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-rw-r--r--kernel/kallsyms.c112
1 files changed, 25 insertions, 87 deletions
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 016d997131d4..049e296f586c 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -103,8 +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]]];
}
@@ -148,56 +151,8 @@ static unsigned int get_symbol_offset(unsigned long pos)
unsigned long kallsyms_sym_address(int idx)
{
- if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE))
- return kallsyms_addresses[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];
-
- /* ...otherwise, positive offsets are absolute values */
- if (kallsyms_offsets[idx] >= 0)
- return kallsyms_offsets[idx];
-
- /* ...and negative offsets are relative to kallsyms_relative_base - 1 */
- return kallsyms_relative_base - 1 - kallsyms_offsets[idx];
-}
-
-static bool cleanup_symbol_name(char *s)
-{
- char *res;
-
- if (!IS_ENABLED(CONFIG_LTO_CLANG))
- return false;
-
- /*
- * 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 only in LLVM LTO observed:
- * - foo.llvm.[0-9a-f]+
- */
- res = strstr(s, ".llvm.");
- if (res) {
- *res = '\0';
- return true;
- }
-
- return false;
-}
-
-static int compare_symbol_name(const char *name, char *namebuf)
-{
- int ret;
-
- ret = strcmp(name, namebuf);
- if (!ret)
- return ret;
-
- if (cleanup_symbol_name(namebuf) && !strcmp(name, namebuf))
- return 0;
-
- return ret;
+ /* values are unsigned offsets */
+ return kallsyms_relative_base + (u32)kallsyms_offsets[idx];
}
static unsigned int get_symbol_seq(int index)
@@ -227,7 +182,7 @@ static int kallsyms_lookup_names(const char *name,
seq = get_symbol_seq(mid);
off = get_symbol_offset(seq);
kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
- ret = compare_symbol_name(name, namebuf);
+ ret = strcmp(name, namebuf);
if (ret > 0)
low = mid + 1;
else if (ret < 0)
@@ -244,7 +199,7 @@ static int kallsyms_lookup_names(const char *name,
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))
+ if (strcmp(name, namebuf))
break;
low--;
}
@@ -256,7 +211,7 @@ static int kallsyms_lookup_names(const char *name,
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))
+ if (strcmp(name, namebuf))
break;
high++;
}
@@ -330,13 +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;
@@ -399,12 +348,12 @@ int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize,
!!__bpf_address_lookup(addr, symbolsize, offset, namebuf);
}
-static const char *kallsyms_lookup_buildid(unsigned long addr,
+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;
@@ -421,8 +370,7 @@ static const char *kallsyms_lookup_buildid(unsigned long addr,
if (modbuildid)
*modbuildid = NULL;
- ret = namebuf;
- goto found;
+ return strlen(namebuf);
}
/* See if it's in a module or a BPF JITed image. */
@@ -436,8 +384,6 @@ static const char *kallsyms_lookup_buildid(unsigned long addr,
ret = ftrace_mod_address_lookup(addr, symbolsize,
offset, modname, namebuf);
-found:
- cleanup_symbol_name(namebuf);
return ret;
}
@@ -453,14 +399,17 @@ const char *kallsyms_lookup(unsigned long addr,
unsigned long *offset,
char **modname, char *namebuf)
{
- return kallsyms_lookup_buildid(addr, symbolsize, offset, modname,
- NULL, 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)
{
- int res;
-
symname[0] = '\0';
symname[KSYM_NAME_LEN - 1] = '\0';
@@ -471,16 +420,10 @@ int lookup_symbol_name(unsigned long addr, char *symname)
/* Grab name */
kallsyms_expand_symbol(get_symbol_offset(pos),
symname, KSYM_NAME_LEN);
- goto found;
+ return 0;
}
/* See if it's in a module. */
- res = lookup_module_symbol_name(addr, symname);
- if (res)
- return res;
-
-found:
- cleanup_symbol_name(symname);
- return 0;
+ return lookup_module_symbol_name(addr, symname);
}
/* Look up a kernel symbol and return it in a text buffer. */
@@ -489,19 +432,15 @@ static int __sprint_symbol(char *buffer, unsigned long address,
{
char *modname;
const unsigned char *buildid;
- const char *name;
unsigned long offset, size;
int len;
address += symbol_offset;
- name = kallsyms_lookup_buildid(address, &size, &offset, &modname, &buildid,
+ len = kallsyms_lookup_buildid(address, &size, &offset, &modname, &buildid,
buffer);
- if (!name)
+ 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)
@@ -893,8 +832,7 @@ static struct bpf_iter_reg ksym_iter_reg_info = {
.seq_info = &ksym_iter_seq_info,
};
-BTF_ID_LIST(btf_ksym_iter_id)
-BTF_ID(struct, kallsym_iter)
+BTF_ID_LIST_SINGLE(btf_ksym_iter_id, struct, kallsym_iter)
static int __init bpf_ksym_iter_register(void)
{
generated by cgit (git 2.34.1) at 2025-12-25 06:39:40 +0000