From 0e6017f5b4f13906dd2c09b25403ffa94a80181f Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Wed, 11 Aug 2021 10:23:34 +0200 Subject: [PATCH] sanitizer: Cherry-pick realpath fix tsan in some cases starts ignoring interceptors and only calls the intercepted functions. But for realpath the behavior for NULL second argument was only handled in the interceptor and intercepted function was the one found by dlsym which is often one that doesn't handle NULL as second argument. Fixed by using dlvsym with "GLIBC_2.3" if possible for intercepted function and don't emulate behavior in the wrapper. 2021-08-11 Jakub Jelinek * sanitizer_common/sanitizer_common_interceptors.inc: Cherry-pick llvm-project revision faef0d042f523357fe5590e7cb6a8391cf0351a8. --- .../sanitizer_common_interceptors.inc | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc b/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc index 6205d853a4c9..5ac6cf45fd2a 100644 --- a/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc +++ b/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc @@ -3664,21 +3664,11 @@ INTERCEPTOR(char *, realpath, const char *path, char *resolved_path) { void *ctx; COMMON_INTERCEPTOR_ENTER(ctx, realpath, path, resolved_path); if (path) COMMON_INTERCEPTOR_READ_RANGE(ctx, path, REAL(strlen)(path) + 1); - - // Workaround a bug in glibc where dlsym(RTLD_NEXT, ...) returns the oldest - // version of a versioned symbol. For realpath(), this gives us something - // (called __old_realpath) that does not handle NULL in the second argument. - // Handle it as part of the interceptor. - char *allocated_path = nullptr; - if (!resolved_path) - allocated_path = resolved_path = (char *)WRAP(malloc)(path_max + 1); - char *res = REAL(realpath)(path, resolved_path); - if (allocated_path && !res) WRAP(free)(allocated_path); if (res) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, res, REAL(strlen)(res) + 1); return res; } -#define INIT_REALPATH COMMON_INTERCEPT_FUNCTION(realpath); +#define INIT_REALPATH COMMON_INTERCEPT_FUNCTION_GLIBC_VER_MIN(realpath, "GLIBC_2.3"); #else #define INIT_REALPATH #endif -- 2.47.2