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UserspaceEmulator: Support the name argument in mmap for file backed mappings

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Itamar 2020-11-27 15:45:49 +02:00 • committed by Andreas Kling
parent d2262b8f6d
commit 28cda567c1
3 changed files with 27 additions and 5 deletions
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20
DevTools/UserspaceEmulator/Emulator.cpp
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@ -874,11 +874,27 @@ u32 Emulator::virt$mmap(u32 params_addr)
u32 final_size = round_up_to_power_of_two(params.size, PAGE_SIZE);
u32 final_address = allocate_vm(final_size, params.alignment);
if (params.addr != 0) {
// NOTE: We currently do not support allocating VM at a requeted address in the emulator.
// The loader needs this functionality to load .data just after .text.
// Luckily, since the loader calls mmap for .data right after it calls mmap for .text,
// the emulator will allocate a chunk of memory that is just after what we allocated for .text
// becuase of the way we currently allocate VM.
ASSERT(params.addr == final_address);
}
if (params.flags & MAP_ANONYMOUS)
mmu().add_region(MmapRegion::create_anonymous(final_address, final_size, params.prot));
else
mmu().add_region(MmapRegion::create_file_backed(final_address, final_size, params.prot, params.flags, params.fd, params.offset));
else {
dbgln("chars: {:p}, len: {}", params.name.characters, params.name.length);
String name_str;
if (params.name.characters) {
auto name = ByteBuffer::create_uninitialized(params.name.length);
mmu().copy_from_vm(name.data(), (FlatPtr)params.name.characters, params.name.length);
name_str = { name.data(), name.size() };
}
mmu().add_region(MmapRegion::create_file_backed(final_address, final_size, params.prot, params.flags, params.fd, params.offset, name_str));
}
return final_address;
}