well-known race condition, which elimination was the reason for the
function appearance in first place. If sigmask supplied as argument to
pselect() enables a signal, the signal might be delivered before thread
called select(2), causing lost wakeup. Reimplement pselect() in kernel,
making change of sigmask and sleep atomic.
Since signal shall be delivered to the usermode, but sigmask restored,
set TDP_OLDMASK and save old mask in td_oldsigmask. The TDP_OLDMASK
should be cleared by ast() in case signal was not gelivered during
syscall execution.
Reviewed by: davidxu
Tested by: pho
MFC after: 1 month
while in kernel mode, and later changing signal mask to block the
signal, was fixed for sigprocmask(2) and ptread_exit(3). The same race
exists for sigreturn(2), setcontext(2) and swapcontext(2) syscalls.
Use kern_sigprocmask() instead of direct manipulation of td_sigmask to
reschedule newly blocked signals, closing the race.
Reviewed by: davidxu
Tested by: pho
MFC after: 1 month
kern_sigprocmask() to properly notify other possible candidate threads
for signal delivery.
Since sigsuspend() shall only return to usermode after a signal was
delivered, do cursig/postsig loop immediately after waiting for
signal, repeating the wait if wakeup was spurious due to race with
other thread fetching signal from the process queue before us. Add
thread_suspend_check() call to allow the thread to be stopped or killed
while in loop.
Modify last argument of kern_sigprocmask() from boolean to flags,
allowing the function to be called with locked proc. Convertion of the
callers that supplied 1 to the old argument will be done in the next
commit, and due to SIGPROCMASK_OLD value equial to 1, code is formally
correct in between.
Reviewed by: davidxu
Tested by: pho
MFC after: 1 month
install new shadow object behind the map entry and copy the pages
from the underlying objects to it. This makes the mprotect(2) call to
actually perform the requested operation instead of silently do nothing
and return success, that causes SIGSEGV on later write access to the
mapping.
Reuse vm_fault_copy_entry() to do the copying, modifying it to behave
correctly when src_entry == dst_entry.
Reviewed by: alc
MFC after: 3 weeks
value is preceded by an option without value (for example -o
option1,option2=value). Options must be separated before searching for
'='. Also compare pnextopt explicitly against NULL.
PR: bin/134069
Approved by: trasz (mentor)
Pull upstream patch to fix ee(1) crash when received SIGWINCH:
modify _nc_wgetch() to check for a -1 in the fifo, e.g., after a
SIGWINCH, and discard that value, to avoid confusing application
(patch by Eygene Ryabinkin, FreeBSD bin/136223).
PR: 136223
Submitted by: Eygene Ryabinkin
Obtained from: ncurses-5.7-20091024 snapshot
MFC after: 3 days
modify _nc_wgetch() to check for a -1 in the fifo, e.g., after a
SIGWINCH, and discard that value, to avoid confusing application
(patch by Eygene Ryabinkin, FreeBSD bin/136223).
PR: 136223
Submitted by: Eygene Ryabinkin
Obtained from: ncurses-5.7-20091024 snapshot
MFC after: 3 days
both static and dynamic binaries compiled with or without stack
protection and should not depend on libssp_nonshared.a symbols.
Discussed with: kib
PR: bin/139052
no matter whether we are compiled as module or if our default of the
net.inet6.ip6.v6only sysctl already matches what we would set.
This avoids unnecessary complications with modules, VIMAGES, INET6 and
the sysctl value, especially considering that most users will use
linux compat as a module.
Discussed with: kib, rwatson (weeks ago)
Reviewed by: rwatson
MFC after: 6 weeks
This seems more useful and will likely be in the next POSIX standard.
Also document more precisely in the man page what set -u does (note that
$@, $* and $! are the only special parameters that can ever be unset, all
the others are always set, although they may be empty).
