Atmosphere/stratosphere/ro/source/impl/ro_map_utils.cpp

84 lines
3.6 KiB
C++

/*
* Copyright (c) Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stratosphere.hpp>
#include "ro_map_utils.hpp"
namespace ams::ro::impl {
namespace {
ALWAYS_INLINE u64 GetCurrentProcessInfo(svc::InfoType info_type) {
u64 value;
R_ABORT_UNLESS(svc::GetInfo(std::addressof(value), info_type, svc::PseudoHandle::CurrentProcess, 0));
return value;
}
}
Result SearchFreeRegion(uintptr_t *out, size_t mapping_size) {
/* Get address space extents. */
const uintptr_t heap_start = GetCurrentProcessInfo(svc::InfoType_HeapRegionAddress);
const size_t heap_size = GetCurrentProcessInfo(svc::InfoType_HeapRegionSize);
const uintptr_t alias_start = GetCurrentProcessInfo(svc::InfoType_AliasRegionAddress);
const size_t alias_size = GetCurrentProcessInfo(svc::InfoType_AliasRegionSize);
const uintptr_t aslr_start = GetCurrentProcessInfo(svc::InfoType_AslrRegionAddress);
const size_t aslr_size = GetCurrentProcessInfo(svc::InfoType_AslrRegionSize);
/* Iterate upwards to find a free region. */
uintptr_t address = aslr_start;
while (true) {
/* Declare variables for memory querying. */
svc::MemoryInfo mem_info;
svc::PageInfo page_info;
/* Check that we're still within bounds. */
R_UNLESS(address < address + mapping_size, ro::ResultOutOfAddressSpace());
/* If we're within the heap region, skip to the end of the heap region. */
if (heap_size != 0 && !(address + mapping_size - 1 < heap_start || heap_start + heap_size - 1 < address)) {
R_UNLESS(address < heap_start + heap_size, ro::ResultOutOfAddressSpace());
address = heap_start + heap_size;
continue;
}
/* If we're within the alias region, skip to the end of the alias region. */
if (alias_size != 0 && !(address + mapping_size - 1 < alias_start || alias_start + alias_size - 1 < address)) {
R_UNLESS(address < alias_start + alias_size, ro::ResultOutOfAddressSpace());
address = alias_start + alias_size;
continue;
}
/* Get the current memory range. */
R_ABORT_UNLESS(svc::QueryMemory(std::addressof(mem_info), std::addressof(page_info), address));
/* If the memory range is free and big enough, use it. */
if (mem_info.state == svc::MemoryState_Free && mapping_size <= ((mem_info.addr + mem_info.size) - address)) {
*out = address;
return ResultSuccess();
}
/* Check that we can advance. */
R_UNLESS(address < mem_info.addr + mem_info.size, ro::ResultOutOfAddressSpace());
R_UNLESS(mem_info.addr + mem_info.size - 1 < aslr_start + aslr_size - 1, ro::ResultOutOfAddressSpace());
/* Advance. */
address = mem_info.addr + mem_info.size;
}
}
}