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#include <errno.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <unistd.h>
#include "POSIXPrivate.h"
#include "WAVM/Inline/Assert.h"
#include "WAVM/Inline/BasicTypes.h"
#include "WAVM/Inline/Errors.h"
#include "WAVM/Platform/Intrinsic.h"
#include "WAVM/Platform/Memory.h"
#include "WAVM/Platform/Mutex.h"
#ifdef __APPLE__
#define MAP_ANONYMOUS MAP_ANON
#endif
using namespace WAVM;
using namespace WAVM::Platform;
static Uptr internalGetPreferredVirtualPageSizeLog2()
{
U32 preferredVirtualPageSize = sysconf(_SC_PAGESIZE);
// Verify our assumption that the virtual page size is a power of two.
WAVM_ASSERT(!(preferredVirtualPageSize & (preferredVirtualPageSize - 1)));
return floorLogTwo(preferredVirtualPageSize);
}
Uptr Platform::getBytesPerPageLog2()
{
static Uptr preferredVirtualPageSizeLog2 = internalGetPreferredVirtualPageSizeLog2();
return preferredVirtualPageSizeLog2;
}
static U32 memoryAccessAsPOSIXFlag(MemoryAccess access)
{
switch(access)
{
default:
case MemoryAccess::none: return PROT_NONE;
case MemoryAccess::readOnly: return PROT_READ;
case MemoryAccess::readWrite: return PROT_READ | PROT_WRITE;
case MemoryAccess::readExecute: return PROT_READ | PROT_EXEC;
case MemoryAccess::readWriteExecute: return PROT_EXEC | PROT_READ | PROT_WRITE;
}
}
static bool isPageAligned(U8* address)
{
const Uptr addressBits = reinterpret_cast<Uptr>(address);
return (addressBits & (getBytesPerPage() - 1)) == 0;
}
U8* Platform::allocateVirtualPages(Uptr numPages)
{
Uptr numBytes = numPages << getBytesPerPageLog2();
void* result = mmap(nullptr, numBytes, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if(result == MAP_FAILED)
{
if(errno != ENOMEM)
{
fprintf(stderr,
"mmap(0, %" WAVM_PRIuPTR
", PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) failed! errno=%s\n",
numBytes,
strerror(errno));
dumpErrorCallStack(0);
}
return nullptr;
}
return (U8*)result;
}
U8* Platform::allocateAlignedVirtualPages(Uptr numPages,
Uptr alignmentLog2,
U8*& outUnalignedBaseAddress)
{
const Uptr pageSizeLog2 = getBytesPerPageLog2();
const Uptr numBytes = numPages << pageSizeLog2;
if(alignmentLog2 > pageSizeLog2)
{
// Call mmap with enough padding added to the size to align the allocation within the
// unaligned mapping.
const Uptr alignmentBytes = 1ull << alignmentLog2;
U8* unalignedBaseAddress = (U8*)mmap(
nullptr, numBytes + alignmentBytes, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if(unalignedBaseAddress == MAP_FAILED)
{
if(errno != ENOMEM)
{
fprintf(stderr,
"mmap(0, %" WAVM_PRIuPTR
", PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) failed! errno=%s\n",
numBytes + alignmentBytes,
strerror(errno));
dumpErrorCallStack(0);
}
return nullptr;
}
const Uptr address = reinterpret_cast<Uptr>(unalignedBaseAddress);
const Uptr alignedAddress = (address + alignmentBytes - 1) & ~(alignmentBytes - 1);
U8* result = reinterpret_cast<U8*>(alignedAddress);
// Unmap the start and end of the unaligned mapping, leaving the aligned mapping in the
// middle.
const Uptr numHeadPaddingBytes = alignedAddress - address;
if(numHeadPaddingBytes > 0)
{ WAVM_ERROR_UNLESS(!munmap(unalignedBaseAddress, numHeadPaddingBytes)); }
const Uptr numTailPaddingBytes = alignmentBytes - (alignedAddress - address);
if(numTailPaddingBytes > 0)
{ WAVM_ERROR_UNLESS(!munmap(result + (numPages << pageSizeLog2), numTailPaddingBytes)); }
outUnalignedBaseAddress = result;
return result;
}
else
{
outUnalignedBaseAddress = allocateVirtualPages(numPages);
return outUnalignedBaseAddress;
}
}
bool Platform::commitVirtualPages(U8* baseVirtualAddress, Uptr numPages, MemoryAccess access)
{
WAVM_ERROR_UNLESS(isPageAligned(baseVirtualAddress));
int result = mprotect(
baseVirtualAddress, numPages << getBytesPerPageLog2(), memoryAccessAsPOSIXFlag(access));
if(result != 0)
{
fprintf(stderr,
"mprotect(0x%" WAVM_PRIxPTR ", %" WAVM_PRIuPTR ", %u) failed: %s\n",
reinterpret_cast<Uptr>(baseVirtualAddress),
numPages << getBytesPerPageLog2(),
memoryAccessAsPOSIXFlag(access),
strerror(errno));
dumpErrorCallStack(0);
}
return result == 0;
}
bool Platform::setVirtualPageAccess(U8* baseVirtualAddress, Uptr numPages, MemoryAccess access)
{
WAVM_ERROR_UNLESS(isPageAligned(baseVirtualAddress));
int result = mprotect(
baseVirtualAddress, numPages << getBytesPerPageLog2(), memoryAccessAsPOSIXFlag(access));
if(result != 0)
{
fprintf(stderr,
"mprotect(0x%" WAVM_PRIxPTR ", %" WAVM_PRIuPTR ", %u) failed: %s\n",
reinterpret_cast<Uptr>(baseVirtualAddress),
numPages << getBytesPerPageLog2(),
memoryAccessAsPOSIXFlag(access),
strerror(errno));
dumpErrorCallStack(0);
}
return result == 0;
}
void Platform::decommitVirtualPages(U8* baseVirtualAddress, Uptr numPages)
{
WAVM_ERROR_UNLESS(isPageAligned(baseVirtualAddress));
auto numBytes = numPages << getBytesPerPageLog2();
if(mmap(baseVirtualAddress, numBytes, PROT_NONE, MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0)
== MAP_FAILED)
{
Errors::fatalf("mmap(0x%" WAVM_PRIxPTR ", %" WAVM_PRIuPTR
", PROT_NONE, MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) failed: %s",
reinterpret_cast<Uptr>(baseVirtualAddress),
numBytes,
strerror(errno));
}
}
void Platform::freeVirtualPages(U8* baseVirtualAddress, Uptr numPages)
{
WAVM_ERROR_UNLESS(isPageAligned(baseVirtualAddress));
if(munmap(baseVirtualAddress, numPages << getBytesPerPageLog2()))
{
Errors::fatalf("munmap(0x%" WAVM_PRIxPTR ", %u) failed: %s",
reinterpret_cast<Uptr>(baseVirtualAddress),
numPages << getBytesPerPageLog2(),
strerror(errno));
}
}
void Platform::freeAlignedVirtualPages(U8* unalignedBaseAddress, Uptr numPages, Uptr alignmentLog2)
{
WAVM_ERROR_UNLESS(isPageAligned(unalignedBaseAddress));
if(munmap(unalignedBaseAddress, numPages << getBytesPerPageLog2()))
{
Errors::fatalf("munmap(0x%" WAVM_PRIxPTR ", %u) failed: %s",
reinterpret_cast<Uptr>(unalignedBaseAddress),
numPages << getBytesPerPageLog2(),
strerror(errno));
}
}
Uptr Platform::getPeakMemoryUsageBytes()
{
struct rusage ru;
WAVM_ERROR_UNLESS(!getrusage(RUSAGE_SELF, &ru));
#ifdef __APPLE__
// POSIX and even the Mac OS X docs say this is in KB, but it's actually in bytes.
return Uptr(ru.ru_maxrss);
#else
return Uptr(ru.ru_maxrss) * 1024;
#endif
}
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