GCC reports that stat can be uninitialized when used, prevent this with
changing the construction of the code a little bit.
Keep original indent in order to not generate diff with upstream.
Solution suggested by <mrg>
Detected with GCC7 when building NetBSD/i386 with kUBSan.
On such CPUs, these bits are ignored by the hardware. We don't care about
setting them, however, we must always assume they are set. Modify the pmap
code to do that.
While here, in pmap_ept_remove_pte, don't flush the TLB when it's not
needed.
Tested on an old Intel Celeron.
Previously spi would configure the controller to use the lowest speed of
all connected devices since the kernel started and to fail attempted mode
changes. This is now improved to keep individual modes and speeds for each
slave and to reconfigure the controller as necessary for each transfer.
Added man page for spi(9).
Restrict the 64-bit atomics to ports defining __HAVE_ATOMIC64_OPS.
Using 64-bit atomics is still good for i586 fuzzing, but the tests are
build for earlier CPUs. This makes this code to be disabled in i386 builds.
There is a similar situation with few other ports that offer 64-bit atomics
in certain CPU models and ABIs.
The KCOV driver implements collection of code coverage inside the kernel.
It can be enabled on a per process basis from userland, allowing the kernel
program counter to be collected during syscalls triggered by the same
process.
The device is oriented towards kernel fuzzers, in particular syzkaller.
Currently the only supported coverage type is -fsanitize-coverage=trace-pc.
The KCOV driver was initially developed in Linux. A driver based on the
same concept was then implemented in FreeBSD and OpenBSD.
Documentation is borrowed from OpenBSD and ATF tests from FreeBSD.
This patch has been prepared by Siddharth Muralee, improved by <maxv>
and polished by myself before importing into the mainline tree.
All ATF tests pass.
Call cleanup(SIGHUP) if we get local EOF, as if we've got SIGHUP.
While here, use EOF constant instead of literal -1 in an existing
check.
PR bin/53996
The long-standing GCC default is to not respect rounding mode.
it looks like GCC 7 optimizes rint to a builtin, causing our few
rounding mode tests to fail.
Fixes PR port-amd64/54000: FP tests failing on amd64 since gcc7 import
instruction would have resulted in Long Mode being enabled, we need to
manually enable Long Mode ourselves. We were already doing that correctly
in setstate, but not in the CR0 trap handler.
Problem initially reported by Aymeric Vincent; ArchLinux wouldn't boot,
now it does and works correctly.
While here, add CR0_ET in the CR0 mask, for the associated shadow to
be taken into account. Normally this shadow bit shouldn't be necessary,
but for now I keep it regardless.
mutexes which can sleep, but their context does not allow it.
Rewrite the TLB handling code to fix that. It becomes a bit complex. In
short, we use a per-VM generation number, which we increase on each TLB
flush, before sending a broadcast IPI to everybody. The IPIs cause a
#VMEXIT of each VCPU, and each VCPU Loop will synchronize the per-VM gen
with a per-VCPU copy, and apply the flushes as neededi lazily.
The behavior differs between AMD and Intel; in short, on Intel we don't
flush the hTLB (EPT cache) if a context switch of a VCPU occurs, so now,
we need to maintain a kcpuset to know which VCPU's hTLBs are active on
which hCPU. This creates some redundancy on Intel, ie there are cases
where we flush the hTLB several times unnecessarily; but hTLB flushes are
very rare, so there is no real performance regression.
The thing is lock-less and non-blocking, so it solves our problem.
