exec_map_first_page() would unconditionally free an unbacked, invalid
page from the executable image. However, it is possible that the page
is wired, in which case it is incorrect to free the page, so check for
additional wirings first.
Reported by: syzkaller
Tested by: pho
Reviewed by: kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21767
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
syn cache overflows. Whether this is due to an attack or due to the system
having more legitimate connections than the syn cache can hold, this
situation can quickly impact performance.
To make the system perform better during these periods, the code will now
switch to exclusively using cookies until the syn cache stops overflowing.
In order for this to occur, the system must be configured to use the syn
cache with syn cookie fallback. If syn cookies are completely disabled,
this change should have no functional impact.
When the system is exclusively using syn cookies (either due to
configuration or the overflow detection enabled by this change), the
code will now skip acquiring a lock on the syn cache bucket. Additionally,
the code will now skip lookups in several places (such as when the system
receives a RST in response to a SYN|ACK frame).
Reviewed by: rrs, gallatin (previous version)
Discussed with: tuexen
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D21644
rather than indirectly through the backpointer to the tcp_syncache
structure stored in the hashtable bucket.
This also allows us to remove the requirement in syncookie_generate()
and syncookie_lookup() that the syncache hashtable bucket must be
locked.
Reviewed by: gallatin, rrs
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D21644
use of this parameter was removed in r313330. This commit now removes
passing this now-unused parameter.
Reviewed by: gallatin, rrs
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D21644
Introduce a new add_off_t static function that exits with an error
message if there's an overflow, otherwise returns their sum. Use this
when adding values obtained from the input patch.
Reviewed by: delphij, allanjude (earlier)
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D7897
We have two ways to check if kenv variable exists - either we check return
value from TUNABLE_INT_FETCH, or we pre-initialize the variable and check
if this value did change. In terminal_init() it is more convinient to
use pre-initialized variables.
Problem was revealed by older loader.efi, which did not set teken.* variables.
Reported by: tuexen
The TUNABLE_INT_FETCH is macro around getenv_int() and we will get
return value 0 or 1 for failure or success, we can use it to decide
which background color to use.
To be consistent with replacing the mtx_lock()/mtx_unlock() calls on
the NFS node mutex (n_mtx) and ncl_iod_mutex, this patch replaces
all mtx_assert() calls on these mutexes with macros as well.
This will simplify changing these locks to sx locks in a future commit.
However, this change may be delayed indefinitely, since it appears there
is a deadlock when vnode_pager_setsize() is called to shrink the size
and the NFS node lock is held.
There is no semantic change as a result of this commit.
Suggested by: kib
MFC after: 1 week
Sync libarchive with vendor.
Relevant vendor changes:
Issue #1237: Fix integer overflow in archive_read_support_filter_lz4.c
PR #1249: Correct some typographical and grammatical errors.
PR #1250: Minor corrections to the formatting of manual pages
MFC after: 1 week
Relevant vendor changes:
Issue #1237: Fix integer overflow in archive_read_support_filter_lz4.c
PR #1249: Correct some typographical and grammatical errors.
PR #1250: Minor corrections to the formatting of manual pages
In a few cases, the symbol lookup is missing before attempting to
perform the relocation. While the relocation types affected are
currently unused, this results in an uninitialized variable warning,
that is escalated to an error when building with clang.
Reviewed by: markj
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D21773
Fix some style(9) violations.
This also changes the name of the machine-dependent sysctl kern.debug_kld to
debug.kld_reloc, and changes its type from int to bool. This is acceptable
since we are not currently concerned with preserving the RISC-V ABI.
Reviewed by: markj, kp
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D21772
Use of CPU_FFS() to implement CPUSET_FOREACH() allows to save up to ~0.5%
of CPU time on 72-thread SMT system doing 80K IOPS to NVMe from one thread.
MFC after: 1 month
Sponsored by: iXsystems, Inc.
- split synopsis into separate options that can't be used together
- sort options
- fix (style) issues reported by mandoc lint
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D21710
I've noticed that I missed intr check at one more SCHED_AFFINITY(),
so instead of adding one more branching I prefer to remove few.
Profiler shows the function CPU time reduction from 0.24% to 0.16%.
MFC after: 1 month
Sponsored by: iXsystems, Inc.
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
C/C++) in exp(3), expf(3), expm1(3) and expm1f(3) during intermediate
computations that compute the IEEE-754 bit pattern for |2**k| for
integer |k|.
The implementations of exp(3), expf(3), expm1(3) and expm1f(3) need to
compute IEEE-754 bit patterns for 2**k in certain places. (k is an
integer and 2**k is exactly representable in IEEE-754.)
Currently they do things like 0x3FF0'0000+(k<<20), which is to say they
take the bit pattern representing 1 and then add directly to the
exponent field to get the desired power of two. This is fine when k is
non-negative.
But when k<0 (and certain classes of input trigger this), this
left-shifts a negative number -- an operation with undefined behavior in
C and C++.
The desired semantics can be achieved by instead adding the
possibly-negative k to the IEEE-754 exponent bias to get the desired
exponent field, _then_ shifting that into its proper overall position.
(Note that in case of s_expm1.c and s_expm1f.c, there are SET_HIGH_WORD
and SET_FLOAT_WORD uses further down in each of these files that perform
shift operations involving k, but by these points k's range has been
restricted to 2 < k <= 56, and the shift operations under those
circumstances can't do anything that would be UB.)
Submitted by: Jeff Walden, https://github.com/jswalden
Obtained from: https://github.com/freebsd/freebsd/pull/411
Obtained from: https://github.com/freebsd/freebsd/pull/412
MFC after: 3 days
properly nested and warns about recursive entrances. Unlike with locks,
there is nothing fundamentally wrong with such use, the intent of tracer
is to help to review complex epoch-protected code paths, and we mean the
network stack here.
Reviewed by: hselasky
Sponsored by: Netflix
Pull Request: https://reviews.freebsd.org/D21610
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
per thread, so that instead of repeating the same info for all threads
in proc, it would print thread specific info. Also includes thread number
that would match 'info threads' info and can be used as argument for
thread swithcing with 'thread' command.
shm_open2 allows a little more flexibility than the original shm_open.
shm_open2 doesn't enforce CLOEXEC on its callers, and it has a separate
shmflag argument that can be expanded later. Currently the only shmflag is
to allow file sealing on the returned fd.
shm_open and memfd_create will both be implemented in libc to use this new
syscall.
__FreeBSD_version is bumped to indicate the presence.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D21393
chflags -R on it, otherwise the command will error out. (Note that
adding -f to the chflags invocation does not help, unlike with rm.)
MFC after: 3 days
Now that flags may be set on posixshm, add an argument to kern_shm_open()
for the initial seals. To maintain past behavior where callers of
shm_open(2) are guaranteed to not have any seals applied to the fd they're
given, apply F_SEAL_SEAL for existing callers of kern_shm_open. A special
flag could be opened later for shm_open(2) to indicate that sealing should
be allowed.
We currently restrict initial seals to F_SEAL_SEAL. We cannot error out if
F_SEAL_SEAL is re-applied, as this would easily break shm_open() twice to a
shmfd that already existed. A note's been added about the assumptions we've
made here as a hint towards anyone wanting to allow other seals to be
applied at creation.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D21392
File sealing applies protections against certain actions
(currently: write, growth, shrink) at the inode level. New fileops are added
to accommodate seals - EINVAL is returned by fcntl(2) if they are not
implemented.
Reviewed by: markj, kib
Differential Revision: https://reviews.freebsd.org/D21391
When an empty pattern is encountered in the pattern list, I had previously
broken bsdgrep to count that as a "match all" and ignore any other patterns
in the list. This commit rectifies that mistake, among others:
- The -v flag semantics were not quite right; lines matched should have been
counted differently based on whether the -v flag was set or not. procline
now definitively returns whether it's matched or not, and interpreting
that result has been kicked up a level.
- Empty patterns with the -x flag was broken similarly to empty patterns
with the -w flag. The former is a whole-line match and should be more
strict, only matching blank lines. No -x and no -w will will match the
empty string at the beginning of each line.
- The exit code with -L was broken, w.r.t. modern grep. Modern grap will
exit(0) if any file that didn't match was output, so our interpretation
was simply backwards. The new interpretation makes sense to me.
Tests updated and added to try and catch some of this.
This misbehavior was found by autoconf while fixing ports found in PR 229925
expecting either a more sane or a more GNU-like sed.
MFC after: 1 week
For now, just count batched page queue state operations.
vm.stats.page.queue_ops counts the number of batch entries that
successfully completed, while queue_nops counts entries that had no
effect, which occurs when the queue operation had been completed before
the batch entry was processed.
Reviewed by: alc, kib
MFC after: 1 week
Sponsored by: Intel, Netflix
Differential Revision: https://reviews.freebsd.org/D21782
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
