`snprintf()` is meant to protect against buffer overflows, but operating
on the buffer using its return value, possibly by calling it again, can
cause a buffer overflow, because it will return how many characters it
would have written if it had enough space even when it did not. In a
number of places, we repeatedly call snprintf() by successively
incrementing a buffer offset and decrementing a buffer length, by its
return value. This is a potentially unsafe usage of `snprintf()`
whenever the buffer length is reached. CodeQL complained about this.
To fix this, we introduce `kmem_scnprintf()`, which will return 0 when
the buffer is zero or the number of written characters, minus 1 to
exclude the NULL character, when the buffer was too small. In all other
cases, it behaves like snprintf(). The name is inspired by the Linux and
XNU kernels' `scnprintf()`. The implementation was written before I
thought to look at `scnprintf()` and had a good name for it, but it
turned out to have identical semantics to the Linux kernel version.
That lead to the name, `kmem_scnprintf()`.
CodeQL only catches this issue in loops, so repeated use of snprintf()
outside of a loop was not caught. As a result, a thorough audit of the
codebase was done to examine all instances of `snprintf()` usage for
potential problems and a few were caught. Fixes for them are included in
this patch.
Unfortunately, ZED is one of the places where `snprintf()` is
potentially used incorrectly. Since using `kmem_scnprintf()` in it would
require changing how it is linked, we modify its usage to make it safe,
no matter what buffer length is used. In addition, there was a bug in
the use of the return value where the NULL format character was not
being written by pwrite(). That has been fixed.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14098
Apply similar options to BLAKE3 as it is done for zfs_fletcher_4_impl.
The zfs module parameter on Linux changes from icp_blake3_impl to
zfs_blake3_impl.
You can check and set it on Linux via sysfs like this:
```
[bash]# cat /sys/module/zfs/parameters/zfs_blake3_impl
cycle [fastest] generic sse2 sse41 avx2
[bash]# echo sse2 > /sys/module/zfs/parameters/zfs_blake3_impl
[bash]# cat /sys/module/zfs/parameters/zfs_blake3_impl
cycle fastest generic [sse2] sse41 avx2
```
The modprobe module parameters may also be used now:
```
[bash]# modprobe zfs zfs_blake3_impl=sse41
[bash]# cat /sys/module/zfs/parameters/zfs_blake3_impl
cycle fastest generic sse2 [sse41] avx2
```
On FreeBSD the BLAKE3 implementation can be set via sysctl like this:
```
[bsd]# sysctl vfs.zfs.blake3_impl
vfs.zfs.blake3_impl: cycle [fastest] generic sse2 sse41 avx2
[bsd]# sysctl vfs.zfs.blake3_impl=sse2
vfs.zfs.blake3_impl: cycle [fastest] generic sse2 sse41 avx2 \
-> cycle fastest generic [sse2] sse41 avx2
```
This commit changes also some Blake3 internals like these:
- blake3_impl_ops_t was renamed to blake3_ops_t
- all functions are named blake3_impl_NAME() now
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13725
The checksum benchmarking on module load may take a really long time
on embedded systems with a slow cpu. Avoid all benchmarks >= 1MiB on
systems, where EdonR is slower then 300 MiB/s.
This limit is currently hardcoded via the define LIMIT_PERF_MBS.
This is the new benchmark output of a slow Intel Atom:
```
implementation 1k 4k 16k 64k 256k 1m 4m 16m
edonr-generic 209 257 268 259 262 0 0 0
skein-generic 129 150 151 150 150 0 0 0
sha256-generic 50 55 56 56 56 0 0 0
sha512-generic 76 86 88 89 88 0 0 0
blake3-generic 63 62 62 62 61 0 0 0
blake3-sse2 114 292 301 307 309 0 0 0
```
Reviewed-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13695
Allocation via kmem_cache_alloc() is limited to less then 4m for
some architectures.
This commit limits the benchmarks with the linear abd cache to 1m
on all architectures and adds 4m + 16m benchmarks via non-linear
abd_alloc().
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Co-authored-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13669Closes#13670
The kmem_alloc(sizeof (*ctx), KM_NOSLEEP) call on FreeBSD can't be
used in this code segment. Work around this by pre-allocating a percpu
context array for later use.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13568
This commit adds BLAKE3 checksums to OpenZFS, it has similar
performance to Edon-R, but without the caveats around the latter.
Homepage of BLAKE3: https://github.com/BLAKE3-team/BLAKE3
Wikipedia: https://en.wikipedia.org/wiki/BLAKE_(hash_function)#BLAKE3
Short description of Wikipedia:
BLAKE3 is a cryptographic hash function based on Bao and BLAKE2,
created by Jack O'Connor, Jean-Philippe Aumasson, Samuel Neves, and
Zooko Wilcox-O'Hearn. It was announced on January 9, 2020, at Real
World Crypto. BLAKE3 is a single algorithm with many desirable
features (parallelism, XOF, KDF, PRF and MAC), in contrast to BLAKE
and BLAKE2, which are algorithm families with multiple variants.
BLAKE3 has a binary tree structure, so it supports a practically
unlimited degree of parallelism (both SIMD and multithreading) given
enough input. The official Rust and C implementations are
dual-licensed as public domain (CC0) and the Apache License.
Along with adding the BLAKE3 hash into the OpenZFS infrastructure a
new benchmarking file called chksum_bench was introduced. When read
it reports the speed of the available checksum functions.
On Linux: cat /proc/spl/kstat/zfs/chksum_bench
On FreeBSD: sysctl kstat.zfs.misc.chksum_bench
This is an example output of an i3-1005G1 test system with Debian 11:
implementation 1k 4k 16k 64k 256k 1m 4m
edonr-generic 1196 1602 1761 1749 1762 1759 1751
skein-generic 546 591 608 615 619 612 616
sha256-generic 240 300 316 314 304 285 276
sha512-generic 353 441 467 476 472 467 426
blake3-generic 308 313 313 313 312 313 312
blake3-sse2 402 1289 1423 1446 1432 1458 1413
blake3-sse41 427 1470 1625 1704 1679 1607 1629
blake3-avx2 428 1920 3095 3343 3356 3318 3204
blake3-avx512 473 2687 4905 5836 5844 5643 5374
Output on Debian 5.10.0-10-amd64 system: (Ryzen 7 5800X)
implementation 1k 4k 16k 64k 256k 1m 4m
edonr-generic 1840 2458 2665 2719 2711 2723 2693
skein-generic 870 966 996 992 1003 1005 1009
sha256-generic 415 442 453 455 457 457 457
sha512-generic 608 690 711 718 719 720 721
blake3-generic 301 313 311 309 309 310 310
blake3-sse2 343 1865 2124 2188 2180 2181 2186
blake3-sse41 364 2091 2396 2509 2463 2482 2488
blake3-avx2 365 2590 4399 4971 4915 4802 4764
Output on Debian 5.10.0-9-powerpc64le system: (POWER 9)
implementation 1k 4k 16k 64k 256k 1m 4m
edonr-generic 1213 1703 1889 1918 1957 1902 1907
skein-generic 434 492 520 522 511 525 525
sha256-generic 167 183 187 188 188 187 188
sha512-generic 186 216 222 221 225 224 224
blake3-generic 153 152 154 153 151 153 153
blake3-sse2 391 1170 1366 1406 1428 1426 1414
blake3-sse41 352 1049 1212 1174 1262 1258 1259
Output on Debian 5.10.0-11-arm64 system: (Pi400)
implementation 1k 4k 16k 64k 256k 1m 4m
edonr-generic 487 603 629 639 643 641 641
skein-generic 271 299 303 308 309 309 307
sha256-generic 117 127 128 130 130 129 130
sha512-generic 145 165 170 172 173 174 175
blake3-generic 81 29 71 89 89 89 89
blake3-sse2 112 323 368 379 380 371 374
blake3-sse41 101 315 357 368 369 364 360
Structurally, the new code is mainly split into these parts:
- 1x cross platform generic c variant: blake3_generic.c
- 4x assembly for X86-64 (SSE2, SSE4.1, AVX2, AVX512)
- 2x assembly for ARMv8 (NEON converted from SSE2)
- 2x assembly for PPC64-LE (POWER8 converted from SSE2)
- one file for switching between the implementations
Note the PPC64 assembly requires the VSX instruction set and the
kfpu_begin() / kfpu_end() calls on PowerPC were updated accordingly.
Reviewed-by: Felix Dörre <felix@dogcraft.de>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Co-authored-by: Rich Ercolani <rincebrain@gmail.com>
Closes#10058Closes#12918
