Add getauxval() compat for NetBSD
Summary:
getauxval() is not available on NetBSD and there is no a direct equivalent.
Add a function that implements the same semantics with NetBSD internals.
Reorder the GetPageSize() functions to prefer the sysctl approach for NetBSD.
It no longer makes a difference which approach is better. Avoid changing
conditional code path.
Reviewers: vitalybuka, dvyukov, mgorny, joerg
Reviewed By: vitalybuka
Subscribers: llvm-commits, #sanitizers
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D67329
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@371758 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/sanitizer_common/sanitizer_getauxval.h b/lib/sanitizer_common/sanitizer_getauxval.h
index f1ca0be..777b1212 100644
--- a/lib/sanitizer_common/sanitizer_getauxval.h
+++ b/lib/sanitizer_common/sanitizer_getauxval.h
@@ -9,6 +9,7 @@
// Common getauxval() guards and definitions.
// getauxval() is not defined until glibc version 2.16, or until API level 21
// for Android.
+// Implement the getauxval() compat function for NetBSD.
//
//===----------------------------------------------------------------------===//
@@ -41,6 +42,23 @@
extern "C" SANITIZER_WEAK_ATTRIBUTE unsigned long getauxval(unsigned long type);
# endif
-#endif // SANITIZER_LINUX || SANITIZER_FUCHSIA
+#elif SANITIZER_NETBSD
+
+#define SANITIZER_USE_GETAUXVAL 1
+
+#include <dlfcn.h>
+#include <elf.h>
+
+static inline decltype(AuxInfo::a_v) getauxval(decltype(AuxInfo::a_type) type) {
+ for (const AuxInfo *aux = (const AuxInfo *)_dlauxinfo();
+ aux->a_type != AT_NULL; ++aux) {
+ if (type == aux->a_type)
+ return aux->a_v;
+ }
+
+ return 0;
+}
+
+#endif
#endif // SANITIZER_GETAUXVAL_H
diff --git a/lib/sanitizer_common/sanitizer_linux.cpp b/lib/sanitizer_common/sanitizer_linux.cpp
index e666290..d230090 100644
--- a/lib/sanitizer_common/sanitizer_linux.cpp
+++ b/lib/sanitizer_common/sanitizer_linux.cpp
@@ -1062,8 +1062,6 @@
uptr GetPageSize() {
#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__))
return EXEC_PAGESIZE;
-#elif SANITIZER_USE_GETAUXVAL
- return getauxval(AT_PAGESZ);
#elif SANITIZER_FREEBSD || SANITIZER_NETBSD
// Use sysctl as sysconf can trigger interceptors internally.
int pz = 0;
@@ -1072,6 +1070,8 @@
int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0);
CHECK_EQ(rv, 0);
return (uptr)pz;
+#elif SANITIZER_USE_GETAUXVAL
+ return getauxval(AT_PAGESZ);
#else
return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy.
#endif
