This reduces the overhead of TLB invalidations by ensuring that we
only interrupt CPUs which are using the given pmap. Tracking is
performed in pmap_activate(), which gets called during context switches:
from cpu_throw(), if a thread is exiting or an AP is starting, or
cpu_switch() for a regular context switch.
For now, pmap_sync_icache() still must interrupt all CPUs.
Reviewed by: kib (earlier version), jhb
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18874
This includes support for pmap_enter(..., psind=1) as described in the
commit log message for r321378.
The changes are largely modelled after amd64. arm64 has more stringent
requirements around superpage creation to avoid the possibility of TLB
conflict aborts, and these requirements do not apply to RISC-V, which
like amd64 permits simultaneous caching of 4KB and 2MB translations for
a given page. RISC-V's PTE format includes only two software bits, and
as these are already consumed we do not have an analogue for amd64's
PG_PROMOTED. Instead, pmap_remove_l2() always invalidates the entire
2MB address range.
pmap_ts_referenced() is modified to clear PTE_A, now that we support
both hardware- and software-managed reference and dirty bits. Also
fix pmap_fault_fixup() so that it does not set PTE_A or PTE_D on kernel
mappings.
Reviewed by: kib (earlier version)
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18863
Differential Revision: https://reviews.freebsd.org/D18864
Differential Revision: https://reviews.freebsd.org/D18865
Differential Revision: https://reviews.freebsd.org/D18866
Differential Revision: https://reviews.freebsd.org/D18867
Differential Revision: https://reviews.freebsd.org/D18868
There's no need to worry about potential backwards compatibility issues
in a brand-new architecture, so avoid stack PROT_EXEC as with arm64.
Discussed with: br
The existence of a PV entry for a mapping guarantees that the mapping
exists, so we should not need to test for that.
Reviewed by: kib
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18866
The existing copyin(9) and copyout(9) routines on RISC-V perform only a
simple byte-by-byte copy. Improve their performance by performing
word-sized copies where possible.
Submitted by: Mitchell Horne <mhorne063@gmail.com>
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D18851
The MI kernel assumes that interrupts will not be enabled on APs until
after the first context switch. In particular, the problem was causing
occasional deadlocks during boot.
Remove an unneeded intr_disable() added in r335005.
Reviewed by: jhb (previous version)
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18738
Don't bother zeroing the top-level page before freeing it. Previously,
the page was freed before being zeroed.
Reviewed by: jhb, kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18720
The list will be removed with some future work.
Reviewed by: jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18721
- Handle VM_PROT_EXECUTE.
- Clear PTE_D and mark the page dirty when removing write access
from a mapping.
- Atomically clear PTE_W to avoid clobbering a hardware PTE update.
Reviewed by: jhb, kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18719
Otherwise prefaulted entries are not accessible from user mode and
end up triggering a fault upon access, so prefaulting has no effect.
Reviewed by: jhb, kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18718
There's no need to use atomics when the previous value isn't needed.
No functional change intended.
Reviewed by: kib
Discussed with: jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18717
We currently don't have a good way to dynamically detect whether the
kernel is running as a guest.
Reviewed by: jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18715
The sbadaddr register was renamed in version 1.10 of the privileged
architecture specification. No functional change intended.
Submitted by: Mitchell Horne <mhorne063@gmail.com>
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D18594
- Panic immediately if witness says we're holding non-sleepable locks.
This helps ensure that we don't recurse on the pmap lock in
pmap_fault_fixup().
- Panic if the kernel faults on a user address without setting an
onfault handler.
- Panic if the fault occurred in a critical section or interrupt
handler, like we do on other platforms.
- Fix some style issues in trap_pfault().
Reviewed by: jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18561
pmap_remove_pages() is called during process termination, when it is
guaranteed that no other CPU may access the mappings being torn down.
In particular, it unnecessary to invalidate each mapping individually
since we do a pmap_invalidate_all() at the end of the function.
Also don't call pmap_invalidate_all() while holding a PV list lock, the
global pvh lock is sufficient.
Reviewed by: jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18562
pmaps on RISC-V always have an L1 page table page, so we don't need to
check for this when performing lookups.
Reviewed by: jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18563
- Build up phys_avail[] in a single loop, excluding memory used by
the loaded kernel.
- Fix an array indexing bug in the aforementioned phys_avail[]
initialization.[1]
- Remove some unneeded code copied from the arm64 implementation.
PR: 231515 [1]
Reviewed by: jhb
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18464
Inline tests for PTE_* bits are easy to read and don't really require a
predicate function, and predicates which operate on a pt_entry_t are
inconvenient when working with L1 and L2 page table entries.
Reviewed by: jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18461
This adds more detail and fixes some inaccuracies.
Reviewed by: jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18463
Add a subroutine for updating satp, for use when updating the
active pmap. No functional change intended.
Reviewed by: jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18462
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
The RISC-V spec defines several performance counter CSRs such as: cycle,
time, instret, hpmcounter(3...31). They are defined to be 64-bits wide
on all RISC-V architectures. On RV64 and RV128 they can be read from a
single CSR. On RV32, additional CSRs (given the suffix "h") are present
which contain the upper 32 bits of these counters, and must be read as
well. (See section 2.8 in the User ISA Spec for full details.)
This change adds macros for reading these values safely on any RISC-V
ISA length. Obviously we aren't supporting anything other than RV64
at the moment, but this ensures we won't need to change how we read
these values if we ever do.
Submitted by: Mitchell Horne <mhorne063@gmail.com>
Reviewed by: jhb
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D17952
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
machine/vmparam.h already defines the SHAREDPAGE constant. This
change just enables it for ELF executables. The only use of the
shared page currently is to hold the signal trampoline.
Reviewed by: markj, kib
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D17875
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
Rather than unconditionally setting PTE_D for all writeable kernel
mappings, set PTE_D for writable mappings of unmanaged pages (whether
user or kernel). This matches what amd64 does and also matches what
the RISC-V spec suggests (preset the A and D bits on mappings where
the OS doesn't care about the state).
Suggested by: alc
Reviewed by: alc, markj
Sponsored by: DARPA
Previously, RISC-V was enabling execute permissions in PTEs for any
readable page. Now, execute permissions are only enabled if they were
explicitly specified (e.g. via PROT_EXEC to mmap). The one exception
is that the initial kernel mapping in locore still maps all of the
kernel RWX.
While here, change the fault type passed to vm_fault and
pmap_fault_fixup to only include a single VM_PROT_* value representing
the faulting access to match other architectures rather than passing a
bitmask.
Reviewed by: markj
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D17783
This assumes that an access according to the prot in 'flags' triggered
a fault and is going to be retried after the fault returns, so the two
flags are set preemptively to avoid refaulting on the retry.
While here, only bother setting PTE_D for kernel mappings in pmap_enter
for writable mappings.
Reviewed by: markj
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D17782
This is just cosmetic.
A weirder issue is that the SBI doc claims the hart mask pointer should
be a physical address, not a virtual address. However, the implementation
in bbl seems to just dereference the address directly.
Reviewed by: markj
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D17781
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
modify l3 pte after we loaded old value and before we stored new value.
o Preset A(accessed), D(dirty) bits for kernel mappings.
Reported by: kib
Reviewed by: markj
Discussed with: jhb
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
(e.g. RocketChip, lowRISC and derivatives).
RISC-V page table entries support A (accessed) and D (dirty) bits. The
spec makes hardware support for these bits optional. Implementations that
do not manage these bits in hardware raise page faults for accesses to a
valid page without A set and writes to a writable page without D set.
Check for these types of faults when handling a page fault and fixup the
PTE without calling vm_fault if they occur.
Reviewed by: jhb, markj
Approved by: re (gjb)
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D17424
(e.g. RocketChip, lowRISC and derivatives).
RISC-V page table entries support A (accessed) and D (dirty) bits. The
spec makes hardware support for these bits optional. Implementations that
do not manage these bits in hardware raise page faults for accesses to a
valid page without A set and writes to a writable page without D set.
Check for these types of faults when handling a page fault and fixup the
PTE without calling vm_fault if they occur.
Reviewed by: jhb, markj
Approved by: re (gjb)
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D17424
