Kernel: Pass 'prot' argument to File::mmap() and act on it.

Nothing crazy, this just means that PROT_READ allocates readable regions, and that PROT_WRITE allocates writable ones.
luteresa · May 30, 2019 · 66c1a9b · 66c1a9b
1 parent 004a630
commit 66c1a9b
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Showing 7 changed files with 11 additions and 9 deletions.
diff --git a/Kernel/Devices/BXVGADevice.cpp b/Kernel/Devices/BXVGADevice.cpp
@@ -84,7 +84,7 @@ dword BXVGADevice::find_framebuffer_address()
  return framebuffer_address;
 }
 
-KResultOr<Region*> BXVGADevice::mmap(Process& process, LinearAddress preferred_laddr, size_t offset, size_t size)
+KResultOr<Region*> BXVGADevice::mmap(Process& process, LinearAddress preferred_laddr, size_t offset, size_t size, int prot)
 {
  ASSERT(offset == 0);
  ASSERT(size == framebuffer_size_in_bytes());
@@ -95,7 +95,9 @@ KResultOr<Region*> BXVGADevice::mmap(Process& process, LinearAddress preferred_l
  move(vmo),
  0,
  "BXVGA Framebuffer",
- true, true);
+ prot & PROT_READ,
+ prot & PROT_WRITE
+ );
  kprintf("BXVGA: %s(%u) created Region{%p} with size %u for framebuffer P%x with laddr L%x\n",
  process.name().characters(), process.pid(),
  region, region->size(), framebuffer_address().as_ptr(), region->laddr().get());

diff --git a/Kernel/Devices/BXVGADevice.h b/Kernel/Devices/BXVGADevice.h
@@ -18,7 +18,7 @@ class BXVGADevice final : public BlockDevice {
  void set_y_offset(int);
 
  virtual int ioctl(FileDescriptor&, unsigned request, unsigned arg) override;
- virtual KResultOr<Region*> mmap(Process&, LinearAddress preferred_laddr, size_t offset, size_t) override;
+ virtual KResultOr<Region*> mmap(Process&, LinearAddress preferred_laddr, size_t offset, size_t, int prot) override;
 
  size_t framebuffer_size_in_bytes() const { return m_framebuffer_size.area() * sizeof(dword) * 2; }
  Size framebuffer_size() const { return m_framebuffer_size; }

diff --git a/Kernel/File.cpp b/Kernel/File.cpp
@@ -24,7 +24,7 @@ int File::ioctl(FileDescriptor&, unsigned, unsigned)
  return -ENOTTY;
 }
 
-KResultOr<Region*> File::mmap(Process&, LinearAddress, size_t, size_t)
+KResultOr<Region*> File::mmap(Process&, LinearAddress, size_t, size_t, int)
 {
  return KResult(-ENODEV);
 }

diff --git a/Kernel/File.h b/Kernel/File.h
@@ -24,7 +24,7 @@ class File : public Retainable<File> {
  virtual ssize_t read(FileDescriptor&, byte*, ssize_t) = 0;
  virtual ssize_t write(FileDescriptor&, const byte*, ssize_t) = 0;
  virtual int ioctl(FileDescriptor&, unsigned request, unsigned arg);
- virtual KResultOr<Region*> mmap(Process&, LinearAddress preferred_laddr, size_t offset, size_t size);
+ virtual KResultOr<Region*> mmap(Process&, LinearAddress preferred_laddr, size_t offset, size_t size, int prot);
 
  virtual String absolute_path(FileDescriptor&) const = 0;
 

diff --git a/Kernel/FileSystem/FileDescriptor.cpp b/Kernel/FileSystem/FileDescriptor.cpp
@@ -324,7 +324,7 @@ InodeMetadata FileDescriptor::metadata() const
 KResultOr<Region*> FileDescriptor::mmap(Process& process, LinearAddress laddr, size_t offset, size_t size, int prot)
 {
  if (m_file)
- return m_file->mmap(process, laddr, offset, size);
+ return m_file->mmap(process, laddr, offset, size, prot);
 
  if (!is_fsfile())
  return KResult(-ENODEV);

diff --git a/Kernel/SharedMemory.cpp b/Kernel/SharedMemory.cpp
@@ -89,9 +89,9 @@ int SharedMemory::write(FileDescriptor&, const byte* data, int data_size)
  ASSERT_NOT_REACHED();
 }
 
-KResultOr<Region*> SharedMemory::mmap(Process& process, LinearAddress laddr, size_t offset, size_t size)
+KResultOr<Region*> SharedMemory::mmap(Process& process, LinearAddress laddr, size_t offset, size_t size, int prot)
 {
  if (!vmo())
  return KResult(-ENODEV);
- return process.allocate_region_with_vmo(laddr, size, *vmo(), offset, name(), true, true);
+ return process.allocate_region_with_vmo(laddr, size, *vmo(), offset, name(), prot & PROT_READ, prot & PROT_WRITE);
 }
diff --git a/Kernel/SharedMemory.h b/Kernel/SharedMemory.h
@@ -31,7 +31,7 @@ class SharedMemory : public File {
  virtual String absolute_path(FileDescriptor&) const override;
  virtual const char* class_name() const override { return "SharedMemory"; }
  virtual bool is_shared_memory() const override { return true; }
- virtual KResultOr<Region*> mmap(Process&, LinearAddress, size_t offset, size_t size) override;
+ virtual KResultOr<Region*> mmap(Process&, LinearAddress, size_t offset, size_t size, int prot) override;
 
  SharedMemory(const String& name, uid_t, gid_t, mode_t);