This was causing some obvious-in-hindsight but hard to spot bugs where
we'd implicitly convert the bool to an integer type and carry on with
the number 1 instead of the actual value().
Also, InterruptDisabler were added to prevent critical function from
being interrupted. In addition, the interrupt numbers are abstracted
from IDT offsets, thus, allowing to create a better routing scheme
when using IOAPICs for interrupt redirection.
This was caught by running all crash tests with "crash -A".
Basically, non-readable pages need to not be mapped *at all* so that
a "page not present" exception is provoked on access.
Unfortunately x86 does not support write-only mappings, so this is
the best we can do.
Fixes#1336.
This is a complete fix of clock_nanosleep, because the thread holds the
process lock again when returning from sleep()/sleep_until().
Therefore, no further concurrent invalidation can occur.
Now it actually defaults to "a < b" comparison, instead of forcing you
to provide a trivial less-than comparator. Also you can pass in any
collection type that has .begin() and .end() and we'll sort it for you.
Also, duplicate data in dbg() and klog() calls were removed.
In addition, leakage of virtual address to kernel log is prevented.
This is done by replacing kprintf() calls to dbg() calls with the
leaked data instead.
Also, other kprintf() calls were replaced with klog().
This was only used by the mechanism for mapping executables into each
process's own address space. Now that we remap executables on demand
when needed for symbolication, this can go away.
Previously we would map the entire executable of a program in its own
address space (but make it unavailable to userspace code.)
This patch removes that and changes the symbolication code to remap
the executable on demand (and into the kernel's own address space
instead of the process address space.)
This opens up a couple of further simplifications that will follow.
I had the wrong idea about this. Thanks to Sergey for pointing it out!
Here's what he says (reproduced for posterity):
> Private mappings protect the underlying file from the changes made by
> you, not the other way around. To quote POSIX, "If MAP_PRIVATE is
> specified, modifications to the mapped data by the calling process
> shall be visible only to the calling process and shall not change the
> underlying object. It is unspecified whether modifications to the
> underlying object done after the MAP_PRIVATE mapping is established
> are visible through the MAP_PRIVATE mapping." In practice that means
> that the pages that were already paged in don't get updated when the
> underlying file changes, and the pages that weren't paged in yet will
> load the latest data at that moment.
> The only thing MAP_FILE | MAP_PRIVATE is really useful for is mapping
> a library and performing relocations; it's definitely useless (and
> actively harmful for the system memory usage) if you only read from
> the file.
This effectively reverts e2697c2ddd.
This patch reduces the number of code paths that lead to the allocation
of a Region object. It's quite hard to follow the various ways in which
this can happen, so this is an effort to simplify.
When stopping a thread with the SIGSTOP signal, we now store the thread
state in Thread::m_stop_state. That state is then restored on SIGCONT.
This fixes an issue where previously-blocked threads would unblock
upon resume. Now they simply resume in the Blocked state, and it's up
to the regular unblocking mechanism to unblock them.
Fixes#1326.
