[safestack] Return syscalls for mmap, munmap and mprotect

This function can be already intercepted by instrumented code.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@351783 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 31 insertions, 4 deletions

diff --git a/lib/safestack/safestack.cc b/lib/safestack/safestack.cc
index c5622d226..ff840a5c1 100644
--- a/lib/safestack/safestack.cc
+++ b/lib/safestack/safestack.cc
@@ -17,7 +17,6 @@
 #include "safestack_util.h"
 
 #include <errno.h>
-#include <sys/mman.h>
 #include <sys/resource.h>
 
 #include "interception/interception.h"
@@ -94,10 +93,10 @@ __thread size_t unsafe_stack_guard = 0;
 
 inline void *unsafe_stack_alloc(size_t size, size_t guard) {
   SFS_CHECK(size + guard >= size);
-  void *addr = mmap(nullptr, RoundUpTo(size + guard, pageSize),
+  void *addr = Mmap(nullptr, RoundUpTo(size + guard, pageSize),
                     PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
   SFS_CHECK(MAP_FAILED != addr);
-  mprotect(addr, guard, PROT_NONE);
+  Mprotect(addr, guard, PROT_NONE);
   return (char *)addr + guard;
 }
 
@@ -181,7 +180,7 @@ void thread_cleanup_handler(void *_iter) {
     thread_stack_ll *stack = *stackp;
     if (stack->pid != pid ||
         (-1 == TgKill(stack->pid, stack->tid, 0) && errno == ESRCH)) {
-      munmap(stack->stack_base, stack->size);
+      Munmap(stack->stack_base, stack->size);
       *stackp = stack->next;
       free(stack);
     } else
diff --git a/lib/safestack/safestack_platform.h b/lib/safestack/safestack_platform.h
index 6b042f4b4..b906d52d5 100644
--- a/lib/safestack/safestack_platform.h
+++ b/lib/safestack/safestack_platform.h
@@ -16,6 +16,7 @@
 #include "sanitizer_common/sanitizer_platform.h"
 
 #include <stdint.h>
+#include <sys/mman.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -59,6 +60,33 @@ inline int TgKill(pid_t pid, ThreadId tid, int sig) {
 #endif
 }
 
+inline void *Mmap(void *addr, size_t length, int prot, int flags, int fd,
+                  off_t offset) {
+#if SANITIZER_NETBSD
+  return mmap(addr, length, prot, flags, fd, offset);
+#elif defined(__x86_64__) && (SANITIZER_FREEBSD)
+  return (void *)__syscall(SYS_mmap, addr, length, prot, flags, fd, offset);
+#else
+  return (void *)syscall(SYS_mmap, addr, length, prot, flags, fd, offset);
+#endif
+}
+
+inline int Munmap(void *addr, size_t length) {
+#if SANITIZER_NETBSD
+  return munmap(addr, length);
+#else
+  return syscall(SYS_munmap, addr, length);
+#endif
+}
+
+inline int Mprotect(void *addr, size_t length, int prot) {
+#if SANITIZER_NETBSD
+  return mprotect(addr, length, prot);
+#else
+  return syscall(SYS_mprotect, addr, length, prot);
+#endif
+}
+
 }  // namespace safestack
 
 #endif  // SAFESTACK_PLATFORM_H