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df154028dc
Upstream commit:
Date: Sat, 19 May 2018 02:39:56 +0800
eval: Add vfork support
This patch adds basic vfork support for the case of a simple command.
Upstream commit:
Date: Tue, 12 Jan 2021 17:11:19 +1100
jobs: Always reset SIGINT/SIGQUIT handlers
On Fri, Jan 08, 2021 at 08:55:41PM +0000, Harald van Dijk wrote:
> On 18/05/2018 19:39, Herbert Xu wrote:
> > This patch adds basic vfork support for the case of a simple command.
> > ... @@ -879,17 +892,30 @@ forkchild(struct job *jp, union node *n, int
> > mode)
> > }
> > }
> > if (!oldlvl && iflag) {
> > - setsignal(SIGINT);
> > - setsignal(SIGQUIT);
> > + if (mode != FORK_BG) {
> > + setsignal(SIGINT);
> > + setsignal(SIGQUIT);
> > + }
> > setsignal(SIGTERM);
> > }
> > +
> > + if (lvforked)
> > + return;
> > +
> > for (jp = curjob; jp; jp = jp->prev_job)
> > freejob(jp);
> > }
>
> This leaves SIGQUIT ignored in background jobs in interactive shells.
>
> ENV= dash -ic 'dash -c "kill -QUIT \$\$; echo huh" & wait'
>
> As of dash 0.5.11, this prints "huh". Before, the subprocess process killed
> itself before it could print anything. Other shells do not leave SIGQUIT
> ignored.
>
> (In a few other shells, this also prints "huh", but in those other shells,
> that is because the inner shell chooses to ignore SIGQUIT, not because the
> outer shell leaves it ignored.)
Thanks for catching this. I have no idea how that got in there
and it makes no sense whatsoever. This patch removes the if
conditional.
Fixes: e94a964e7dd0 ("eval: Add vfork support")
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
|
||
|---|---|---|
| .. | ||
| ash_test | ||
| hush_test | ||
| ash.c | ||
| ash_doc.txt | ||
| ash_ptr_hack.c | ||
| ash_remove_unnecessary_code_in_backquote_expansion.patch | ||
| brace.txt | ||
| Config.src | ||
| cttyhack.c | ||
| hush.c | ||
| hush_doc.txt | ||
| hush_leaktool.sh | ||
| Kbuild.src | ||
| match.c | ||
| match.h | ||
| math.c | ||
| math.h | ||
| random.c | ||
| random.h | ||
| README | ||
| README.job | ||
| shell_common.c | ||
| shell_common.h | ||
http://www.opengroup.org/onlinepubs/9699919799/ Open Group Base Specifications Issue 7 http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap01.html Shell & Utilities It says that any of the standard utilities may be implemented as a regular shell built-in. It gives a list of utilities which are usually implemented that way (and some of them can only be implemented as built-ins, like "alias"): alias bg cd command false fc fg getopts jobs kill newgrp pwd read true umask unalias wait http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html Shell Command Language It says that shell must implement special built-ins. Special built-ins differ from regular ones by the fact that variable assignments done on special builtin are *PRESERVED*. That is, VAR=VAL special_builtin; echo $VAR should print VAL. (Another distinction is that an error in special built-in should abort the shell, but this is not such a critical difference, and moreover, at least bash's "set" does not follow this rule, which is even codified in autoconf configure logic now...) List of special builtins: . file : [argument...] break [n] continue [n] eval [argument...] exec [command [argument...]] exit [n] export name[=word]... export -p readonly name[=word]... readonly -p return [n] set [-abCefhmnuvx] [-o option] [argument...] set [+abCefhmnuvx] [+o option] [argument...] set -- [argument...] set -o set +o shift [n] times trap n [condition...] trap [action condition...] unset [-fv] name... In practice, no one uses this obscure feature - none of these builtins gives any special reasons to play such dirty tricks. However. This section also says that *function invocation* should act similar to special built-in. That is, variable assignments done on function invocation should be preserved after function invocation. This is significant: it is not unthinkable to want to run a function with some variables set to special values. But because of the above, it does not work: variable will "leak" out of the function.