Further contemplation has convinced me that this was
not going to really solve the problem of environment-poisoning
without raising serious administrative headaches. There
must be a better way...
- Fix syntax
- Remove the (slightly wrong) duplicate explanation of the error condition
- Change reference to invalid multibyte character into invalid wide character
This function removes all environment variables except
the ones listed on a "whitelist."
The function accepts two whitelist arguments.
If the first is NULL, a built-in default list will be
used. This allows callers to get a variety of behaviors:
* Default screening: provide NULL for both lists
* Custom screening: provide a custom list for the first argument
* Modified default screening: provide NULL for first arg,
list of additional variables to preserve in the second arg
Idea from: Jacques Vidrine
MFC after: 2 weeks
-static to CFLAGS). It just turned rev.1.5 into an obfuscated no-op.
As explained in the log for rev.1.5, testing should be done in the
host environment but there is a problem in cross-compilation environments.
As not explained in the log for rev.1.6, there was apparently a practical
problem with cross-compiling (makeworld should have set -static in
LDFLAGS but apparently didn't). Cross-compilation was especially
complicated because the relevant programs are test programs that were
run at beforeinstall time -- dynamic libraries might or might not exist
depending on the build options. The complications became moot in
rev.1.8 when beforeinstall was renamed "test".
The getaddrinfo(3), getipnodebyname(3) and resolver(3) can coincide now
with what should be totally reentrant, and h_errno values will now
be preserved correctly, but this does not affect interfaces such as
gethostbyname(3) which are still mostly non-reentrant.
In all of these relevant functions, the thread-safety has been pushed
down as far as it seems possible right now. This means that operations
that are selected via nsdispatch(3) (i.e. files, yp, dns) are protected
still under global locks that getaddrinfo(3) defines, but where possible
the locking is greatly reduced. The most noticeable improvement is
that multiple DNS lookups can now be run at the same time, and this
shows major improvement in performance of DNS-lookup threaded programs,
and solves the "Mozilla tab serialization" problem.
No single-threaded applications need to be recompiled. Multi-threaded
applications that reference "_res" to change resolver(3) options will
need to be recompiled, and ones which reference "h_errno" will also
if they desire the correct h_errno values. If the applications already
understood that _res and h_errno were not thread-safe and had their own
locking, they will see no performance improvement but will not
actually break in any way.
Please note that when NSS modules are used, or when nsdispatch(3)
defaults to adding any lookups of its own to the individual libc
_nsdispatch() calls, those MUST be reentrant as well.
the caller does not specify the rule number -- instead, the kernel
module is probed for the next available rule, which is then used.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, McAfee Research
through a realloc like function.
Make the malloc_active variable a local static to this new function.
Don't warn about recursion more than once per base call.
constify malloc_func.
has been hit, this makes it cover more cases.
Call the message function directly rather than fiddle with flag-saving
when we find an unknown character in our options.
The 'A' flag should not trigger on legal out of memory conditions.
has been executed. On return from the signal handler
the call will either be restarted or EINTR will be returned,
but it will not go back to its previous state. So, it is
sufficient to simply change the state to 'running' without
actually trying to wake up the thread.
a PTHREAD_RWLOCK_INITIALIZER to do for rwlocks what
a similarly named symbol does for statically initialized mutexes.
This symbol was dropped in The Open Group Base Specifications Issue 6
and does not exist in IEEE Std 1003.1, 2003, but it should still be
supported for backwards compatibility.
Pointy hat: mtm
o Instead of checking both the passed in pointer and its value
for NULL, only check the latter. Any caller that passes in
a NULL pointer is obviously wrong.
o Fix mutex priority protocols. Keep separate counts of priority
inheritance and protection mutexes to make things easier.
This will not have much affect since this is only the
userland side, and the rest involves kernel scheduling.
