The obsolete ttyname and ptsname syscalls are removed.
LibC doesn't rely on these anymore, and it helps simplifying the Kernel
in many places, so it's an overall an improvement.
In addition to that, /proc/PID/tty node is removed too as it is not
needed anymore by userspace to get the attached TTY of a process, as
/dev/tty (which is already a character device) represents that as well.
This function is an extended version of `chmod(2)` that lets one control
whether to dereference symlinks, and specify a file descriptor to a
directory that will be used as the base for relative paths.
We only froward String setting and FlagPost creation for now, due to the
other performance events being nonsensical to forward.
We also record these signposts in the optionally generated profile.
It was fragile to use the address of the body of the memory management
functions to disable memory auditing within them. Functions called from
these did not get exempted from the audits, so in some cases
UserspaceEmulator reported bogus heap buffer overflows.
Memory auditing did not work at all on Clang because when querying the
addresses, their offset was taken relative to the base of `.text` which
is not the first segment in the `R/RX/RW(RELRO)/RW(non-RELRO)` layout
produced by LLD.
Similarly to when setting metadata about the allocations, we now use the
`emuctl` system call to selectively suppress auditing when we reach
these functions. This ensures that functions called from `malloc` are
affected too, and no issues occur because of the inconsistency between
Clang and GCC memory layouts.
... segment
This happens with binaries build with Clang or with a custom linker
script. If this is the case, offsets should be calculated not from the
base address of `.text`, but from the first section loaded for the
library.
This commit moves all UserspaceEmulator symbolication into a common
helper function and fixes a FIXME.
`ue --profile --profile-file ~/some-file.profile id` can now generate a
full profile (instruction-by-instruction, if needed), at the cost of not
being able to see past the syscall boundary (a.la. callgrind).
This makes it significantly easier to profile seemingly fast userspace
things, like Loader.so :^)
For now this only allows us to single-step through execution and inspect
part of the execution environment for debugging
This also allows to run to function return and sending signals to the VM
This changes the behavior of SIGINT for UE to pause execution and then
terminate if already paused
A way of setting a watchpoint for a function would be a good addition in
the future, the scaffold for this is already present, we only need to
figure out a way to find the address of a function
On a side note I have changed all occurences of west-const to east const
Unlike accept() the new accept4() system call lets the caller specify
flags for the newly accepted socket file descriptor, such as
SOCK_CLOEXEC and SOCK_NONBLOCK.
With the new InodeWatcher API, the old style of creating a watcher per
inode will no longer work. Therefore the FileWatcher API has been
updated to support multiple watches, and its users have also been
refactored to the new style. At the moment, all operations done on a
(Blocking)FileWatcher return Result objects, however, this may be
changed in the future if it becomes too obnoxious. :^)
Co-authored-by: Gunnar Beutner <gunnar@beutner.name>
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
The auditing code always starts by checking if we're in one of the
ignored code ranges (malloc, free, realloc, syscall, etc.)
To reduce the number of checks needed, we can cache the bounds of
the LibC text segment. This allows us to fast-reject addresses that
cannot possibly be a LibC function.
This returns ENOSYS if you are running in the real kernel, and some
other result if you are running in UserspaceEmulator.
There are other ways we could check if we're inside an emulator, but
it seemed easier to just ask. :^)
This patch brings Kernel::RangeAllocator to UserspaceEmulator in a
slightly simplified form.
It supports the basic three allocation types needed by virt$mmap():
allocate_anywhere, allocate_specific, and allocate_randomized.
Porting virt$mmap() and virt$munmap() to use the allocator makes
UE work correctly once again. :^)
All users of this mechanism have been switched to anonymous files and
passing file descriptors with sendfd()/recvfd().
Shbufs got us where we are today, but it's time we say good-bye to them
and welcome a much more idiomatic replacement. :^)
