diff options
Diffstat (limited to 'kernel/kallsyms.c')
| -rw-r--r-- | kernel/kallsyms.c | 71 |
1 files changed, 51 insertions, 20 deletions
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index fafd1a3ef0da..127e7cfafa55 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -23,16 +23,11 @@ #include <linux/mm.h> #include <linux/ctype.h> #include <linux/slab.h> +#include <linux/filter.h> #include <linux/compiler.h> #include <asm/sections.h> -#ifdef CONFIG_KALLSYMS_ALL -#define all_var 1 -#else -#define all_var 0 -#endif - /* * These will be re-linked against their real values * during the second link stage. @@ -81,7 +76,7 @@ static inline int is_kernel(unsigned long addr) static int is_ksym_addr(unsigned long addr) { - if (all_var) + if (IS_ENABLED(CONFIG_KALLSYMS_ALL)) return is_kernel(addr); return is_kernel_text(addr) || is_kernel_inittext(addr); @@ -279,7 +274,7 @@ static unsigned long get_symbol_pos(unsigned long addr, if (!symbol_end) { if (is_kernel_inittext(addr)) symbol_end = (unsigned long)_einittext; - else if (all_var) + else if (IS_ENABLED(CONFIG_KALLSYMS_ALL)) symbol_end = (unsigned long)_end; else symbol_end = (unsigned long)_etext; @@ -300,10 +295,11 @@ int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, unsigned long *offset) { char namebuf[KSYM_NAME_LEN]; + if (is_ksym_addr(addr)) return !!get_symbol_pos(addr, symbolsize, offset); - - return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf); + return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf) || + !!__bpf_address_lookup(addr, symbolsize, offset, namebuf); } /* @@ -318,6 +314,8 @@ const char *kallsyms_lookup(unsigned long addr, unsigned long *offset, char **modname, char *namebuf) { + const char *ret; + namebuf[KSYM_NAME_LEN - 1] = 0; namebuf[0] = 0; @@ -333,9 +331,13 @@ const char *kallsyms_lookup(unsigned long addr, return namebuf; } - /* See if it's in a module. */ - return module_address_lookup(addr, symbolsize, offset, modname, - namebuf); + /* See if it's in a module or a BPF JITed image. */ + ret = module_address_lookup(addr, symbolsize, offset, + modname, namebuf); + if (!ret) + ret = bpf_address_lookup(addr, symbolsize, + offset, modname, namebuf); + return ret; } int lookup_symbol_name(unsigned long addr, char *symname) @@ -471,6 +473,7 @@ EXPORT_SYMBOL(__print_symbol); /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */ struct kallsym_iter { loff_t pos; + loff_t pos_mod_end; unsigned long value; unsigned int nameoff; /* If iterating in core kernel symbols. */ char type; @@ -481,13 +484,27 @@ struct kallsym_iter { static int get_ksymbol_mod(struct kallsym_iter *iter) { - if (module_get_kallsym(iter->pos - kallsyms_num_syms, &iter->value, - &iter->type, iter->name, iter->module_name, - &iter->exported) < 0) + int ret = module_get_kallsym(iter->pos - kallsyms_num_syms, + &iter->value, &iter->type, + iter->name, iter->module_name, + &iter->exported); + if (ret < 0) { + iter->pos_mod_end = iter->pos; return 0; + } + return 1; } +static int get_ksymbol_bpf(struct kallsym_iter *iter) +{ + iter->module_name[0] = '\0'; + iter->exported = 0; + return bpf_get_kallsym(iter->pos - iter->pos_mod_end, + &iter->value, &iter->type, + iter->name) < 0 ? 0 : 1; +} + /* Returns space to next name. */ static unsigned long get_ksymbol_core(struct kallsym_iter *iter) { @@ -508,16 +525,30 @@ static void reset_iter(struct kallsym_iter *iter, loff_t new_pos) iter->name[0] = '\0'; iter->nameoff = get_symbol_offset(new_pos); iter->pos = new_pos; + if (new_pos == 0) + iter->pos_mod_end = 0; +} + +static int update_iter_mod(struct kallsym_iter *iter, loff_t pos) +{ + iter->pos = pos; + + if (iter->pos_mod_end > 0 && + iter->pos_mod_end < iter->pos) + return get_ksymbol_bpf(iter); + + if (!get_ksymbol_mod(iter)) + return get_ksymbol_bpf(iter); + + return 1; } /* Returns false if pos at or past end of file. */ static int update_iter(struct kallsym_iter *iter, loff_t pos) { /* Module symbols can be accessed randomly. */ - if (pos >= kallsyms_num_syms) { - iter->pos = pos; - return get_ksymbol_mod(iter); - } + if (pos >= kallsyms_num_syms) + return update_iter_mod(iter, pos); /* If we're not on the desired position, reset to new position. */ if (pos != iter->pos) |