As mandated by POSIX. Also clarify the kill(2) manpage.
While there, restructure the code in killpg1() to use helper which
keeps overall state of the process list iteration in the killpg1_ctx
structued, later used to infer the error returned.
Reported by: amdmi3
Reviewed by: jilles
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D22621
Conditional branch and jump instructions do not always call via PLT
stubs and thus will not honor LD_PRELOAD, etc. lld warns about using
non-preemptible relocations for preemptible or unknown symbols whereas
bfd does not (at least for RISC-V).
Reviewed by: br, James Clarke
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22658
This saves an instruction in each case as well as an extra memory
indirection via the GOT for PIC code.
Reviewed by: br, James Clarke
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22656
o Remove All Rights Reserved from my notices
o imp@FreeBSD.org everywhere
o regularize punctiation, eliminate date ranges
o Make sure that it's clear that I don't claim All Rights reserved by listing
All Rights Reserved on same line as other copyright holders (but not
me). Other such holders are also listed last where it's clear.
Theoretically, this was breaking the size calculation for the symbol.
Noticed when doing a readthrough.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D22525
Due to ELFv1 specific code in _ctx_start.S and makecontext.c, userspace
context switching was completely broken on ELFv2.
With this change, we now pass the libthr test suite.
Approved by: jhibbits (mentor)
Differential Revision: https://reviews.freebsd.org/D22421
Add ifdefs in the assembler for soft-float compile case.
Submitted by: Hiroki Mori
Reviewed by: ray@
Differential Review: https://reviews.freebsd.org/D22352
__has_attribute(__constructor__) is a better test for clang than
defined(__clang__). Switch to it instead.
While we're already here and touching it, pfg@ nailed down when GCC actually
introduced the priority argument -- 4.3. Use that instead of our
hammer-guess of GCC >= 5 for the sake of correctness.
The preproc logic was added at the last minute to appease GCC 4.2, and
kevans@ did clearly not go back and double-check that the logic worked out
for clang builds to use the new variant.
It turns out that clang defines __GNUC__ == 4. Flip it around and check
__clang__ as well, leaving a note to remove it later.
Reported by: cem
First, this commit is a NOP on GCC <= 4.x; this decidedly doesn't work
cleanly on GCC 4.2, and it will be gone soon anyways so I chose not to dump
time into figuring out if there's a way to make it work. xtoolchain-gcc,
clocking in as GCC6, can cope with it just fine and later versions are also
generally ok with the syntax. I suspect very few users are running GCC4.2
built worlds and also experiencing potential fallout from the status quo.
For dynamically linked applications, this change also means very little.
rtld will run libc ctors before most others, so the situation is
approximately a NOP for these as well.
The real cause for this change is statically linked applications doing
almost questionable things in their constructors. qemu-user-static, for
instance, creates a thread in a global constructor for their async rcu
callbacks. In general, this works in other places-
- On OpenBSD, __stack_chk_guard is stored in an .openbsd.randomdata section
that's initialized by the kernel in the static case, or ld.so in the
dynamic case
- On Linux, __stack_chk_guard is apparently stored in TLS and such a problem
is circumvented there because the value is presumed stable in the new
thread.
On FreeBSD, the rcu thread creation ctor and __guard_setup are both unmarked
priority. qemu-user-static spins up the rcu thread prior to __guard_setup
which starts making function calls- some of these are sprinkled with the
canary. In the middle of one of these functions, __guard_setup is invoked in
the main thread and __stack_chk_guard changes- qemu-user-static is promptly
terminated for an SSP violation that didn't actually happen.
This is not an all-too-common problem. We circumvent it here by giving the
__stack_chk_guard constructor a solid priority. 200 was chosen because that
gives static applications ample range (down to 101) for working around it
if they really need to. I suspect most applications will "just work" as
expected- the default/non-prioritized flavor of __constructor__ functions
run last, and the canary is generally not expected to change as of this
point at the very least.
This took approximately three weeks of spare time debugging to pin down.
PR: 241905
Even though clang comes with a number of internal CUDA wrapper headers,
compiling sample CUDA programs will result in errors similar to:
In file included from <built-in>:1:
In file included from /usr/lib/clang/9.0.0/include/__clang_cuda_runtime_wrapper.h:204:
/usr/home/arr/cuda/var/cuda-repo-10-0-local-10.0.130-410.48/usr/local/cuda-10.0//include/crt/math_functions.hpp:2910:7: error: no matching function for call to '__isnan'
if (__isnan(a)) {
^~~~~~~
/usr/lib/clang/9.0.0/include/__clang_cuda_device_functions.h:460:16: note: candidate function not viable: call to __device__ function from __host__ function
__DEVICE__ int __isnan(double __a) { return __nv_isnand(__a); }
^
CUDA expects __isnan() and __isnanf() declarations to be available,
which are glibc specific extensions, equivalent to the regular isnan()
and isnanf().
To provide these, define __isnan() and __isnanf() as aliases of the
already existing static inline functions __inline_isnan() and
__inline_isnanf() from math.h.
Reported by: arrowd
PR: 241550
MFC after: 1 week
This warning (comparing a pointer against a zero character literal
rather than NULL) has existed since GCC 7.1.0, and was recently added to
Clang trunk.
Almost all of these are harmless, except for fwcontrol's str2node, which
needs to both guard against dereferencing a NULL pointer (though in
practice it appears none of the callers will ever pass one in), as well
as ensure it doesn't parse the empty string as node 0 due to strtol's
awkward interface.
Submitted by: James Clarke <jtrc27@jrtc27.com>
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D21914
While FreeBSD's implementation of these expect an int inside of libc, that's an
implementation detail that we can hide from the user as it's the natural
promotion of the current mode_t type and before it is used in the kernel, it's
converted back to the narrower type that's the current definition of mode_t. As
such, documenting int is at best confusing and at worst misleading. Instead add
a note that these args are variadic and as such calling conventions may differ
from non-variadic arguments.
promoted to ints).
- `mode_t` is `uint16_t` (`sys/sys/_types.h`)
- `openat` takes variadic args
- variadic args cannot be 16-bit, and indeed the code uses int
- the manpage currently kinda implies the argument is 16-bit by saying `mode_t`
Prompted by Rust things: https://github.com/tailhook/openat/issues/21
Submitted by: Greg V at unrelenting
Differential Revision: https://reviews.freebsd.org/D21816
Add an atomic shm rename operation, similar in spirit to a file
rename. Atomically unlink an shm from a source path and link it to a
destination path. If an existing shm is linked at the destination
path, unlink it as part of the same atomic operation. The caller needs
the same permissions as shm_unlink to the shm being renamed, and the
same permissions for the shm at the destination which is being
unlinked, if it exists. If those fail, EACCES is returned, as with the
other shm_* syscalls.
truss support is included; audit support will come later.
This commit includes only the implementation; the sysent-generated
bits will come in a follow-on commit.
Submitted by: Matthew Bryan <matthew.bryan@isilon.com>
Reviewed by: jilles (earlier revision)
Reviewed by: brueffer (manpages, earlier revision)
Relnotes: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D21423
Described in [1], signal handlers running in a vfork child have
opportunities to corrupt the parent's state. Address this by adding a new
rfork(2) flag, RFSPAWN, that has vfork(2) semantics but also resets signal
handlers in the child during creation.
x86 uses rfork_thread(3) instead of a direct rfork(2) because rfork with
RFMEM/RFSPAWN cannot work when the return address is stored on the stack --
further information about this problem is described under RFMEM in the
rfork(2) man page.
Addressing this has been identified as a prerequisite to using posix_spawn
in subprocess on FreeBSD [2].
[1] https://ewontfix.com/7/
[2] https://bugs.python.org/issue35823
Reviewed by: jilles, kib
Differential Revision: https://reviews.freebsd.org/D19058
When RFSPAWN is passed, rfork exhibits vfork(2) semantics but also resets
signal handlers in the child during creation to avoid a point of corruption
of parent state from the child.
This flag will be used by posix_spawn(3) to handle potential signal issues.
Reviewed by: jilles, kib
Differential Revision: https://reviews.freebsd.org/D19058
memfd_create is effectively a SHM_ANON shm_open(2) mapping with optional
CLOEXEC and file sealing support. This is used by some mesa parts, some
linux libs, and qemu can also take advantage of it and uses the sealing to
prevent resizing the region.
This reimplements shm_open in terms of shm_open2(2) at the same time.
shm_open(2) will be moved to COMPAT12 shortly.
Reviewed by: markj, kib
Differential Revision: https://reviews.freebsd.org/D21393
bde reports (in a reply to r351700 commit mail):
This uses scasb, which was last optimal on the 8086, or perhaps the
original i386. On freefall, it is several times slower than the
naive translation of the naive C code.
Reported by: bde
Reviewed by: kib, markj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21785
The two options are
* nocover/cover: Prevent/allow mounting over an existing root mountpoint.
E.g., "mount -t ufs -o nocover /dev/sd1a /usr/local" will fail if /usr/local
is already a mountpoint.
* emptydir/noemptydir: Prevent/allow mounting on a non-empty directory.
E.g., "mount -t ufs -o emptydir /dev/sd1a /usr" will fail.
Neither of these options is intended to be a default, for historical and
compatibility reasons.
Reviewed by: allanjude, kib
Differential Revision: https://reviews.freebsd.org/D21458
calls to max allowed UDP datagram size.
Since max allowed size both for keys and values where increased, the
old sizes of around 1K cause ypmatch(3) failures, while plain maps
fetches work.
The buffers were reduced in r34146 from default UDP rpcclient values
to 1024/2304 due to the key and value size being 1K.
Reviewed by: slavash
Sponsored by: Mellanox Technologies
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D21586
- Fix the statement that big5 is a de facto standard of Traditional Chinese
text [1]
- Add a BUGS section describes the problem of big5 and suggests use utf8
PR: 189095
Submitted by: Brennan Vincent <brennan@umanwizard.com> [1]
Reviewed by: Ting-Wei Lan <lantw44@gmail.com>
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21622
When SO_TIMESTAMP is set, the kernel will attempt to attach a timestamp as
ancillary data to each IP datagram that is received on the socket. However,
it may fail, for example due to insufficient memory. In that case the
packet will still be received but not timestamp will be attached.
Reviewed by: kib
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D21607
heap buffer overflow. This was discovered by a Google fuzzer test.
This can lead to remote denial of service. User interaction and
execution privileges are not a prerequisite for exploitation.
Reported by: enh at Google, to FreeBSD by maya@NetBSD.org
Obtained from: enh at Google
See also: NetBSD ns_name.c r1.12
Reviewed by: delphij, ume
MFC after: 3 days
https://android-review.googlesource.com/c/platform/bionic/+/1093130
Differential Revision: https://reviews.freebsd.org/D21523
It allows a process to request that stack gap was not applied to its
stacks, retroactively. Also it is possible to control the gaps in the
process after exec.
PR: 239894
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D21352
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
