kallsyms_symbol(mod, addr, size, offset);
|
|
||||||
}
|
|
||||||
/* Make a copy in here where it's safe */
|
|
||||||
if (ret) {
|
|
||||||
strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
|
|
||||||
ret = namebuf;
|
|
||||||
}
|
|
||||||
preempt_enable();
|
|
||||||
|
|
||||||
return ret;
|
|
||||||
}
|
|
||||||
|
|
||||||
int lookup_module_symbol_name(unsigned long addr, char *symname)
|
|
||||||
{
|
|
||||||
struct module *mod;
|
|
||||||
|
|
||||||
preempt_disable();
|
|
||||||
list_for_each_entry_rcu(mod, &modules, list) {
|
|
||||||
if (mod->state == MODULE_STATE_UNFORMED)
|
|
||||||
continue;
|
|
||||||
if (within_module(addr, mod)) {
|
|
||||||
const char *sym;
|
|
||||||
|
|
||||||
sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
|
|
||||||
if (!sym)
|
|
||||||
goto out;
|
|
||||||
|
|
||||||
strlcpy(symname, sym, KSYM_NAME_LEN);
|
|
||||||
preempt_enable();
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
out:
|
|
||||||
preempt_enable();
|
|
||||||
return -ERANGE;
|
|
||||||
}
|
|
||||||
|
|
||||||
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
|
|
||||||
unsigned long *offset, char *modname, char *name)
|
|
||||||
{
|
|
||||||
struct module *mod;
|
|
||||||
|
|
||||||
preempt_disable();
|
|
||||||
list_for_each_entry_rcu(mod, &modules, list) {
|
|
||||||
if (mod->state == MODULE_STATE_UNFORMED)
|
|
||||||
continue;
|
|
||||||
if (within_module(addr, mod)) {
|
|
||||||
const char *sym;
|
|
||||||
|
|
||||||
sym = find_kallsyms_symbol(mod, addr, size, offset);
|
|
||||||
if (!sym)
|
|
||||||
goto out;
|
|
||||||
if (modname)
|
|
||||||
strlcpy(modname, mod->name, MODULE_NAME_LEN);
|
|
||||||
if (name)
|
|
||||||
strlcpy(name, sym, KSYM_NAME_LEN);
|
|
||||||
preempt_enable();
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
out:
|
|
||||||
preempt_enable();
|
|
||||||
return -ERANGE;
|
|
||||||
}
|
|
||||||
|
|
||||||
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
|
|
||||||
char *name, char *module_name, int *exported)
|
|
||||||
{
|
|
||||||
struct module *mod;
|
|
||||||
|
|
||||||
preempt_disable();
|
|
||||||
list_for_each_entry_rcu(mod, &modules, list) {
|
|
||||||
struct mod_kallsyms *kallsyms;
|
|
||||||
|
|
||||||
if (mod->state == MODULE_STATE_UNFORMED)
|
|
||||||
continue;
|
|
||||||
kallsyms = rcu_dereference_sched(mod->kallsyms);
|
|
||||||
if (symnum < kallsyms->num_symtab) {
|
|
||||||
const Elf_Sym *sym = &kallsyms->symtab[symnum];
|
|
||||||
|
|
||||||
*value = kallsyms_symbol_value(sym);
|
|
||||||
*type = kallsyms->typetab[symnum];
|
|
||||||
strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
|
|
||||||
strlcpy(module_name, mod->name, MODULE_NAME_LEN);
|
|
||||||
*exported = is_exported(name, *value, mod);
|
|
||||||
preempt_enable();
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
symnum -= kallsyms->num_symtab;
|
|
||||||
}
|
|
||||||
preempt_enable();
|
|
||||||
return -ERANGE;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Given a module and name of symbol, find and return the symbol's value */
|
|
||||||
static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
|
|
||||||
{
|
|
||||||
unsigned int i;
|
|
||||||
struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
|
|
||||||
|
|
||||||
for (i = 0; i < kallsyms->num_symtab; i++) {
|
|
||||||
const Elf_Sym *sym = &kallsyms->symtab[i];
|
|
||||||
|
|
||||||
if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
|
|
||||||
sym->st_shndx != SHN_UNDEF)
|
|
||||||
return kallsyms_symbol_value(sym);
|
|
||||||
}
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Look for this name: can be of form module:name. */
|
|
||||||
unsigned long module_kallsyms_lookup_name(const char *name)
|
|
||||||
{
|
|
||||||
struct module *mod;
|
|
||||||
char *colon;
|
|
||||||
unsigned long ret = 0;
|
|
||||||
|
|
||||||
/* Don't lock: we're in enough trouble already. */
|
|
||||||
preempt_disable();
|
|
||||||
if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
|
|
||||||
if ((mod = find_module_all(name, colon - name, false)) != NULL)
|
|
||||||
ret = find_kallsyms_symbol_value(mod, colon+1);
|
|
||||||
} else {
|
|
||||||
list_for_each_entry_rcu(mod, &modules, list) {
|
|
||||||
if (mod->state == MODULE_STATE_UNFORMED)
|
|
||||||
continue;
|
|
||||||
if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
|
|
||||||
break;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
preempt_enable();
|
|
||||||
return ret;
|
|
||||||
}
|
|
||||||
|
|
||||||
#ifdef CONFIG_LIVEPATCH
|
|
||||||
int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
|
|
||||||
struct module *, unsigned long),
|
|
||||||
void *data)
|
|
||||||
{
|
|
||||||
struct module *mod;
|
|
||||||
unsigned int i;
|
|
||||||
int ret = 0;
|
|
||||||
|
|
||||||
mutex_lock(&module_mutex);
|
|
||||||
list_for_each_entry(mod, &modules, list) {
|
|
||||||
/* We hold module_mutex: no need for rcu_dereference_sched */
|
|
||||||
struct mod_kallsyms *kallsyms = mod->kallsyms;
|
|
||||||
|
|
||||||
if (mod->state == MODULE_STATE_UNFORMED)
|
|
||||||
continue;
|
|
||||||
for (i = 0; i < kallsyms->num_symtab; i++) {
|
|
||||||
const Elf_Sym *sym = &kallsyms->symtab[i];
|
|
||||||
|
|
||||||
if (sym->st_shndx == SHN_UNDEF)
|
|
||||||
continue;
|
|
||||||
|
|
||||||
ret = fn(data, kallsyms_symbol_name(kallsyms, i),
|
|
||||||
mod, kallsyms_symbol_value(sym));
|
|
||||||
if (ret != 0)
|
|
||||||
goto out;
|
|
||||||
|
|
||||||
cond_resched();
|
|
||||||
}
|
|
||||||
}
|
|
||||||
out:
|
|
||||||
mutex_unlock(&module_mutex);
|
|
||||||
return ret;
|
|
||||||
}
|
|
||||||
#endif /* CONFIG_LIVEPATCH */
|
|
||||||
#endif /* CONFIG_KALLSYMS */
|
|
||||||
|
|
||||||
static void cfi_init(struct module *mod)
|
static void cfi_init(struct module *mod)
|
||||||
{
|
{
|
||||||
#ifdef CONFIG_CFI_CLANG
|
#ifdef CONFIG_CFI_CLANG
|
||||||
|
|||||||
Loading…
Reference in New Issue
Block a user