Shared locking routines explicitly read the value and test it. If the
change attempt fails, they fall back to a regular function which would
retry in a loop.
The problem is that with many concurrent readers the risk of failure is pretty
high and even the value returned by fcmpset is very likely going to be stale
by the time the loop in the fallback routine is reached.
Uninline said primitives. It gives a throughput increase when doing concurrent
slocks/sunlocks with 80 hardware threads from ~50 mln/s to ~56 mln/s.
Interestingly, rwlock primitives are already not inlined.
The found value is passed to locking routines in order to reduce cacheline
accesses.
mtx_unlock grows an explicit check for regular unlock. On ll/sc architectures
the routine can fail even if the lock could have been handled by the inline
primitive.
Discussed with: jhb
Tested by: pho (previous version)
It is an ASCII encoding of a hexadecimal representation of the DOF file
used to enable anonymous tracing, so its length should always be even.
MFC after: 1 week
libdtrace needs to append to the input object files' string and symbol
tables. Currently it does so by allocating a larger buffer, copying the
existing sections into them, and swapping pointers in the libelf data
descriptors. However, it also frees those buffers when its processing is
complete, which leads to a double free since the elftoolchain libelf
owns them and also frees them in elf_end(3). Instead, free the buffers
originally allocated by libelf.
MFC after: 2 weeks
When recording probe site addresses in the output DOF file, dtrace -G
needs to emit relocations for the .SUNW_dof section in order to obtain
the addresses of functions containing probe sites. DTrace expects the
addresses to be relative to the base address of the final ELF file,
and the amd64 USDT implementation was relying on some unspecified and
incorrect behaviour in the base system GNU ld to achieve this.
This change reimplements the probe site relocation handling to allow
USDT to be used with lld and newer GNU binutils. Specifically, it
makes use of R_X86_64_PC64/R_386_PC32 relocations to obtain the
probe site address relative to the DOF file address, and adds and uses a
new DOF relocation type which computes the final probe site address using
these relative offsets.
Reported by and discussed with: Rafael Espíndola
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D9374
witness_warn() either breaks into the debugger or panics the system, so its
output should go to the console regardless of the witness(4) output channel
configuration.
MFC after: 1 week
Sponsored by: Dell EMC Isilon
- Perform final decryption and write decrypted data in case of non-block aligned
input data;
- Use strlcpy(3) instead of strncpy(3) to verify if paths aren't too long;
- Check errno after calling unlink(2) instead of calling stat(2) in order to
verify if a decrypted core was created by a child process;
- Free dumpkey.
Reported by: Coverity, cem, pfg
Suggested by: cem
CID: 1366936, 1366942, 1366951, 1366952
Approved by: pjd (mentor)
The types are for the byte offset and page index in vm object. They
are similar to off_t, which is defined as 64bit MI integer. Using MI
definitions will allow to provide consistent MD values of vm
object-related maximum sizes.
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The switch to get_pcpu() in MI code seems to cause hangs on MIPS.
Back out until we can get a better idea of what's happening there.
Reported by: kan, lidl
wdc cap-diag Capture diagnostic data from drive
wdc drive-log Capture drive history data from drive
wdc get-crash-dump Retrieve firmware crash dump from drive
one respect. When determining how many page structures to allocate,
contrary to what the comments say, the code does not account for the
overhead of a page structure per page of physical memory. This revision
changes the code to match the comments.
Reviewed by: kib, markj
MFC after: 6 weeks
Differential Revision: https://reviews.freebsd.org/D9081
The case for which this was added, r274807, causes this warning to
always show. LOCAL_DIRS=foo LOCAL_LIB_DIRS=foo/lib. The only case in
which r274807 is a problem is if foo/Makefile does not contain
SUBDIR+=lib, which is a normal convention. LOCAL_LIB_DIRS is a special
hack only to get a library into the _generic_libs list for the
'make libraries' bootstrapping phase. The old behavior changed in
r274807 was only in head during the 10.0 cycle, so the warning was
only ever needed until release anyhow.
Reported by: ngie
MFC after: 1 week
Sponsored by: Dell EMC Isilon
As of r313097, the HotPlug code requires the link to support
reporting of the data-link status. Remove tests for this capability
from code that can now assume its presence.
Suggested by: jhb
Reviewed by: jhb
MFC after: 3 days
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D9431
low-quality random numbers with a modern implementation (xoroshiro128+)
that is capable of generating better quality randomness without compromising performance.
Submitted by: Graeme Jenkinson
Reviewed by: markj
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D9051
Document AF_UNIX control messages in unix(4) only, not split between unix(4)
and recv(2).
Also, warn about LOCAL_CREDS effective uid/gid fields, since the write could
be from a setuid or setgid program (with the explicit SCM_CREDS and
LOCAL_PEERCRED, the credentials are read at such a time that it can be
assumed that the process intends for them to be used in this context).
Reviewed by: wblock
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D9298
not being initialized, and the per-vnet fastopen context was only
being initialized for the default vnet.
PR: 216613
Reported by: Alex Deiter <alex dot deiter at gmail dot com>
MFC after: 1 week
The arm build has revealed some of the warnings, the fix for CHAR16
warning is to switch the warning off for env.c (same as for efinet.c).
For error code we need to use macro.
Reported by: gjb
Reviewed by: imp
Approved by: imp (mentor)
Differential Revision: https://reviews.freebsd.org/D9422
The switch to elftoolchain's readelf in r280859 caused native-xtools
to no longer build readelf. This fixes poudriere builds not using
a native readelf when expected.
Reported by: strejda on freenode
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
r312992 removed RESTARTCMD_WITH_ARG for @RESTARTCMD something@ but
reverted the sed to be '@RESTARTCMD \(.*\)@' and RESTARTCMD= to be
the value of RESTARTCMD_WITH_ARG.
Submitted by: Guy Yur
x_MFC with: r312992
and device npx.
This means that FPU is always initialized and handled when available,
and SSE+ register file and exception are handled when available. This
makes the kernel FPU code much easier to maintain by the cost of
slight bloat for CPUs older than 25 years.
CPU_DISABLE_CMPXCHG outlived its usefulness, see the removed comment
explaining the original purpose.
Suggested by and discussed with: bde
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
