[scudo] 32-bit and hardware agnostic support
Summary:
This update introduces i386 support for the Scudo Hardened Allocator, and
offers software alternatives for functions that used to require hardware
specific instruction sets. This should make porting to new architectures
easier.
Among the changes:
- The chunk header has been changed to accomodate the size limitations
encountered on 32-bit architectures. We now fit everything in 64-bit. This
was achieved by storing the amount of unused bytes in an allocation rather
than the size itself, as one can be deduced from the other with the help
of the GetActuallyAllocatedSize function. As it turns out, this header can
be used for both 64 and 32 bit, and as such we dropped the requirement for
the 128-bit compare and exchange instruction support (cmpxchg16b).
- Add 32-bit support for the checksum and the PRNG functions: if the SSE 4.2
instruction set is supported, use the 32-bit CRC32 instruction, and in the
XorShift128, use a 32-bit based state instead of 64-bit.
- Add software support for CRC32: if SSE 4.2 is not supported, fallback on a
software implementation.
- Modify tests that were not 32-bit compliant, and expand them to cover more
allocation and alignment sizes. The random shuffle test has been deactivated
for linux-i386 & linux-i686 as the 32-bit sanitizer allocator doesn't
currently randomize chunks.
Reviewers: alekseyshl, kcc
Subscribers: filcab, llvm-commits, tberghammer, danalbert, srhines, mgorny, modocache
Differential Revision: https://reviews.llvm.org/D26358
llvm-svn: 288255
diff --git a/compiler-rt/lib/scudo/scudo_utils.cpp b/compiler-rt/lib/scudo/scudo_utils.cpp
index 9e6a351..2d66865 100644
--- a/compiler-rt/lib/scudo/scudo_utils.cpp
+++ b/compiler-rt/lib/scudo/scudo_utils.cpp
@@ -17,6 +17,7 @@
#include <fcntl.h>
#include <stdarg.h>
#include <unistd.h>
+#include <cpuid.h>
#include <cstring>
@@ -28,7 +29,7 @@
extern int VSNPrintf(char *buff, int buff_length, const char *format,
va_list args);
-} // namespace __sanitizer
+} // namespace __sanitizer
namespace __scudo {
@@ -44,60 +45,61 @@
Die();
}
+#if defined(__x86_64__) || defined(__i386__)
+// i386 and x86_64 specific code to detect CRC32 hardware support via CPUID.
+// CRC32 requires the SSE 4.2 instruction set.
typedef struct {
u32 Eax;
u32 Ebx;
u32 Ecx;
u32 Edx;
-} CPUIDInfo;
+} CPUIDRegs;
-static void getCPUID(CPUIDInfo *info, u32 leaf, u32 subleaf)
+static void getCPUID(CPUIDRegs *Regs, u32 Level)
{
- asm volatile("cpuid"
- : "=a" (info->Eax), "=b" (info->Ebx), "=c" (info->Ecx), "=d" (info->Edx)
- : "a" (leaf), "c" (subleaf)
- );
+ __get_cpuid(Level, &Regs->Eax, &Regs->Ebx, &Regs->Ecx, &Regs->Edx);
}
-// Returns true is the CPU is a "GenuineIntel" or "AuthenticAMD"
-static bool isSupportedCPU()
-{
- CPUIDInfo Info;
-
- getCPUID(&Info, 0, 0);
- if (memcmp(reinterpret_cast<char *>(&Info.Ebx), "Genu", 4) == 0 &&
- memcmp(reinterpret_cast<char *>(&Info.Edx), "ineI", 4) == 0 &&
- memcmp(reinterpret_cast<char *>(&Info.Ecx), "ntel", 4) == 0) {
- return true;
+CPUIDRegs getCPUFeatures() {
+ CPUIDRegs VendorRegs = {};
+ getCPUID(&VendorRegs, 0);
+ bool IsIntel =
+ (VendorRegs.Ebx == signature_INTEL_ebx) &&
+ (VendorRegs.Edx == signature_INTEL_edx) &&
+ (VendorRegs.Ecx == signature_INTEL_ecx);
+ bool IsAMD =
+ (VendorRegs.Ebx == signature_AMD_ebx) &&
+ (VendorRegs.Edx == signature_AMD_edx) &&
+ (VendorRegs.Ecx == signature_AMD_ecx);
+ // Default to an empty feature set if not on a supported CPU.
+ CPUIDRegs FeaturesRegs = {};
+ if (IsIntel || IsAMD) {
+ getCPUID(&FeaturesRegs, 1);
}
- if (memcmp(reinterpret_cast<char *>(&Info.Ebx), "Auth", 4) == 0 &&
- memcmp(reinterpret_cast<char *>(&Info.Edx), "enti", 4) == 0 &&
- memcmp(reinterpret_cast<char *>(&Info.Ecx), "cAMD", 4) == 0) {
- return true;
- }
- return false;
+ return FeaturesRegs;
}
-bool testCPUFeature(CPUFeature feature)
-{
- static bool InfoInitialized = false;
- static CPUIDInfo CPUInfo = {};
+#ifndef bit_SSE4_2
+#define bit_SSE4_2 bit_SSE42 // clang and gcc have different defines.
+#endif
- if (InfoInitialized == false) {
- if (isSupportedCPU() == true)
- getCPUID(&CPUInfo, 1, 0);
- else
- UNIMPLEMENTED();
- InfoInitialized = true;
- }
- switch (feature) {
- case SSE4_2:
- return ((CPUInfo.Ecx >> 20) & 0x1) != 0;
+bool testCPUFeature(CPUFeature Feature)
+{
+ static CPUIDRegs FeaturesRegs = getCPUFeatures();
+
+ switch (Feature) {
+ case CRC32CPUFeature: // CRC32 is provided by SSE 4.2.
+ return !!(FeaturesRegs.Ecx & bit_SSE4_2);
default:
break;
}
return false;
}
+#else
+bool testCPUFeature(CPUFeature Feature) {
+ return false;
+}
+#endif // defined(__x86_64__) || defined(__i386__)
// readRetry will attempt to read Count bytes from the Fd specified, and if
// interrupted will retry to read additional bytes to reach Count.
@@ -117,17 +119,77 @@
return AmountRead;
}
-// Default constructor for Xorshift128Plus seeds the state with /dev/urandom
-Xorshift128Plus::Xorshift128Plus() {
+static void fillRandom(u8 *Data, ssize_t Size) {
int Fd = open("/dev/urandom", O_RDONLY);
- bool Success = readRetry(Fd, reinterpret_cast<u8 *>(&State_0_),
- sizeof(State_0_)) == sizeof(State_0_);
- Success &= readRetry(Fd, reinterpret_cast<u8 *>(&State_1_),
- sizeof(State_1_)) == sizeof(State_1_);
+ if (Fd < 0) {
+ dieWithMessage("ERROR: failed to open /dev/urandom.\n");
+ }
+ bool Success = readRetry(Fd, Data, Size) == Size;
close(Fd);
if (!Success) {
dieWithMessage("ERROR: failed to read enough data from /dev/urandom.\n");
}
}
-} // namespace __scudo
+// Default constructor for Xorshift128Plus seeds the state with /dev/urandom.
+// TODO(kostyak): investigate using getrandom() if available.
+Xorshift128Plus::Xorshift128Plus() {
+ fillRandom(reinterpret_cast<u8 *>(State), sizeof(State));
+}
+
+const static u32 CRC32Table[] = {
+ 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
+ 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+ 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
+ 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+ 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+ 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+ 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
+ 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+ 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
+ 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+ 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
+ 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+ 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
+ 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+ 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+ 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+ 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
+ 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+ 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
+ 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+ 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
+ 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+ 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
+ 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+ 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+ 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+ 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
+ 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+ 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
+ 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+ 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
+ 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+ 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
+ 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+ 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+ 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+ 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
+ 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+ 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
+ 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+ 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
+ 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+ 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+};
+
+u32 computeCRC32(u32 Crc, uptr Data)
+{
+ for (uptr i = 0; i < sizeof(Data); i++) {
+ Crc = CRC32Table[(Crc ^ Data) & 0xff] ^ (Crc >> 8);
+ Data >>= 8;
+ }
+ return Crc;
+}
+
+} // namespace __scudo