Add an "nextnoskip" sysctl that allows for listing of sysctls intended to be
normally skipped for cost reasons.
This makes it so the names/descriptions of those sysctls can be discovered with
sysctl -aN/sysctl -ad/sysctl -at.
It also makes it so children are visited when a node flagged with CTLFLAG_SKIP
is explicitly requested.
The intended use case is to mark the root "kstat" node with CTLFLAG_SKIP so that
the extensive and expensive stats are skipped by default but may still be easily
obtained without having to know them all (which may not even be possible) and
request each one-by-one.
Reviewed by: jhb
MFC after: 2 weeks
Relnotes: yes
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D26560
Since the code exits smr section prior to calling pwd_hold, the used
pwd can be freed and a new one allocated with the same address, making
the comparison erroneously true.
Note it is very unlikely anyone ran into it.
It gives the answer would the thread sleep according to current state
of signals and suspensions. Of course the answer is racy and allows
for false-negatives (no sleep when signal is delivered after process
lock is dropped). Also the answer might change due to signal
rescheduling among threads in multi-threaded process.
Still it is the best approximation I can provide, to answering the
question was the thread interrupted.
Reviewed by: markj
Tested by: pho, rmacklem
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D26628
- Extract suspension check into sig_ast_checksusp() helper.
- Extract signal check and calculation of the interruption errno into
sig_ast_needsigchk() helper.
The helpers are moved to kern_sig.c which is the proper place for
signal-related code.
Improve control flow in sleepq_catch_signals(), to handle ret == 0
(can sleep) and ret != 0 (interrupted) only once, by separating
checking code into sleepq_check_ast_sq_locked(), which return value is
interpreted at single location.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D26628
detour - it writes ktrace entries to the filesystem - so the overhead
of ast() won't make any difference.
Reviewed by: kib
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26404
Currently we allocate and map zero-filled anonymous pages when dumping
core. This can result in lots of needless disk I/O and page
allocations. This change tries to make the core dumper more clever and
represent unbacked ranges of virtual memory by holes in the core dump
file.
Add a new page fault type, VM_FAULT_NOFILL, which causes vm_fault() to
clean up and return an error when it would otherwise map a zero-filled
page. Then, in the core dumper code, prefault all user pages and handle
errors by simply extending the size of the core file. This also fixes a
bug related to the fact that vn_io_fault1() does not attempt partial I/O
in the face of errors from vm_fault_quick_hold_pages(): if a truncated
file is mapped into a user process, an attempt to dump beyond the end of
the file results in an error, but this means that valid pages
immediately preceding the end of the file might not have been dumped
either.
The change reduces the core dump size of trivial programs by a factor of
ten simply by excluding unaccessed libc.so pages.
PR: 249067
Reviewed by: kib
Tested by: pho
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26590
OBJT_DEFAULT, _SWAP, _VNODE and _PHYS is exactly the set of
non-fictitious object types, so just check for OBJ_FICTITIOUS. The
check no longer excludes dead objects, but such objects have to be
handled regardless.
No functional change intended.
Reviewed by: alc, dougm, kib
Tested by: pho
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26589
hole size boundary.
By clipping the len argument of vn_generic_copy_file_range() to end at
an exact multiple of hole size, holes are more likely to be maintained
during the copy.
A hole can still straddle the boundary at the end of the
copy range, resulting in a block being allocated in the
output file as it is being grown in size, but this will reduce the
likelyhood of this happening.
While here, also modify setting of blksize to better handle the
case where _PC_MIN_HOLE_SIZE is returned as 1.
Reviewed by: asomers
Differential Revision: https://reviews.freebsd.org/D26570
A user pointer is not a suitable value for bio_data and the next block
of code always overwrites bio_data anyway. Just use cb->aio_buf
directly in the call to vm_fault_quick_hold_pages().
Reviewed by: kib
Obtained from: CheriBSD
MFC after: 1 month
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26595
Without this patch, if a call to copy_file_range(2) specifies an input file
offset + len that would wrap around, EINVAL is returned.
I thought that was the Linux behaviour, but recent testing showed that
Linux accepts this case and does the copy_file_range() to EOF.
This patch changes the FreeBSD code to exhibit the same behaviour as
Linux for this case.
Reviewed by: asomers, kib
Differential Revision: https://reviews.freebsd.org/D26569
Until we can do proper /etc/rc output on both consoles in multicons
boot (or all of them if we ever generalize), report when we are
booting multicons. Also report the primary console. This will be a big
hint why output stops after this line (though some slow USB discovery
still happens after mountroot / init starts).
Reviewed by: scottl@, tsoome@
Differential Revision: https://reviews.freebsd.org/D26574
It is only ever called for negative entries and for those it is
just a wrapper around cache_zap_negative_locked_vnode_kl which
always succeeds.
This also fixes a bug where cache_lookup_fallback should have been
calling cache_zap_locked_bucket instead. Note that in order to trigger
the bug NOCACHE must not be set, which currently only happens when
creating a new coredump (and then the coredump-to-be has to have a
negative entry).
and current address space is already destroyed, so kern_execve()
terminates the process.
While there, clean up some internals of post_execve() inlined in init_main.
Reported by: Peter <pmc@citylink.dinoex.sub.org>
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D26525
The entire cache scan was a leftover from the old implementation.
It is incredibly wasteful in presence of several mount points and does not
win much even for single ones.
It is like O_BENEATH, but disables to walk out of the subtree rooted
in the starting directory. O_BENEATH does not care if path walks out
if it returned.
Requested by: Dan Gohman <dev@sunfishcode.online>
PR: 248335
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25886
Do not care if path walks out of the topping directory if it returns back.
Requested and reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25886
not unconditionally on any dotdot component.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25886
the helper to calculate namei flags both for open(2) and creat(2).
Suggested and reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25886
the helper to convert AT_ flags for *at() syscalls to namei flags.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25886
Stop abusing internal namei flag NI_LCF_STRICTRELATIVE as indicator of
cap-restricted lookup. Add designated returned flag NIRES_STRICTREL
to inform kern_openat() that lookup was restricted.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25886
This makes open("/a/../a", O_BENEATH) with cwd == "/a" work.
Reviewed by: markj
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25886
Explain why tracker is needed at all.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25886
A small example of how these functions can be used to simplify checks of
this nature.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26271
This adds the getenv_bool() function, to parse a boolean value from a
kernel environment variable or tunable. This works for traditional
boolean values like "0" and "1", and also "true" and "false"
(case-insensitive). These semantics do not yet apply to sysctls declared
using SYSCTL_BOOL with CTLFLAG_TUN (they still only parse 1 and 0).
Also added are two wrapper functions, getenv_is_true() and
getenv_is_false(). These are slightly simpler for callers wishing to
perform a single check of a configuration variable.
Reviewed by: jhb (slightly earlier version)
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26270
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
vm_ooffset_t is now unsigned. Remove some tests for negative values,
or make other adjustments accordingly.
Reported by: Coverity
Reviewed by: kib markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D26214
Change the zone setup:
- Allow slabs to be returned to the OS
- Set the number of slots to the max devctl will queue before discarding
- Reserve 2% of the max (capped at 100) for low memory allocations
- Disable per-cpu caching since we don't need it and we avoid some pathologies
Change the alloation strategiy a bit:
- If a normal allocation fails, try to get the reserve
- If a reserve allocation fails, re-use the oldest-queued entry for storage
- If there's a weird race/failure and nothing on the queue to steal, return NULL
This addresses two main issues in the old code:
- If devd had died, and we're generating a lot of messages, we have an
unbounded leak. This new scheme avoids the issue that lead to this.
- The MPASS that was 'sure' the allocation couldn't have failed turned out
to be wrong in some rare cases. The new code doesn't make this assumption.
Since we reserve only 2% of the space, we go from about 1MB of
allocation all the time to more like 50kB for the reserve.
Reviewed by: markj@
Differential Revision: https://reviews.freebsd.org/D26448
Both before and after job control adjustments.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D26416
Orphans affect job control state, we must account for them when
changing pg_jobc.
Instead of p_pptr, use proc_realparent() to get parent relevant for
job control.
Use correct calculation of the parent for exiting process. For jobc
purposes, we must use realparent, but if it is also exiting, we should
fall to reaper, then recursively find non-exiting reaper.
Reported by: trasz
PR: 249257
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D26416
