children happens to exit while we are waiting for another child
to exit.
This can happen with code like
sh -c '
sleep 5 &
exec sh -c "sleep 10 & wait !$"
'
when the inner "sh" is waiting for the 10 second sleep to be
done, the 5 second sleep started earlier terminates. It is
a child of our process, as the inner shell is the same process
as the outer one, but not a known child (the inner shell has no
idea what the outer one did before it started).
This was observed in the wild by Martijn Dekker (where the outer
shell was bash but that's irrelevant).
XXX pullup -9
that we can always wait(2) for our children, and an ignored SIGCHLD
prevents that. Recent versions of bash can be convinced (due to a
bug most likely) to invoke us that way. Always return SIGCHLD to
SIG_DFL during init - we already prevent scripts from fiddling it.
All ash derived shells apparently have this problem (observed by
Martijn Dekker, and notified on the bash-bug list). Actual issue
diagnosed by Harald van Dijk (same list).
Mark the variable as volatile as it can be clobbered when a vfork occurs.
Error was reported when build.sh was run with MKLIBCSANITIZER=yes flag.
Reviewed by: kamil@
https://austingroupbugs.net/view.php?id=252
the Austin Group decided to require processing of "--" by the "."
and "exec" commands to solve a problem where some shells did
option processing for those commands (permitted) and others did
not (also permitted) which left no safe way to process a file
with a name beginning with "-".
This has finally made its way into what will be the next version of
the POSIX standard.
Since this shell did no option processing at all for those commands,
we need to update. This is that update.
The sole effect is that a "--" 'option' (to "." or "exec") is ignored.
This means that if you want to use "--" as the arg to one of those
commands, it needs to be given twice ". -- --". Apart from that there
should be no difference at all (though the "--" can now be used in other
situations, where we did not require it before, and still do not).
process with redirects. If we use vfork() and a redirect hangs
(eg: opening a fifo) which the parent was intended to unhang,
then the parent never gets to continue to unhang the child.
eg: mkfifo f; cat <f &; echo foo>f
The parent should not be waiting for a background process, even
just for its exec() to complete. if there are no redirects there
is (should be) nothing left that might be done that will cause any
noticeable delay, so vfork() should be safe in all other cases.
If a builtin command or function is the final command intended to be
executed, and is interrupted by a caught signal, the trap handler for
that signal was not executed - the shell simply exited (an exit trap
handler would still have been run - if there was one the handler
for the signal may have been invoked during the execution of the
exit trap handler, which, if it happened, is incorrect sequencing).
Now, if we're exiting, and there are pending signals, run their handlers
just before running the EXIT trap handler, if any.
There are almost certainly plenty more issues with traps that need
solving. Later,
XXX pullup -9
(-8 is too different in this area, and this problem suitably obscure,
that we won't bother) (the -7 sh is simply obsolete).
Having traps set should not enforce a fork for the next command,
whatever that command happens to be, only for commands which would
normally fork if they weren't the last command expected to be
executed (ie: builtins and functions shouldn't be exexuted in a
sub-shell merely because a trap is set).
As it was (for example)
trap 'whatever' SIGANY; wait $anypid
was guaranteed to fail the wait, as the subshell it was executed
in could not have any children.
XXX pullup -9
GCC_NO_FORMAT_TRUNCATION -Wno-format-truncation (GCC 7/8)
GCC_NO_STRINGOP_TRUNCATION -Wno-stringop-truncation (GCC 8)
GCC_NO_STRINGOP_OVERFLOW -Wno-stringop-overflow (GCC 8)
GCC_NO_CAST_FUNCTION_TYPE -Wno-cast-function-type (GCC 8)
use these to turn off warnings for most GCC-8 complaints. many
of these are false positives, most of the real bugs are already
commited, or are yet to come.
we plan to introduce versions of (some?) of these that use the
"-Wno-error=" form, which still displays the warnings but does
not make it an error, and all of the above will be re-considered
as either being "fix me" (warning still displayed) or "warning
is wrong."
a bracket expression in a pattern (ie: [[:THISNAME:]]). Previously
the code used strspn() to look for invalid chars in the name, and
then memcpy(), now we do the test and copy a character at a time.
This might, or might not, be faster, but it now correctly handles
\ quoted characters in the name (' and " quoting were already
dealt with, \ was too in an earlier version, but when the \ handling
changes were made, this piece of code broke).
Not exactly a vital bug fix (who writes [[:\alpha:]] or similar?)
but it should work correctly regardless of how obscure the usage is.
Problem noted by Harald van Dijk
XXX pullup -9
our implementation was fine, but the restrict marker is problematic
as gcc 8 is now more strict about checking for restrict issues.
this is the only actual consumer of swab(3) in our tree, though,
besides the test for it. oh well.
The new member is caled f_mntfromlabel and it is the dkw_wname
of the corresponding wedge. This is now used by df -W to display
the mountpoint name as NAME=
like the other tty ioctls that we only warn about). Do the main
ioctl (tcgetattr) first, since that provides a better error message
(ENOTTY instead of EINVAL).
The RSS related statistics are now back in the NetBSD kernel.
These values were disabled since day0 until today.
libkvm(3) users will still receive inappropriate values as RSS statistics
are updated upon sysctl(3) call.
Patch submitted by <Krzysztof Lasocki>
(inside a function or dot script) the exit status of that return
statement should become the exit status of the function (or dot
script) - we were ignoring it,
That is
fn() { while return 7; do return 9; done; return 11; }
should exit with status 7. It was exiting 0.
This is apparently another old ash bug that has been fixed
everywhere else in the past.
Issue pointed out by Martijn Dekker, (fairly obvious) fix borrowed
from FreeBSD, due for return sometime next century.
in the past, but managed to re-surface...
The expression "${0+\}}" should expand to "}" not "\}"
Almost all other shells handle it that way (incl FreeBSD & dash).
Issue pointed out by Martijn Dekker.
Add ATF sub-tests for the 4 old var expand operators (${var+word}
${var-word} ${var-word} and ${var?word} - including the forms
with the ':' included) and amongst those tests include test cases
for this issue, so if the bug tries to appear again, we can squash
it quicker. (The newer pattern matching operators are already
well tested as part of testing patterns.)
cleanups to the trap code. No longer silently ignore attempts to
do anything other than set SIGKILL or SIGSTOP to the default ('-")
state. Don't include those in trap or trap -p output (the former
because they cannot be other than in default state, so simply aren't
included, the latter because it is pointless) but do list them
when requested with trap -p SIG.
Interactive mode SIGINT traps are now run ASAP, rather than after
a command has been entered (so the sequence ^C \n is no longer needed
to generate one). Further, when trapped, in interactive mode,
while waiting for a user command, a SIGINT acts (aside from the
trap being run) just like when not trapped, aborts the command being
entered (rather than leaving it, which it did when libedit was in use)
prints a new prompt, and starts again (which is what should happen.)
Traps other than SIGINT (which has always been handled special in
interactive mode) are unaffected by this change, as are SIGINT traps
in non-interactive shells. Or that is the intent anyway.
Fix an in_dotrap ref count bug (was never being decremented... that
was inserted in a place never executed) (relatively harmless) and
add/improve some trap/signal related DEBUG mode tracing.
Update the description of the <& and >& redirection operators
(as indicated would happen in a message appended to the PR a week ago,
which received no opposition - no feedback).
Some rewriting of the section on redirects (including how the word
expansion of the "file" works) to make this simpler & more accurate.
Fix handling of "$@" (that is, double quoted dollar at), when it
appears in a string which will be subject to field splitting.
Eg:
${0+"$@" }
More common usages, like the simple "$@" or ${0+"$@"} end up
being entirely quoted, so no field splitting happens, and the
problem was avoided.
See the PR for more details.
This ends up making a bunch of old hack code (and some that was
relatively new) vanish - for now it is just #if 0'd or commented out.
Cleanups of that stuff will happen later.
That some of the worst $@ hacks are now gone does not mean that processing
of "$@" does not retain a very special place in every hackers heart.
RIP extreme ugliness - long live the merely ordinary ugly.
Added a new bin/sh ATF test case to verify that all this remains fixed.
finding a job that had previously terminated.
Now in that case JOBWANTED is set on all jobs (since any will do)
which then simplifies a later test which no longer needs to special
case "wait -n". Further, we always look to see if any wanted
job has already terminated, even if there are still running jobs
we can wait upon - if anything is already ready, that's where we start
harvesting (and finish, if -n is specified).
Stamp out "greengrocers' apostrophes" in various places (arguably there
are still more present, but style guides vary on that, and my energies
spent corralling wayward punctuation marks could be spent elsewhere).
