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Kernel: Move mmap validation functions to Process

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int16 2022-03-10 11:53:40 +11:00 • committed by Andreas Kling
parent 479929b06c
commit 4b96d9c813
2 changed files with 14 additions and 11 deletions
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22
Kernel/Syscalls/mmap.cpp
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@ -69,7 +69,7 @@ static bool should_make_executable_exception_for_dynamic_loader(bool make_readab
return true;
}
static bool validate_mmap_prot(const Process& process, int prot, bool map_stack, bool map_anonymous, Memory::Region const* region = nullptr)
bool Process::validate_mmap_prot(int prot, bool map_stack, bool map_anonymous, Memory::Region const* region) const
{
bool make_readable = prot & PROT_READ;
bool make_writable = prot & PROT_WRITE;
@ -99,17 +99,17 @@ static bool validate_mmap_prot(const Process& process, int prot, bool map_stack,
return true;
}
static bool validate_inode_mmap_prot(const Process& process, int prot, const Inode& inode, bool map_shared)
bool Process::validate_inode_mmap_prot(int prot, const Inode& inode, bool map_shared) const
{
auto metadata = inode.metadata();
if ((prot & PROT_READ) && !metadata.may_read(process))
if ((prot & PROT_READ) && !metadata.may_read(*this))
return false;
if (map_shared) {
// FIXME: What about readonly filesystem mounts? We cannot make a
// decision here without knowing the mount flags, so we would need to
// keep a Custody or something from mmap time.
if ((prot & PROT_WRITE) && !metadata.may_write(process))
if ((prot & PROT_WRITE) && !metadata.may_write(*this))
return false;
if (auto shared_vmobject = inode.shared_vmobject()) {
if ((prot & PROT_EXEC) && shared_vmobject->writable_mappings())
@ -180,7 +180,7 @@ ErrorOr<FlatPtr> Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> use
if ((map_fixed || map_fixed_noreplace) && map_randomized)
return EINVAL;
if (!validate_mmap_prot(*this, prot, map_stack, map_anonymous))
if (!validate_mmap_prot(prot, map_stack, map_anonymous))
return EINVAL;
if (map_stack && (!map_private || !map_anonymous))
@ -232,7 +232,7 @@ ErrorOr<FlatPtr> Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> use
return EACCES;
}
if (description->inode()) {
if (!validate_inode_mmap_prot(*this, prot, *description->inode(), map_shared))
if (!validate_inode_mmap_prot(prot, *description->inode(), map_shared))
return EACCES;
}
@ -273,12 +273,12 @@ ErrorOr<FlatPtr> Process::sys$mprotect(Userspace<void*> addr, size_t size, int p
if (auto* whole_region = address_space().find_region_from_range(range_to_mprotect)) {
if (!whole_region->is_mmap())
return EPERM;
if (!validate_mmap_prot(*this, prot, whole_region->is_stack(), whole_region->vmobject().is_anonymous(), whole_region))
if (!validate_mmap_prot(prot, whole_region->is_stack(), whole_region->vmobject().is_anonymous(), whole_region))
return EINVAL;
if (whole_region->access() == Memory::prot_to_region_access_flags(prot))
return 0;
if (whole_region->vmobject().is_inode()
&& !validate_inode_mmap_prot(*this, prot, static_cast<Memory::InodeVMObject const&>(whole_region->vmobject()).inode(), whole_region->is_shared())) {
&& !validate_inode_mmap_prot(prot, static_cast<Memory::InodeVMObject const&>(whole_region->vmobject()).inode(), whole_region->is_shared())) {
return EACCES;
}
whole_region->set_readable(prot & PROT_READ);
@ -293,12 +293,12 @@ ErrorOr<FlatPtr> Process::sys$mprotect(Userspace<void*> addr, size_t size, int p
if (auto* old_region = address_space().find_region_containing(range_to_mprotect)) {
if (!old_region->is_mmap())
return EPERM;
if (!validate_mmap_prot(*this, prot, old_region->is_stack(), old_region->vmobject().is_anonymous(), old_region))
if (!validate_mmap_prot(prot, old_region->is_stack(), old_region->vmobject().is_anonymous(), old_region))
return EINVAL;
if (old_region->access() == Memory::prot_to_region_access_flags(prot))
return 0;
if (old_region->vmobject().is_inode()
&& !validate_inode_mmap_prot(*this, prot, static_cast<Memory::InodeVMObject const&>(old_region->vmobject()).inode(), old_region->is_shared())) {
&& !validate_inode_mmap_prot(prot, static_cast<Memory::InodeVMObject const&>(old_region->vmobject()).inode(), old_region->is_shared())) {
return EACCES;
}
@ -333,7 +333,7 @@ ErrorOr<FlatPtr> Process::sys$mprotect(Userspace<void*> addr, size_t size, int p
for (const auto* region : regions) {
if (!region->is_mmap())
return EPERM;
if (!validate_mmap_prot(*this, prot, region->is_stack(), region->vmobject().is_anonymous(), region))
if (!validate_mmap_prot(prot, region->is_stack(), region->vmobject().is_anonymous(), region))
return EINVAL;
if (region->vmobject().is_inode()
&& !validate_inode_mmap_prot(*this, prot, static_cast<Memory::InodeVMObject const&>(region->vmobject()).inode(), region->is_shared())) {