[Msan] Generalize mapping facilities to add FreeBSD support

[kutuzov.viktor.84]

lib/msan/msan_linux.cc

108–109

Ah, these calls should be rewritten to check returning values.

[kutuzov.viktor.84]

Updated.

• Fixed the #if condition for the case of __mips64.
• SHADOW_TO_ORIGIN() moved out from the platform-specific sections.
• InitShadow replaced with __msan_init in the diagnostic message.
• The calls to TakeMapRange() fixed to check returning values.
• Minor spacing fixes.

[kutuzov.viktor.84]

Fixed parameter names for the case of FreeBSD.

[kutuzov.viktor.84]

lib/msan/msan.h

66

It shall be 0x210000000000. Otherwise, the patch works as expected on Linux and FreeBSD.

[eugenis]

lib/msan/msan.h

66

Are you saying you will change it to 0x210..? Please do.

73

Please take a look at https://code.google.com/p/memory-sanitizer/issues/detail?id=76
I wonder if it is applicable to FreeBSD as well.

lib/msan/msan_linux.cc

43

TakeMemoryRange

I don't like that it's asymmetrical, i.e. "check that memory is available and maybe protect it". Makes it hard to find a good name for the function.

Please either make it "check and either protect or reserve", or just do everything in InitShadow.

58

prot1 .. prot3 are always true, just remove them

[kutuzov.viktor.84]

Updated:

• TakeMapRange() is split into two different functions;
• The prot1 and prot2 parameters removed;
• The kShadowSize value fixed;
• A minor fix for the code-in-app-range check.

[kutuzov.viktor.84]

Please take a look at https://code.google.com/p/memory-sanitizer/issues/detail?id=76
I wonder if it is applicable to FreeBSD as well.

Umm, I suspect we can't really reserve 600000000000-7cffffffffff for Msan needs on FreeBSD. Ed, can you please confirm that?

[eugenis]

LGTM

lib/msan/msan.h

36

There are no "traces" in MSan.

Closed by commit rL222919 (authored by vkutuzov).

lib/msan/msan.h

 #include "sanitizer_common/sanitizer_stacktrace.h"
 #include "msan_interface_internal.h"
 #include "msan_flags.h"
 
 #ifndef MSAN_REPLACE_OPERATORS_NEW_AND_DELETE
 # define MSAN_REPLACE_OPERATORS_NEW_AND_DELETE 1
 #endif
 
-#if defined(__mips64)
-#define MEM_TO_SHADOW(mem)       (((uptr)mem) & ~0x4000000000ULL)
-#define SHADOW_TO_ORIGIN(shadow) (((uptr)shadow) + 0x2000000000ULL)
-#define MEM_TO_ORIGIN(mem)       (SHADOW_TO_ORIGIN(MEM_TO_SHADOW(mem)))
-#define MEM_IS_APP(mem)          ((uptr)mem >= 0xe000000000ULL)
-#define MEM_IS_SHADOW(mem) \
-  ((uptr)mem >= 0xa000000000ULL && (uptr)mem <= 0xc000000000ULL)
-#elif defined(__x86_64__)
-#define MEM_TO_SHADOW(mem)       (((uptr)mem) & ~0x400000000000ULL)
-#define SHADOW_TO_ORIGIN(shadow) (((uptr)shadow) + 0x200000000000ULL)
-#define MEM_TO_ORIGIN(mem)       (SHADOW_TO_ORIGIN(MEM_TO_SHADOW(mem)))
-#define MEM_IS_APP(mem)          ((uptr)mem >= 0x600000000000ULL)
-#define MEM_IS_SHADOW(mem) \
-  ((uptr)mem >= 0x200000000000ULL && (uptr)mem <= 0x400000000000ULL)
+/*
+C/C++ on FreeBSD
+0000 0000 0000 - 00ff ffff ffff: Low memory: main binary, MAP_32BIT mappings and modules
+0100 0000 0000 - 0fff ffff ffff: Bad1
[phone] - 30ff ffff ffff: Shadow
[phone] - 37ff ffff ffff: Bad2
[phone] - 58ff ffff ffff: Origins
[phone] - 5fff ffff ffff: Bad3
[phone] - 7fff ffff ffff: High memory: traces, heap, modules and main thread stack
+
+C/C++ on Linux/PIE
+0000 0000 0000 - 1fff ffff ffff: Bad1
[phone] - 3fff ffff ffff: Shadow
[phone] - 5fff ffff ffff: Origins
[phone] - 7fff ffff ffff: Main memory
+
+C/C++ on Mips
+0000 0000 0000 - 009f ffff ffff: Bad1
+00a0 0000 0000 - 00bf ffff ffff: Shadow
+00c0 0000 0000 - 00df ffff ffff: Origins
+00e0 0000 0000 - 00ff ffff ffff: Main memory
+*/
+
+#if SANITIZER_LINUX && defined(__mips64)
+const uptr kLowMemBeg   = 0;
+const uptr kLowMemSize  = 0;
+const uptr kHighMemBeg  = 0x00e000000000;
+const uptr kHighMemSize = 0x002000000000;
+const uptr kShadowBeg   = 0x00a000000000;
+const uptr kShadowSize  = 0x002000000000;
+const uptr kOriginsBeg  = 0x00c000000000;
+# define MEM_TO_SHADOW(mem) (((uptr)(mem)) & ~0x4000000000ULL)
+#elif SANITIZER_FREEBSD && SANITIZER_WORDSIZE == 64
+const uptr kLowMemBeg   = 0x000000000000;
+const uptr kLowMemsize  = 0x010000000000;
+const uptr kHighMemBeg  = 0x600000000000;
+const uptr kHighMemsize = 0x200000000000;
+const uptr kShadowBeg   = 0x100000000000;
+const uptr kShadowSize  = 0x110000000000;
+const uptr kOriginsBeg  = 0x380000000000;
+// Maps low and high app ranges to contiguous space with zero base:
+//   Low:  0000 0000 0000 - 00ff ffff ffff  ->  2000 0000 0000 - 20ff ffff ffff
+//   High: 6000 0000 0000 - 7fff ffff ffff  ->  0000 0000 0000 - 1fff ffff ffff
+# define LINEARIZE_MEM(mem) \
+    (((uptr)(mem) & ~0xc00000000000ULL) ^ 0x200000000000ULL)
+# define MEM_TO_SHADOW(mem) (LINEARIZE_MEM((mem)) + 0x100000000000ULL)
+#elif SANITIZER_LINUX && SANITIZER_WORDSIZE == 64
+const uptr kLowMemBeg   = 0;
+const uptr kLowMemSize  = 0;
+const uptr kHighMemBeg  = 0x600000000000;
+const uptr kHighMemSize = 0x200000000000;
+const uptr kShadowBeg   = 0x200000000000;
+const uptr kShadowSize  = 0x200000000000;
+const uptr kOriginsBeg  = 0x400000000000;
+# define MEM_TO_SHADOW(mem) (((uptr)(mem)) & ~0x400000000000ULL)
+#else
+#error "Unsupported platform"
 #endif
 
+const uptr kBad1Beg  = kLowMemBeg + kLowMemSize;
+const uptr kBad1Size = kShadowBeg - kBad1Beg;
+
+const uptr kBad2Beg  = kShadowBeg + kShadowSize;
+const uptr kBad2Size = kOriginsBeg - kBad2Beg;
+
+const uptr kOriginsSize = kShadowSize;
+
+const uptr kBad3Beg  = kOriginsBeg + kOriginsSize;
+const uptr kBad3Size = kHighMemBeg - kBad3Beg;
+
+#define SHADOW_TO_ORIGIN(shadow) \
+  (((uptr)(shadow)) + (kOriginsBeg - kShadowBeg))
+
+#define MEM_TO_ORIGIN(mem) (SHADOW_TO_ORIGIN(MEM_TO_SHADOW((mem))))
+
+#define MEM_IS_APP(mem) \
+  ((kLowMemSize > 0 && (uptr)(mem) < kLowMemSize) || \
+    (uptr)(mem) >= kHighMemBeg)
+
+#define MEM_IS_SHADOW(mem) \
+  ((uptr)(mem) >= kShadowBeg && (uptr)(mem) < kShadowBeg + kShadowSize)
+
+#define MEM_IS_ORIGIN(mem) \
+  ((uptr)(mem) >= kOriginsBeg && (uptr)(mem) < kOriginsBeg + kOriginsSize)
+
 // These constants must be kept in sync with the ones in MemorySanitizer.cc.
 const int kMsanParamTlsSize = 800;
 const int kMsanRetvalTlsSize = 800;
 
 namespace __msan {
 extern int msan_inited;
 extern bool msan_init_is_running;
 extern int msan_report_count;
 
 bool ProtectRange(uptr beg, uptr end);
-bool InitShadow(bool prot1, bool prot2, bool map_shadow, bool init_origins);
+bool InitShadow(bool prot1, bool prot2, bool prot3,
+                bool map_shadow, bool init_origins);
 char *GetProcSelfMaps();
 void InitializeInterceptors();
 
 void MsanAllocatorThreadFinish();
 void *MsanReallocate(StackTrace *stack, void *oldp, uptr size,
                      uptr alignment, bool zeroise);
 void MsanDeallocate(StackTrace *stack, void *ptr);
 void InstallTrapHandler();

lib/msan/msan.cc

if (StackSizeIsUnlimited()) {
     ReExec();
   }
 
   VPrintf(1, "MSAN_OPTIONS: %s\n", msan_options ? msan_options : "<empty>");
 
   __msan_clear_on_return();
   if (__msan_get_track_origins())
     VPrintf(1, "msan_track_origins\n");
-  if (!InitShadow(/* prot1 */ true, /* prot2 */ true,
+  if (!InitShadow(/* prot1 */ true, /* prot2 */ true, /* prot3 */ true,
                   /* map_shadow */ true, __msan_get_track_origins())) {
     Printf("FATAL: MemorySanitizer can not mmap the shadow memory.\n");
     Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
     Printf("FATAL: Disabling ASLR is known to cause this error.\n");
     Printf("FATAL: If running under GDB, try "
            "'set disable-randomization off'.\n");
     DumpProcessMap();
     Die();

lib/msan/msan_interceptors.cc

 }
 
 namespace __msan {
 
 u32 GetOriginIfPoisoned(uptr addr, uptr size) {
   unsigned char *s = (unsigned char *)MEM_TO_SHADOW(addr);
   for (uptr i = 0; i < size; ++i)
     if (s[i])
-      return *(u32 *)SHADOW_TO_ORIGIN((s + i) & ~3UL);
+      return *(u32 *)SHADOW_TO_ORIGIN(((uptr)s + i) & ~3UL);
   return 0;
 }
 
 void SetOriginIfPoisoned(uptr addr, uptr src_shadow, uptr size,
                          u32 src_origin) {
   uptr dst_s = MEM_TO_SHADOW(addr);
   uptr src_s = src_shadow;
   uptr src_s_end = src_s + size;

lib/msan/msan_linux.cc

 //===-- msan_linux.cc -----------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file is a part of MemorySanitizer.
 //
-// Linux-specific code.
+// Linux- and FreeBSD-specific code.
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_platform.h"
-#if SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_LINUX
 
 #include "msan.h"
 #include "msan_thread.h"
 
 #include <elf.h>
 #include <link.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
 #include <unistd.h>
 #include <unwind.h>
 #include <execinfo.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 
 #include "sanitizer_common/sanitizer_common.h"
 #include "sanitizer_common/sanitizer_procmaps.h"
 
 namespace __msan {
 
-#if defined(__mips64)
-static const uptr kMemBeg     = 0xe000000000;
-static const uptr kMemEnd     = 0xffffffffff;
-#elif defined(__x86_64__)
-static const uptr kMemBeg     = 0x600000000000;
-static const uptr kMemEnd     = 0x7fffffffffff;
-#endif
-
-static const uptr kShadowBeg  = MEM_TO_SHADOW(kMemBeg);
-static const uptr kShadowEnd  = MEM_TO_SHADOW(kMemEnd);
-static const uptr kBad1Beg    = 0;
-static const uptr kBad1End    = kShadowBeg - 1;
-static const uptr kBad2Beg    = kShadowEnd + 1;
-static const uptr kBad2End    = kMemBeg - 1;
-static const uptr kOriginsBeg = kBad2Beg;
-static const uptr kOriginsEnd = kBad2End;
+static void ReportMapRange(const char *descr, uptr beg, uptr size) {
+  if (size > 0)
+    VPrintf(1, "%s : %p - %p\n", descr, beg, beg + size - 1);
+}
 
-bool InitShadow(bool prot1, bool prot2, bool map_shadow, bool init_origins) {
-  if ((uptr) & InitShadow < kMemBeg) {
-    Printf("FATAL: Code below application range: %p < %p. Non-PIE build?\n",
-           &InitShadow, (void *)kMemBeg);
+static bool TakeMapRange(uptr beg, uptr size, bool protect) {
+  if (size > 0) {
+    uptr end = beg + size - 1;
+    if (!MemoryRangeIsAvailable(beg, end)) {
+      Printf("FATAL: Memory range %p - %p is not available.\n", beg, end);
+      return false;
+    }
+    if (protect && !Mprotect(beg, size)) {
+      Printf("FATAL: Cannot protect memory range %p - %p.\n", beg, end);
       return false;
     }
+  }
+  return true;
+}
 
+bool InitShadow(bool prot1, bool prot2, bool prot3,
+                bool map_shadow, bool init_origins) {
+  // Let user know mapping parameters first.
   VPrintf(1, "__msan_init %p\n", &__msan_init);
-  VPrintf(1, "Memory   : %p %p\n", kMemBeg, kMemEnd);
-  VPrintf(1, "Bad2     : %p %p\n", kBad2Beg, kBad2End);
-  VPrintf(1, "Origins  : %p %p\n", kOriginsBeg, kOriginsEnd);
-  VPrintf(1, "Shadow   : %p %p\n", kShadowBeg, kShadowEnd);
-  VPrintf(1, "Bad1     : %p %p\n", kBad1Beg, kBad1End);
-
-  if (!MemoryRangeIsAvailable(kShadowBeg,
-                              init_origins ? kOriginsEnd : kShadowEnd) ||
-      (prot1 && !MemoryRangeIsAvailable(kBad1Beg, kBad1End)) ||
-      (prot2 && !MemoryRangeIsAvailable(kBad2Beg, kBad2End))) {
-    Printf("FATAL: Shadow memory range is not available.\n");
+  ReportMapRange("Low Memory ", kLowMemBeg, kLowMemSize);
+  ReportMapRange("Bad1       ", kBad1Beg, kBad1Size);
+  ReportMapRange("Shadow     ", kShadowBeg, kShadowSize);
+  ReportMapRange("Bad2       ", kBad2Beg, kBad2Size);
+  ReportMapRange("Origins    ", kOriginsBeg, kOriginsSize);
+  ReportMapRange("Bad3       ", kBad3Beg, kBad3Size);
+  ReportMapRange("High Memory", kHighMemBeg, kHighMemSize);
+
+  // Check mapping sanity (the invariant).
+  CHECK_EQ(kLowMemBeg, 0);
+  CHECK_EQ(kBad1Beg, kLowMemBeg + kLowMemSize);
+  CHECK_EQ(kShadowBeg, kBad1Beg + kBad1Size);
+  CHECK_GT(kShadowSize, 0);
+  CHECK_GE(kShadowSize, kLowMemSize + kHighMemSize);
+  CHECK_EQ(kBad2Beg, kShadowBeg + kShadowSize);
+  CHECK_EQ(kOriginsBeg, kBad2Beg + kBad2Size);
+  CHECK_EQ(kOriginsSize, kShadowSize);
+  CHECK_EQ(kBad3Beg, kOriginsBeg + kOriginsSize);
+  CHECK_EQ(kHighMemBeg, kBad3Beg + kBad3Size);
+  CHECK_GT(kHighMemSize, 0);
+  CHECK_GE(kHighMemBeg + kHighMemSize, kHighMemBeg);  // Tests for no overflow.
+
+  if (kLowMemSize > 0) {
+    CHECK(MEM_IS_SHADOW(MEM_TO_SHADOW(kLowMemBeg)));
+    CHECK(MEM_IS_SHADOW(MEM_TO_SHADOW(kLowMemBeg + kLowMemSize - 1)));
+    CHECK(MEM_IS_ORIGIN(MEM_TO_ORIGIN(kLowMemBeg)));
+    CHECK(MEM_IS_ORIGIN(MEM_TO_ORIGIN(kLowMemBeg + kLowMemSize - 1)));
+  }
+  CHECK(MEM_IS_SHADOW(MEM_TO_SHADOW(kHighMemBeg)));
+  CHECK(MEM_IS_SHADOW(MEM_TO_SHADOW(kHighMemBeg + kHighMemSize - 1)));
+  CHECK(MEM_IS_ORIGIN(MEM_TO_ORIGIN(kHighMemBeg)));
+  CHECK(MEM_IS_ORIGIN(MEM_TO_ORIGIN(kHighMemBeg + kHighMemSize - 1)));
+
+  if (kLowMemSize == 0 && (uptr)&__msan_init < kHighMemBeg) {
+    Printf("FATAL: Code below application range: %p < %p. Non-PIE build?\n",
+           (uptr)&__msan_init, (void*)kHighMemBeg);
     return false;
   }
 
-  if (prot1 && !Mprotect(kBad1Beg, kBad1End - kBad1Beg))
-    return false;
-  if (prot2 && !Mprotect(kBad2Beg, kBad2End - kBad2Beg))
+  if (!TakeMapRange(kShadowBeg, kShadowSize, false) ||
+      (init_origins && !TakeMapRange(kOriginsBeg, kOriginsSize, false)) ||
+      (prot1 && !TakeMapRange(kBad1Beg, kBad1Size, true)) ||
+      (prot2 && !TakeMapRange(kBad2Beg, kBad2Size, true)) ||
+      (prot3 && !TakeMapRange(kBad3Beg, kBad3Size, true))) {
     return false;
+  }
+
   if (map_shadow) {
-    void *shadow = MmapFixedNoReserve(kShadowBeg, kShadowEnd - kShadowBeg);
+    void *shadow = MmapFixedNoReserve(kShadowBeg, kShadowSize);
     if (shadow != (void*)kShadowBeg) return false;
   }
   if (init_origins) {
-    void *origins = MmapFixedNoReserve(kOriginsBeg, kOriginsEnd - kOriginsBeg);
+    void *origins = MmapFixedNoReserve(kOriginsBeg, kOriginsSize);
     if (origins != (void*)kOriginsBeg) return false;
   }
   return true;
 }
 
 void MsanDie() {
   if (death_callback)
     death_callback();
if (t->destructor_iterations_ > 1) {
     CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
     return;
   }
   MsanThread::TSDDtor(tsd);
 }
 
 }  // namespace __msan
 
-#endif  // __linux__
+#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX