Commit Graph

7 Commits

Author SHA1 Message Date
Andreas Kling
862b3ccb4e Kernel: Enforce W^X between sys$mmap() and sys$execve()
It's now an error to sys$mmap() a file as writable if it's currently
mapped executable by anyone else.

It's also an error to sys$execve() a file that's currently mapped
writable by anyone else.

This fixes a race condition vulnerability where one program could make
modifications to an executable while another process was in the kernel,
in the middle of exec'ing the same executable.

Test: Kernel/elf-execve-mmap-race.cpp
2020-01-18 23:40:12 +01:00
Andreas Kling
94ca55cefd Meta: Add license header to source files
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.

For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.

Going forward, all new source files should include a license header.
2020-01-18 09:45:54 +01:00
Andreas Kling
aba7829724 Kernel: InodeVMObject can't call Inode::size() with interrupts disabled
Inode::size() may try to take a lock, so we can't be calling it with
interrupts disabled.

This fixes a kernel hang when trying to execute a binary in a TmpFS.
2020-01-03 15:40:03 +01:00
Andreas Kling
1f31156173 Kernel: Add a mode flag to sys$purge and allow purging clean inodes 2019-12-29 13:16:53 +01:00
Andreas Kling
c74cde918a Kernel+SystemMonitor: Expose amount of per-process clean inode memory
This is memory that's loaded from an inode (file) but not modified in
memory, so still identical to what's on disk. This kind of memory can
be freed and reloaded transparently from disk if needed.
2019-12-29 12:45:58 +01:00
Andreas Kling
0d5e0e4cad Kernel+SystemMonitor: Expose amount of per-process dirty private memory
Dirty private memory is all memory in non-inode-backed mappings that's
process-private, meaning it's not shared with any other process.

This patch exposes that number via SystemMonitor, giving us an idea of
how much memory each process is responsible for all on its own.
2019-12-29 12:28:32 +01:00
Andreas Kling
6bdb81ad87 Kernel: Split VMObject into two classes: Anonymous- and InodeVMObject
InodeVMObject is a VMObject with an underlying Inode in the filesystem.
AnonymousVMObject has no Inode.

I'm happy that InodeVMObject::inode() can now return Inode& instead of
VMObject::inode() return Inode*. :^)
2019-08-07 18:09:32 +02:00