#include <linux/bsearch.h>
#include <linux/btf_ids.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 int kallsyms_num_syms
-__section(".rodata") __attribute__((weak));
-
-extern const unsigned long kallsyms_relative_base
-__section(".rodata") __attribute__((weak));
-
-extern const char kallsyms_token_table[] __weak;
-extern const u16 kallsyms_token_index[] __weak;
-
-extern const unsigned int kallsyms_markers[] __weak;
+#include "kallsyms_internal.h"
/*
* Expand a compressed symbol data into the resulting uncompressed string,
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
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,
* 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];
return kallsyms_relative_base - 1 - kallsyms_offsets[idx];
}
-static bool cleanup_symbol_name(char *s)
+static void cleanup_symbol_name(char *s)
{
char *res;
if (!IS_ENABLED(CONFIG_LTO_CLANG))
- return false;
+ return;
/*
* LLVM appends various suffixes for local functions and variables that
* must be promoted to global scope as part of LTO. This can break
* hooking of static functions with kprobes. '.' is not a valid
- * character in an identifier in C. Suffixes observed:
+ * character in an identifier in C. Suffixes only in LLVM LTO observed:
* - foo.llvm.[0-9a-f]+
- * - foo.[0-9a-f]+
- * - foo.[0-9a-f]+.cfi_jt
*/
- res = strchr(s, '.');
- if (res) {
+ res = strstr(s, ".llvm.");
+ if (res)
*res = '\0';
- return true;
- }
- if (!IS_ENABLED(CONFIG_CFI_CLANG) ||
- !IS_ENABLED(CONFIG_LTO_CLANG_THIN) ||
- CONFIG_CLANG_VERSION >= 130000)
- return false;
+ return;
+}
- /*
- * Prior to LLVM 13, the following suffixes were observed when thinLTO
- * and CFI are both enabled:
- * - foo$[0-9]+
+static int compare_symbol_name(const char *name, char *namebuf)
+{
+ /* The kallsyms_seqs_of_names is sorted based on names after
+ * cleanup_symbol_name() (see scripts/kallsyms.c) if clang lto is enabled.
+ * To ensure correct bisection in kallsyms_lookup_names(), do
+ * cleanup_symbol_name(namebuf) before comparing name and namebuf.
*/
- res = strrchr(s, '$');
- if (res) {
- *res = '\0';
- return true;
+ cleanup_symbol_name(namebuf);
+ return strcmp(name, namebuf);
+}
+
+static unsigned int get_symbol_seq(int index)
+{
+ unsigned int i, seq = 0;
+
+ for (i = 0; i < 3; i++)
+ seq = (seq << 8) | kallsyms_seqs_of_names[3 * index + i];
+
+ return seq;
+}
+
+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];
+
+ 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 = compare_symbol_name(name, namebuf);
+ if (ret > 0)
+ low = mid + 1;
+ else if (ret < 0)
+ high = mid - 1;
+ else
+ break;
+ }
+
+ if (low > high)
+ return -ESRCH;
+
+ low = mid;
+ while (low) {
+ seq = get_symbol_seq(low - 1);
+ off = get_symbol_offset(seq);
+ kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
+ if (compare_symbol_name(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 (compare_symbol_name(name, namebuf))
+ break;
+ high++;
+ }
+ *end = high;
}
- return false;
+ return 0;
}
/* Lookup the address for this symbol. Returns 0 if not found. */
unsigned long kallsyms_lookup_name(const char *name)
{
- char namebuf[KSYM_NAME_LEN];
- unsigned long i;
- unsigned int off;
+ int ret;
+ unsigned int i;
/* Skip the search for empty string. */
if (!*name)
return 0;
- for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
- off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
-
- if (strcmp(namebuf, name) == 0)
- return kallsyms_sym_address(i);
+ ret = kallsyms_lookup_names(name, &i, NULL);
+ if (!ret)
+ return kallsyms_sym_address(get_symbol_seq(i));
- if (cleanup_symbol_name(namebuf) && strcmp(namebuf, name) == 0)
- return kallsyms_sym_address(i);
- }
return module_kallsyms_lookup_name(name);
}
* 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 *, struct module *,
- unsigned long),
+int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
void *data)
{
char namebuf[KSYM_NAME_LEN];
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 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;
+}
+
static unsigned long get_symbol_pos(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset)
return 0;
}
-int lookup_symbol_attrs(unsigned long addr, unsigned long *size,
- unsigned long *offset, char *modname, char *name)
-{
- int res;
-
- 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';
- goto found;
- }
- /* See if it's in a module. */
- res = lookup_module_symbol_attrs(addr, size, offset, modname, name);
- if (res)
- return res;
-
-found:
- cleanup_symbol_name(name);
- return 0;
-}
-
/* 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 add_buildid)
/* To avoid using get_symbol_offset for every symbol, we carry prefix along. */
struct kallsym_iter {
loff_t pos;
- loff_t pos_arch_end;
loff_t pos_mod_end;
loff_t pos_ftrace_mod_end;
loff_t pos_bpf_end;
int show_value;
};
-int __weak arch_get_kallsym(unsigned int symnum, unsigned long *value,
- char *type, char *name)
-{
- return -EINVAL;
-}
-
-static int get_ksymbol_arch(struct kallsym_iter *iter)
-{
- int ret = arch_get_kallsym(iter->pos - kallsyms_num_syms,
- &iter->value, &iter->type,
- iter->name);
-
- if (ret < 0) {
- iter->pos_arch_end = iter->pos;
- return 0;
- }
-
- return 1;
-}
-
static int get_ksymbol_mod(struct kallsym_iter *iter)
{
- int ret = module_get_kallsym(iter->pos - iter->pos_arch_end,
+ int ret = module_get_kallsym(iter->pos - kallsyms_num_syms,
&iter->value, &iter->type,
iter->name, iter->module_name,
&iter->exported);
{
int ret;
- strlcpy(iter->module_name, "bpf", MODULE_NAME_LEN);
+ strscpy(iter->module_name, "bpf", MODULE_NAME_LEN);
iter->exported = 0;
ret = bpf_get_kallsym(iter->pos - iter->pos_ftrace_mod_end,
&iter->value, &iter->type,
*/
static int get_ksymbol_kprobe(struct kallsym_iter *iter)
{
- strlcpy(iter->module_name, "__builtin__kprobes", MODULE_NAME_LEN);
+ 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->nameoff = get_symbol_offset(new_pos);
iter->pos = new_pos;
if (new_pos == 0) {
- iter->pos_arch_end = 0;
iter->pos_mod_end = 0;
iter->pos_ftrace_mod_end = 0;
iter->pos_bpf_end = 0;
{
iter->pos = pos;
- if ((!iter->pos_arch_end || iter->pos_arch_end > pos) &&
- get_ksymbol_arch(iter))
- return 1;
-
if ((!iter->pos_mod_end || iter->pos_mod_end > pos) &&
get_ksymbol_mod(iter))
return 1;
#endif /* CONFIG_BPF_SYSCALL */
-static inline int kallsyms_for_perf(void)
-{
-#ifdef CONFIG_PERF_EVENTS
- extern int sysctl_perf_event_paranoid;
- if (sysctl_perf_event_paranoid <= 1)
- return 1;
-#endif
- return 0;
-}
-
-/*
- * We show kallsyms information even to normal users if we've enabled
- * kernel profiling and are explicitly not paranoid (so kptr_restrict
- * is clear, and sysctl_perf_event_paranoid isn't set).
- *
- * Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to
- * block even that).
- */
-bool kallsyms_show_value(const struct cred *cred)
-{
- switch (kptr_restrict) {
- case 0:
- if (kallsyms_for_perf())
- return true;
- fallthrough;
- case 1:
- if (security_capable(cred, &init_user_ns, CAP_SYSLOG,
- CAP_OPT_NOAUDIT) == 0)
- return true;
- fallthrough;
- default:
- return false;
- }
-}
-
static int kallsyms_open(struct inode *inode, struct file *file)
{
/*
projects / linux-2.6-microblaze.git / blobdiff