1 files changed, 150 insertions, 0 deletions
diff --git a/lib/scudo/standalone/linux.cc b/lib/scudo/standalone/linux.cc
new file mode 100644
index 000000000..5e695d72f
--- /dev/null
+++ b/lib/scudo/standalone/linux.cc
@@ -0,0 +1,150 @@
+//===-- linux.cc ------------------------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "platform.h"
+
+#if SCUDO_LINUX
+
+#include "common.h"
+#include "linux.h"
+#include "mutex.h"
+#include "string_utils.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/futex.h>
+#include <sched.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+
+#if SCUDO_ANDROID
+#include <sys/prctl.h>
+// Definitions of prctl arguments to set a vma name in Android kernels.
+#define ANDROID_PR_SET_VMA 0x53564d41
+#define ANDROID_PR_SET_VMA_ANON_NAME 0
+#endif
+
+namespace scudo {
+
+void yieldPlatform() { sched_yield(); }
+
+uptr getPageSize() { return static_cast<uptr>(sysconf(_SC_PAGESIZE)); }
+
+void NORETURN die() { abort(); }
+
+void *map(void *Addr, uptr Size, UNUSED const char *Name, uptr Flags,
+          UNUSED MapPlatformData *Data) {
+  int MmapFlags = MAP_PRIVATE | MAP_ANON;
+  if (Flags & MAP_NOACCESS)
+    MmapFlags |= MAP_NORESERVE;
+  if (Addr) {
+    // Currently no scenario for a noaccess mapping with a fixed address.
+    DCHECK_EQ(Flags & MAP_NOACCESS, 0);
+    MmapFlags |= MAP_FIXED;
+  }
+  const int MmapProt =
+      (Flags & MAP_NOACCESS) ? PROT_NONE : PROT_READ | PROT_WRITE;
+  void *P = mmap(Addr, Size, MmapProt, MmapFlags, -1, 0);
+  if (P == MAP_FAILED) {
+    if (!(Flags & MAP_ALLOWNOMEM) || errno != ENOMEM)
+      dieOnMapUnmapError(errno == ENOMEM);
+    return nullptr;
+  }
+#if SCUDO_ANDROID
+  if (!(Flags & MAP_NOACCESS))
+    prctl(ANDROID_PR_SET_VMA, ANDROID_PR_SET_VMA_ANON_NAME, P, Size, Name);
+#endif
+  return P;
+}
+
+void unmap(void *Addr, uptr Size, UNUSED uptr Flags,
+           UNUSED MapPlatformData *Data) {
+  if (munmap(Addr, Size) != 0)
+    dieOnMapUnmapError();
+}
+
+void releasePagesToOS(uptr BaseAddress, uptr Offset, uptr Size,
+                      UNUSED MapPlatformData *Data) {
+  void *Addr = reinterpret_cast<void *>(BaseAddress + Offset);
+  while (madvise(Addr, Size, MADV_DONTNEED) == -1 && errno == EAGAIN) {
+  }
+}
+
+// Calling getenv should be fine (c)(tm) at any time.
+const char *getEnv(const char *Name) { return getenv(Name); }
+
+void BlockingMutex::wait() {
+  syscall(SYS_futex, reinterpret_cast<uptr>(OpaqueStorage), FUTEX_WAIT_PRIVATE,
+          MtxSleeping, nullptr, nullptr, 0);
+}
+
+void BlockingMutex::wake() {
+  syscall(SYS_futex, reinterpret_cast<uptr>(OpaqueStorage), FUTEX_WAKE_PRIVATE,
+          1, nullptr, nullptr, 0);
+}
+
+u64 getMonotonicTime() {
+  timespec TS;
+  clock_gettime(CLOCK_MONOTONIC, &TS);
+  return static_cast<u64>(TS.tv_sec) * (1000ULL * 1000 * 1000) +
+         static_cast<u64>(TS.tv_nsec);
+}
+
+u32 getNumberOfCPUs() {
+  cpu_set_t CPUs;
+  CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0);
+  return static_cast<u32>(CPU_COUNT(&CPUs));
+}
+
+// Blocking is possibly unused if the getrandom block is not compiled in.
+bool getRandom(void *Buffer, uptr Length, UNUSED bool Blocking) {
+  if (!Buffer || !Length || Length > MaxRandomLength)
+    return false;
+  ssize_t ReadBytes;
+#if defined(SYS_getrandom)
+#if !defined(GRND_NONBLOCK)
+#define GRND_NONBLOCK 1
+#endif
+  // Up to 256 bytes, getrandom will not be interrupted.
+  ReadBytes =
+      syscall(SYS_getrandom, Buffer, Length, Blocking ? 0 : GRND_NONBLOCK);
+  if (ReadBytes == static_cast<ssize_t>(Length))
+    return true;
+#endif // defined(SYS_getrandom)
+  // Up to 256 bytes, a read off /dev/urandom will not be interrupted.
+  // Blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
+  const int FileDesc = open("/dev/urandom", O_RDONLY);
+  if (FileDesc == -1)
+    return false;
+  ReadBytes = read(FileDesc, Buffer, Length);
+  close(FileDesc);
+  return (ReadBytes == static_cast<ssize_t>(Length));
+}
+
+void outputRaw(const char *Buffer) {
+  static StaticSpinMutex Mutex;
+  SpinMutexLock L(&Mutex);
+  write(2, Buffer, strlen(Buffer));
+}
+
+extern "C" WEAK void android_set_abort_message(const char *);
+
+void setAbortMessage(const char *Message) {
+  if (&android_set_abort_message)
+    android_set_abort_message(Message);
+}
+
+} // namespace scudo
+
+#endif // SCUDO_LINUX