hypervisor. This prevents an infinite loop where processes with evicted
pages would page fault forever when PMAP decided the evicted pages on
which the process was faulting was actually present and did not need to
be restored.
Found while building LLVM with make -j32.
Sponsored by: FreeBSD Foundation
POWER8 systems. During thread switch, there was a very small window when
the stack pointer was set to the stack pointer of the outgoing thread, but
after the lock on that thread had already been released.
If, during that window, the outgoing thread were rescheduled on another CPU
and begin execution and an exception were taken on the original CPU, the
trap handler and the outgoing thread would simultaneously execute on the same
stack, causing memory corruption. Fix this by making sure to release the
old thread only after cpu_switch() is done with its stack.
MFC after: 2 weeks
Sponsored by: FreeBSD Foundation
every possible trap address by default. This also makes sure the kernel
notices (and panics at) traps from newer CPUs that the kernel was not
expecting rather than executing gibberish memory.
that we (a) get the correct large page size to provide to pmap and (b)
we can alert the user if running under incorrectly-configured PowerKVM
on POWER7 and POWER8 systems.
MFC after: 1 week
const. On x86, even after the machine context is supposedly read into
the struct ucontext, lazy FPU state save code might only mark the FPU
data as hardware-owned. Later, set_fpcontext() needs to fetch the
state from hardware, modifying the *mcp.
The set_mcontext(9) is called from sigreturn(2) and setcontext(2)
implementations and old create_thread(2) interface, which throw the
*mcp out after the set_mcontext() call.
Reported by: dim
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
support in QEMU. Each page of a many page mapping was getting mapped to
the same physical address, which is not the desired behavior.
MFC after: 1 week
A "size" symbol with its address set to the length of handler would be
shifted forward with all other addresses when relocations are processed.
Instead, just note the end and do the subtraction at runtime.
mostly a no-op since all currently-supported instances of these CPUs give
the number of SLB slots in the device tree, but keep it here as well just
in case.
instructions to call through pointers instead. In general, these are set
implicitly through relocation processing. One has to be set explicitly in
machdep.c, however, to fit one handler in the tiny (8 instruction) space
available.
Reviewed by: andreast
Differential revision: D1554
Tested on: UP and SMP G5, Cell, POWER5+
sequences, like are used to read the HIDs. This is both easier to read
and avoids a miscompilation by GCC in certain circumstances. Also avoid
double restoration of HID4 and HID5.
MFC after: 2 weeks
in ofw_mem_regions(). This function is actually MI and should move to
dev/ofw at some point in the near future so that ARM and MIPS can use the
same code.
PVO pool size. The default errs on the exceedingly large side, so absent
any intelligent automatic tuning, at least let the user set it to save
RAM on memory-constrained systems.
MFC after: 2 weeks
This allows executing static clang built with -O0.
The value is configurable by a sysctl, so if one needs to clamp it down, they
still can.
Discussed with: nwhitehorn,emaste
code in sys/kern/kern_dump.c. Most dumpsys() implementations are nearly
identical and simply redefine a number of constants and helper subroutines;
a generic implementation will make it easier to implement features around
kernel core dumps. This change does not alter any minidump code and should
have no functional impact.
PR: 193873
Differential Revision: https://reviews.freebsd.org/D904
Submitted by: Conrad Meyer <conrad.meyer@isilon.com>
Reviewed by: jhibbits (earlier version)
Sponsored by: EMC / Isilon Storage Division
the Open Firmware, as provided by petitboot, for example. Note that this is
not quite complete, since RTAS instantiation still depends on callable
firmware.
MFC after: 2 weeks
It's redundant at the moment since it can be obtained from the trapframe
on the architectures where DTrace is supported, but this won't be the case
with ARM.
WITNESS and INVARIANTS checking, which are known to have significant
performance impact on running systems. When benchmarking new features
this kernel should be used instead of the standard GENERIC.
This kernel configuration should never appear outside of the HEAD
of the FreeBSD tree.
Summary:
Revert the initial FBT-with-KDB changes for trap_subr*.S, and instead use the
db_trap filter function to handle dtrace trap filtering. With this, the MMU is
enabled by the support code, simplifying the codepath altogether.
Test Plan: Tested on my G4 PowerBook
Reviewers: #powerpc, nwhitehorn
Reviewed By: nwhitehorn
Differential Revision: https://reviews.freebsd.org/D1207
MFC after: 3 weeks
