- lock all relevant mutexes just before fork
- unlock all mutexes just after fork in the parent
- full reinit non-spinlocks in the child
This is not using the normal pthread_atfork interface to ensure order of
operation, malloc is used as implementation detail too often.
They deliver the logic of bypassing selected signals directly to the
debuggee, without informing the debugger.
This can be used to implement the QPassSignals GDB/LLDB protocol.
This call can be useful to avoid signal races in ATF ptrace tests.
CLONE_PID was removed in Linux 2.5.15 and recycled for
CLONE_PIDFD since Linux 5.2.
CLONE_STOPPED was removed in Linux 2.6.38 and recycled
for CLONE_NEWCGROUP since Linux 4.6.
the environment rather than simply turning into posix_spawn() in that case.
Also, we cannot use strtok() to parse PATH, the semantics don't fit the API.
Borrow the guts of execvp for the PATH search.
We still simply check for a file with 'x' permission, and assume that one
will do, whatever it is, which isn't really correct, but ...
Still being discussed in tech-userlevel. If we wait any longer someone
is going to try the excuse that the discussion is entirely pointless, since
removing symbols is too hard.
Posted to tech-userlevel@ a week ago and reviewed by riastradh@.
GETENTROPY(3) Library Functions Manual GETENTROPY(3)
NAME
getentropy - fill a buffer with high quality random data
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
int
getentropy(void *buf, size_t buflen);
DESCRIPTION
The getentropy() function fills a buffer with high quality random data,
suitable for seeding cryptographically secure psuedorandom number
generators.
getentropy() is only intended for seeding random number generators and is
not intended for use by regular code which simply needs secure random
data. For this purpose, please use arc4random(3).
The maximum value for buflen is 256 bytes.
IMPLEMENTATION NOTES
getentropy() reads from the sysctl(7) variable kern.arandom.
RETURN VALUES
The getentropy() function returns 0 on success, and -1 if an error
occurred.
ERRORS
getentropy() will succeed unless:
[EFAULT] The buf argument points to an invalid memory address.
[EIO] Too many bytes were requested.
SEE ALSO
arc4random(3), rnd(4)
STANDARDS
The getentropy() function is non-standard.
HISTORY
The getentropy() function first appeared in OpenBSD 5.6, then in
FreeBSD 12.0, and NetBSD 10.
This avoids leaking NO_STATIC_MODULES into the public header, which
has led to considerable confusion and workarounds in pkgrsc.
PR security/39313
PR security/55216
ok christos
changes don't get propagated back, and then write to the private buffer.
This is not useful yes, but it is simple enough to make pread use the buffer
if it is available.
kernel and bootloader for 68010.
They requires a special calling convention to udivsi3, and cannot to be
mixed up in normal routines provided by libgcc or compiler_rt. Although,
there's no problem for using them in a controlled situation, i.e., kernel
and standalone programs.
Note that this does not affect at all m68k ports other than sun2, since
codes generated by gcc do not call these routines.
Assembler files are moved from common/lib/libc/arch/m68k/gen to
sys/lib/libkern/arch/m68k in order not to be compiled in libc.
Revert hack introduced to lib/libc/compiler_rt/Makefile.inc rev 1.37:
http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/compiler_rt/Makefile.inc#rev1.37
Proposed on port-sun2@ with no response...
(Again, this does not affect m68k ports other than sun2.)
http://mail-index.netbsd.org/port-sun2/2020/03/10/msg000102.html
Optimistically check whether the key has been used by this thread
already and avoid locking in that case. This avoids the atomic operation
in the hot path. When the value is set to non-NULL for the first time,
put the entry on the to-be-freed list and keep it their until
destruction or thread exit. Setting the key to NULL and back is common
enough and updating the list is more expensive than the extra check on
the final round.
Problems in the previous code include returning values in the 0-255
range NetBSD uses instead of the 0-100 range OSSv4 expects, using
AUDIO_GETBUFINFO (which doesn't even return the mixer bits), and
not encoding channels as specified: "level=(left)|(right << 8)".
In reality, setting the gain in this way (through /dev/audio rather
than /dev/mixer) doesn't seem to work properly, and the mixer-set
value seems to be retained.
However, these changes at least ensure that the return values are
correct and the balance is set correctly.
I've only found one application using this API (audio/audacious), and
OSSv4 support in it is currently disabled precisely because it breaks
when it attempts to set the track volume using it.
rtld and libc use different storage, so the initial version would
incorrectly report the failure reason for fork().
There is still a small race condition inside ld.elf_so as it doesn't use
thread-safe errno internally, but that's a more contained internal
issue.
