copy_file_range.2 is a new man page (content change).
Reviewed by: kib, asomers
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D20584
fusefs file systems may have a fsname subtype (set by mount_fusefs's "-o
subtype" option) that gets appended to the fsname as returned by statfs(2).
The subtype is set on a per-mount basis so it isn't part of the struct
vfsconf. Special-case getvfsbyname to match either the full "fusefs.foobar"
or short "fusefs" fsname.
This is a merge of r348007, r348054, and r350093 from projects/fuse2
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21043
This avoids reading past the end of the static strings. On a system
with bounds checking these tests fault.
Reviewed by: asomers
Obtained from: CheriBSD
MFC after: 1 week
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D21004
In some circumstances, setmode(3) may call umask(2) twice to retrieve
the current mode and then restore it. Between calls, the process will
have a umask of 0.
Reviewed by: markj
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D20982
This ptrace operation returns a structure containing the error and
return values from the current system call. It is only valid when a
thread is stopped during a system call exit (PL_FLAG_SCX is set).
The sr_error member holds the error value from the system call. Note
that this error value is the native FreeBSD error value that has _not_
been translated to an ABI-specific error value similar to the values
logged to ktrace.
If sr_error is zero, then the return values of the system call will be
set in sr_retval[0] and sr_retval[1].
Reviewed by: kib
MFC after: 1 month
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D20901
NetBSD and OpenBSD have libc wrapper functions for the ARM_SYNC_ICACHE and
ARM_DRAIN_WRITEBUF sysarch operations. This change adds compatible functions
to our library. This should make it easier for various upstream sources to
support *BSD operating systems with a single variation of cache maintence
code in tools like interpreters and JIT compilers.
I consider the argument types passed to arm_sync_icache() to be especially
unfortunate, but this is intended to match the other BSDs.
Differential Revision: https://reviews.freebsd.org/D20906
Take part of the text from POSIX 2018 edition and describe the
atomicity requirements for read and write syscalls. See p1003.1-2018,
Vol.2, 2.9.7 Threads interaction with Regular File Operations.
Reviewed by: asomers
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Differential revision: https://reviews.freebsd.org/D20867
feature bit.
In particular, allocate the bit to opt-out the image from implicit
PROTMAX enablement. Provide procctl(2) verbs to set and query
implicit PROTMAX handling. The knobs mimic the same per-image flag
and per-process controls for ASLR.
Reviewed by: emaste, markj (previous version)
Discussed with: brooks
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D20795
Currently RTLD is linked against libc_nossp_pic which means that any libc
symbol used in rtld can pull in a lot of depedencies. This was causing
symbol such as __libc_interposing and all the pthread stubs to be included
in RTLD even though they are not required. It turns out most of these
dependencies can easily be avoided by providing overrides inside of rtld.
This change is motivated by CHERI, where we have an experimental ABI that
requires additional relocation processing to allow the use of function
pointers inside of rtld. Instead of adding this self-relocation code to
RTLD I attempted to remove most function pointers from RTLD and discovered
that most of them came from the libc dependencies instead of being actually
used inside rtld.
A nice side-effect of this change is that rtld is now 22% smaller on amd64.
text data bss dec hex filename
0x21eb6 0xce0 0xe60 145910 239f6 /home/alr48/ld-elf-x86.before.so.1
0x1a6ed 0x728 0xdd8 113645 1bbed /home/alr48/ld-elf-x86.after.so.1
The number of R_X86_64_RELATIVE relocations that need to be processed on
startup has also gone down from 368 to 187 (almost 50% less).
Reviewed By: kib
Differential Revision: https://reviews.freebsd.org/D20663
Summary:
PowerPC has two PLT models: BSS-PLT and Secure-PLT. BSS-PLT uses runtime
code generation to generate the PLT stubs. Secure-PLT was introduced with
GCC 4.1 and Binutils 2.17 (base has GCC 4.2.1 and Binutils 2.17), and is a
more secure PLT format, using a read-only linkage table, with the dynamic
linker populating a non-executable index table.
This is the libc, rtld, and kernel support only. The toolchain and build
parts will be updated separately.
Reviewed By: nwhitehorn, bdragon, pfg
Differential Revision: https://reviews.freebsd.org/D20598
MFC after: 1 month
This is in preparation for compiling these files as part of rtld (which is
built with WARNS=6). See https://reviews.freebsd.org/D20663 for more details.
In the case of mmap(), add a HISTORY section. Mention that mmap() and
mprotect()'s documentation predates an implementation. The
implementation first saw wide use in 4.3-Reno, but there seems to be no
easy way to express that in mdoc so stick with 4.4BSD.
Reviewed by: emaste
Requested by: cem
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D20713
A new macro PROT_MAX() alters a protection value so it can be OR'd with
a regular protection value to specify the maximum permissions. If
present, these flags specify the maximum permissions.
While these flags are non-portable, they can be used in portable code
with simple ifdefs to expand PROT_MAX() to 0.
This change allows (e.g.) a region that must be writable during run-time
linking or JIT code generation to be made permanently read+execute after
writes are complete. This complements W^X protections allowing more
precise control by the programmer.
This change alters mprotect argument checking and returns an error when
unhandled protection flags are set. This differs from POSIX (in that
POSIX only specifies an error), but is the documented behavior on Linux
and more closely matches historical mmap behavior.
In addition to explicit setting of the maximum permissions, an
experimental sysctl vm.imply_prot_max causes mmap to assume that the
initial permissions requested should be the maximum when the sysctl is
set to 1. PROT_NONE mappings are excluded from this for compatibility
with rtld and other consumers that use such mappings to reserve
address space before mapping contents into part of the reservation. A
final version this is expected to provide per-binary and per-process
opt-in/out options and this sysctl will go away in its current form.
As such it is undocumented.
Reviewed by: emaste, kib (prior version), markj
Additional suggestions from: alc
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D18880
The man page claims that with O_FSYNC (aka O_SYNC) the kernel will not cache
written data. However, that's not true. Nor does POSIX require it.
Perhaps it was true when that section of the man page was written in r69336
(I haven't checked). But it's not true now. Now the effect is simply that
writes are sent to disk immediately and synchronously, but they're still
cached.
See also: https://pubs.opengroup.org/onlinepubs/9699919799/
See also: ffs_write in sys/ufs/ffs/ffs_vnops.c
Reviewed by: cem
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20641
port number, properly access them by their IPv6 names.
This will make it easier to slice up and compile out address families
in the future.
No functional change intended.
MFC after: 6 weeks
Use the .PATH mechanism instead so keep installing them from lib/libc/gen
While here revert 347961 and 347893 which are no longer needed
Discussed with: manu
Tested by: manu
ok manu@
Clang is smart enough to evaluate strlen() of a constant at compile-time.
However, that won't work in the future if we compile libc with
-ffreestanding.
Reported by: kib
Dissenting: ngie, cem
Sponsored by: The FreeBSD Foundation
fusefs file systems may have a fsname subtype (set by mount_fusefs's "-o
subtype" option) that gets appended to the fsname as returned by statfs(2).
The subtype is set on a per-mount basis so it isn't part of the struct
vfsconf. Special-case getvfsbyname to match either the full "fusefs.foobar"
or short "fusefs" fsname.
Sponsored by: The FreeBSD Foundation
In all practical situations, the resolver visibility is static.
Requested by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: so (emaste)
Differential revision: https://reviews.freebsd.org/D20281
libc was picked as the destination location for these because of the syscalls
that use these files as the lowest level place they are referenced.
Approved by: will (mentor), rgrimes, manu
Differential Revision: https://reviews.freebsd.org/D16728
Historically we have not distinguished between kernel wirings and user
wirings for accounting purposes. User wirings (via mlock(2)) were
subject to a global limit on the number of wired pages, so if large
swaths of physical memory were wired by the kernel, as happens with
the ZFS ARC among other things, the limit could be exceeded, causing
user wirings to fail.
The change adds a new counter, v_user_wire_count, which counts the
number of virtual pages wired by user processes via mlock(2) and
mlockall(2). Only user-wired pages are subject to the system-wide
limit which helps provide some safety against deadlocks. In
particular, while sources of kernel wirings typically support some
backpressure mechanism, there is no way to reclaim user-wired pages
shorting of killing the wiring process. The limit is exported as
vm.max_user_wired, renamed from vm.max_wired, and changed from u_int
to u_long.
The choice to count virtual user-wired pages rather than physical
pages was done for simplicity. There are mechanisms that can cause
user-wired mappings to be destroyed while maintaining a wiring of
the backing physical page; these make it difficult to accurately
track user wirings at the physical page layer.
The change also closes some holes which allowed user wirings to succeed
even when they would cause the system limit to be exceeded. For
instance, mmap() may now fail with ENOMEM in a process that has called
mlockall(MCL_FUTURE) if the new mapping would cause the user wiring
limit to be exceeded.
Note that bhyve -S is subject to the user wiring limit, which defaults
to 1/3 of physical RAM. Users that wish to exceed the limit must tune
vm.max_user_wired.
Reviewed by: kib, ngie (mlock() test changes)
Tested by: pho (earlier version)
MFC after: 45 days
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D19908
The rewrite of strcmp in assembly uses an instruction added in PowerISA
2.05, making it SIGILL on CPUs older than the POWER6, such as the PPC970 in
the PowerMac G5. Revert this until we get clang+lld, or retire the in-tree
binutils in favor of newer binutils with IFUNC support, whichever comes
first.
Summary:
Optimize strcmp for powerpc64.
Data is loaded by double words and cmpb intruction is used to find '\0'.
Some performance gain rates between the current and the optimized solution:
String size (bytes) Gain rate
<=8 0.59%
<=16 1.92%
32 3.02%
64 5.60%
128 10.16%
256 18.05%
512 30.18%
1024 42.82%
Submitted by: alexandre.yamashita_eldorado.org.br,
leonardo.bianconi_eldorado.org.br
Differential Revision: https://reviews.freebsd.org/D15220
Relative performance to rand(3) is sort of irrelevant; they do different things
and a user with sensitivity to RNG performance won't use libc random(3) anyway.
The historical note about bad seeding is long obsolete, referring to a 1996 or
earlier version of FreeBSD.
Sponsored by: Dell EMC Isilon
Initialize `oldlen` to the size of the value, instead of leaving the value
unitialized. Leaving it unitialized seems to work by accident on amd64 when
running 64-bit programs, but not on i386.
This matches patterns in use in other programs.
PR: 237458
Approved by: emaste (mentor; implicit)
MFC after: 1 week
Tested on: ^/head (amd64), ^/stable/11 (i386)
It is a useful arc4random wrapper in the kernel for much the same reasons as
in userspace. Move the source to libkern (because kernel build is
restricted to sys/, but userspace can include any file it likes) and build
kernel and libc versions from the same source file.
Copy the documentation from arc4random_uniform(3) to the section 9 page.
While here, add missing arc4random_buf(9) symlink.
Sponsored by: Dell EMC Isilon
random.3 is only "better" in contrast to rand.3. Both are non-cryptographic
pseudo-random number generators. The opening blurbs of each's DESCRIPTION
section does emphasize this, and correctly directs unfamiliar developers to
arc4random(3). However, the summary (".Nd" or Name description) of random.3
conflicted in tone and message with that warning.
Resolve the conflict by clarifying in the Nd section that random(3) is
non-cryptographic and pseudo-random. Elide the "better" qualifier which
implied a comparison but did not provide a specific object to contrast.
Sponsored by: Dell EMC Isilon
