Address review comments around memory and patches.

This commit is contained in:
squidbus 2024-07-15 16:01:34 -07:00 committed by TheTurtle
parent b3d97dcd89
commit f943ce2710
2 changed files with 41 additions and 33 deletions

View File

@ -58,20 +58,28 @@ struct AddressSpace::Impl {
static constexpr size_t ReductionOnFail = 1_GB;
static constexpr size_t MaxReductions = 10;
system_managed_size = SystemManagedSize;
system_reserved_size = SystemReservedSize + ReductionOnFail;
user_size = UserSize;
for (u32 i = 0; i < MaxReductions && !virtual_base; i++) {
system_reserved_size -= ReductionOnFail;
virtual_base = static_cast<u8*>(
VirtualAlloc2(process, NULL, system_managed_size + system_reserved_size + user_size,
MEM_RESERVE | MEM_RESERVE_PLACEHOLDER, PAGE_NOACCESS, &param, 1));
size_t reduction = 0;
for (u32 i = 0; i < MaxReductions; i++) {
virtual_base = static_cast<u8*>(VirtualAlloc2(
process, NULL, SystemManagedSize + SystemReservedSize + UserSize - reduction,
MEM_RESERVE | MEM_RESERVE_PLACEHOLDER, PAGE_NOACCESS, &param, 1));
if (virtual_base) {
break;
}
reduction += ReductionOnFail;
}
ASSERT_MSG(virtual_base, "Unable to reserve virtual address space!");
system_managed_base = virtual_base;
system_reserved_base = virtual_base + system_managed_size;
user_base = system_reserved_base + system_reserved_size;
system_managed_size = SystemManagedSize - reduction;
system_reserved_base =
virtual_base + (SYSTEM_RESERVED_MIN - SYSTEM_MANAGED_MIN) - reduction;
system_reserved_size = SystemReservedSize;
user_base = virtual_base + (USER_MIN - SYSTEM_MANAGED_MIN) - reduction;
user_size = UserSize;
ASSERT_MSG(user_base == reinterpret_cast<u8*>(USER_MIN),
"Unexpected user address space location: {}", fmt::ptr(user_base));
LOG_INFO(Kernel_Vmm, "System managed virtual memory region: {} - {}",
fmt::ptr(system_managed_base),
@ -277,23 +285,24 @@ struct AddressSpace::Impl {
system_managed_size = SystemManagedSize;
system_reserved_size = SystemReservedSize;
user_size = UserSize;
constexpr int protection_flags = PROT_READ | PROT_WRITE;
constexpr int base_map_flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
#ifdef __APPLE__
system_managed_base = reinterpret_cast<u8*>(
mmap(reinterpret_cast<void*>(SYSTEM_MANAGED_MIN), system_managed_size,
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE | MAP_FIXED,
-1, 0));
mmap(reinterpret_cast<void*>(SYSTEM_MANAGED_MIN), system_managed_size, protection_flags,
base_map_flags | MAP_FIXED, -1, 0));
// Cannot guarantee enough space for these areas at the desired addresses, so not MAP_FIXED.
system_reserved_base = reinterpret_cast<u8*>(
mmap(reinterpret_cast<void*>(SYSTEM_RESERVED_MIN), system_reserved_size,
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0));
protection_flags, base_map_flags, -1, 0));
user_base = reinterpret_cast<u8*>(mmap(reinterpret_cast<void*>(USER_MIN), user_size,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0));
protection_flags, base_map_flags, -1, 0));
#else
const auto virtual_size = system_managed_size + system_reserved_size + user_size;
const auto virtual_base = reinterpret_cast<u8*>(
mmap(reinterpret_cast<void*>(SYSTEM_MANAGED_MIN), virtual_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE | MAP_FIXED, -1, 0));
const auto virtual_base =
reinterpret_cast<u8*>(mmap(reinterpret_cast<void*>(SYSTEM_MANAGED_MIN), virtual_size,
protection_flags, base_map_flags | MAP_FIXED, -1, 0));
system_managed_base = virtual_base;
system_managed_base = virtual_base + (SYSTEM_RESERVED_MIN - SYSTEM_MANAGED_MIN);
user_base = virtual_base + (USER_MIN - SYSTEM_MANAGED_MIN);
@ -331,9 +340,6 @@ struct AddressSpace::Impl {
#else
madvise(virtual_base, virtual_size, MADV_HUGEPAGE);
const VAddr start_addr = reinterpret_cast<VAddr>(virtual_base);
m_free_regions.insert({start_addr, start_addr + virtual_size});
backing_fd = memfd_create("BackingDmem", 0);
if (backing_fd < 0) {
LOG_CRITICAL(Kernel_Vmm, "memfd_create failed: {}", strerror(errno));

View File

@ -16,6 +16,8 @@
#include <pthread.h>
#endif
using namespace Xbyak::util;
namespace Core {
static Xbyak::Reg ZydisToXbyakRegister(const ZydisRegister reg) {
@ -54,7 +56,7 @@ static Xbyak::Address ZydisToXbyakMemoryOperand(const ZydisDecodedOperand& opera
expression = expression + operand.mem.disp.value;
}
return Xbyak::util::ptr[expression];
return ptr[expression];
}
static std::unique_ptr<Xbyak::Operand> ZydisToXbyakOperand(const ZydisDecodedOperand& operand) {
@ -125,8 +127,8 @@ static void SaveRegisters(Xbyak::CodeGenerator& c, const std::initializer_list<X
for (const auto& reg : regs) {
const auto offset = reinterpret_cast<void*>(register_save_slots[index++] * sizeof(void*));
c.putSeg(Xbyak::util::gs);
c.mov(Xbyak::util::qword[offset], reg.cvt64());
c.putSeg(gs);
c.mov(qword[offset], reg.cvt64());
}
}
@ -141,8 +143,8 @@ static void RestoreRegisters(Xbyak::CodeGenerator& c,
for (const auto& reg : regs) {
const auto offset = reinterpret_cast<void*>(register_save_slots[index++] * sizeof(void*));
c.putSeg(Xbyak::util::gs);
c.mov(reg.cvt64(), Xbyak::util::qword[offset]);
c.putSeg(gs);
c.mov(reg.cvt64(), qword[offset]);
}
}
@ -277,20 +279,20 @@ static void GenerateTcbAccess(const ZydisDecodedOperand* operands, Xbyak::CodeGe
const u32 tls_index = slot < TlsMinimumAvailable ? slot : slot - TlsMinimumAvailable;
// Load the pointer to the table of TLS slots.
c.putSeg(Xbyak::util::gs);
c.mov(dst, Xbyak::util::ptr[reinterpret_cast<void*>(teb_offset)]);
c.putSeg(gs);
c.mov(dst, ptr[reinterpret_cast<void*>(teb_offset)]);
// Load the pointer to our buffer.
c.mov(dst, Xbyak::util::qword[dst + tls_index * sizeof(LPVOID)]);
c.mov(dst, qword[dst + tls_index * sizeof(LPVOID)]);
#elif defined(__APPLE__)
// The following logic is based on the Darwin implementation of _os_tsd_get_direct, used by
// pthread_getspecific https://github.com/apple/darwin-xnu/blob/main/libsyscall/os/tsd.h#L89-L96
c.putSeg(Xbyak::util::gs);
c.mov(dst, Xbyak::util::qword[reinterpret_cast<void*>(slot * sizeof(void*))]);
c.putSeg(gs);
c.mov(dst, qword[reinterpret_cast<void*>(slot * sizeof(void*))]);
#else
const auto src = ZydisToXbyakMemoryOperand(operands[1]);
// Replace fs read with gs read.
c.putSeg(Xbyak::util::gs);
c.putSeg(gs);
c.mov(dst, src);
#endif
}