1 files changed, 260 insertions, 0 deletions
diff --git a/lib/asan/asan_linux.cpp b/lib/asan/asan_linux.cpp
new file mode 100644
index 0000000000000..ce5e873dc5180
--- /dev/null
+++ b/lib/asan/asan_linux.cpp
@@ -0,0 +1,260 @@
+//===-- asan_linux.cpp ----------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// Linux-specific details.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
+    SANITIZER_SOLARIS
+
+#include "asan_interceptors.h"
+#include "asan_internal.h"
+#include "asan_premap_shadow.h"
+#include "asan_thread.h"
+#include "sanitizer_common/sanitizer_flags.h"
+#include "sanitizer_common/sanitizer_freebsd.h"
+#include "sanitizer_common/sanitizer_libc.h"
+#include "sanitizer_common/sanitizer_procmaps.h"
+
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/mman.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <dlfcn.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <unwind.h>
+
+#if SANITIZER_FREEBSD
+#include <sys/link_elf.h>
+#endif
+
+#if SANITIZER_SOLARIS
+#include <link.h>
+#endif
+
+#if SANITIZER_ANDROID || SANITIZER_FREEBSD || SANITIZER_SOLARIS
+#include <ucontext.h>
+extern "C" void* _DYNAMIC;
+#elif SANITIZER_NETBSD
+#include <link_elf.h>
+#include <ucontext.h>
+extern Elf_Dyn _DYNAMIC;
+#else
+#include <sys/ucontext.h>
+#include <link.h>
+#endif
+
+// x86-64 FreeBSD 9.2 and older define 'ucontext_t' incorrectly in
+// 32-bit mode.
+#if SANITIZER_FREEBSD && (SANITIZER_WORDSIZE == 32) && \
+  __FreeBSD_version <= 902001  // v9.2
+#define ucontext_t xucontext_t
+#endif
+
+typedef enum {
+  ASAN_RT_VERSION_UNDEFINED = 0,
+  ASAN_RT_VERSION_DYNAMIC,
+  ASAN_RT_VERSION_STATIC,
+} asan_rt_version_t;
+
+// FIXME: perhaps also store abi version here?
+extern "C" {
+SANITIZER_INTERFACE_ATTRIBUTE
+asan_rt_version_t  __asan_rt_version;
+}
+
+namespace __asan {
+
+void InitializePlatformInterceptors() {}
+void InitializePlatformExceptionHandlers() {}
+bool IsSystemHeapAddress (uptr addr) { return false; }
+
+void *AsanDoesNotSupportStaticLinkage() {
+  // This will fail to link with -static.
+  return &_DYNAMIC;  // defined in link.h
+}
+
+static void UnmapFromTo(uptr from, uptr to) {
+  CHECK(to >= from);
+  if (to == from) return;
+  uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from);
+  if (UNLIKELY(internal_iserror(res))) {
+    Report(
+        "ERROR: AddresSanitizer failed to unmap 0x%zx (%zd) bytes at address "
+        "%p\n",
+        to - from, to - from, from);
+    CHECK("unable to unmap" && 0);
+  }
+}
+
+#if ASAN_PREMAP_SHADOW
+uptr FindPremappedShadowStart() {
+  uptr granularity = GetMmapGranularity();
+  uptr shadow_start = reinterpret_cast<uptr>(&__asan_shadow);
+  uptr premap_shadow_size = PremapShadowSize();
+  uptr shadow_size = RoundUpTo(kHighShadowEnd, granularity);
+  // We may have mapped too much. Release extra memory.
+  UnmapFromTo(shadow_start + shadow_size, shadow_start + premap_shadow_size);
+  return shadow_start;
+}
+#endif
+
+uptr FindDynamicShadowStart() {
+#if ASAN_PREMAP_SHADOW
+  if (!PremapShadowFailed())
+    return FindPremappedShadowStart();
+#endif
+
+  uptr granularity = GetMmapGranularity();
+  uptr alignment = granularity * 8;
+  uptr left_padding = granularity;
+  uptr shadow_size = RoundUpTo(kHighShadowEnd, granularity);
+  uptr map_size = shadow_size + left_padding + alignment;
+
+  uptr map_start = (uptr)MmapNoAccess(map_size);
+  CHECK_NE(map_start, ~(uptr)0);
+
+  uptr shadow_start = RoundUpTo(map_start + left_padding, alignment);
+  UnmapFromTo(map_start, shadow_start - left_padding);
+  UnmapFromTo(shadow_start + shadow_size, map_start + map_size);
+
+  return shadow_start;
+}
+
+void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
+  UNIMPLEMENTED();
+}
+
+#if SANITIZER_ANDROID
+// FIXME: should we do anything for Android?
+void AsanCheckDynamicRTPrereqs() {}
+void AsanCheckIncompatibleRT() {}
+#else
+static int FindFirstDSOCallback(struct dl_phdr_info *info, size_t size,
+                                void *data) {
+  VReport(2, "info->dlpi_name = %s\tinfo->dlpi_addr = %p\n",
+          info->dlpi_name, info->dlpi_addr);
+
+  // Continue until the first dynamic library is found
+  if (!info->dlpi_name || info->dlpi_name[0] == 0)
+    return 0;
+
+  // Ignore vDSO
+  if (internal_strncmp(info->dlpi_name, "linux-", sizeof("linux-") - 1) == 0)
+    return 0;
+
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
+  // Ignore first entry (the main program)
+  char **p = (char **)data;
+  if (!(*p)) {
+    *p = (char *)-1;
+    return 0;
+  }
+#endif
+
+#if SANITIZER_SOLARIS
+  // Ignore executable on Solaris
+  if (info->dlpi_addr == 0)
+    return 0;
+#endif
+
+  *(const char **)data = info->dlpi_name;
+  return 1;
+}
+
+static bool IsDynamicRTName(const char *libname) {
+  return internal_strstr(libname, "libclang_rt.asan") ||
+    internal_strstr(libname, "libasan.so");
+}
+
+static void ReportIncompatibleRT() {
+  Report("Your application is linked against incompatible ASan runtimes.\n");
+  Die();
+}
+
+void AsanCheckDynamicRTPrereqs() {
+  if (!ASAN_DYNAMIC || !flags()->verify_asan_link_order)
+    return;
+
+  // Ensure that dynamic RT is the first DSO in the list
+  const char *first_dso_name = nullptr;
+  dl_iterate_phdr(FindFirstDSOCallback, &first_dso_name);
+  if (first_dso_name && !IsDynamicRTName(first_dso_name)) {
+    Report("ASan runtime does not come first in initial library list; "
+           "you should either link runtime to your application or "
+           "manually preload it with LD_PRELOAD.\n");
+    Die();
+  }
+}
+
+void AsanCheckIncompatibleRT() {
+  if (ASAN_DYNAMIC) {
+    if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
+      __asan_rt_version = ASAN_RT_VERSION_DYNAMIC;
+    } else if (__asan_rt_version != ASAN_RT_VERSION_DYNAMIC) {
+      ReportIncompatibleRT();
+    }
+  } else {
+    if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
+      // Ensure that dynamic runtime is not present. We should detect it
+      // as early as possible, otherwise ASan interceptors could bind to
+      // the functions in dynamic ASan runtime instead of the functions in
+      // system libraries, causing crashes later in ASan initialization.
+      MemoryMappingLayout proc_maps(/*cache_enabled*/true);
+      char filename[PATH_MAX];
+      MemoryMappedSegment segment(filename, sizeof(filename));
+      while (proc_maps.Next(&segment)) {
+        if (IsDynamicRTName(segment.filename)) {
+          Report("Your application is linked against "
+                 "incompatible ASan runtimes.\n");
+          Die();
+        }
+      }
+      __asan_rt_version = ASAN_RT_VERSION_STATIC;
+    } else if (__asan_rt_version != ASAN_RT_VERSION_STATIC) {
+      ReportIncompatibleRT();
+    }
+  }
+}
+#endif // SANITIZER_ANDROID
+
+#if !SANITIZER_ANDROID
+void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
+  ucontext_t *ucp = (ucontext_t*)context;
+  *stack = (uptr)ucp->uc_stack.ss_sp;
+  *ssize = ucp->uc_stack.ss_size;
+}
+#else
+void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
+  UNIMPLEMENTED();
+}
+#endif
+
+void *AsanDlSymNext(const char *sym) {
+  return dlsym(RTLD_NEXT, sym);
+}
+
+bool HandleDlopenInit() {
+  // Not supported on this platform.
+  static_assert(!SANITIZER_SUPPORTS_INIT_FOR_DLOPEN,
+                "Expected SANITIZER_SUPPORTS_INIT_FOR_DLOPEN to be false");
+  return false;
+}
+
+} // namespace __asan
+
+#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD ||
+        // SANITIZER_SOLARIS