diff options
Diffstat (limited to 'kernel/kallsyms.c')
| -rw-r--r-- | kernel/kallsyms.c | 579 |
1 files changed, 408 insertions, 171 deletions
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 127e7cfafa55..049e296f586c 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * kallsyms.c: in-kernel printing of symbolic oopses and stack traces. * @@ -12,7 +13,6 @@ * compression (see scripts/kallsyms.c for a more complete description) */ #include <linux/kallsyms.h> -#include <linux/module.h> #include <linux/init.h> #include <linux/seq_file.h> #include <linux/fs.h> @@ -20,67 +20,19 @@ #include <linux/err.h> #include <linux/proc_fs.h> #include <linux/sched.h> /* for cond_resched */ -#include <linux/mm.h> #include <linux/ctype.h> #include <linux/slab.h> #include <linux/filter.h> +#include <linux/ftrace.h> +#include <linux/kprobes.h> +#include <linux/build_bug.h> #include <linux/compiler.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/bsearch.h> +#include <linux/btf_ids.h> -#include <asm/sections.h> - -/* - * These will be re-linked against their real values - * during the second link stage. - */ -extern const unsigned long kallsyms_addresses[] __weak; -extern const int kallsyms_offsets[] __weak; -extern const u8 kallsyms_names[] __weak; - -/* - * Tell the compiler that the count isn't in the small data section if the arch - * has one (eg: FRV). - */ -extern const unsigned long kallsyms_num_syms -__attribute__((weak, section(".rodata"))); - -extern const unsigned long kallsyms_relative_base -__attribute__((weak, section(".rodata"))); - -extern const u8 kallsyms_token_table[] __weak; -extern const u16 kallsyms_token_index[] __weak; - -extern const unsigned long kallsyms_markers[] __weak; - -static inline int is_kernel_inittext(unsigned long addr) -{ - if (addr >= (unsigned long)_sinittext - && addr <= (unsigned long)_einittext) - return 1; - return 0; -} - -static inline int is_kernel_text(unsigned long addr) -{ - if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) || - arch_is_kernel_text(addr)) - return 1; - return in_gate_area_no_mm(addr); -} - -static inline int is_kernel(unsigned long addr) -{ - if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) - return 1; - return in_gate_area_no_mm(addr); -} - -static int is_ksym_addr(unsigned long addr) -{ - if (IS_ENABLED(CONFIG_KALLSYMS_ALL)) - return is_kernel(addr); - - return is_kernel_text(addr) || is_kernel_inittext(addr); -} +#include "kallsyms_internal.h" /* * Expand a compressed symbol data into the resulting uncompressed string, @@ -91,18 +43,27 @@ static unsigned int kallsyms_expand_symbol(unsigned int off, char *result, size_t maxlen) { int len, skipped_first = 0; - const u8 *tptr, *data; + const char *tptr; + const u8 *data; /* Get the compressed symbol length from the first symbol byte. */ data = &kallsyms_names[off]; len = *data; data++; + off++; + + /* If MSB is 1, it is a "big" symbol, so needs an additional byte. */ + if ((len & 0x80) != 0) { + len = (len & 0x7F) | (*data << 7); + data++; + off++; + } /* * Update the offset to return the offset for the next symbol on * the compressed stream. */ - off += len + 1; + off += len; /* * For every byte on the compressed symbol data, copy the table @@ -142,8 +103,11 @@ static char kallsyms_get_symbol_type(unsigned int off) { /* * Get just the first code, look it up in the token table, - * and return the first char from this token. + * and return the first char from this token. If MSB of length + * is 1, it is a "big" symbol, so needs an additional byte. */ + if (kallsyms_names[off] & 0x80) + off++; return kallsyms_token_table[kallsyms_token_index[kallsyms_names[off + 1]]]; } @@ -155,7 +119,7 @@ static char kallsyms_get_symbol_type(unsigned int off) static unsigned int get_symbol_offset(unsigned long pos) { const u8 *name; - int i; + int i, len; /* * Use the closest marker we have. We have markers every 256 positions, @@ -169,48 +133,116 @@ static unsigned int get_symbol_offset(unsigned long pos) * so we just need to add the len to the current pointer for every * symbol we wish to skip. */ - for (i = 0; i < (pos & 0xFF); i++) - name = name + (*name) + 1; + for (i = 0; i < (pos & 0xFF); i++) { + len = *name; + + /* + * If MSB is 1, it is a "big" symbol, so we need to look into + * the next byte (and skip it, too). + */ + if ((len & 0x80) != 0) + len = ((len & 0x7F) | (name[1] << 7)) + 1; + + name = name + len + 1; + } return name - kallsyms_names; } -static unsigned long kallsyms_sym_address(int idx) +unsigned long kallsyms_sym_address(int idx) { - if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE)) - return kallsyms_addresses[idx]; + /* values are unsigned offsets */ + return kallsyms_relative_base + (u32)kallsyms_offsets[idx]; +} - /* values are unsigned offsets if --absolute-percpu is not in effect */ - if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU)) - return kallsyms_relative_base + (u32)kallsyms_offsets[idx]; +static unsigned int get_symbol_seq(int index) +{ + unsigned int i, seq = 0; - /* ...otherwise, positive offsets are absolute values */ - if (kallsyms_offsets[idx] >= 0) - return kallsyms_offsets[idx]; + for (i = 0; i < 3; i++) + seq = (seq << 8) | kallsyms_seqs_of_names[3 * index + i]; - /* ...and negative offsets are relative to kallsyms_relative_base - 1 */ - return kallsyms_relative_base - 1 - kallsyms_offsets[idx]; + return seq; } -/* Lookup the address for this symbol. Returns 0 if not found. */ -unsigned long kallsyms_lookup_name(const char *name) +static int kallsyms_lookup_names(const char *name, + unsigned int *start, + unsigned int *end) { + int ret; + int low, mid, high; + unsigned int seq, off; char namebuf[KSYM_NAME_LEN]; - unsigned long i; - unsigned int off; - for (i = 0, off = 0; i < kallsyms_num_syms; i++) { - off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); + low = 0; + high = kallsyms_num_syms - 1; + + while (low <= high) { + mid = low + (high - low) / 2; + seq = get_symbol_seq(mid); + off = get_symbol_offset(seq); + kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); + ret = strcmp(name, namebuf); + if (ret > 0) + low = mid + 1; + else if (ret < 0) + high = mid - 1; + else + break; + } + + if (low > high) + return -ESRCH; - if (strcmp(namebuf, name) == 0) - return kallsyms_sym_address(i); + low = mid; + while (low) { + seq = get_symbol_seq(low - 1); + off = get_symbol_offset(seq); + kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); + if (strcmp(name, namebuf)) + break; + low--; + } + *start = low; + + if (end) { + high = mid; + while (high < kallsyms_num_syms - 1) { + seq = get_symbol_seq(high + 1); + off = get_symbol_offset(seq); + kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); + if (strcmp(name, namebuf)) + break; + high++; + } + *end = high; } + + return 0; +} + +/* Lookup the address for this symbol. Returns 0 if not found. */ +unsigned long kallsyms_lookup_name(const char *name) +{ + int ret; + unsigned int i; + + /* Skip the search for empty string. */ + if (!*name) + return 0; + + ret = kallsyms_lookup_names(name, &i, NULL); + if (!ret) + return kallsyms_sym_address(get_symbol_seq(i)); + return module_kallsyms_lookup_name(name); } -EXPORT_SYMBOL_GPL(kallsyms_lookup_name); -int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, - unsigned long), +/* + * Iterate over all symbols in vmlinux. For symbols from modules use + * module_kallsyms_on_each_symbol instead. + */ +int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long), void *data) { char namebuf[KSYM_NAME_LEN]; @@ -220,13 +252,31 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, for (i = 0, off = 0; i < kallsyms_num_syms; i++) { off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); - ret = fn(data, namebuf, NULL, kallsyms_sym_address(i)); + ret = fn(data, namebuf, kallsyms_sym_address(i)); if (ret != 0) return ret; + cond_resched(); } - return module_kallsyms_on_each_symbol(fn, data); + return 0; +} + +int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long), + const char *name, void *data) +{ + int ret; + unsigned int i, start, end; + + ret = kallsyms_lookup_names(name, &start, &end); + if (ret) + return 0; + + for (i = start; !ret && i <= end; i++) { + ret = fn(data, kallsyms_sym_address(get_symbol_seq(i))); + cond_resched(); + } + + return ret; } -EXPORT_SYMBOL_GPL(kallsyms_on_each_symbol); static unsigned long get_symbol_pos(unsigned long addr, unsigned long *symbolsize, @@ -235,13 +285,7 @@ static unsigned long get_symbol_pos(unsigned long addr, unsigned long symbol_start = 0, symbol_end = 0; unsigned long i, low, high, mid; - /* This kernel should never had been booted. */ - if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE)) - BUG_ON(!kallsyms_addresses); - else - BUG_ON(!kallsyms_offsets); - - /* Do a binary search on the sorted kallsyms_addresses array. */ + /* Do a binary search on the sorted kallsyms_offsets array. */ low = 0; high = kallsyms_num_syms; @@ -296,25 +340,20 @@ int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, { 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) || + if (is_ksym_addr(addr)) { + get_symbol_pos(addr, symbolsize, offset); + return 1; + } + return !!module_address_lookup(addr, symbolsize, offset, NULL, NULL, namebuf) || !!__bpf_address_lookup(addr, symbolsize, offset, namebuf); } -/* - * Lookup an address - * - modname is set to NULL if it's in the kernel. - * - We guarantee that the returned name is valid until we reschedule even if. - * It resides in a module. - * - We also guarantee that modname will be valid until rescheduled. - */ -const char *kallsyms_lookup(unsigned long addr, - unsigned long *symbolsize, - unsigned long *offset, - char **modname, char *namebuf) +static int kallsyms_lookup_buildid(unsigned long addr, + unsigned long *symbolsize, + unsigned long *offset, char **modname, + const unsigned char **modbuildid, char *namebuf) { - const char *ret; + int ret; namebuf[KSYM_NAME_LEN - 1] = 0; namebuf[0] = 0; @@ -328,18 +367,47 @@ const char *kallsyms_lookup(unsigned long addr, namebuf, KSYM_NAME_LEN); if (modname) *modname = NULL; - return namebuf; + if (modbuildid) + *modbuildid = NULL; + + return strlen(namebuf); } /* See if it's in a module or a BPF JITed image. */ ret = module_address_lookup(addr, symbolsize, offset, - modname, namebuf); + modname, modbuildid, namebuf); if (!ret) ret = bpf_address_lookup(addr, symbolsize, offset, modname, namebuf); + + if (!ret) + ret = ftrace_mod_address_lookup(addr, symbolsize, + offset, modname, namebuf); + return ret; } +/* + * Lookup an address + * - modname is set to NULL if it's in the kernel. + * - We guarantee that the returned name is valid until we reschedule even if. + * It resides in a module. + * - We also guarantee that modname will be valid until rescheduled. + */ +const char *kallsyms_lookup(unsigned long addr, + unsigned long *symbolsize, + unsigned long *offset, + char **modname, char *namebuf) +{ + int ret = kallsyms_lookup_buildid(addr, symbolsize, offset, modname, + NULL, namebuf); + + if (!ret) + return NULL; + + return namebuf; +} + int lookup_symbol_name(unsigned long addr, char *symname) { symname[0] = '\0'; @@ -358,50 +426,39 @@ int lookup_symbol_name(unsigned long addr, char *symname) return lookup_module_symbol_name(addr, symname); } -int lookup_symbol_attrs(unsigned long addr, unsigned long *size, - unsigned long *offset, char *modname, char *name) -{ - name[0] = '\0'; - name[KSYM_NAME_LEN - 1] = '\0'; - - if (is_ksym_addr(addr)) { - unsigned long pos; - - pos = get_symbol_pos(addr, size, offset); - /* Grab name */ - kallsyms_expand_symbol(get_symbol_offset(pos), - name, KSYM_NAME_LEN); - modname[0] = '\0'; - return 0; - } - /* See if it's in a module. */ - return lookup_module_symbol_attrs(addr, size, offset, modname, name); -} - /* Look up a kernel symbol and return it in a text buffer. */ static int __sprint_symbol(char *buffer, unsigned long address, - int symbol_offset, int add_offset) + int symbol_offset, int add_offset, int add_buildid) { char *modname; - const char *name; + const unsigned char *buildid; unsigned long offset, size; int len; address += symbol_offset; - name = kallsyms_lookup(address, &size, &offset, &modname, buffer); - if (!name) + len = kallsyms_lookup_buildid(address, &size, &offset, &modname, &buildid, + buffer); + if (!len) return sprintf(buffer, "0x%lx", address - symbol_offset); - if (name != buffer) - strcpy(buffer, name); - len = strlen(buffer); offset -= symbol_offset; if (add_offset) len += sprintf(buffer + len, "+%#lx/%#lx", offset, size); - if (modname) - len += sprintf(buffer + len, " [%s]", modname); + if (modname) { + len += sprintf(buffer + len, " [%s", modname); +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) + if (add_buildid && buildid) { + /* build ID should match length of sprintf */ +#if IS_ENABLED(CONFIG_MODULES) + static_assert(sizeof(typeof_member(struct module, build_id)) == 20); +#endif + len += sprintf(buffer + len, " %20phN", buildid); + } +#endif + len += sprintf(buffer + len, "]"); + } return len; } @@ -419,11 +476,28 @@ static int __sprint_symbol(char *buffer, unsigned long address, */ int sprint_symbol(char *buffer, unsigned long address) { - return __sprint_symbol(buffer, address, 0, 1); + return __sprint_symbol(buffer, address, 0, 1, 0); } EXPORT_SYMBOL_GPL(sprint_symbol); /** + * sprint_symbol_build_id - Look up a kernel symbol and return it in a text buffer + * @buffer: buffer to be stored + * @address: address to lookup + * + * This function looks up a kernel symbol with @address and stores its name, + * offset, size, module name and module build ID to @buffer if possible. If no + * symbol was found, just saves its @address as is. + * + * This function returns the number of bytes stored in @buffer. + */ +int sprint_symbol_build_id(char *buffer, unsigned long address) +{ + return __sprint_symbol(buffer, address, 0, 1, 1); +} +EXPORT_SYMBOL_GPL(sprint_symbol_build_id); + +/** * sprint_symbol_no_offset - Look up a kernel symbol and return it in a text buffer * @buffer: buffer to be stored * @address: address to lookup @@ -436,7 +510,7 @@ EXPORT_SYMBOL_GPL(sprint_symbol); */ int sprint_symbol_no_offset(char *buffer, unsigned long address) { - return __sprint_symbol(buffer, address, 0, 0); + return __sprint_symbol(buffer, address, 0, 0, 0); } EXPORT_SYMBOL_GPL(sprint_symbol_no_offset); @@ -456,30 +530,42 @@ EXPORT_SYMBOL_GPL(sprint_symbol_no_offset); */ int sprint_backtrace(char *buffer, unsigned long address) { - return __sprint_symbol(buffer, address, -1, 1); + return __sprint_symbol(buffer, address, -1, 1, 0); } -/* Look up a kernel symbol and print it to the kernel messages. */ -void __print_symbol(const char *fmt, unsigned long address) +/** + * sprint_backtrace_build_id - Look up a backtrace symbol and return it in a text buffer + * @buffer: buffer to be stored + * @address: address to lookup + * + * This function is for stack backtrace and does the same thing as + * sprint_symbol() but with modified/decreased @address. If there is a + * tail-call to the function marked "noreturn", gcc optimized out code after + * the call so that the stack-saved return address could point outside of the + * caller. This function ensures that kallsyms will find the original caller + * by decreasing @address. This function also appends the module build ID to + * the @buffer if @address is within a kernel module. + * + * This function returns the number of bytes stored in @buffer. + */ +int sprint_backtrace_build_id(char *buffer, unsigned long address) { - char buffer[KSYM_SYMBOL_LEN]; - - sprint_symbol(buffer, address); - - printk(fmt, buffer); + return __sprint_symbol(buffer, address, -1, 1, 1); } -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; + loff_t pos_ftrace_mod_end; + loff_t pos_bpf_end; unsigned long value; unsigned int nameoff; /* If iterating in core kernel symbols. */ char type; char name[KSYM_NAME_LEN]; char module_name[MODULE_NAME_LEN]; int exported; + int show_value; }; static int get_ksymbol_mod(struct kallsym_iter *iter) @@ -496,13 +582,54 @@ static int get_ksymbol_mod(struct kallsym_iter *iter) return 1; } +/* + * ftrace_mod_get_kallsym() may also get symbols for pages allocated for ftrace + * purposes. In that case "__builtin__ftrace" is used as a module name, even + * though "__builtin__ftrace" is not a module. + */ +static int get_ksymbol_ftrace_mod(struct kallsym_iter *iter) +{ + int ret = ftrace_mod_get_kallsym(iter->pos - iter->pos_mod_end, + &iter->value, &iter->type, + iter->name, iter->module_name, + &iter->exported); + if (ret < 0) { + iter->pos_ftrace_mod_end = iter->pos; + return 0; + } + + return 1; +} + static int get_ksymbol_bpf(struct kallsym_iter *iter) { - iter->module_name[0] = '\0'; + int ret; + + strscpy(iter->module_name, "bpf", MODULE_NAME_LEN); iter->exported = 0; - return bpf_get_kallsym(iter->pos - iter->pos_mod_end, - &iter->value, &iter->type, - iter->name) < 0 ? 0 : 1; + ret = bpf_get_kallsym(iter->pos - iter->pos_ftrace_mod_end, + &iter->value, &iter->type, + iter->name); + if (ret < 0) { + iter->pos_bpf_end = iter->pos; + return 0; + } + + return 1; +} + +/* + * This uses "__builtin__kprobes" as a module name for symbols for pages + * allocated for kprobes' purposes, even though "__builtin__kprobes" is not a + * module. + */ +static int get_ksymbol_kprobe(struct kallsym_iter *iter) +{ + strscpy(iter->module_name, "__builtin__kprobes", MODULE_NAME_LEN); + iter->exported = 0; + return kprobe_get_kallsym(iter->pos - iter->pos_bpf_end, + &iter->value, &iter->type, + iter->name) < 0 ? 0 : 1; } /* Returns space to next name. */ @@ -525,22 +652,35 @@ 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) + if (new_pos == 0) { iter->pos_mod_end = 0; + iter->pos_ftrace_mod_end = 0; + iter->pos_bpf_end = 0; + } } +/* + * The end position (last + 1) of each additional kallsyms section is recorded + * in iter->pos_..._end as each section is added, and so can be used to + * determine which get_ksymbol_...() function to call next. + */ 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 ((!iter->pos_mod_end || iter->pos_mod_end > pos) && + get_ksymbol_mod(iter)) + return 1; - if (!get_ksymbol_mod(iter)) - return get_ksymbol_bpf(iter); + if ((!iter->pos_ftrace_mod_end || iter->pos_ftrace_mod_end > pos) && + get_ksymbol_ftrace_mod(iter)) + return 1; - return 1; + if ((!iter->pos_bpf_end || iter->pos_bpf_end > pos) && + get_ksymbol_bpf(iter)) + return 1; + + return get_ksymbol_kprobe(iter); } /* Returns false if pos at or past end of file. */ @@ -582,12 +722,15 @@ static void s_stop(struct seq_file *m, void *p) static int s_show(struct seq_file *m, void *p) { + void *value; struct kallsym_iter *iter = m->private; /* Some debugging symbols have no name. Ignore them. */ if (!iter->name[0]) return 0; + value = iter->show_value ? (void *)iter->value : NULL; + if (iter->module_name[0]) { char type; @@ -597,10 +740,10 @@ static int s_show(struct seq_file *m, void *p) */ type = iter->exported ? toupper(iter->type) : tolower(iter->type); - seq_printf(m, "%pK %c %s\t[%s]\n", (void *)iter->value, + seq_printf(m, "%px %c %s\t[%s]\n", value, type, iter->name, iter->module_name); } else - seq_printf(m, "%pK %c %s\n", (void *)iter->value, + seq_printf(m, "%px %c %s\n", value, iter->type, iter->name); return 0; } @@ -612,6 +755,95 @@ static const struct seq_operations kallsyms_op = { .show = s_show }; +#ifdef CONFIG_BPF_SYSCALL + +struct bpf_iter__ksym { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct kallsym_iter *, ksym); +}; + +static int ksym_prog_seq_show(struct seq_file *m, bool in_stop) +{ + struct bpf_iter__ksym ctx; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + + meta.seq = m; + prog = bpf_iter_get_info(&meta, in_stop); + if (!prog) + return 0; + + ctx.meta = &meta; + ctx.ksym = m ? m->private : NULL; + return bpf_iter_run_prog(prog, &ctx); +} + +static int bpf_iter_ksym_seq_show(struct seq_file *m, void *p) +{ + return ksym_prog_seq_show(m, false); +} + +static void bpf_iter_ksym_seq_stop(struct seq_file *m, void *p) +{ + if (!p) + (void) ksym_prog_seq_show(m, true); + else + s_stop(m, p); +} + +static const struct seq_operations bpf_iter_ksym_ops = { + .start = s_start, + .next = s_next, + .stop = bpf_iter_ksym_seq_stop, + .show = bpf_iter_ksym_seq_show, +}; + +static int bpf_iter_ksym_init(void *priv_data, struct bpf_iter_aux_info *aux) +{ + struct kallsym_iter *iter = priv_data; + + reset_iter(iter, 0); + + /* cache here as in kallsyms_open() case; use current process + * credentials to tell BPF iterators if values should be shown. + */ + iter->show_value = kallsyms_show_value(current_cred()); + + return 0; +} + +DEFINE_BPF_ITER_FUNC(ksym, struct bpf_iter_meta *meta, struct kallsym_iter *ksym) + +static const struct bpf_iter_seq_info ksym_iter_seq_info = { + .seq_ops = &bpf_iter_ksym_ops, + .init_seq_private = bpf_iter_ksym_init, + .fini_seq_private = NULL, + .seq_priv_size = sizeof(struct kallsym_iter), +}; + +static struct bpf_iter_reg ksym_iter_reg_info = { + .target = "ksym", + .feature = BPF_ITER_RESCHED, + .ctx_arg_info_size = 1, + .ctx_arg_info = { + { offsetof(struct bpf_iter__ksym, ksym), + PTR_TO_BTF_ID_OR_NULL }, + }, + .seq_info = &ksym_iter_seq_info, +}; + +BTF_ID_LIST_SINGLE(btf_ksym_iter_id, struct, kallsym_iter) + +static int __init bpf_ksym_iter_register(void) +{ + ksym_iter_reg_info.ctx_arg_info[0].btf_id = *btf_ksym_iter_id; + return bpf_iter_reg_target(&ksym_iter_reg_info); +} + +late_initcall(bpf_ksym_iter_register); + +#endif /* CONFIG_BPF_SYSCALL */ + static int kallsyms_open(struct inode *inode, struct file *file) { /* @@ -625,6 +857,11 @@ static int kallsyms_open(struct inode *inode, struct file *file) return -ENOMEM; reset_iter(iter, 0); + /* + * Instead of checking this on every s_show() call, cache + * the result here at open time. + */ + iter->show_value = kallsyms_show_value(file->f_cred); return 0; } @@ -648,16 +885,16 @@ const char *kdb_walk_kallsyms(loff_t *pos) } #endif /* CONFIG_KGDB_KDB */ -static const struct file_operations kallsyms_operations = { - .open = kallsyms_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release_private, +static const struct proc_ops kallsyms_proc_ops = { + .proc_open = kallsyms_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = seq_release_private, }; static int __init kallsyms_init(void) { - proc_create("kallsyms", 0444, NULL, &kallsyms_operations); + proc_create("kallsyms", 0444, NULL, &kallsyms_proc_ops); return 0; } device_initcall(kallsyms_init); |