Add interceptor for the setvbuf(3) from NetBSD

[krytarowski]

Summary

setvbuf(3) is a routine to setup stream buffering.

Enable the interceptor for NetBSD.

Add dedicated tests for setvbuf(3) and functions
on top of this interface: setbuf, setbuffer, setlinebuf.

Based on original work by Yang Zheng.

[vitalybuka]

lib/sanitizer_common/sanitizer_common_interceptors.inc

7274

do you need unpoison_file?

lib/sanitizer_common/sanitizer_platform_interceptors.h

519

This is not NETBSD specific?

[vitalybuka]

lib/sanitizer_common/sanitizer_common_interceptors.inc

7274

unpoison_file does nothing on netbsd
so it could be needed for Linux

[krytarowski]

lib/sanitizer_common/sanitizer_common_interceptors.inc

7274

FILE is not sanitized as of today on NetBSD.

lib/sanitizer_common/sanitizer_platform_interceptors.h

519

It originated in BSD, went into SunOS, and from there to C89 or similar.. but I cannot test it on other OSes. Please enable and test it on them in a separate commit.

[devnexen]

lib/sanitizer_common/sanitizer_platform_interceptors.h

519

Would it be possible to put the test in the posix folder ? Would enable the feature on FreeBSD later on.

[vitalybuka]

lib/sanitizer_common/sanitizer_platform_interceptors.h

519

up to you. you can move it now with XFAIL, or move later

[krytarowski]

lib/sanitizer_common/sanitizer_platform_interceptors.h

519

Committed!

Sorry for inappropriate place, but when I've included an interceptor for devname_r(3), it was enabled for !NetBSD.. however there is wrong prototype for !NetBSD. NetBSD uses int as a return value, others use char*.

@devnexen could we drop SI_OPENBSD from this file, it's not used and probably won't be used.

[devnexen]

lib/sanitizer_common/sanitizer_platform_interceptors.h

519

I hesitate doing so ... Someone contacted me he would try to find a way to port asan on openbsd and thought I would drop this for good after a while (beginning next year) if I see no sign ...

lib/sanitizer_common/sanitizer_common_interceptors.inc

 #define INIT_NETENT
 #endif
 
+#if SANITIZER_INTERCEPT_SETVBUF
+INTERCEPTOR(int, setvbuf, __sanitizer_FILE *stream, char *buf, int mode,
+  SIZE_T size) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, setvbuf, stream, buf, mode, size);
+  int ret = REAL(setvbuf)(stream, buf, mode, size);
+  if (buf)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, buf, size);
+  return ret;
+}
+#define INIT_SETVBUF COMMON_INTERCEPT_FUNCTION(setvbuf)
+#else
+#define INIT_SETVBUF
+#endif
+
 static void InitializeCommonInterceptors() {
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
   interceptor_metadata_map = new((void *)&metadata_mem) MetadataHashMap();

   INIT_TTYENT;
   INIT_PROTOENT;
   INIT_NETENT;
+  INIT_SETVBUF;
 
   INIT___PRINTF_CHK;
 }

lib/sanitizer_common/sanitizer_platform_interceptors.h

 #define SANITIZER_INTERCEPT_TTYENT SI_NETBSD
 #define SANITIZER_INTERCEPT_PROTOENT SI_NETBSD
 #define SANITIZER_INTERCEPT_NETENT SI_NETBSD
+#define SANITIZER_INTERCEPT_SETVBUF SI_NETBSD
 
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H

test/sanitizer_common/TestCases/NetBSD/setvbuf.cc

+// RUN: %clangxx -O0 -g %s -o %t && %run %t 2>&1 | FileCheck %s
+
+#include <stdio.h>
+
+void print_something() {
+  for (size_t i = 0; i < 10 * BUFSIZ; i++)
+    printf("Hello world %zu\n", i);
+}
+
+void test_setbuf() {
+  char buf[BUFSIZ];
+
+  setbuf(stdout, NULL);
+
+  print_something();
+
+  setbuf(stdout, buf);
+
+  print_something();
+}
+
+void test_setbuffer() {
+  char buf[BUFSIZ];
+
+  setbuffer(stdout, NULL, 0);
+
+  print_something();
+
+  setbuffer(stdout, buf, BUFSIZ);
+
+  print_something();
+}
+
+void test_setlinebuf() {
+  char buf[BUFSIZ];
+
+  setlinebuf(stdout);
+
+  print_something();
+}
+
+void test_setvbuf() {
+  char buf[BUFSIZ];
+
+  setvbuf(stdout, NULL, _IONBF, 0);
+
+  print_something();
+
+  setvbuf(stdout, buf, _IOLBF, BUFSIZ);
+
+  print_something();
+
+  setvbuf(stdout, buf, _IOFBF, BUFSIZ);
+
+  print_something();
+}
+
+int main(void) {
+  printf("setvbuf\n");
+
+  test_setbuf();
+  test_setbuffer();
+  test_setlinebuf();
+  test_setvbuf();
+
+  // CHECK: setvbuf
+
+  return 0;
+}