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Kernel: Hoist VM range allocation up to sys$mmap() itself

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Instead of letting each File subclass do range allocation in their
mmap() override, do it up front in sys$mmap().

This makes us honor alignment requests for file-backed memory mappings
and simplifies the code somwhat.
This commit is contained in:
Andreas Kling 2021-01-25 14:52:36 +01:00
parent adcc1c1eff
commit ab14b0ac64
13 changed files with 26 additions and 36 deletions
Download patch file Download diff file Expand all files Collapse all files

7
Kernel/Devices/BXVGADevice.cpp
View file

@ -172,19 +172,18 @@ u32 BXVGADevice::find_framebuffer_address()
return framebuffer_address; return framebuffer_address;
} }
KResultOr<Region*> BXVGADevice::mmap(Process& process, FileDescription&, VirtualAddress preferred_vaddr, size_t offset, size_t size, int prot, bool shared) KResultOr<Region*> BXVGADevice::mmap(Process& process, FileDescription&, const Range& range, size_t offset, int prot, bool shared)
{ {
REQUIRE_PROMISE(video); REQUIRE_PROMISE(video);
if (!shared) if (!shared)
return ENODEV; return ENODEV;
ASSERT(offset == 0); ASSERT(offset == 0);
ASSERT(size == framebuffer_size_in_bytes()); ASSERT(range.size() == framebuffer_size_in_bytes());
auto vmobject = AnonymousVMObject::create_for_physical_range(m_framebuffer_address, framebuffer_size_in_bytes()); auto vmobject = AnonymousVMObject::create_for_physical_range(m_framebuffer_address, framebuffer_size_in_bytes());
if (!vmobject) if (!vmobject)
return ENOMEM; return ENOMEM;
return process.allocate_region_with_vmobject( return process.allocate_region_with_vmobject(
preferred_vaddr, range,
framebuffer_size_in_bytes(),
vmobject.release_nonnull(), vmobject.release_nonnull(),
0, 0,
"BXVGA Framebuffer", "BXVGA Framebuffer",

2
Kernel/Devices/BXVGADevice.h
View file

@ -42,7 +42,7 @@ public:
BXVGADevice(); BXVGADevice();
virtual int ioctl(FileDescription&, unsigned request, FlatPtr arg) override; virtual int ioctl(FileDescription&, unsigned request, FlatPtr arg) override;
virtual KResultOr<Region*> mmap(Process&, FileDescription&, VirtualAddress preferred_vaddr, size_t offset, size_t, int prot, bool shared) override; virtual KResultOr<Region*> mmap(Process&, FileDescription&, const Range&, size_t offset, int prot, bool shared) override;
// ^Device // ^Device
virtual mode_t required_mode() const override { return 0660; } virtual mode_t required_mode() const override { return 0660; }

7
Kernel/Devices/MBVGADevice.cpp
View file

@ -51,19 +51,18 @@ MBVGADevice::MBVGADevice(PhysicalAddress addr, size_t pitch, size_t width, size_
s_the = this; s_the = this;
} }
KResultOr<Region*> MBVGADevice::mmap(Process& process, FileDescription&, VirtualAddress preferred_vaddr, size_t offset, size_t size, int prot, bool shared) KResultOr<Region*> MBVGADevice::mmap(Process& process, FileDescription&, const Range& range, size_t offset, int prot, bool shared)
{ {
REQUIRE_PROMISE(video); REQUIRE_PROMISE(video);
if (!shared) if (!shared)
return ENODEV; return ENODEV;
ASSERT(offset == 0); ASSERT(offset == 0);
ASSERT(size == framebuffer_size_in_bytes()); ASSERT(range.size() == framebuffer_size_in_bytes());
auto vmobject = AnonymousVMObject::create_for_physical_range(m_framebuffer_address, framebuffer_size_in_bytes()); auto vmobject = AnonymousVMObject::create_for_physical_range(m_framebuffer_address, framebuffer_size_in_bytes());
if (!vmobject) if (!vmobject)
return ENOMEM; return ENOMEM;
return process.allocate_region_with_vmobject( return process.allocate_region_with_vmobject(
preferred_vaddr, range,
framebuffer_size_in_bytes(),
vmobject.release_nonnull(), vmobject.release_nonnull(),
0, 0,
"MBVGA Framebuffer", "MBVGA Framebuffer",

2
Kernel/Devices/MBVGADevice.h
View file

@ -41,7 +41,7 @@ public:
MBVGADevice(PhysicalAddress addr, size_t pitch, size_t width, size_t height); MBVGADevice(PhysicalAddress addr, size_t pitch, size_t width, size_t height);
virtual int ioctl(FileDescription&, unsigned request, FlatPtr arg) override; virtual int ioctl(FileDescription&, unsigned request, FlatPtr arg) override;
virtual KResultOr<Region*> mmap(Process&, FileDescription&, VirtualAddress preferred_vaddr, size_t offset, size_t, int prot, bool shared) override; virtual KResultOr<Region*> mmap(Process&, FileDescription&, const Range&, size_t offset, int prot, bool shared) override;
// ^Device // ^Device
virtual mode_t required_mode() const override { return 0660; } virtual mode_t required_mode() const override { return 0660; }

6
Kernel/FileSystem/AnonymousFile.cpp
View file

@ -39,15 +39,15 @@ AnonymousFile::~AnonymousFile()
{ {
} }
KResultOr<Region*> AnonymousFile::mmap(Process& process, FileDescription&, VirtualAddress preferred_vaddr, size_t offset, size_t size, int prot, bool shared) KResultOr<Region*> AnonymousFile::mmap(Process& process, FileDescription&, const Range& range, size_t offset, int prot, bool shared)
{ {
if (offset != 0) if (offset != 0)
return EINVAL; return EINVAL;
if (size != m_vmobject->size()) if (range.size() != m_vmobject->size())
return EINVAL; return EINVAL;
return process.allocate_region_with_vmobject(preferred_vaddr, size, m_vmobject, offset, {}, prot, shared); return process.allocate_region_with_vmobject(range, m_vmobject, offset, {}, prot, shared);
} }
} }

2
Kernel/FileSystem/AnonymousFile.h
View file

@ -39,7 +39,7 @@ public:
virtual ~AnonymousFile() override; virtual ~AnonymousFile() override;
virtual KResultOr<Region*> mmap(Process&, FileDescription&, VirtualAddress preferred_vaddr, size_t offset, size_t size, int prot, bool shared) override; virtual KResultOr<Region*> mmap(Process&, FileDescription&, const Range&, size_t offset, int prot, bool shared) override;
private: private:
virtual const char* class_name() const override { return "AnonymousFile"; } virtual const char* class_name() const override { return "AnonymousFile"; }

2
Kernel/FileSystem/File.cpp
View file

@ -59,7 +59,7 @@ int File::ioctl(FileDescription&, unsigned, FlatPtr)
return -ENOTTY; return -ENOTTY;
} }
KResultOr<Region*> File::mmap(Process&, FileDescription&, VirtualAddress, size_t, size_t, int, bool) KResultOr<Region*> File::mmap(Process&, FileDescription&, const Range&, size_t, int, bool)
{ {
return ENODEV; return ENODEV;
} }

2
Kernel/FileSystem/File.h
View file

@ -114,7 +114,7 @@ public:
virtual KResultOr<size_t> read(FileDescription&, size_t, UserOrKernelBuffer&, size_t) = 0; virtual KResultOr<size_t> read(FileDescription&, size_t, UserOrKernelBuffer&, size_t) = 0;
virtual KResultOr<size_t> write(FileDescription&, size_t, const UserOrKernelBuffer&, size_t) = 0; virtual KResultOr<size_t> write(FileDescription&, size_t, const UserOrKernelBuffer&, size_t) = 0;
virtual int ioctl(FileDescription&, unsigned request, FlatPtr arg); virtual int ioctl(FileDescription&, unsigned request, FlatPtr arg);
virtual KResultOr<Region*> mmap(Process&, FileDescription&, VirtualAddress preferred_vaddr, size_t offset, size_t size, int prot, bool shared); virtual KResultOr<Region*> mmap(Process&, FileDescription&, const Range&, size_t offset, int prot, bool shared);
virtual KResult stat(::stat&) const { return EBADF; } virtual KResult stat(::stat&) const { return EBADF; }
virtual String absolute_path(const FileDescription&) const = 0; virtual String absolute_path(const FileDescription&) const = 0;

4
Kernel/FileSystem/FileDescription.cpp
View file

@ -328,10 +328,10 @@ InodeMetadata FileDescription::metadata() const
return {}; return {};
} }
KResultOr<Region*> FileDescription::mmap(Process& process, VirtualAddress vaddr, size_t offset, size_t size, int prot, bool shared) KResultOr<Region*> FileDescription::mmap(Process& process, const Range& range, size_t offset, int prot, bool shared)
{ {
LOCKER(m_lock); LOCKER(m_lock);
return m_file->mmap(process, *this, vaddr, offset, size, prot, shared); return m_file->mmap(process, *this, range, offset, prot, shared);
} }
KResult FileDescription::truncate(u64 length) KResult FileDescription::truncate(u64 length)

2
Kernel/FileSystem/FileDescription.h
View file

@ -108,7 +108,7 @@ public:
Custody* custody() { return m_custody.ptr(); } Custody* custody() { return m_custody.ptr(); }
const Custody* custody() const { return m_custody.ptr(); } const Custody* custody() const { return m_custody.ptr(); }
KResultOr<Region*> mmap(Process&, VirtualAddress, size_t offset, size_t, int prot, bool shared); KResultOr<Region*> mmap(Process&, const Range&, size_t offset, int prot, bool shared);
bool is_blocking() const { return m_is_blocking; } bool is_blocking() const { return m_is_blocking; }
void set_blocking(bool b) { m_is_blocking = b; } void set_blocking(bool b) { m_is_blocking = b; }

4
Kernel/FileSystem/InodeFile.cpp
View file

@ -69,7 +69,7 @@ KResultOr<size_t> InodeFile::write(FileDescription& description, size_t offset,
return nwritten; return nwritten;
} }
KResultOr<Region*> InodeFile::mmap(Process& process, FileDescription& description, VirtualAddress preferred_vaddr, size_t offset, size_t size, int prot, bool shared) KResultOr<Region*> InodeFile::mmap(Process& process, FileDescription& description, const Range& range, size_t offset, int prot, bool shared)
{ {
// FIXME: If PROT_EXEC, check that the underlying file system isn't mounted noexec. // FIXME: If PROT_EXEC, check that the underlying file system isn't mounted noexec.
RefPtr<InodeVMObject> vmobject; RefPtr<InodeVMObject> vmobject;
@ -79,7 +79,7 @@ KResultOr<Region*> InodeFile::mmap(Process& process, FileDescription& descriptio
vmobject = PrivateInodeVMObject::create_with_inode(inode()); vmobject = PrivateInodeVMObject::create_with_inode(inode());
if (!vmobject) if (!vmobject)
return ENOMEM; return ENOMEM;
return process.allocate_region_with_vmobject(preferred_vaddr, size, *vmobject, offset, description.absolute_path(), prot, shared); return process.allocate_region_with_vmobject(range, vmobject.release_nonnull(), offset, description.absolute_path(), prot, shared);
} }
String InodeFile::absolute_path(const FileDescription& description) const String InodeFile::absolute_path(const FileDescription& description) const

2
Kernel/FileSystem/InodeFile.h
View file

@ -49,7 +49,7 @@ public:
virtual KResultOr<size_t> read(FileDescription&, size_t, UserOrKernelBuffer&, size_t) override; virtual KResultOr<size_t> read(FileDescription&, size_t, UserOrKernelBuffer&, size_t) override;
virtual KResultOr<size_t> write(FileDescription&, size_t, const UserOrKernelBuffer&, size_t) override; virtual KResultOr<size_t> write(FileDescription&, size_t, const UserOrKernelBuffer&, size_t) override;
virtual KResultOr<Region*> mmap(Process&, FileDescription&, VirtualAddress preferred_vaddr, size_t offset, size_t size, int prot, bool shared) override; virtual KResultOr<Region*> mmap(Process&, FileDescription&, const Range&, size_t offset, int prot, bool shared) override;
virtual String absolute_path(const FileDescription&) const override; virtual String absolute_path(const FileDescription&) const override;

18
Kernel/Syscalls/mmap.cpp
View file

@ -133,16 +133,13 @@ void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
return (void*)-EINVAL; return (void*)-EINVAL;
Region* region = nullptr; Region* region = nullptr;
Optional<Range> range; auto range = allocate_range(VirtualAddress(addr), size, alignment);
if (map_noreserve || map_anonymous) { if (!range.is_valid())
range = allocate_range(VirtualAddress(addr), size, alignment);
if (!range.value().is_valid())
return (void*)-ENOMEM; return (void*)-ENOMEM;
}
if (map_anonymous) { if (map_anonymous) {
auto strategy = map_noreserve ? AllocationStrategy::None : AllocationStrategy::Reserve; auto strategy = map_noreserve ? AllocationStrategy::None : AllocationStrategy::Reserve;
auto region_or_error = allocate_region(range.value(), !name.is_null() ? name : "mmap", prot, strategy); auto region_or_error = allocate_region(range, !name.is_null() ? name : "mmap", prot, strategy);
if (region_or_error.is_error() && (!map_fixed && addr != 0)) if (region_or_error.is_error() && (!map_fixed && addr != 0))
region_or_error = allocate_region(allocate_range({}, size), !name.is_null() ? name : "mmap", prot, strategy); region_or_error = allocate_region(allocate_range({}, size), !name.is_null() ? name : "mmap", prot, strategy);
if (region_or_error.is_error()) if (region_or_error.is_error())
@ -169,13 +166,8 @@ void* Process::sys$mmap(Userspace<const Syscall::SC_mmap_params*> user_params)
if (!validate_inode_mmap_prot(*this, prot, *description->inode(), map_shared)) if (!validate_inode_mmap_prot(*this, prot, *description->inode(), map_shared))
return (void*)-EACCES; return (void*)-EACCES;
} }
auto region_or_error = description->mmap(*this, VirtualAddress(addr), static_cast<size_t>(offset), size, prot, map_shared);
if (region_or_error.is_error()) { auto region_or_error = description->mmap(*this, range, static_cast<size_t>(offset), prot, map_shared);
// Fail if MAP_FIXED or address is 0, retry otherwise
if (map_fixed || addr == 0)
return (void*)region_or_error.error().error();
region_or_error = description->mmap(*this, {}, static_cast<size_t>(offset), size, prot, map_shared);
}
if (region_or_error.is_error()) if (region_or_error.is_error())
return (void*)region_or_error.error().error(); return (void*)region_or_error.error().error();
region = region_or_error.value(); region = region_or_error.value();