When building with KCOV enabled the compiler will insert function calls
to probes allowing us to trace the execution of the kernel from userspace.
These probes are on function entry (trace-pc) and on comparison operations
(trace-cmp).
Userspace can enable the use of these probes on a single kernel thread with
an ioctl interface. It can allocate space for the probe with KIOSETBUFSIZE,
then mmap the allocated buffer and enable tracing with KIOENABLE, with the
trace mode being passed in as the int argument. When complete KIODISABLE
is used to disable tracing.
The first item in the buffer is the number of trace event that have
happened. Userspace can write 0 to this to reset the tracing, and is
expected to do so on first use.
The format of the buffer depends on the trace mode. When in PC tracing just
the return address of the probe is stored. Under comparison tracing the
comparison type, the two arguments, and the return address are traced. The
former method uses on entry per trace event, while the later uses 4. As
such they are incompatible so only a single mode may be enabled.
KCOV is expected to help fuzzing the kernel, and while in development has
already found a number of issues. It is required for the syzkaller system
call fuzzer [1]. Other kernel fuzzers could also make use of it, either
with the current interface, or by extending it with new modes.
A man page is currently being worked on and is expected to be committed
soon, however having the code in the kernel now is useful for other
developers to use.
[1] https://github.com/google/syzkaller
Submitted by: Mitchell Horne <mhorne063@gmail.com> (Earlier version)
Reviewed by: kib
Testing by: tuexen
Sponsored by: DARPA, AFRL
Sponsored by: The FreeBSD Foundation (Mitchell Horne)
Differential Revision: https://reviews.freebsd.org/D14599
In cpu_thread_alloc we would allocate space for the trap frame at the top of
the kernel stack. This is just below the pcb, however due to a missing cast
the pointer arithmetic would use the pcb size, not the trapframe size. As
the pcb is larger than the trapframe this is safe, however later in cpu_fork
we include the case leading to the two disagreeing on the location.
Fix by using the same arithmetic in both locations.
Found by: An early KASAN patch
Sponsored by: DARPA, AFRL
We need to tell vm_fault the reason for the fault was because we tried to
execute from the memory location. Without this it may return with success
as we only request read-only memory, then we return to the same location
and try to execute from the same memory address. This leads to an infinite
loop raising the same fault and returning to the same invalid location.
MFC after: 1 week
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D18511
icu is a interrupt concentrator in the CP110 block and gicp
is a gic extension to allow interrupts in the CP block to be turned
into GIC SPI interrupts
Sponsored by: Rubicon Communications, LLC ("Netgate")
Use the newly defined SRAT/SLIT parsing APIs in arm64 to support
ACPI based NUMA.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D17943
PLLs on the RK3399 are different than the ones on the RK3328.
Add a new type and some dedicated recalc and set_freq functions.
Rename the RK3328 dedicated rk_clk_pll function with rk3328_ prefix.
MFC after: 1 month
Fix reporting of SS_ONSTACK in nested signal delivery when sigaltstack()
is used on some architectures.
Add a unit test for this. I tested the test by introducing the bug
on amd64. I did not test it on other architectures.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D18347
On arm64 and riscv platforms, sendsig() failed to zero the signal
frame before copying it out to userspace. Zero it.
On arm, I believe all the contents of the frame were initialized,
so there was no disclosure. However, explicitly zero the whole frame
because that fact could inadvertently change in the future,
it's more clear to the reader, and I could be wrong in the first place.
MFC after: 2 days
Security: similar to FreeBSD-EN-18:12.mem and CVE-2018-17155
Sponsored by: Dell EMC Isilon
First pass of support for multiple GIC ITS blocks with ACPI.
Changes are to:
* register the correct subset of interrupts with pic_register
in case of ACPI.
* initialize just the cpu interface for the first ITS, when
domain information is not avialable. This has to be done
until we split the per-CPU init to do LPI setup just once.
* remove duplicate check for the GIC ITS domain, the sc_cpus
are setup from domain, so the check again in per-CPU init
seems unnecessary.
Reviewed by: andrew
Differential Revision: https://reviews.freebsd.org/D17841
These architectures never shipped binaries with an rtld path of
/usr/libexec/ld-elf.so.1.
Reviewed by: markj
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D17876
Replace a call to DELAY(1) with a new cpu_lock_delay() KPI. Currently
cpu_lock_delay() is defined to DELAY(1) on all platforms. However,
platforms with a DELAY() implementation that uses spin locks should
implement a custom cpu_lock_delay() doesn't use locks.
Reviewed by: kib
MFC after: 3 days
Add a new 'debugger_on_trap' knob separate from 'debugger_on_panic'
and make the calls to kdb_trap() in MD fatal trap handlers prior to
calling panic() conditional on this new knob instead of
'debugger_on_panic'. Disable the new knob by default. Developers who
wish to recover from a fatal fault by adjusting saved register state
and retrying the faulting instruction can still do so by enabling the
new knob. However, for the more common case this makes the user
experience for panics due to a fatal fault match the user experience
for other panics, e.g. 'c' in DDB will generate a crash dump and
reboot the system rather than being stuck in an infinite loop of fatal
fault messages and DDB prompts.
Reviewed by: kib, avg
MFC after: 2 months
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D17768
While here tag which architecture release fields were added and remove a
field that only existed in very early releases of the ARMv8 spec.
Sponsored by: DARPA, AFRL
The loader tunable 'debug.verbose_sysinit' may be used to toggle verbosity.
This is added to the debugging section of these kernconfs to be turned off
in stable branches for clarity of intent.
MFC after: never
check to only set it for emulators as the CPU list may be changed when
the emulator starts. Until this is working just always set it.
Sponsored by: DARPA, AFRL
the early pmap_mapbios/unmapbios code. It is even worse when there are
multiple L2 entries to handle as we would need to iterate over all pages.
Sponsored by: DARPA, AFRL
All platforms except powerpc use the same values and powerpc shares a
majority of them.
Go ahead and declare AT_NOTELF, AT_UID, and AT_EUID in favor of the
unused AT_DCACHEBSIZE, AT_ICACHEBSIZE, and AT_UCACHEBSIZE for powerpc.
Reviewed by: jhb, imp
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D17397
This provides a chicken switch for anyone negatively impacted by
enabling NUMA in the amd64 GENERIC kernel configuration. With
NUMA disabled at boot-time, information about the NUMA topology
is not exposed to the rest of the kernel, and all of physical
memory is viewed as coming from a single domain.
This method still has some performance overhead relative to disabling
NUMA support at compile time.
PR: 231460
Reviewed by: alc, gallatin, kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17439
We should only unmask interrupts when creating a new thread and leave the
other exceptions in teh same state as before creating the thread.
Reported by: jhibbits
Reviewed by: jhibbits
MFC after: 1 month
Sponsored by: https://reviews.freebsd.org/D17497
configuring kernels for i386, amd64, and arm64.
The 'GEOM_PART_GPT' option was added to the DEFAULTS configuration
in r337967.
Approved by: re (kib@)
Reviewed by: ler@
Differential Revision: https://reviews.freebsd.org/D17458
Sponsored by: Netflix, Inc.
Tested with ifunc resolvers in the kernel and module with calls from
kernel to kernel, module to kernel, and module to module.
Reviewed by: kib (previous version)
Approved by: re (gjb)
Differential Revision: https://reviews.freebsd.org/D17370
