Previously userspace would issue one syscall to resolve the sysctl and then
another one to actually use it. Do it all in one trip.
Fallback is provided in case newer libc happens to be running on an older
kernel.
Submitted by: Pawel Biernacki
Reported by: kib, brooks
Differential Revision: https://reviews.freebsd.org/D17282
Parentheses added to HASZERO macro to avoid a GCC warning.
Reviewed by: kib, mjg
Obtained from: musl (snapshot at commit 4d0a82170a)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17631
The symbol version for _mcount was removed 12 years ago in r169525 from
gmon/Symbol.map, to be added to the per-arch Symbol.map. mips was overlooked
in this, so _mcount has no symver. Add it back to where it should have been,
rather than where it would go if it were added today, since we're correcting
a historical mistake.
Additionally, _mcount is getting thrown into .mdebug.abi32 in the llvm80/90
world as it's not getting explicitly thrown into .text, so do this now. This
fixes the libc build that was previously failing due to relocations in
.mdebug.abi32. This is specifically due to the way clang's integrated AS
works and that they emit the .mdebug.abiNN section early in the process. An
LLVM bug has been submitted[0] and an agreement has been made that the
mips backend should switch to .text following .mdebug.abiNN for
compatibility.
[0] https://bugs.llvm.org/show_bug.cgi?id=43119
Reviewed by: imp, arichardson
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D21435
The page daemon periodically invokes uma_reclaim() to reclaim cached
items from each zone when the system is under memory pressure. This
is important since the size of these caches is unbounded by default.
However it also results in bursts of high latency when allocating from
heavily used zones as threads miss in the per-CPU caches and must
access the keg in order to allocate new items.
With r340405 we maintain an estimate of each zone's usage of its
(per-NUMA domain) cache of full buckets. Start making use of this
estimate to avoid reclaiming the entire cache when under memory
pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU
verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only
items in excess of the estimate are reclaimed. Draining a zone
reclaims all of the cached full buckets (the previous behaviour of
uma_reclaim()), and may further drain the per-CPU caches in extreme
cases.
Now, when under memory pressure, the page daemon will trim zones
rather than draining them. As a result, heavily used zones do not incur
bursts of bucket cache misses following reclamation, but large, unused
caches will be reclaimed as before.
Reviewed by: jeff
Tested by: pho (an earlier version)
MFC after: 2 months
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D16667
gets is unsafe and shouldn't be used (for many years now). Leave it in
the existing symbol version so anything that previously linked aginst it
still runs, but do not allow new software to link against it.
(The compatability/legacy implementation must not be static so that
the symbol and in particular the compat sym gets@FBSD_1.0 make it
into libc.)
PR: 222796 (exp-run)
Reported by: Paul Vixie
Reviewed by: allanjude, cy, eadler, gnn, jhb, kib, ngie (some earlier)
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D12298
This unskips:
- lib.libc.stdlib.strtod_test.strtod_round
- lib.msun.fe_round_test.t_nofe_round
In lib/msun/tests/Makefile only define on fe_round_test.c because
lib.msun.ilogb_test.ilogb will get wrong results and needs more examination.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
This makes it possible to perform mathematical operations on
fractional values without using floating point. It operates on Q
numbers, which are integer-sized, opaque structures initialized
to hold a chosen number of integer and fractional bits.
For a general description of the Q number system, see the "Fixed Point
Representation & Fractional Math" whitepaper[1]; for the actual
API see the qmath(3) man page.
This is one of dependencies for the upcoming stats(3) framework[2]
that will be applied to the TCP stack in a later commit.
1. https://www.superkits.net/whitepapers/Fixed%20Point%20Representation%20&%20Fractional%20Math.pdf
2. https://reviews.freebsd.org/D20477
Reviewed by: bcr (man pages, earlier version), sef (earlier version)
Discussed with: cem, dteske, imp, lstewart
Sponsored By: Klara Inc, Netflix
Obtained from: Netflix
Differential Revision: https://reviews.freebsd.org/D20116
machine/regnum.h ends up being included by sys/procfs.h and sys/ptrace.h via
machine/reg.h. Many of the regnum definitions are too short and too generic
to be exposing to any userland application including one of these two
headers. Moreover, these actively cause build failures in googletest
(template <typename T1 ...> expanding to template <typename 9 ...>).
Hide the definitions behind _KERNEL or _WANT_MIPS_REGNUM, and patch all of
the userland consumers to define as needed.
Discussed with: imp, jhb
Reviewed by: imp, jhb
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D21330
Although libc syscall wrappers do not get checked in this can aid in
finding the source of generated files when spelunking in the objdir.
Multiple tools use @generated to identify generated files (for example,
in a review Phabricator will by default hide diffs in generated files).
For consistency use the @generated tag in makesyscalls.sh as we've done
for other generated files, even though these wrappers aren't checked in
to the tree.
Use quad.h from libc instead for the time being. This reduces the number of
nearly-identical-quad.h we have in tree to two with only minor changes.
Prototypes for some *sh*di3 have been added to match the copy in libkern.
The differences between the two are likely few enough that they can perhaps
be merged with little additional effort to bring us down to 1.
MFC after: 3 days
As with other archs the compiler may emit calls to the byte swap routines
under certain conditions.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Since YP protocol definition uses the constant to declare
variable-size opaque byte strings, the change should be binary
compatible with existing installations which do not expose keys or
values larger than 1024 bytes.
All uses of local variables with YPMAXRECORD sizes were removed to
avoid insane stack use. On the other hand, variables with static
lifetime should be fine and only result in increased VA use.
Glibc made same change, increasing the allowed length for keys and
values in YP to 16M, in 2013.
Reviewed by: markj
Discussed with: ian
Sponsored by: Mellanox Technologies
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D20900
As per r177853, we need to avoid using errno inside user mutex code, since
signal handlers can interfere with it and mess up libthr internal state.
So, implement _umtx_op_err() instead, which makes a raw syscall and
returns the error value directly instead of using errno.
Approved by: jhibbits (mentor)
Differential Revision: https://reviews.freebsd.org/D20946
If the length of the source wide character string, passed in via the
"size_t n" parameter, is set to zero, the function should only return
the required length for the destination wide character string. In this
case, it should *not* attempt to write to the destination, so the "dst"
parameter is permitted to be NULL.
However, when the internally called _collate_wxfrm() function returns an
error, such as when using the "C" locale, as a fallback wcscpy(3) or
wcsncpy(3) are used. But if the input length is zero, wcsncpy(3) will
be called with a length of -1! If the "dst" parameter is NULL, this
will immediately result in a segfault, or if "dst" is a valid pointer,
it will most likely result in unexpectedly overwritten memory.
Fix this by explicitly checking for an input length greater than zero,
before calling wcsncpy(3).
Note that a similar situation does not occur in strxfrm(3), the plain
character version of this function, as it uses strlcpy(3) for the error
case. The strlcpy(3) function does not write to the destination if the
input length is zero.
MFC after: 1 week
