[PATCH v4 1/3] module/kallsyms: Rename is_mapping_symbol() to is_ignored_kernel_symbol()

The helper function is_mapping_symbol() historically checks for both
local labels prefixed with ".L" or "L0" and mapping symbols prefixed
with "$".

Rename it to is_ignored_kernel_symbol() to better reflect this actual
behavior and scope, preventing conceptual confusion.

While at it, update the related non-module files, no functional changes.

Suggested-by: Petr Pavlu <[email protected]>
Signed-off-by: Tiezhu Yang <[email protected]>
Reviewed-by: Huacai Chen <[email protected]>
---
 include/linux/module_symbol.h | 7 +++++--
 kernel/module/kallsyms.c      | 2 +-
 scripts/faddr2line            | 2 +-
 scripts/mod/modpost.h         | 2 +-
 tools/perf/util/symbol.h      | 4 +---
 5 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/linux/module_symbol.h b/include/linux/module_symbol.h
index 574609aced99..698d3db2b37e 100644
--- a/include/linux/module_symbol.h
+++ b/include/linux/module_symbol.h
@@ -7,8 +7,11 @@ enum ksym_flags {
 	KSYM_FLAG_GPL_ONLY	= 1 << 0,
 };
 
-/* This ignores the intensely annoying "mapping symbols" found in ELF files. */
-static inline bool is_mapping_symbol(const char *str)
+/*
+ * Ignore local labels (.L*, L0*) and mapping symbols ($*). These symbols are
+ * not useful for the kernel, for example, they should not appear in kallsyms.
+ */
+static inline bool is_ignored_kernel_symbol(const char *str)
 {
 	if (str[0] == '.' && str[1] == 'L')
 		return true;
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index f23126d804b2..a52942fd0e07 100644
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c
@@ -294,7 +294,7 @@ static const char *find_kallsyms_symbol(struct module *mod,
 		 * and inserted at a whim.
 		 */
 		if (*kallsyms_symbol_name(kallsyms, i) == '\0' ||
-		    is_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
+		    is_ignored_kernel_symbol(kallsyms_symbol_name(kallsyms, i)))
 			continue;
 
 		if (thisval <= addr && thisval > bestval) {
diff --git a/scripts/faddr2line b/scripts/faddr2line
index 622875396bcf..3aca197d513f 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -243,7 +243,7 @@ __faddr2line() {
 			local cur_sym_elf_size=${fields[2]}
 			local cur_sym_name=${fields[7]:-}
 
-			# is_mapping_symbol(cur_sym_name)
+			# is_ignored_kernel_symbol(cur_sym_name)
 			if [[ ${cur_sym_name} =~ ^(\.L|L0|\$) ]]; then
 				continue
 			fi
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 2aecb8f25c87..d9c21d479dd8 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -198,7 +198,7 @@ static inline bool is_valid_name(struct elf_info *elf, Elf_Sym *sym)
 
 	if (!name || !strlen(name))
 		return false;
-	return !is_mapping_symbol(name);
+	return !is_ignored_kernel_symbol(name);
 }
 
 /* symsearch.c */
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index a71525335703..8b0780046938 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -31,9 +31,7 @@ struct build_id;
 struct perf_env;
 
 /*
- * Ignore kernel mapping symbols, matching kernel is_mapping_symbol() logic.
- * This checks for '$' prefix (used by ARM, AArch64, RISC-V) and
- * x86 local symbol prefixes (.L* and L0*).
+ * Ignore local labels and mapping symbols, matching kernel is_ignored_kernel_symbol() logic.
  * Only use this for kernel symbols (kallsyms, ksymbol events, kernel ELF DSOs).
  */
 static inline bool is_ignored_kernel_symbol(const char *str)
-- 
2.42.0