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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 {
void* Sandbox::sandbox_mmap(void *start, size_t length, int prot, int flags,
int fd, off_t offset) {
long long tm;
Debug::syscall(&tm, __NR_mmap, "Executing handler");
struct {
int sysnum;
long long cookie;
MMap mmap_req;
} __attribute__((packed)) request;
request.sysnum = __NR_MMAP;
request.cookie = cookie();
request.mmap_req.start = start;
request.mmap_req.length = length;
request.mmap_req.prot = prot;
request.mmap_req.flags = flags;
request.mmap_req.fd = fd;
request.mmap_req.offset = offset;
void* rc;
SysCalls sys;
if (write(sys, processFdPub(), &request, sizeof(request)) !=
sizeof(request) ||
read(sys, threadFdPub(), &rc, sizeof(rc)) != sizeof(rc)) {
die("Failed to forward mmap() request [sandbox]");
}
Debug::elapsed(tm, __NR_mmap);
return rc;
}
bool Sandbox::process_mmap(int parentMapsFd, int sandboxFd, int threadFdPub,
int threadFd, SecureMem::Args* mem) {
// Read request
SysCalls sys;
MMap mmap_req;
if (read(sys, sandboxFd, &mmap_req, sizeof(mmap_req)) != sizeof(mmap_req)) {
die("Failed to read parameters for mmap() [process]");
}
if (mmap_req.flags & MAP_FIXED) {
// Cannot map a memory area that was part of the original memory mappings.
void *stop = reinterpret_cast<void *>(
(char *)mmap_req.start + mmap_req.length);
ProtectedMap::const_iterator iter = protectedMap_.lower_bound(
(void *)mmap_req.start);
if (iter != protectedMap_.begin()) {
--iter;
}
for (; iter != protectedMap_.end() && iter->first < stop; ++iter) {
if (mmap_req.start < reinterpret_cast<void *>(
reinterpret_cast<char *>(iter->first) + iter->second) &&
stop > iter->first) {
int rc = -EINVAL;
SecureMem::abandonSystemCall(threadFd, rc);
return false;
}
}
}
// All other mmap() requests are OK
SecureMem::sendSystemCall(threadFdPub, false, -1, mem, __NR_MMAP,
mmap_req.start, mmap_req.length, mmap_req.prot,
mmap_req.flags, mmap_req.fd, mmap_req.offset);
return true;
}
} // namespace
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