allow the built-in operations to be redefined, at least not without
excessive force).
Instead, just disable LLVM's support for atomic operations for now.
Nothing in either clang or the tablegen tools currently depends on it.
This still allows users of head built before r198344 to upgrade to
top-of-head seamlessly.
change here is to ensure that when a process forks after arc4random
is seeded, the parent and child don't observe the same random sequence.
OpenBSD's fix introduces some additional overhead in the form of a
getpid() call. This could be improved upon, e.g., by setting a flag
in fork(), if it proves to be a problem.
This was discussed with secteam (simon, csjp, rwatson) in 2008, shortly
prior to my going out of town and forgetting all about it. The conclusion
was that the problem with forks is worrisome, but it doesn't appear to
have introduced an actual vulnerability for any known programs.
The only significant remaining difference between our arc4random and
OpenBSD's is in how we seed the generator in arc4_stir().
OpenBSD's version (r1.22). While some of our style changes were
indeed small improvements, being able to easily track functionality
changes in OpenBSD seems more useful.
Also fix style bugs in the FreeBSD-specific parts of this file.
No functional changes, as verified with md5.
Some header file parts of this patch were taken from a patch submitted
by Maya Erez <merez@codeaurora.org> to the LibUSB developers list.
MFC after: 1 week
Some consumers of PAM remove the /dev/ component (i.e. login), while
others don't (i.e. su). We must ensure that the /dev/ component is
removed to ensure that the utmpx entries properly work with tools such
as w(1).
Discussed with: des
MFC after: 1 week
to be gcc's default before r198344, calls to atomic builtins will not be
expanded inline. Instead, they will be generated as calls to external
functions (e.g. __sync_fetch_and_add_N), leading to linking errors later
on.
Put in a seatbelt that disables use of atomic builtins in libstdc++ and
llvm, when tuning specifically for the real i386 CPU. This does not
protect against all possible issues, but it is better than nothing.
This variable was added in r82352 back in 2001, but even then it didn't
have any use. Because it's not marked static, the C compiler won't
complain about it.
Discussed with: des
The size passed to strlcat() must depend on the input length, not the
output length. Because the input and output buffers are equal in size,
the resulting binary does not change at all.
madvise(2) except that it operates on a file descriptor instead of a
memory region. It is currently only supported on regular files.
Just as with madvise(2), the advice given to posix_fadvise(2) can be
divided into two types. The first type provide hints about data access
patterns and are used in the file read and write routines to modify the
I/O flags passed down to VOP_READ() and VOP_WRITE(). These modes are
thus filesystem independent. Note that to ease implementation (and
since this API is only advisory anyway), only a single non-normal
range is allowed per file descriptor.
The second type of hints are used to hint to the OS that data will or
will not be used. These hints are implemented via a new VOP_ADVISE().
A default implementation is provided which does nothing for the WILLNEED
request and attempts to move any clean pages to the cache page queue for
the DONTNEED request. This latter case required two other changes.
First, a new V_CLEANONLY flag was added to vinvalbuf(). This requests
vinvalbuf() to only flush clean buffers for the vnode from the buffer
cache and to not remove any backing pages from the vnode. This is
used to ensure clean pages are not wired into the buffer cache before
attempting to move them to the cache page queue. The second change adds
a new vm_object_page_cache() method. This method is somewhat similar to
vm_object_page_remove() except that instead of freeing each page in the
specified range, it attempts to move clean pages to the cache queue if
possible.
To preserve the ABI of struct file, the f_cdevpriv pointer is now reused
in a union to point to the currently active advice region if one is
present for regular files.
Reviewed by: jilles, kib, arch@
Approved by: re (kib)
MFC after: 1 month
the word alignment, some versions of gcc do require 16-byte alignment.
Make sure the stack is 16-byte aligned before calling a subroutine.
Inspired by: PR amd64/162214
MFC after: 1 week
as it is required by amd64 ABI. Add a comment for the places were
the stack is accidentally properly aligned already.
PR: amd64/162214
Submitted by: yamayan <yamayan kbh biglobe ne jp>
MFC after: 1 week
When booting the system, truncate the utx.active file, but do write the
BOOT_TIME record into it afterwards. This allows one to obtain the boot
time of the system as follows:
struct utmpx u1 = { .ut_type = BOOT_TIME }, *u2;
setutxent();
u2 = getutxid(&u1);
Now, the boot time is stored in u2->ut_tv, just like on Linux and other
systems.
We don't open the utx.active file with O_EXLOCK. It's rather unlikely
that other applications use this database at the same time and I want to
prevent the possibility of deadlocks in init(8).
Discussed with: pluknet
working MI one. The MI one only needs to be overridden on machines
with non-IEEE754 arithmetic. (The last supported one was the VAX.)
It can also be overridden if someone comes up with a faster one that
actually passes the regression tests -- but this is harder than it sounds.
- Handle cases where exp(x) would overflow, but ccosh(x) ~= exp(x) / 2
shouldn't.
- Use the ccosh(x) ~= exp(x) / 2 approximation to simplify the calculation
when x is large.
Similarly for csinh(). Also fixed the return value of csinh(-Inf +- 0i).
exp(x) scaled down by some factor, and the challenge is doing this
accurately when exp(x) would overflow. This change replaces all of
the tricks we've been using with common __ldexp_exp() and
__ldexp_cexp() routines that handle all the scaling.
bde plans to improve on this further by moving the guts of exp() into
k_exp.c and handling the scaling in a more direct manner. But the
current approach is simple and adequate for now.
As the underlying block is 4KB if the PMC throughput is low the measurement
will be reported on the next tick. pmcstat(8) use the modified flush API to
reclaim current buffer before displaying next top.
MFC after: 1 month
library," since complex.h, tgmath.h, and fenv.h are also part of the
math library. Replace the outdated sentence with some references to
the other parts.
and the caller requested other process' PID by passing non-NULL pidptr
argument, we will wait at most 100ms for the PID to show up in the file and if
it won't, we will store -1 in *pidptr.
From now on, pidfile_open() function never sets errno to EAGAIN on failure.
In collaboration with: des
MFC after: 1 week
