[sanitizer] Add early call handling to strchr + strrchr interceptors

Summary:
The strchr and strrchr interceptors are sometimes invoked too early
for their REAL() counterparts to be initialized.  We have seen this in
hooks invoked from tcmalloc on the dlsym() used in initializing
interceptors.  A special check is added to use internal_ routines for
this situation.

Reviewers: vitalybuka, aizatsky, filcab

Subscribers: filcab, llvm-commits, eugenis, kcc, zhaoqin, aizatsky, kubabrecka

Differential Revision: http://reviews.llvm.org/D19607

llvm-svn: 267793

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index 2e0c48e..85e60ca 100644 (file)
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -401,6 +401,8 @@ INTERCEPTOR(char*, strcasestr, const char *s1, const char *s2) {
 #if SANITIZER_INTERCEPT_STRCHR
 INTERCEPTOR(char*, strchr, const char *s, int c) {
   void *ctx;
+  if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED)
+    return internal_strchr(s, c);
   COMMON_INTERCEPTOR_ENTER(ctx, strchr, s, c);
   char *result = REAL(strchr)(s, c);
   uptr len = internal_strlen(s);
@@ -432,6 +434,8 @@ INTERCEPTOR(char*, strchrnul, const char *s, int c) {
 #if SANITIZER_INTERCEPT_STRRCHR
 INTERCEPTOR(char*, strrchr, const char *s, int c) {
   void *ctx;
+  if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED)
+    return internal_strrchr(s, c);
   COMMON_INTERCEPTOR_ENTER(ctx, strrchr, s, c);
   uptr len = internal_strlen(s);
   if (common_flags()->intercept_strchr)