Add new interceptor for strtonum(3)

Summary:
strtonum(3) reliably convertss string value to an integer.
This function is used in OpenBSD compat namespace
and is located inside NetBSD's libc.

Add a dedicated test for this interface.

It's a reworked version of the original code by Yang Zheng.

Reviewers: joerg, vitalybuka

Reviewed By: vitalybuka

Subscribers: tomsun.0.7, kubamracek, llvm-commits, mgorny, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D54527

llvm-svn: 348651

compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc

@@ -7728,6 +7728,30 @@ INTERCEPTOR(int, modctl, int operation, void *argp) {
 #define INIT_MODCTL
 #endif
 
+#if SANITIZER_INTERCEPT_STRTONUM
+INTERCEPTOR(long long, strtonum, const char *nptr, long long minval,
+            long long maxval, const char **errstr) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, strtonum, nptr, minval, maxval, errstr);
+
+  // TODO(kamil): Implement strtoll as a common inteceptor
+  char *real_endptr;
+  long long ret = (long long)REAL(strtoimax)(nptr, &real_endptr, 10);
+  StrtolFixAndCheck(ctx, nptr, nullptr, real_endptr, 10);
+
+  ret = REAL(strtonum)(nptr, minval, maxval, errstr);
+  if (errstr) {
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, errstr, sizeof(const char *));
+     if (*errstr)
+      COMMON_INTERCEPTOR_WRITE_RANGE(ctx, *errstr, REAL(strlen)(*errstr) + 1);
+  }
+  return ret;
+}
+#define INIT_STRTONUM COMMON_INTERCEPT_FUNCTION(strtonum)
+#else
+#define INIT_STRTONUM
+#endif
+
 static void InitializeCommonInterceptors() {
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
   interceptor_metadata_map = new((void *)&metadata_mem) MetadataHashMap();
@@ -7992,6 +8016,7 @@ static void InitializeCommonInterceptors() {
   INIT_SYSCTLGETMIBINFO;
   INIT_NL_LANGINFO;
   INIT_MODCTL;
+  INIT_STRTONUM;
 
   INIT___PRINTF_CHK;
 }

compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h

@@ -529,5 +529,6 @@
 #define SANITIZER_INTERCEPT_SYSCTLGETMIBINFO SI_NETBSD
 #define SANITIZER_INTERCEPT_NL_LANGINFO (SI_NETBSD || SI_FREEBSD)
 #define SANITIZER_INTERCEPT_MODCTL SI_NETBSD
+#define SANITIZER_INTERCEPT_STRTONUM SI_NETBSD
 
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H

compiler-rt/test/sanitizer_common/TestCases/NetBSD/strtonum.cc

@@ -0,0 +1,52 @@
+// RUN: %clangxx -O0 -g %s -o %t && %run %t 2>&1 | FileCheck %s
+
+#define _OPENBSD_SOURCE
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void) {
+  const char *errstr;
+
+  printf("strtonum\n");
+
+  long long l = strtonum("100", 1, 100, &errstr);
+  assert(!errstr);
+  printf("%lld\n", l);
+
+  l = strtonum("200", 1, 100, &errstr);
+  assert(errstr);
+  printf("%s\n", errstr);
+
+  l = strtonum("300", 1000, 1001, &errstr);
+  assert(errstr);
+  printf("%s\n", errstr);
+
+  l = strtonum("abc", 1000, 1001, &errstr);
+  assert(errstr);
+  printf("%s\n", errstr);
+
+  l = strtonum("1000", 1001, 1000, &errstr);
+  assert(errstr);
+  printf("%s\n", errstr);
+
+  l = strtonum("1000abc", 1000, 1001, &errstr);
+  assert(errstr);
+  printf("%s\n", errstr);
+
+  l = strtonum("1000.0", 1000, 1001, &errstr);
+  assert(errstr);
+  printf("%s\n", errstr);
+
+  // CHECK: strtonum
+  // CHECK: 100
+  // CHECK: too large
+  // CHECK: too small
+  // CHECK: invalid
+  // CHECK: invalid
+  // CHECK: invalid
+  // CHECK: invalid
+
+  return 0;
+}