[Sanitizer] Intercept getusershell

- If entries are properly copied (there were a bug in FreeBSD implementation in earlier version), or list properly reset.

Reviewers: vitalybuka, krytarowski

Reviewed By: krytarowski

Differential Revision: https://reviews.llvm.org/D56562


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@350919 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 38 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_common_interceptors.inc b/lib/sanitizer_common/sanitizer_common_interceptors.inc
index 252f55552..f3ea863bd 100644
--- a/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -9399,6 +9399,21 @@ INTERCEPTOR(char *, fdevname_r,  int fd, char *buf, SIZE_T len) {
 #define INIT_FDEVNAME
 #endif
 
+#if SANITIZER_INTERCEPT_GETUSERSHELL
+INTERCEPTOR(char *, getusershell) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getusershell);
+  char *res = REAL(getusershell)();
+  if (res)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, res, REAL(strlen)(res) + 1);
+  return res;
+}
+
+#define INIT_GETUSERSHELL COMMON_INTERCEPT_FUNCTION(getusershell);
+#else
+#define INIT_GETUSERSHELL
+#endif
+
 static void InitializeCommonInterceptors() {
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
   interceptor_metadata_map =
@@ -9687,6 +9702,7 @@ static void InitializeCommonInterceptors() {
   INIT_FUNOPEN;
   INIT_FUNOPEN2;
   INIT_FDEVNAME;
+  INIT_GETUSERSHELL;
 
   INIT___PRINTF_CHK;
 }
diff --git a/lib/sanitizer_common/sanitizer_platform_interceptors.h b/lib/sanitizer_common/sanitizer_platform_interceptors.h
index da51d4741..96fb0b84e 100644
--- a/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -548,6 +548,7 @@
 #define SANITIZER_INTERCEPT_GETFSENT (SI_FREEBSD || SI_NETBSD || SI_MAC)
 #define SANITIZER_INTERCEPT_ARC4RANDOM (SI_FREEBSD || SI_NETBSD)
 #define SANITIZER_INTERCEPT_FDEVNAME SI_FREEBSD
+#define SANITIZER_INTERCEPT_GETUSERSHELL SI_POSIX
 
 #define SANITIZER_INTERCEPT_POPEN SI_POSIX
 #define SANITIZER_INTERCEPT_POPENVE SI_NETBSD
diff --git a/test/sanitizer_common/TestCases/Posix/getusershell.cc b/test/sanitizer_common/TestCases/Posix/getusershell.cc
new file mode 100644
index 000000000..6ad1c5bd1
--- /dev/null
+++ b/test/sanitizer_common/TestCases/Posix/getusershell.cc
@@ -0,0 +1,21 @@
+// RUN: %clangxx -O0 -g %s -o %t && %run %t 2>&1 | FileCheck %s
+
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int main(void) {
+  printf("getusershell\n");
+
+  setusershell();
+  char *fentry = getusershell();
+
+  printf("First entry: '%s'\n", fentry);
+
+  endusershell();
+
+  return 0;
+  // CHECK: getusershell
+  // CHECK: First entry: '{{.*}}'
+}