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// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "debug.h"
#include "sandbox_impl.h"
namespace playground {
int Sandbox::sandbox_munmap(void* start, size_t length) {
Debug::syscall(__NR_munmap, "Executing handler");
struct {
int sysnum;
long long cookie;
MUnmap munmap_req;
} __attribute__((packed)) request;
request.sysnum = __NR_munmap;
request.cookie = cookie();
request.munmap_req.start = start;
request.munmap_req.length = length;
long rc;
SysCalls sys;
if (write(sys, processFdPub(), &request, sizeof(request)) !=
sizeof(request) ||
read(sys, threadFdPub(), &rc, sizeof(rc)) != sizeof(rc)) {
die("Failed to forward munmap() request [sandbox]");
}
return static_cast<int>(rc);
}
bool Sandbox::process_munmap(int parentMapsFd, int sandboxFd, int threadFdPub,
int threadFd, SecureMem::Args* mem) {
// Read request
SysCalls sys;
MUnmap munmap_req;
if (read(sys, sandboxFd, &munmap_req, sizeof(munmap_req)) !=
sizeof(munmap_req)) {
die("Failed to read parameters for munmap() [process]");
}
// Cannot unmap any memory region that was part of the original memory
// mappings.
int rc = -EINVAL;
void *stop = reinterpret_cast<void *>(
reinterpret_cast<char *>(munmap_req.start) + munmap_req.length);
ProtectedMap::const_iterator iter = protectedMap_.lower_bound(
munmap_req.start);
if (iter != protectedMap_.begin()) {
--iter;
}
for (; iter != protectedMap_.end() && iter->first < stop; ++iter) {
if (munmap_req.start < reinterpret_cast<void *>(
reinterpret_cast<char *>(iter->first) + iter->second) &&
stop > iter->first) {
SecureMem::abandonSystemCall(threadFd, rc);
return false;
}
}
// Unmapping memory regions that were newly mapped inside of the sandbox
// is OK.
SecureMem::sendSystemCall(threadFdPub, false, -1, mem, __NR_munmap,
munmap_req.start, munmap_req.length);
return true;
}
} // namespace
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