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Date: Thu, 28 May 2020 21:31:45 +1000
redir: Retry open64 on EINTR
It is possible for open64 to block on named pipes, and therefore
it can be interrupted by signals and return EINTR. We should only
let it fail with EINTR if real signals are pending (i.e., it should
not fail on SIGCHLD if SIGCHLD has not been trapped).
This patch adds a new helper sh_open to retry the open64 call if
necessary. It also calls sh_error when appropriate.
Fixes: 3800d4934391 ("[JOBS] Fix dowait signal race")
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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| .. | ||
| 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.