This is useful for stack unwinders which need to avoid out-of-bounds
reads of a kernel stack which can trigger kernel faults.
Reviewed by: kib, markj
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27356
This allows GDB to print more useful backtraces when setting a breakpoint
on an assembly function.
Reviewed By: jhb
Differential Revision: https://reviews.freebsd.org/D27177
Ensure we initialize the static environment when not booting via
loader(8), and provide a static buffer if this is the case. This fixes
two issues.
First, performing the initialization ensures that kenv variables set in
the kernel's config file are honored. Previously, any new or overridden
values were ignored.
Second, providing the static buffer allows variables to be set in the
device tree's bootargs property of the chosen node. This can be set by
u-boot or by QEMU's '-append' flag. Attempting to this prior to this
change resulted in an early panic, since the static environment had no
buffer backing it.
Submitted by: syrinx (earlier version)
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D25034
In pmap_bootstrap(), we fill kernel_pmap->pm_active since it is
invariably active on all harts. However, this marks it as active even
for harts that don't exist in the system, which can cause issue when the
mask is passed to the SBI firmware via sbi_remote_sfence_vma().
Specifically, the SBI spec allows SBI_ERR_INVALID_PARAM to be returned
when an invalid hart is set in the mask.
The latest version of OpenSBI does not have this issue, but v0.6 does,
and this is triggering a recently added KASSERT in CI. Switch to only
setting bits in pm_active for harts that enter the system.
Reported by: Jenkins
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D27080
VM_ALLOC_WAITOK and vm_page_unwire_noq(), have eliminated the need for
many of the #includes.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D27052
- remove setting of register value which is not used until the next value is
set
- Use the L2_SHIFT constant when setting up L2 superpages
Submitted by: Antonin Houska <ah AT melesmeles DOT cz>
Version 0.2 of the SBI specification [1] marked the existing SBI
functions as "legacy" in order to move to a newer calling convention. It
also introduced a set of replacement extensions for some of the legacy
functionality. In particular, the TIME, IPI, and RFENCE extensions
implement and extend the semantics of their legacy counterparts, while
conforming to the newer version of the spec.
Update our SBI code to use the new replacement extensions when
available, and fall back to the legacy ones. These will eventually be
dropped, when support for version 0.2 is ubiquitous.
[1] https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc
Submitted by: Danjel Q. <danq1222@gmail.com>
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D26953
S-mode software has write access to the SIP.SSIP bit, so instead of
making a second round-trip through the SBI we can clear it ourselves.
The SBI spec has deprecated this function for this exactly this reason.
Submitted by: Danjel Q. <danq1222@gmail.com
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D26952
The existing names were inherited from arm64, but we should prefer
RISC-V terminology. Change the prefix to SCAUSE, and further change the
names to better match the RISC-V spec and be more consistent with one
another. Also, remove two codes that are not defined for S-mode (machine
and hypervisor ecall).
While here, apply style(9) to some condition checks.
Reviewed by: kp
Discussed with: jrtc27
Differential Revision: https://reviews.freebsd.org/D26918
As was done for L3 PTEs in r362853, mask out the reserved bits when
extracting the physical address from an L2 PTE. Future versions of the
spec or custom implementations may make use of these reserved bits, in
which case the resulting physical address could be incorrect.
Submitted by: Nathaniel Filardo <nwf20@cl.cam.ac.uk>
Reviewed by: kp, mhorne
Differential Revision: https://reviews.freebsd.org/D26607
Hiding this feature behind RB_VERBOSE is gratuitous. The tunable is enough
to limit its use to only those who explicitly request it.
Suggested by: kevans
Move dump_avail[] extern declaration and inlines into a new header
vm/vm_dumpset.h. This fixes default gcc build for mips.
Reviewed by: alc, scottph
Tested by: kevans (previous version)
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D26741
Push the root seed version to userspace through the VDSO page, if
the RANDOM_FENESTRASX algorithm is enabled. Otherwise, there is no
functional change. The mechanism can be disabled with
debug.fxrng_vdso_enable=0.
arc4random(3) obtains a pointer to the root seed version published by
the kernel in the shared page at allocation time. Like arc4random(9),
it maintains its own per-process copy of the seed version corresponding
to the root seed version at the time it last rekeyed. On read requests,
the process seed version is compared with the version published in the
shared page; if they do not match, arc4random(3) reseeds from the
kernel before providing generated output.
This change does not implement the FenestrasX concept of PCPU userspace
generators seeded from a per-process base generator. That change is
left for future discussion/work.
Reviewed by: kib (previous version)
Approved by: csprng (me -- only touching FXRNG here)
Differential Revision: https://reviews.freebsd.org/D22839
Create the RISC-V NOTES and LINT files. As of r366559, LINT configs are
no longer generated but checked in to the tree.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D26502
The boot metadata (also referred to as modinfo, or preload metadata)
provides information about the size and location of the kernel,
pre-loaded modules, and other metadata (e.g. the EFI framebuffer) to be
consumed during by the kernel during early boot. It is encoded as a
series of type-length-value entries and is usually constructed by
loader(8) and passed to the kernel. It is also faked on some
architectures when booted by other means.
Although much of the module information is available via kldstat(8),
there is no easy way to debug the metadata in its entirety. Add some
routines to parse this data and allow it to be printed to the console
during early boot or output via a sysctl.
Since the output can be lengthly, printing to the console is gated
behind the debug.dump_modinfo_at_boot kenv variable as well as the
BOOTVERBOSE flag. The sysctl to print the metadata is named
debug.dump_modinfo.
Reviewed by: tsoome
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26687
It is unlikely, but possible, that an unrecognized or unsupported
relocation type is encountered while trying to load a kernel module. If
this occurs we should offer the symbol index as a hint to the user.
While here, fix some small style issues.
Reviewed by: markj, kib (amd64 part, in D26701)
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Since r366355 and r366284 we panic on access faults rather than treating
them like page faults so this condition is never true.
Reviewed by: jhb (mentor), markj, mhorne
Approved by: jhb (mentor), markj, mhorne
Differential Revision: https://reviews.freebsd.org/D26686
We should never take instruction page faults when in the kernel, but by
using the standard page fault code we should get a more-informative
message about faulting on a NOFAULT page rather than branching to the
default case here and printing an "Unknown kernel exception ..."
message.
Reviewed by: jhb (mentor), markj
Approved by: jhb (mentor), markj
Differential Revision: https://reviews.freebsd.org/D26685
These names were inherited from the arm64 port and should be changed to
the RISC-V terminology.
Reviewed by: jhb (mentor), kp, markj
Approved by: jhb (mentor), kp, markj
Differential Revision: https://reviews.freebsd.org/D26671
Access faults in user mode are treated like TLB misses, which leads to an
endless loop of faults. It's less serious than the same fault in kernel mode,
because we can just terminate the process, but that's not ideal.
Treat user mode access faults as a bus error.
Suggested by: jrtc27
Reviewed by: br, jhb
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D26621
Load/store/fetch access exceptions always indicate a violation of a PMP
rule. We can't treat those as page faults, because updating the page
table and trying again will only result in exactly the same access
exception recurring. This leaves us in an endless exception loop.
We cannot recover from these exceptions, so panic instead.
Reviewed by: jhb
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D26544
Every other architecture defines this and this is required for
interrupts to work when using QEMU's PCI VirtIO devices (which all
report an interrupt line of 0) for two reasons.
Firstly, interrupt line 0 is wrong; they use one of 0x20-0x23 with the
lines being cycled across devices like normal. Moreover, RISC-V uses
INTRNG, whose IRQs are virtual as indices into its irq_map, so even if
we have the right interrupt line we still need to try and route the
interrupt in order to ultimately call into intr_map_irq and get back a
unique index into the map for the given line, otherwise we will use
whatever happens to be in irq_map[line] (which for QEMU where the line
is initialised to 0 results in using the first allocated interrupt,
namely the RTC on IRQ 11 at time of commit).
Note that pci_assign_interrupt will still do the wrong thing for INTRNG
when using a tunable, as it will bypass INTRNG entirely and use the
tunable's value as the index into irq_map, when it should instead
(indirectly) call intr_map_irq to allocate a new entry for the given
IRQ and treat the tunable as stating the physical line in use, which is
what one would expect. This, however, is a problem shared by all INTRNG
architectures, and not exclusive to RISC-V.
Reviewed by: kib
Approved by: kib
Differential Revision: https://reviews.freebsd.org/D26564
In the spirit of the GENERIC config, we should include the drivers required to
run on most supported platforms.
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D26501
On Ampere Altra systems, the sparse population of RAM within the
physical address space causes the vm_page_dump bitmap to be much
larger than necessary, increasing the size from ~8 Mib to > 2 Gib
(and overflowing `int` for the size).
Changing the page dump bitmap also changes the minidump file
format, so changes are also necessary in libkvm.
Reviewed by: jhb
Approved by: scottl (implicit)
MFC after: 1 week
Sponsored by: Ampere Computing, Inc.
Differential Revision: https://reviews.freebsd.org/D26131
These definitions were repeated by all architectures, with small
variations. Consolidate the common definitons in machine
independent code and use bitset(9) macros for manipulation. Many
opportunities for deduplication remain in the machine dependent
minidump logic. The only intended functional change is increasing
the bit index type to vm_pindex_t, allowing the indexing of pages
with address of 8 TiB and greater.
Reviewed by: kib, markj
Approved by: scottl (implicit)
MFC after: 1 week
Sponsored by: Ampere Computing, Inc.
Differential Revision: https://reviews.freebsd.org/D26129
One problem with the bus_space_read_N() and bus_space_write_N() family of
functions is that they provide no protection against exceptions which can
occur when no physical hardware or device responds to the read or write
cycles. In such a situation, the system typically would panic due to a
kernel-mode bus error. The bus_space_peek_N() and bus_space_poke_N() family
of functions provide a mechanism to handle these exceptions gracefully
without the risk of crashing the system.
Typical example is access to PCI(e) configuration space in bus enumeration
function on badly implemented PCI(e) root complexes (RK3399 or Neoverse
N1 N1SDP and/or access to PCI(e) register when device is in deep sleep state.
This commit adds a real implementation for arm64 only. The remaining
architectures have bus_space_peek()/bus_space_poke() emulated by using
bus_space_read()/bus_space_write() (without exception handling).
MFC after: 1 month
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D25371
that can be extended, but also ensure compile-time type checking. Refactor
common code out of arch-specific implementations. Move the mpr and mps
drivers to this new API. The template type remains visible to the consumer
so that it can be allocated on the stack, but should be considered opaque.
RISC-V is currently built with -Wno-format, which is how these went
undetected. Address them now before re-enabling those warnings.
Differential Revision: https://reviews.freebsd.org/D26319
The kernel adjusts the stack by TF_SIZE and the RISC-V ABI requires
that it remain 16-byte aligned.
Reported by: CHERI, jrtc27
Reviewed by: mhorne
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26328
Currently we use a single bit to indicate whether the virtual page is
part of a superpage. To support a forthcoming implementation of
non-transparent 1GB superpages, it is useful to provide more detailed
information about large page sizes.
The change converts MINCORE_SUPER into a mask for MINCORE_PSIND(psind)
values, indicating a mapping of size psind, where psind is an index into
the pagesizes array returned by getpagesizes(3), which in turn comes
from the hw.pagesizes sysctl. MINCORE_PSIND(1) is equal to the old
value of MINCORE_SUPER.
For now, two bits are used to record the page size, permitting values
of MAXPAGESIZES up to 4.
Reviewed by: alc, kib
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26238
This allows privileged userspace processes to find information about the
physical page backing a given mapping. It is useful in applications
such as DPDK which perform some of their own memory management.
Reviewed by: kib, jhb (previous version)
MFC after: 2 weeks
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara Inc.
Differential Revision: https://reviews.freebsd.org/D26237
sbi_init() sets mimpid, we can use that value.
Reviewed by: philip (mentor), kp (mentor)
Approved by: philip (mentor), kp (mentor)
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D26092
I observed hangs post-r362977 in QEMU with -smp 2, in which one thread
would acquire write access to an rm_lock (sysctllock) and get stuck
waiting in smp_rendezvous_cpus while the other CPU was servicing a trap.
The other thread was waiting for read access to the same lock, thus
causing deadlock.
It's clear that this is just one symptom of a larger problem. The
general expectation of MI kernel code is that interrupts are enabled.
Violating this assumption will at best create some additional latency,
but otherwise might cause locking or other unforeseen issues. All other
architectures do so for some subset of trap values, but this somehow got
missed in the RISC-V port. Enable interrupts now during kernel page
faults and for all user trap types.
The code in exception.S already knows to disable interrupts while
handling the return from exception, so there are no changes required
there.
Reviewed by: jhb, markj
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D26017
- Properly set up the frame pointer
- Hang if we return from mi_startup
- Whitespace
Clearing the frame pointer marks the end of the backtrace. This fixes
"bt 0" in ddb, which previously would unwind one frame too far.
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D26016
This same check is used on other architectures. Previously this would
permit a stack frame to unwind into any arbitrary kernel address
(including unmapped addresses).
Reviewed by: mhorne
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D25996
