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-rw-r--r--lib/dfsan/dfsan.cc59
-rw-r--r--lib/dfsan/dfsan.h13
-rw-r--r--lib/dfsan/dfsan_platform.h107
3 files changed, 138 insertions, 41 deletions
diff --git a/lib/dfsan/dfsan.cc b/lib/dfsan/dfsan.cc
index f4bef921a..7285f202d 100644
--- a/lib/dfsan/dfsan.cc
+++ b/lib/dfsan/dfsan.cc
@@ -42,6 +42,8 @@ Flags __dfsan::flags_data;
SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL dfsan_label __dfsan_retval_tls;
SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL dfsan_label __dfsan_arg_tls[64];
+SANITIZER_INTERFACE_ATTRIBUTE uptr __dfsan_shadow_ptr_mask;
+
// On Linux/x86_64, memory is laid out as follows:
//
// +--------------------+ 0x800000000000 (top of memory)
@@ -114,35 +116,18 @@ SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL dfsan_label __dfsan_arg_tls[64];
typedef atomic_dfsan_label dfsan_union_table_t[kNumLabels][kNumLabels];
-#if defined(__x86_64__)
-static const uptr kShadowAddr = 0x10000;
-static const uptr kUnionTableAddr = 0x200000000000;
-static const uptr kUnusedAddr = kUnionTableAddr + sizeof(dfsan_union_table_t);
-static const uptr kAppAddr = 0x700000008000;
-#elif defined(__mips64)
-static const uptr kShadowAddr = 0x10000;
-static const uptr kUnionTableAddr = 0x2000000000;
-static const uptr kUnusedAddr = kUnionTableAddr + sizeof(dfsan_union_table_t);
-static const uptr kAppAddr = 0xF000008000;
-#elif defined(__aarch64__)
-static const uptr kShadowAddr = 0x10000;
-# if SANITIZER_AARCH64_VMA == 39
-static const uptr kUnionTableAddr = 0x1000000000;
-# elif SANITIZER_AARCH64_VMA == 42
-static const uptr kUnionTableAddr = 0x8000000000;
-# endif
-static const uptr kUnusedAddr = kUnionTableAddr + sizeof(dfsan_union_table_t);
-# if SANITIZER_AARCH64_VMA == 39
-static const uptr kAppAddr = 0x7000008000;
-# elif SANITIZER_AARCH64_VMA == 42
-static const uptr kAppAddr = 0x3ff00008000;
-# endif
-#else
-# error "DFSan not supported for this platform!"
+#ifdef DFSAN_RUNTIME_VMA
+// Runtime detected VMA size.
+int __dfsan::vmaSize;
#endif
+static uptr UnusedAddr() {
+ return MappingArchImpl<MAPPING_UNION_TABLE_ADDR>()
+ + sizeof(dfsan_union_table_t);
+}
+
static atomic_dfsan_label *union_table(dfsan_label l1, dfsan_label l2) {
- return &(*(dfsan_union_table_t *) kUnionTableAddr)[l1][l2];
+ return &(*(dfsan_union_table_t *) UnionTableAddr())[l1][l2];
}
// Checks we do not run out of labels.
@@ -382,6 +367,20 @@ static void InitializeFlags() {
if (common_flags()->help) parser.PrintFlagDescriptions();
}
+static void InitializePlatformEarly() {
+#ifdef DFSAN_RUNTIME_VMA
+ __dfsan::vmaSize =
+ (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
+ if (__dfsan::vmaSize == 39 || __dfsan::vmaSize == 42) {
+ __dfsan_shadow_ptr_mask = ShadowMask();
+ } else {
+ Printf("FATAL: DataFlowSanitizer: unsupported VMA range\n");
+ Printf("FATAL: Found %d - Supported 39 and 42\n", __dfsan::vmaSize);
+ Die();
+ }
+#endif
+}
+
static void dfsan_fini() {
if (internal_strcmp(flags().dump_labels_at_exit, "") != 0) {
fd_t fd = OpenFile(flags().dump_labels_at_exit, WrOnly);
@@ -401,9 +400,9 @@ static void dfsan_fini() {
static void dfsan_init(int argc, char **argv, char **envp) {
InitializeFlags();
- CheckVMASize();
+ InitializePlatformEarly();
- MmapFixedNoReserve(kShadowAddr, kUnusedAddr - kShadowAddr);
+ MmapFixedNoReserve(ShadowAddr(), UnusedAddr() - ShadowAddr());
// Protect the region of memory we don't use, to preserve the one-to-one
// mapping from application to shadow memory. But if ASLR is disabled, Linux
@@ -411,8 +410,8 @@ static void dfsan_init(int argc, char **argv, char **envp) {
// works so long as the program doesn't use too much memory. We support this
// case by disabling memory protection when ASLR is disabled.
uptr init_addr = (uptr)&dfsan_init;
- if (!(init_addr >= kUnusedAddr && init_addr < kAppAddr))
- MmapNoAccess(kUnusedAddr, kAppAddr - kUnusedAddr);
+ if (!(init_addr >= UnusedAddr() && init_addr < AppAddr()))
+ MmapNoAccess(UnusedAddr(), AppAddr() - UnusedAddr());
InitializeInterceptors();
diff --git a/lib/dfsan/dfsan.h b/lib/dfsan/dfsan.h
index df222e49b..81f949e30 100644
--- a/lib/dfsan/dfsan.h
+++ b/lib/dfsan/dfsan.h
@@ -16,6 +16,7 @@
#define DFSAN_H
#include "sanitizer_common/sanitizer_internal_defs.h"
+#include "dfsan_platform.h"
// Copy declarations from public sanitizer/dfsan_interface.h header here.
typedef u16 dfsan_label;
@@ -44,17 +45,7 @@ namespace __dfsan {
void InitializeInterceptors();
inline dfsan_label *shadow_for(void *ptr) {
-#if defined(__x86_64__)
- return (dfsan_label *) ((((uptr) ptr) & ~0x700000000000) << 1);
-#elif defined(__mips64)
- return (dfsan_label *) ((((uptr) ptr) & ~0xF000000000) << 1);
-#elif defined(__aarch64__)
-# if SANITIZER_AARCH64_VMA == 39
- return (dfsan_label *) ((((uptr) ptr) & ~0x7800000000) << 1);
-# elif SANITIZER_AARCH64_VMA == 42
- return (dfsan_label *) ((((uptr) ptr) & ~0x3c000000000) << 1);
-# endif
-#endif
+ return (dfsan_label *) ((((uptr) ptr) & ShadowMask()) << 1);
}
inline const dfsan_label *shadow_for(const void *ptr) {
diff --git a/lib/dfsan/dfsan_platform.h b/lib/dfsan/dfsan_platform.h
new file mode 100644
index 000000000..f1d9f108e
--- /dev/null
+++ b/lib/dfsan/dfsan_platform.h
@@ -0,0 +1,107 @@
+//===-- dfsan_platform.h ----------------------------------------*- C++ -*-===//
+//
+// 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 DataFlowSanitizer.
+//
+// Platform specific information for DFSan.
+//===----------------------------------------------------------------------===//
+
+#ifndef DFSAN_PLATFORM_H
+#define DFSAN_PLATFORM_H
+
+namespace __dfsan {
+
+#if defined(__x86_64__)
+struct Mapping {
+ static const uptr kShadowAddr = 0x10000;
+ static const uptr kUnionTableAddr = 0x200000000000;
+ static const uptr kAppAddr = 0x700000008000;
+ static const uptr kShadowMask = ~0x700000000000;
+};
+#elif defined(__mips64)
+struct Mapping {
+ static const uptr kShadowAddr = 0x10000;
+ static const uptr kUnionTableAddr = 0x2000000000;
+ static const uptr kAppAddr = 0xF000008000;
+ static const uptr kShadowMask = ~0xF000000000;
+};
+#elif defined(__aarch64__)
+struct Mapping39 {
+ static const uptr kShadowAddr = 0x10000;
+ static const uptr kUnionTableAddr = 0x1000000000;
+ static const uptr kAppAddr = 0x7000008000;
+ static const uptr kShadowMask = ~0x7800000000;
+};
+
+struct Mapping42 {
+ static const uptr kShadowAddr = 0x10000;
+ static const uptr kUnionTableAddr = 0x8000000000;
+ static const uptr kAppAddr = 0x3ff00008000;
+ static const uptr kShadowMask = ~0x3c000000000;
+};
+
+extern int vmaSize;
+# define DFSAN_RUNTIME_VMA 1
+#else
+# error "DFSan not supported for this platform!"
+#endif
+
+enum MappingType {
+ MAPPING_SHADOW_ADDR,
+ MAPPING_UNION_TABLE_ADDR,
+ MAPPING_APP_ADDR,
+ MAPPING_SHADOW_MASK
+};
+
+template<typename Mapping, int Type>
+uptr MappingImpl(void) {
+ switch (Type) {
+ case MAPPING_SHADOW_ADDR: return Mapping::kShadowAddr;
+ case MAPPING_UNION_TABLE_ADDR: return Mapping::kUnionTableAddr;
+ case MAPPING_APP_ADDR: return Mapping::kAppAddr;
+ case MAPPING_SHADOW_MASK: return Mapping::kShadowMask;
+ }
+}
+
+template<int Type>
+uptr MappingArchImpl(void) {
+#ifdef __aarch64__
+ if (vmaSize == 39)
+ return MappingImpl<Mapping39, Type>();
+ else
+ return MappingImpl<Mapping42, Type>();
+ DCHECK(0);
+#else
+ return MappingImpl<Mapping, Type>();
+#endif
+}
+
+ALWAYS_INLINE
+uptr ShadowAddr() {
+ return MappingArchImpl<MAPPING_SHADOW_ADDR>();
+}
+
+ALWAYS_INLINE
+uptr UnionTableAddr() {
+ return MappingArchImpl<MAPPING_UNION_TABLE_ADDR>();
+}
+
+ALWAYS_INLINE
+uptr AppAddr() {
+ return MappingArchImpl<MAPPING_APP_ADDR>();
+}
+
+ALWAYS_INLINE
+uptr ShadowMask() {
+ return MappingArchImpl<MAPPING_SHADOW_MASK>();
+}
+
+} // namespace __dfsan
+
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-04 10:09:15 +0000