This fixes a regression introduced by the new software context
switching where the Kernel would not deliver a signal unless the
process is making system calls. This is because the TSS no longer
updates the CS value, so the scheduler never considered delivery
as the process always appeared to be in kernel mode. With software
context switching we can just set up the signal trampoline at
any time and when the processor returns back to user mode it'll
get executed. This should fix e.g. killing programs that are
stuck in some tight loop that doesn't make any system calls and
is only pre-empted by the timer interrupt.
Fixes#2958
By making the Process class RefCounted we don't really need
ProcessInspectionHandle anymore. This also fixes some race
conditions where a Process may be deleted while still being
used by ProcFS.
Also make sure to acquire the Process' lock when accessing
regions.
Last but not least, there's no reason why a thread can't be
scheduled while being inspected, though in practice it won't
happen anyway because the scheduler lock is held at the same
time.
Upon leaving a critical section (such as a SpinLock) we need to
check if we're already asynchronously invoking the Scheduler.
Otherwise we might end up triggering another context switch
as soon as leaving the scheduler lock.
Fixes#2883
Note: I switched from copying the single element out of the sched_param
struct, to copy struct it self as it is identical in functionality.
This way the types match up nicer with the Userpace<T> api's and it
conforms to the conventions used in other syscalls.
This commit adds an implementation of memmem, using the Bitap text
search algorithm for needles smaller than 32 bytes, and a naive loop
search for longer needles.
Since we already have the type information in the Userspace template,
it was a bit silly to cast manually everywhere. Just add a sufficiently
scary-sounding getter for a typed pointer.
Thanks @alimpfard for pointing out that I was being silly with tossing
out the type.
In the future we may want to make this API non-public as well.
This unbreaks the gcc and binutils ports.
Previously, when _SC_PAGESIZE was missing, these packages opted to
use their own versions of getpagesize which made their build fail
because of conflicting definitions of the function.
Use copy_{to,from}_user() in the various File::ioctl() implementations
instead of disabling SMAP wholesale in sys$ioctl().
This patch does not port IPv4Socket::ioctl() to those API's since that
will be more involved. That function now creates a local SmapDisabler.
This is something I've been meaning to do for a long time, and here we
finally go. This patch moves all sys$foo functions out of Process.cpp
and into files in Kernel/Syscalls/.
It's not exactly one syscall per file (although it could be, but I got
a bit tired of the repetitive work here..)
This makes hacking on individual syscalls a lot less painful since you
don't have to rebuild nearly as much code every time. I'm also hopeful
that this makes it easier to understand individual syscalls. :^)
I decided to play around with trying to run Serenity in VirtualBox.
It crashed WindowServer with a beautiful array of multi-color
flashing letters :^)
Skipping getting side-tracked seeing that it chose MBVGA in the
serial debug and trying to debug why it caused such a display,
I finally checked BXVGA.
While find_framebuffer_address checks for VBoxVGA, init_stage2 didn't.
Whoops!
We were masking the fragment offset bits incorrectly in the IPv4 header
sent out with fragments. This worked up to ~32KB but after that, things
would get very confused. :^)
Because Thread::sleep is an internal interface, it's easy to check that there
are only few callers: Process::sys$sleep, usleep, and nanosleep are happy
with this increased size, because now they support the entire range of their
arguments (assuming small-ish values for ticks_per_second()).
SyncTask doesn't care.
Note that the old behavior wasn't "cap out at 388 days", which would have been
reasonable. Instead, the code resulted in unsigned overflow, meaning that a
very long sleep would "on average" end after about 194 days, sometimes much
quicker.
Fixes#2871.
Ignoring the 'securely generated bytes' constraint seems to
be fine for Linux, so it's probably fine for Serenity.
Note that there *might* be more bottlenecks down the road
if Serenity is started in a non-GUI way. Currently though,
loading the GUI seems to generate enough interrupts to
seed the entropy pool, even on my non-RDRAND setup. Yay! :^)
Add all 6 shortcuts even if the switch between VirtualConsoles is
currently not available in the graphical console.
Also make the case statement more compact.
It is possible to switch to VirtualConsoles 1 to 4 via the shortcut
ALT + [1-4]. Therefor the array of VirtualConsoles should be guaranteed
to be initialized.
Also add an constant for the maximum number of VirtualConsoles to
guarantee consistency.
For now, only the non-standard _SC_NPROCESSORS_CONF and
_SC_NPROCESSORS_ONLN are implemented.
Use them to make ninja pick a better default -j value.
While here, make the ninja package script not fail if
no other port has been built yet.
To be more in line with other parts of Serenity's procfs, the
"key: value" format of /proc/cpuinfo was replaced with JSON, namely
an array of objects (one for each core).
The available keys remain the same, though "features" has been changed
from a space-separated string to an array of strings.
We need to halt the BSP briefly until all APs are ready for the
first context switch, but we can't hold the same spinlock by all
of them while doing so. So, while the APs are waiting on each other
they need to release the scheduler lock, and then once signaled
re-acquire it. Should solve some timing dependent hangs or crashes,
most easily observed using qemu with kvm disabled.
We now have BlockResult::WokeNormally and BlockResult::NotBlocked,
both of which indicate no error. We can no longer just check for
BlockResult::WokeNormally and assume anything else must be an
interruption.
