POSIX equivalents
Both printf and putchar return int, not void.
This will allow code that leverages the libcalls and checks/rely on the
return type to interchangeably between loader code and non-loader
code.
MFC after: 1 month
- Store the symbol table contents in an anonymous swap-backed object. Have
mmap(/dev/ksyms) map that object, and stop mapping the symbol table into
the calling process in ksyms_open(). Previously we would cache a pointer
to the pmap of the opening process, and mmap(/dev/ksyms) would create a
mapping using the physical address found by a pmap lookup at the initial
mapping address. However, this assumes that the cached pmap is valid,
which may not be the case. [1]
- Remove the ksyms ioctl interface. It appears to have been added to work
around a limitation in libelf that no longer exists; see r321842.
Moreover, the interface is difficult to support and isn't present in
illumos. Since ksyms was added specifically to support lockstat(1), it
is expected that this removal won't have any real impact.
- Simplify ksyms_read() to avoid unnecessary copying.
- Don't call the device handle destructor if we fail to capture a snapshot
of the kernel's symbol table. devfs will do that for us.
Reported by: Ilja van Sprundel <ivansprundel@ioactive.com> [1]
Reviewed by: kib (previous revision)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D11789
"br" or "bridge" where - according to the terminology outlined in
comments of bridge.h and mmcbr_if.m around since their addition in
r163516 - the bus is meant and used instead. Some of these instances
are also rather old, while those in e. g. mmc_subr.c are as new as
r315430 and were caused by choosing mmc_wait_for_request(), i. e. the
one pre-r315430 outliner existing in mmc.c, as template for function
parameters in mmc_subr.c inadvertently. This correction translates to
renaming "brdev" to "busdev" and "mmcbr" to "mmcbus" respectively as
appropriate.
While at it, also rename "reqdev" to just "dev" in mmc_subr.[c,h]
for consistency with was already used in mmm.c pre-r315430, again
modulo mmc_wait_for_request() that is.
- Remove comment lines from bridge.h incorrectly suggesting that there
would be a MMC bridge base class driver.
- Update comments in bridge.h regarding the star topology of SD and SDIO;
since version 3.00 of the SDHCI specification, for eSD and eSDIO bus
topologies are actually possible in form of so called "shared buses"
(in some subcontext later on renamed to "embedded" buses).
as taking a register number, and that would get multiplied by 4 to make
a register address. But the header file that consumers have to reference
this stuff publishes register addresses, not numbers. So now everything
works in terms of register addresses.
Note that the HDMI init code was writing into the wrong register before
this change. Apparently whatever it wrote to was harmless, and apparently
HDMI was working because uboot had set up the right bits.
wide enough to hold the full 64-bit dev_t. Instead use the "dev" field in
the "linux_cdev" structure to store and lookup this value.
While at it remove superfluous use of parenthesis inside the
MAJOR(), MINOR() and MKDEV() macros in the LinuxKPI.
MFC after: 1 week
Sponsored by: Mellanox Technologies
and arm64 so move any truncation to the caller.
Submitted by: Mihai Carabas <mihai.carabas@gmail.com>
X-Differential Revision: https://reviews.freebsd.org/D10213
Similar to r321899, reduce sv_maxuser by one page inside of CloudABI.
This ensures that the stack, the vDSO and any allocations cannot touch
the top page of user virtual memory.
Considering that CloudABI userspace is completely oblivious to virtual
memory layout, don't bother making this conditional based on the CPU of
the running system.
Reviewed by: kib, truckman
Differential Revision: https://reviews.freebsd.org/D11808
Since traditional types for the macros values are int, remove the
cookie trick and just split the dev_t at the word boundary.
Reported by: Victor Stinner <victor.stinner@gmail.com>
PR: 221048
Sponsored by: The FreeBSD Foundation
when a signal is not intended to be sent.
The variable holding the signal number to send is left uninitialized,
which sometimes triggers invalid signal checks.
For NMI, a return to usermode without ast processing is done. On the
other hand, for spurious dtrace probe interrupt it is usermode which
triggered the interrupt, so handle it through userret() as any other
fault.
Reported by: Nils Beyer <nbe@renzel.net>
PR: 221151
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
from the top of user memory to one page lower on machines with the
Ryzen (AMD Family 17h) CPU. This pushes ps_strings and the stack
down by one page as well. On Ryzen there is some sort of interaction
between code running at the top of user memory address space and
interrupts that can cause FreeBSD to either hang or silently reset.
This sounds similar to the problem found with DragonFly BSD that
was fixed with this commit:
https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/b48dd28447fc8ef62fbc963accd301557fd9ac20
but our signal trampoline location was already lower than the address
that DragonFly moved their signal trampoline to. It also does not
appear to be related to SMT as described here:
https://www.phoronix.com/forums/forum/hardware/processors-memory/955368-some-ryzen-linux-users-are-facing-issues-with-heavy-compilation-loads?p=955498#post955498
"Hi, Matt Dillon here. Yes, I did find what I believe to be a
hardware issue with Ryzen related to concurrent operations. In a
nutshell, for any given hyperthread pair, if one hyperthread is
in a cpu-bound loop of any kind (can be in user mode), and the
other hyperthread is returning from an interrupt via IRETQ, the
hyperthread issuing the IRETQ can stall indefinitely until the
other hyperthread with the cpu-bound loop pauses (aka HLT until
next interrupt). After this situation occurs, the system appears
to destabilize. The situation does not occur if the cpu-bound
loop is on a different core than the core doing the IRETQ. The
%rip the IRETQ returns to (e.g. userland %rip address) matters a
*LOT*. The problem occurs more often with high %rip addresses
such as near the top of the user stack, which is where DragonFly's
signal trampoline traditionally resides. So a user program taking
a signal on one thread while another thread is cpu-bound can cause
this behavior. Changing the location of the signal trampoline
makes it more difficult to reproduce the problem. I have not
been because the able to completely mitigate it. When a cpu-thread
stalls in this manner it appears to stall INSIDE the microcode
for IRETQ. It doesn't make it to the return pc, and the cpu thread
cannot take any IPIs or other hardware interrupts while in this
state."
since the system instability has been observed on FreeBSD with SMT
disabled. Interrupts to appear to play a factor since running a
signal-intensive process on the first CPU core, which handles most
of the interrupts on my machine, is far more likely to trigger the
problem than running such a process on any other core.
Also lower sv_maxuser to prevent a malicious user from using mmap()
to load and execute code in the top page of user memory that was made
available when the shared page was moved down.
Make the same changes to the 64-bit Linux emulator.
PR: 219399
Reported by: nbe@renzel.net
Reviewed by: kib
Reviewed by: dchagin (previous version)
Tested by: nbe@renzel.net (earlier version)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D11780
When all instances of a lock type are destroyed (for example, after a
module unload), the corresponding witness entry remains associated with
that lock type. In this case, we shouldn't panic if a new instance of the
lock type is created and its lock class does not match that recorded in the
witness entry.
Reviewed by: jhb
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D11788
According to the PCI Local Specification rev. 3.0 in case of a 64-bit
BAR both the low and the high parts of the register should be set to
~0 before attempting to read back the size.
So far I have found no single device that has problems with the
previous approach, but I think it's better to stay on the safe size.
This commit should not introduce any functional change.
MFC after: 3 weeks
Sponsored by: Citrix Systems R&D
Reviewed by: jhb
Differential revision: https://reviews.freebsd.org/D11750
The removed release stores are not needed since stores are totally
ordered on i386 and amd64.
Reviewed by: alc, kib (previous revision)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D11790
'skip', which denote, respectively, the largest number of blocks that can be
managed by a subtree of that height, and one less than the number of nodes
in a subtree of that height. This change removes the 'skip' argument from
those functions because 'skip' can be trivially computed from 'radius'.
This change also redefines 'skip' so that it denotes the number of nodes in
the subtree, and so changes loop upper bound tests from '<= skip' to '<
skip' to account for the change.
The 'skip' field is also removed from the blist struct.
The self-test program is changed so that the print command includes the
cursor value in the output.
Submitted by: Doug Moore <dougm@rice.edu>
MFC after: 1 week
Linux specific things to the native fdescfs file system.
Unlike FreeBSD, the Linux fdescfs is a directory containing a symbolic
links to the actual files, which the process has open.
A readlink(2) call on this file returns a full path in case of regular file
or a string in a special format (type:[inode], anon_inode:<file-type>, etc..).
As well as in a FreeBSD, opening the file in the Linux fdescfs directory is
equivalent to duplicating the corresponding file descriptor.
Here we have mutually exclusive requirements:
- in case of readlink(2) call fdescfs lookup() method should return VLNK
vnode otherwise our kern_readlink() fail with EINVAL error;
- in the other calls fdescfs lookup() method should return non VLNK vnode.
For what new vnode v_flag VV_READLINK was added, which is set if fdescfs has beed
mounted with linrdlnk option an modified kern_readlinkat() to properly handle it.
For now For Linux ABI compatibility mount fdescfs volume with linrdlnk option:
mount -t fdescfs -o linrdlnk null /compat/linux/dev/fd
Reviewed by: kib@
MFC after: 1 week
Relnotes: yes
This prepares for the upcoming transparent VF support.
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D11708
Don't enable the oscillator when it is found to be stopped at init time,
just let the first setting of valid time start it. But still report a dead
battery if it's stopped at init time.
Don't force the chip into 24hr mode, just cope with whatever mode it is
already in.
Schedule the clock_settime() callbacks to align the RTC clock to top of
second when setting it.
subr_rtc code, switch from CLOCKF_SETTIME_NO_TS to CLOCKF_SETTIME_NO_ADJ
so that we get fed a timestamp, but it's not adjusted to compensate for
inaccuracy in setting time.
Update the use of the B_CACHE flag (since the May 1999 commit
that made it the correct test here).
Reported by: Andreas Longwitz <longwitz@incore.de>
Reviewed by: kib
Tested by: Peter Holm
MFC after: 1 week
Atomic updates to v_wire_count are a significant source of contention, so
combine multiple updates into one in this easy case. Also remove an old
printf that gets executed if the page is shared-busied, which is a case
that will lead to a panic anyway.
Reviewed by: alc, kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D11791
In this case we shouldn't assume that the thread has a valid frame pointer.
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D11787
This change adds two new tunables, allowing to control serialization for
read and write NFS requests separately. It does not change the default
behavior since there are too many factors to consider, but gives additional
space for further experiments and tuning.
The main motivation for this change is very low write speed in case of ZFS
with sync=always or when NFS clients requests sychronous operation, when
every separate request has to be written/flushed to ZIL, and requests are
processed one at a time. Setting vfs.nfsd.fha.write=0 in that case allows
to increase ZIL throughput by several times by coalescing writes and cache
flushes. There is a worry that doing it may increase data fragmentation
on disks, but I suppose it should not happen for pool with SLOG.
MFC after: 1 week
Sponsored by: iXsystems, Inc.
