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-rw-r--r--kernel/kallsyms.c46
1 files changed, 33 insertions, 13 deletions
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 0ba87982d017..3011bc33a5ba 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -164,26 +164,46 @@ static unsigned long kallsyms_sym_address(int idx)
return kallsyms_relative_base - 1 - kallsyms_offsets[idx];
}
-#if defined(CONFIG_CFI_CLANG) && defined(CONFIG_LTO_CLANG_THIN)
-/*
- * LLVM appends a hash to static function names when ThinLTO and CFI are
- * both enabled, i.e. foo() becomes foo$707af9a22804d33c81801f27dcfe489b.
- * This causes confusion and potentially breaks user space tools, so we
- * strip the suffix from expanded symbol names.
- */
-static inline bool cleanup_symbol_name(char *s)
+static bool cleanup_symbol_name(char *s)
{
char *res;
+ if (!IS_ENABLED(CONFIG_LTO_CLANG))
+ return false;
+
+ /*
+ * LLVM appends various suffixes for local functions and variables that
+ * must be promoted to global scope as part of LTO. This can break
+ * hooking of static functions with kprobes. '.' is not a valid
+ * character in an identifier in C. Suffixes observed:
+ * - foo.llvm.[0-9a-f]+
+ * - foo.[0-9a-f]+
+ * - foo.[0-9a-f]+.cfi_jt
+ */
+ res = strchr(s, '.');
+ if (res) {
+ *res = '\0';
+ return true;
+ }
+
+ if (!IS_ENABLED(CONFIG_CFI_CLANG) ||
+ !IS_ENABLED(CONFIG_LTO_CLANG_THIN) ||
+ CONFIG_CLANG_VERSION >= 130000)
+ return false;
+
+ /*
+ * Prior to LLVM 13, the following suffixes were observed when thinLTO
+ * and CFI are both enabled:
+ * - foo$[0-9]+
+ */
res = strrchr(s, '$');
- if (res)
+ if (res) {
*res = '\0';
+ return true;
+ }
- return res != NULL;
+ return false;
}
-#else
-static inline bool cleanup_symbol_name(char *s) { return false; }
-#endif
/* Lookup the address for this symbol. Returns 0 if not found. */
unsigned long kallsyms_lookup_name(const char *name)