I overlooked a corner case where we might call the built-in ctz() on zero.
Furthermore, the calculation of the shift was wrong and the results were often
unusable.
Both issue were caused by a forgotten 36daeee34f.
This time I made sure to look at bmpsuite_files first, and now they look good.
Found by OSS-Fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28985
This caused some confusion: Apparently, clang has no trouble overriding Shell's
main, and this issue only surfaced when I tried to build the fuzzers with
wrong configuration (i.e., without the clang-injected 'main').
The diff is suggested by, and work of, @alimpfard.
Previously regions were stored in a vector and then a pointer to
regions in this vector were taken and stored. The problem is the vector
were still appended after pointers were taken, if enough regions were
present the vector would grow so large that it needed a resize, this
cause his memory to moved and now the previous pointers are now
pointing to old memory we just freed.
Fixes#5160
This used to be in Kernel/, next to the build-root-filesystem.sh script,
which was then moved to Meta/ during the transition to CMake but has the
working directory set to Build/, effectively expecting it there - which
seems silly.
TL;DR: Very confusing. Use an explicit path relative to SERENITY_ROOT
instead and update the .gitignore files.
This commit:
- merges the two(!) places that defined independently the minimum size of a window.
- splits Window::normalize_rect(), which was originally just a function to apply
the minimum size requirement, and has taken on the additional job of nudging
windows back onto the desktop.
This inadvertantly fixes a crash that happens when a malicious program creates a
window of size (0, 0). Now, a window at [0,0 50x50] is created instead.
The ImageDecoder service now returns a list of image frames, each with
a duration value.
The code for in-process image decoding is removed from LibWeb, an all
image decode requests are sent out-of-process to ImageDecoder. :^)
This won't scale super well to very long and/or large animations, but
we can work on improving that separately. The main goal here is simply
to stop doing any image decoding inside LibWeb.
Fixes#5165.
Painter currently tries to load fonts, which won't work if we're in a
tightly pledged process.
It was only used to fill a rect with transparent pixels, so just do
that manually instead.
This replaces the current disk detection and disk access code with
code based on https://wiki.osdev.org/IDE
This allows the system to boot on VirtualBox with serial debugging
enabled and VMWare Player.
I believe there were several issues with the current code:
- It didn't utilise the last 8 bits of the LBA in 24-bit mode.
- {read,write}_sectors_with_dma was not setting the obsolete bits,
which according to OSdev wiki aren't used but should be set.
- The PIO and DMA methods were using slightly different copy
and pasted access code, which is now put into a single
function called "ata_access"
- PIO mode doesn't work. This doesn't fix that and should
be looked into in the future.
- The detection code was not checking for ATA/ATAPI.
- The detection code accidentally had cyls/heads/spt as 8-bit,
when they're 16-bit.
- The capabilities of the device were not considered. This is now
brought in and is currently used to check if the device supports
LBA. If not, use CHS.
This prevents sys$mmap() and sys$mprotect() from creating executable
memory mappings in pledged programs that don't have this promise.
Note that the dynamic loader runs before pledging happens, so it's
unaffected by this.
The random address proposals were not checked with the size so it was
increasely likely to try to allocate outside of available space with
larger and larger sizes.
Now they will be ignored instead of triggering a Kernel assertion
failure.
This is a continuation of: c8e7baf4b8
This adds another layer of defense against introducing new code into a
running process. The only permitted way of doing so is by mmapping an
open file with PROT_READ | PROT_EXEC.
This does make any future JIT implementations slightly more complicated
but I think it's a worthwhile trade-off at this point. :^)
This patch adds enforcement of two new rules:
- Memory that was previously writable cannot become executable
- Memory that was previously executable cannot become writable
Unfortunately we have to make an exception for text relocations in the
dynamic loader. Since those necessitate writing into a private copy
of library code, we allow programs to transition from RW to RX under
very specific conditions. See the implementation of sys$mprotect()'s
should_make_executable_exception_for_dynamic_loader() for details.
To support upcoming W^X changes in the kernel, the dynamic loader needs
to be careful about the order in which permissions are added to shared
library text segments.
We now start by mapping text segments read-only (no-write, no-exec).
If relocations are needed, we make them writable, and then finally,
for all text segments, we finish by making them read+exec.
If an exception was thrown while printing the last computed value in
the REPL, it would always assert on next input.
Something like this would always assert:
> a=[];Object.defineProperty(a,"0",{get:()=>{throw ""}})
> 1 + 2
This fills in a bunch of the FIXMEs that was in prepare_script.
execute_script is almost finished, it's just missing the module side.
As an aside, let's not assert when inserting a script element with
innerHTML.
When mounting an Ext2FS, a block device source is required. All other
filesystem types are unaffected, as most of them ignore the source file
descriptor anyway.
Fixes#5153.
`allocate_randomized` assert an already sanitized size but `mmap` were
just forwarding whatever the process asked so it was possible to
trigger a kernel panic from an unpriviliged process just by asking some
randomly placed memory and a size non alligned with the page size.
This fixes this issue by rounding up to the next page size before
calling `allocate_randomized`.
Fixes#5149
This allows us to get rid of the thread lists in SchedulerData.
Also, instead of iterating over all threads to find a thread by id,
just use a lookup table. In the rare case of having to iterate over
all threads, just iterate the lookup table.
Use mmap() with the new MAP_RANDOMIZED flag to load shared libraries at
random addresses in each process.
To avoid address space collisions, we start by doing a large chunk mmap
that covers enough VM for both text and data, then we unmap and remap
the data segment separately, once we know everything will fit.
This is pretty cool! :^)
This can be used to request random VM placement instead of the highly
predictable regular mmap(nullptr, ...) VM allocation strategy.
It will soon be used to implement ASLR in the dynamic loader. :^)
