src/cmd/ksh93/{sh/path.c,include/shell.h}:
- The sh.defpathlist variable is never set once, which makes every
use of this variable unnecessary (as it's always null). This
commit removes sh.defpathlist while also fixing a possible memory
leak (there was another location where defpathinit() was invoked
without saving the returned pointer, causing a memory leak).
The -f/--noglob shell option is documented simply as: "Disables
pathname expansion." But after 'set -f' on an interactive shell,
command completion and file name completion also stop working. This
is because they internally use the pathname expansion mechanism.
But it is not documented anywhere that 'set -f' disables
completion; it's just a side effect of an implementation detail.
Though ksh has always acted like this, I think it should change
because it's not useful or expected behaviour. Other shells like
bash, yash or zsh don't act like this.
src/cmd/ksh93/sh/expand.c,
src/cmd/ksh93/sh/macro.c:
- Allow the SH_COMPLETE (command completion) or SH_FCOMPLETE
(file name completion) state bit to override SH_NOGLOB in
path_generate() and in sh_macexpand().
The >&- redirection subshell leak fixed in 6304dfce still existed
for shared-state ${ command substitutions; } a.k.a. subshares,
which cannot be forked.
I previously noticed that sh_subsavefd() saves the FD state even
for subshares. That seems logically incorrect as subshares share
their state with the invoking environment by definition.
src/cmd/ksh93/sh/subshell.c: sh_subsavefd():
- Sure enough, adding a check for !sh.subshare fixes the bug.
- Use the sh.subshell counter and not the subshell data pointer to
check for a virtual subshell. If the shell is reinitialised in a
fork to execute a new script (see 0af81992), any parent virtual
subshell data is currently not cleared as it is locally scoped to
subshell.c, so that check would be incorrect then.
src/cmd/ksh93/sh/io.c: sh_redirect:
- Remove now-redundant (and actually incorrectly placed) check for
sh.subshare added in fb755163.
Reproducer:
exec 9>&1
( { exec 9>&1; } 9>&- )
echo "test" >&9 # => 9: cannot open [Bad file descriptor]
The 9>&- incorrectly persists beyond the { } block that it
was attached to *and* beyond the ( ) subshell. This is yet another
bug with non-forking subshells; forking it with something like
'ulimit -t unlimited' works around the bug.
In over a year we have not been able to find a real fix, but I came
up with a workaround that forks a virtual subshell whenever it
executes a code block with a >&- or <&- redirection attached. That
use case is obscure enough that it should not cause any performance
regression except in very rare corner cases.
src/cmd/ksh93/sh/xec.c: sh_exec(): TSETIO:
- This is where redirections attached to code blocks are handled.
Check for a >&- or <&- redirection using bit flaggery from
shnodes.h and fork if we're executing such in a virtual subshell.
Resolves: https://github.com/ksh93/ksh/issues/161
Thanks to @ko1nksm for the bug report.
Notable changes:
- Remove SHOPT_PFSH compile-time option and associated code.
This was meant to work with Solaris rights profiles, see:
https://docs.oracle.com/cd/E23824_01/html/821-1461/profiles-1.html#REFMAN1profiles-1
But it has been obsolete for years as Solaris stopped using
it in its shipped ksh several OS versions ago, preferring a
library-based wrapper around ksh and other shells.
Nonetheless I experimented with the option on Solaris 11.4.
Result: no external command will run; output of unitialised
memory in error message. So it's already fallen victim to bit
rot. There's nothing interesting here, so just get rid.
- Remove SHOPT_TYPEDEF compile-time option (but keep the code!).
Turning it off caused the build to fail. It may be possible to
fix it, but the type definition code is integral to ksh now (e.g.
'enum' depends on much of it) so it makes no sense to disable it.
This was removed in the ksh 93v- beta version as well.
- Remove nv_close() calls and remove nv_close() documentation from
the nval.3 man page. This function is a dummy, present without
any changes since the beginning of the ast-open-archive repo in
1995. The comment was: "Currently this is a dummy, but someday
will be needed for reference counting". 27 or more years later,
it's time to admit it's never going to happen. (And of course,
nv_close() calls were not being used with anything resembling
consistency.)
- Add a null nv_close() macro to nval.h for compatibility with
third party code that follows the old documentation.
- Add a few missing regression tests.
This small commit replaces one instance of memcmp with strncmp to
fix one of the buffer overflows that causes 'typeset -p .sh.type'
to crash (see also https://github.com/ksh93/ksh/issues/456).
This commit backports all of the relevant .sh.match bugfixes from
ksh93v-. Most of the .sh.match rewrite is from versions 2012-08-24
and 2012-10-04, with patches from later releases of 93v- and
ksh2020 also applied. Note that there are still some remaining bugs
in .sh.match, although now the total count of .sh.match bugs should
be less that before.
These are the relevant changes in the ksh93v- changelog that were
backported:
12-08-07 .sh.match no longer gets set for patterns in PS4 during
set -x.
12-08-10 Rewrote .sh.match expansions fixing several bugs and
improving performance.
12-08-22 .sh.match now handles subpatterns that had no matches with
${var//pattern} correctly.
12-08-21 A bug in setting .sh.match after ${var//pattern/string}
when string is empty has been fixed.
12-08-21 A bug in setting .sh.match after [[ string == pattern ]]
has been fixed.
12-08-31 A bug that could cause a core dump after
typeset -m var=.sh.match has been fixed.
12-09-10 Fixed a bug in typeset -m the .sh.match is being renamed.
12-09-07 Fixed a bug in .sh.match code that coud cause the shell
to quitely
13-02-21 The 12-01-16 bug fix prevented .sh.match from being used
in the replacement string. The previous code was restored
and a different fix which prevented .sh.match from being
computed for nested replacement has been used instead.
13-05-28 Fixed two bug for typeset -c and typeset -m for variable
.sh.match.
Changes:
- The SHOPT_2DMATCH option has been removed. This was already the
default behavior previously, and now it's documented in the man
page.
- init.c: Backported the sh_setmatch() rewrite from 93v- 2012-08-24
and 2012-10-04.
- Backported the libast 93v- strngrpmatch() function, as the
.sh.match rewrite requires this API.
- Backported the sh_match regression tests from ksh93v-, with many
other sh_match tests backported from ksh2020. Much of the sh_match
script is based on code from Roland Mainz:
https://marc.info/?l=ast-developers&m=134606574109162&w=2https://marc.info/?l=ast-developers&m=134490505607093
- tests/{substring,treemove}.sh: Backported other relevant .sh.match
fixes, with tests added to the substring and treemove test scripts.
- tests/types.sh: One of the (now reverted) memory leak bugfixes
introduced a CI test failure in this script, so for that test the
error message has been improved.
- string/strmatch.c: The original ksh93v- code for the strngrpmatch()
changes introduced a crash that could occur because strlen would
be used on a null pointer. This has been fixed by avoiding strlen
if the string is null.
One nice side effect of these changes is a considerable performance
improvement in the shbench[1] gsub benchmark (results from 20
iterations with CCFLAGS=-Os):
--------------------------------------------------
name /tmp/ksh-current /tmp/ksh-matchfixes
--------------------------------------------------
gsub.ksh 0.883 [0.822-0.959] 0.457 [0.442-0.505]
--------------------------------------------------
Despite all of the many fixes and improvements in the backported
93v- .sh.match code, there are a few remaining bugs:
- .sh.match is printed with a default [0] subscript (see also
https://github.com/ksh93/ksh/issues/308#issuecomment-1025016088):
$ arch/*/bin/ksh -c 'echo ${!.sh.match}'
.sh.match[0]
This bug appears to have been introduced by the changes from
ksh93v- 2012-08-24.
- The wrong variable name is given for 'parameter not set' errors
(from https://marc.info/?l=ast-developers&m=134489094602596):
$ arch/*/bin/ksh -u
$ x=1234
$ true "${x//~(X)([012])|([345])/}"
$ compound co
$ typeset -m co.array=.sh.match
$ printf "%q\n" "${co.array[2][0]}"
arch/linux.i386-64/bin/ksh: co.array[2][(null)]: parameter not set
- .sh.match leaks out of subshells. Further information and a
reproducer can be found here:
https://marc.info/?l=ast-developers&m=136292897330187
[1]: https://github.com/ksh-community/shbench
When executing a script without a hashbang path like #!/bin/ksh,
ksh forks itself, longjmps back to sh_main(), and then (among other
things) calling sh_reinit() which is the function that tries to
reinitialise as much of the shell as it can. This is its way of
ensuring the child script is run in ksh and not some other shell.
However, this appraoch is incredibly buggy. Among other things,
changes in built-in commands and custom type definitions survived
the reinitialisation, "exporting" variables didn't work properly,
and the hash table and ${.sh.stats} weren't reset. As a result,
depending on what the invoking script did, the invoked script could
easily fail or malfunction.
It is not actually possible to reinitialise the shell correctly,
because some of the shell state is in locally scoped static
variables that cannot simply be reinitialised. There are probably
huge memory leaks with this approach as well. At some point, all
this is going to need a total redesign. Clearly, the only reliable
way involves execve(2) and a start from scratch.
For now though, this seems to fix the known bugs at least. I'm sure
there are more to be discovered.
This commit makes another change: instead of the -h/trackall option
(which has been a no-op for decades), the posix option is now
inherited by the child script. Since there is no hashbang path from
which to decide whether the shell should run in POSIX mode nor not,
the best guess is probably the invoking script's setting.
src/cmd/ksh93/sh/init.c: sh_reinit():
- Keep the SH_INIT state on during the entire procedure.
- Delete remaining non-exported, non-default variables.
- Remove attributes from exported variables. In POSIX mode, remove
all attributes; otherwise, only remove readonly.
- Unset discipline function pointers for variables.
- Delete all custom types.
- Delete all functions and built-ins, then reinitialise the built-ins
table from scatch.
- Free the alias values before clearing the alias table.
- Same with hash table entries (tracked aliases).
- Reset statistics.
- Inherit SH_POSIX instead of SH_TRACKALL.
- Call user init function last, not somewhere in the middle.
src/cmd/ksh93/sh/name.c: sh_envnolocal():
- Be sure to preserve the export attribute of kept variables.
Resolves: https://github.com/ksh93/ksh/issues/350
This bugfix was backported from ksh93v- 2012-10-04. The bug fixed
by this change is one that causes 'typeset -p' to omit the -C flag
when listing compound arrays belonging to a type:
$ typeset -T Foo_t=(compound -a bar)
$ Foo_t baz
$ typeset -p baz.bar
typeset -a baz.bar='' # This should be 'typeset -C -a'
src/cmd/ksh93/sh/nvtype.c:
- Backport change from 93v- 2012-10-04 that sets the array nvalue to
a pointer named Null (which is "") in nv_mktype(), then to Empty
in fixnode().
- Change the Null name from the 93v- code to AltEmpty to avoid
misleading code readers into thinking that it's a null pointer.
src/cmd/ksh93/tests/types.sh:
- Backport the relevant 93v- changes to the types regression tests.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
In ksh93v- 2012-10-04 the following bugfix is noted in the changelog
(this fix was most likely part of ksh93v- 2012-09-27, although that
version is not archived anywhere):
12-09-21 A bug in which the output of a two dimensional sparse
indexed array would cause the second subscript be treated
as an associative array when read back in has been fixed.
Elements that are sparse indexed arrays now are prefixed
type "typeset -a".
Below is a before and after of this change:
# Before
$ typeset -a foo[1][2]=bar
$ typeset -p foo
typeset -a foo=([1]=([2]=bar) )
# After
$ typeset -a foo[1][2]=bar
$ typeset -p foo
typeset -a foo=(typeset -a [1]=([2]=bar) )
src/cmd/ksh93/sh/*.c:
- Backport changes from ksh93v- to print 'typeset -a' before sparse
indexed arrays and properly handle 'typeset -a' in reinput
commands from 'typeset -p'.
src/cmd/ksh93/tests:
- Add two regression tests to arrays.sh for this change.
- Update the existing regression tests for compatibility with the
new printed typeset output.
Special builtins are undeleteable for a reason. But 'enum' and
'typeset -T' allow overriding them, causing an inconsistent state.
@JohnoKing writes:
| The behavior is rather buggy, as it appears to successfully
| override normal builtins but fails to delete the special
| builtins, leading to scenarios where both the original builtin
| and type are run:
|
| $ typeset -T eval=(typeset BAD; typeset TYPE) # This should have failed
| $ eval foo=BAD
| /usr/bin/ksh: eval: line 1: foo: not found
| $ enum trap=(BAD TYPE) # This also should have failed
| $ trap foo=BAD
| /usr/bin/ksh: trap: condition(s) required
| $ enum umask=(BAD TYPE)
| $ umask foo=BAD
| $ echo $foo
| BAD
|
| # Examples of general bugginess
| $ trap bar=TYPE
| /usr/bin/ksh: trap: condition(s) required
| $ echo $bar
| TYPE
| $ eval var=TYPE
| /usr/bin/ksh: eval: line 1: var: not found
| $ echo $var
| TYPE
This commit fixes the following:
The 'enum' and 'typeset -T' commands are no longer allowed to
override and replace special built-in commands, except for type
definition commands previously created by these commands; these
are already (dis)allowed elsewhere.
A command like 'typeset -T foo_t' without any assignments no longer
creates an incompletely defined 'foo_t' built-in comamnd. Instead,
it is now silently ignored for backwards compatibility. This did
have a regression test checking for it, but I'm changing it because
that's just not a valid use case. An incomplete type definition
command does nothing useful and only crashes the shell when run.
src/cmd/ksh93/bltins/enum.c: b_enum():
- Do not allow overriding non-type special built-ins.
src/cmd/ksh93/sh/name.c: nv_setlist():
- Do not allow 'typeset -T' to override non-type special built-ins.
To avoid an inconsistent state, this must be checked for while
processing the assignments list before typeset is really invoked.
src/cmd/ksh93/bltins_typeset.c: b_typeset():
- Only create a type command if sh.envlist is set, i.e., if some
shell assignment(s) were passed to the 'typeset -T' command.
Progresses: https://github.com/ksh93/ksh/issues/350
$ unset foo
$ echo ${foo[42]=bar}
(empty line)
Instead of the empty line, 'bar' was expected. As foo[42] was
unset, the conditional assignment should have worked.
$ unset foo
$ : ${foo[42]?error: unset}
(no output)
The expansion should have thrown an error with the given message.
This bug was introduced in ksh 93t 2008-10-01. Thanks to @JohnoKing
for finding the breaking change.
Analysis: The problem was experimenally determined to be in in the
following lines of nv_putsub(). If the array member is unset (i.e.
null), the value is set to the empty string instead:
src/cmd/ksh93/sh/array.c
1250: else
1251: ap->val[size].cp = Empty;
It makes some sense: if there is a value (even an empty one), the
variable is set and these expansions should behave accordingly.
Sure enough, deleting these lines fixes the bug, but at the expense
of introducing a lot of other array-related regressions. So we need
a way to special-case the affected expansions.
Where to do this? If we replace line 1251 with an abort(3) call, we
get this stack trace:
0 libsystem_kernel.dylib __pthread_kill + 10
1 libsystem_pthread.dylib pthread_kill + 284
2 libsystem_c.dylib abort + 127
3 ksh nv_putsub + 1411 (array.c:1255)
4 ksh nv_endsubscript + 940 (array.c:1547)
5 ksh nv_create + 4732 (name.c:1066)
6 ksh nv_open + 1951 (name.c:1425)
7 ksh varsub + 4934 (macro.c:1322)
[rest omitted]
The special-casing needs to be done on line 1250 of array.c, but
flagged in varsub() which processes these expansions. So, varsub()
calls nv_open() calls nv_create() calls nv_endsubscript() calls
nv_putsub(). That's a fairly deep call stack, so passing an extra
flag argument does not seem doable. I did try an approach using a
couple of new bit flags passed via these functions' flags and mode
parameters, but the way this code base uses bit flags is so
intricate, it does not seem to be possible to add or change
anything without unwanted side effects in all sorts of places.
So the only fix I can think of adds yet another global flag
variable for a very special case. It's ugly, but it works.
An elegant fix would probably involve a fairly comprehensive
redesign, which is simply not going to happen.
src/cmd/ksh93/include/shell.h:
- Add global sh.cond_expan flag.
src/cmd/ksh93/sh/array.c: nv_putsub():
- Do not set value to empty string if sh.cond_expan is set.
src/cmd/ksh93/sh/macro.c: varsub():
- Set sh.cond_expan flag while calling nv_open() for one of the
affected expansions.
- Minor refactoring for legibility and to make the fix fit better.
- SSOT: Instead of repeating string "REPLY", use the node's nvname.
- Do not pointlessly add an extra 0 byte when saving id for error
message; sfstruse() already adds this.
Thanks to @oguz-ismail for the bug report.
Resolves: https://github.com/ksh93/ksh/issues/383
Variables with a dot in their name, such as those declared in
namespace { ... } blocks, are usually stored in a separate tree
with their actual names not containing any dots. But under some
circumstances, including at least direct assignment of a
non-preexisting dot variable, dot variables are stored in the main
sh.var_tree with names actually containing dots. With allexport
active, those could end up exported to the environment. This bug
was also present in previous release versions of ksh.
src/cmd/ksh93/sh/name.c: pushnam():
- Check for a dot in the name before pushing a variable to export.
This fix was backported from ksh 93v- 2012-10-04.
src/cmd/ksh93/sh/nvtree.c: nv_outnode():
- If the array is supposed to be empty, do not continue. This
avoids outputting a nonexistent [0]= element for empty arrays.
Resolves: https://github.com/ksh93/ksh/issues/420
Co-authored-by: Martijn Dekker <martijn@inlv.org>
This commit adds a fix for the trap command, backported from a fork
of ksh2020: 2033375f
src/cmd/ksh93/sh/jobs.c: job_chldtrap():
- Fixed a use after free bug in the for loop. The string pointed to
by sh.st.trapcom[SIGCHLD] may be freed from memory after
sh_trap(), so it must be reobtained each time sh_trap() is called
from within the for loop.
All variables that are assigned a value should be exported while
the allexport shell option is enabled. This works in most cases,
but variables assigned to with ${var:=foo} or $((var=123)) aren't
exported while allexport is on.
src/cmd/ksh93/sh/name.c:
- nv_putval(): This is the central assignment function; all forms
of variable assignment end up here. So this is the best place
to check for SH_ALLEXPORT and turn on the export attribute.
- nv_setlist(): Remove allexport handling, now redundant.
src/cmd/ksh93/bltins/read.c: sh_readline():
- Remove allexport handling, now redundant.
src/cmd/ksh93/sh/main.c: sh_main():
- nv_putval() is used to initialize PS4 and IFS using nv_putval();
this is after an -a/--allexport specified on the ksh command
line has been processed, so temporarily turn that off.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
This commit implements support for the glibc 2.35
posix_spawn_file_actions_addtcsetpgrp_np(3) extension[2][3],
updating spawnveg(3) to use the new function for setting the
terminal group. This was done with the intention of improving
performance in interactive shells without reintroducing previous
race conditions[4][5].
[1]: https://sourceware.org/pipermail/libc-alpha/2022-February/136040.html
[2]: https://sourceware.org/git/?p=glibc.git;a=commit;h=342cc934
[3]: https://sourceware.org/git/?p=glibc.git;a=commit;h=6289d28d
[4]: https://github.com/ksh93/ksh/issues/79
[5]: https://www.mail-archive.com/ast-developers@research.att.com/msg00717.html
src/cmd/ksh93/sh/path.c:
- Tell spawnveg(3) to set the terminal process group when launching
a child process in an interactive shell.
src/cmd/ksh93/sh/xec.c:
- If posix_spawn_file_actions_addtcsetpgrp_np(3) is available,
allow use of spawnveg(3) (via sh_ntfork()) even with job control
active.
- sh_ntfork(): Reimplement most of the SIGTSTP handling code
removed in commit 66c37202.
src/lib/libast/comp/spawnveg.c,
src/lib/libast/misc/procopen.c,
src/lib/libast/features/sys:
- Add support for posix_spawn_file_actions_addtcsetpgrp_np(3).
- Allow spawnveg to set the terminal process group when pgid == 0.
This was necessary to avoid race conditions when using the new
function.
src/lib/libast/features/lib:
- Detect posix_spawn_file_actions_addtcsetpgrp_np(3).
- Do not detect an OS spawnveg(3). With the API changes to spawnveg
in this pull request ksh probably can't use the OS's spawnveg
function anymore. (That's assuming anything else even provides a
spawnveg function to begin with, which is unlikely.)
src/lib/libast/features/api,
src/cmd/ksh93/include/defs.h:
- Bump libast version (20220101 => 20220201) due to the spawnveg(3)
API change.
src/lib/libast/man/spawnveg.3:
- Document the changes to spawnveg(3) in the corresponding man
page. Currently, it will only use the new tcfd argument if
posix_spawn_file_actions_addtcsetpgrp_np(3) is supported. This
could also be implemented for the fork(2) fallback, but for now
I've avoided changing that since actually using it in the fork
code would likely require a lot of hackery to avoid attempting
tcsetpgrp with vfork (the behavior of tcsetpgrp after vfork is
not portable) and would only benefit systems that don't have
posix_spawn and vfork (I can't recall any off the top of my head
that would fall under that category).
- Updated the man page to account for spawnveg's change in
behavior.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
If the VISUAL or EDITOR environment variable is not set to a value
matching *[Vv][Ii]* or *macs* at initialisation time, then ksh does
not turn on any line editor.
This is user-hostile. New users on Unix-like systems typically have
a simple editor like nano preconfigured as their default, or may
not have the VISUAL or EDITOR variable set at all. So if they try
ksh, they find themselves without basic functionality such as arrow
keys and probably go straight back to bash.
The emacs line editor is by far the most widely used, especially
among new users, so ksh should default to that. Most other shells
already do this.
src/cmd/ksh93/sh/main.c: sh_main():
- On an interactive shell, if on editor was turned on based on
$VISUAL or $EDITOR, turn on emacs before reading input.
Reproducer:
$ ksh -c 'bash -c '\''kill -s INT $$'\''; echo "$?, continuing"'
Expected result: output "258, continuing"; exit status 0.
Actual result: no output; exit status 258. The child process sent
SIGINT only to itself and not to the process group, so the parent
script was wrongly interrupted.
Every shell except ksh93 produces the expected result. ksh93 also
gave the expected result before version 2008-01-31 93s+, which
introduced the code below.
Analysis: The problem is in these lines of code in xec.c,
sh_exec(), TFORK case, parent branch of fork:
1649: if(!sh_isstate(SH_MONITOR))
1650: {
1651: if(!(sh.sigflag[SIGINT]&(SH_SIGFAULT|SH_SIGOFF)))
1652: sh_sigtrap(SIGINT);
1653: sh.trapnote |= SH_SIGIGNORE;
1654: }
[...pipe and I/O handling, wait for command to finish...]
1667: if(!sh_isstate(SH_MONITOR))
1668: {
1669: sh.trapnote &= ~SH_SIGIGNORE;
1700: if(sh.exitval == (SH_EXITSIG|SIGINT))
1701: kill(sh.current_pid,SIGINT);
1702: }
When a user presses Ctrl+C, SIGINT is sent to the entire process
group. If job control is fully off (i.e., !sh_isstate(SH_MONITOR)),
then the process group includes the parent script. Therefore, in a
script such as
$ ksh -c 'bash -c '\''read x'\''; echo "$?, continuing"'
when the user presses Ctrl+C while bash waits for 'read x' input,
the parent ksh script should be interrupted as well.
Now, the code above ignores SIGINT while bash is running. (This is
done using special-casing in sh_fault() to handle that SH_SIGIGNORE
flag for SIGINT.) So, when Ctrl+C interrupts the process group, the
parent script is not getting interrupted as it should.
To compensate for that, the code then detects, using sh.exitval
(the child process' exit status), whether the child process was
killed by SIGINT. If so, it simply assumes that the signal was
meant for the process group including the parent script, so it
reissues SIGINT to itself after unignoring it.
But, as we can see from the broken reproducer above, that
assumption is not valid. Scripts are perfectly free to send SIGINT
to themselves only, and that must work as expected.
src/cmd/ksh93/sh/xec.c: sh_exec(): TFORK: parent branch:
- Instead of ignoring SIGINT, sigblock() it, which delays handling
the signal until sigrelease(). (Note that these are macros
defined in src/cmd/ksh93/features/sigfeatures according to OS
capabilities.)
- This makes reissuing SIGINT redundant, so delete that, which
fixes the bug.
src/cmd/ksh93/sh/fault.c:
- Nothing now sets the SH_SIGIGNORE flag in sh.trapnote, so remove
special-casing added in 2008-01-31 93s+.
This commit applies various accumulated bugfixes:
- Applied some fixes for compiler warnings based off of the
following pull requests (with whitespace changes excluded to
avoid inflating the size of the diff):
https://github.com/att/ast/pull/281https://github.com/att/ast/pull/283https://github.com/att/ast/pull/303https://github.com/att/ast/pull/304
- clone_type(): Two separate variables in this function share the
same name. A bugfix from ksh93v- 2013-05-24 was backported to
avoid conflict issues.
- Backported a minor error message improvement from ksh2020 for
when the user attempts to run too many coprocesses.
- Backported a ksh2020 bugfix for a file descriptor leak:
58bc8b56
- Backported ksh2020 bugfixes for unused variable and pointless
assignment lint warnings:
47650fe0df209c0d5e417b00
- Applied a few minor improvements to libast from graphviz:
e7c03541969a7cde
- dtmemory(): Mark unused parameters with NOT_USED(). Based on:
6ac3ad99
- Applied a few documentation/comment tweaks for the NEWS file,
printf -v and spawnveg.
- Added a missing regression test for using the rm builtin's -f
option without additional arguments (this was fixed in
ksh93u+ 2012-02-14).
Currently, running ksh under ASan without the ASAN_OPTIONS variable
set to 'detect_leaks=0' usually ends with ASan complaining about a
memory leak in defpathinit() (this leak doesn't grow in a loop, so
no regression test was added to leaks.sh). Reproducer:
$ ENV=/dev/null arch/*/bin/ksh
$ cp -?
cp: invalid option -- '?'
Try 'cp --help' for more information.
$ exit
=================================================================
==225132==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 85 byte(s) in 1 object(s) allocated from:
#0 0x7f6dab42d459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x5647b77fe144 in sh_calloc /home/johno/GitRepos/KornShell/ksh/src/cmd/ksh93/sh/init.c:265
#2 0x5647b788fea9 in path_addcomp /home/johno/GitRepos/KornShell/ksh/src/cmd/ksh93/sh/path.c:1567
#3 0x5647b78911ed in path_addpath /home/johno/GitRepos/KornShell/ksh/src/cmd/ksh93/sh/path.c:1705
#4 0x5647b7888e82 in defpathinit /home/johno/GitRepos/KornShell/ksh/src/cmd/ksh93/sh/path.c:442
#5 0x5647b78869f3 in ondefpath /home/johno/GitRepos/KornShell/ksh/src/cmd/ksh93/sh/path.c:67
--- cut ---
SUMMARY: AddressSanitizer: 174 byte(s) leaked in 2 allocation(s).
Analysis: The previous code was leaking memory because
defpathinit() returns a pointer from path_addpath(), which has
memory allocated to it in path_addcomp(). This is the code ASan
traced as having allocated memory:
442: return(path_addpath((Pathcomp_t*)0,(defpath),PATH_PATH));
In path_addpath():
1705: first = path_addcomp(first,old,cp,type);
[...]
1729: return(first);
In path_addcomp():
1567: pp = sh_newof((Pathcomp_t*)0,Pathcomp_t,1,len+1);
The ondefpath() function doesn't save a reference to the pointer
returned by defpathinit(), which causes the memory leak:
66: if(!defpath)
67: defpathinit();
The changes in this commit avoid this problem by setting the
defpath variable without also calling path_addpath().
src/cmd/ksh93/sh/path.c:
- Move the code for allocating defpath from defpathinit() into its
own dedicated function called std_path(). This function is called
by defpathinit() and ondefpath() to obtain the current string
stored in the defpath variable. This bugfix is adapted from a
fork of ksh2020: db5c83a6
The array_grow() function calculates the size by multiplying with
sizeof(union Value*), where sizeof(union Value) was clearly meant.
In practice, these are the same size on most (or maybe even all)
systems, as no current member of union Value is larger than a
pointer -- see name.h. But it's still wrong.
Notable changes:
src/cmd/ksh93/*.c:
- Get rid of all the dtuserdata(FOO,&sh,1) calls backported in
cc492752. These set pointers to sh in Cdt objects. As of
b590a9f1, the code does not use any pointers to sh, so these are
superfluous.
src/cmd/ksh93/data/builtins.c,
src/cmd/ksh93/sh.1:
- As of ksh 93l 2001-06-01, the -h/trackall option has no effect at
all, so trim its documentation.
src/lib/libast/man/stk.3,
src/lib/libast/man/stak.3:
- Correct the documentation on what the ST(A)K_SMALL option bit
actually does based on a reading of the code.
- Document the STK_NULL option bit.
README.md,
src/cmd/ksh93/README:
- Add a note that -fdiagnostics-color=always will break the build.
Ref.: https://github.com/ksh93/ksh/issues/379
src/lib/libast/Mamfile:
- Remove a 'rm -f astmath' command -- a file that is never created.
But on Cygwin this removes astmath.exe, which *is* used. As a
result, executing it failed on Cygwin, so the system incorrectly
detected that Cygwin needs -lm for math functions.
This fixes yet another whopper of a bug in job control. And it's
been in every version of ksh93 back to 1995, the beginning of
ast-open-archive. <sigh>
This is also bug number 23 that is fixed by simply removing code.
Reproducer:
1. Run vi, or another suspendable program, from a dot script or
POSIX function (ksh handles them the same way). So either:
$ echo vi >v
$ . ./v
or:
$ v() { vi; }
$ v
2. Suspend vi by typing Ctrl+Z.
3. Not one but two jobs are registered:
$ jobs -l
[2] + 85513 Stopped . ./v
[1] - 85512 Stopped . ./v
4. 'fg' does not work on either of them, just printing the job
command name but not resuming the editor. The second job
disappears from the table after 'fg'.
$ fg %2
. ./v
$ fg %2
ksh: fg: no such job
$ fg %1
. ./v
$ fg %1
. ./v
Either way, you're stuck with an unresumable vi that you have to
'kill -9' manually.
src/cmd/ksh93/sh/xec.c: sh_exec(): TFORK:
- Do *not* turn off the SH_MONITOR state flag (which tells ksh to
keep track of jobs) when running an external command from a
profile script or dot script/POSIX function. It's obvious that
this results in an inconsistent job control state as ksh will not
update it when the external command is suspended. The purpose of
this nonsense is surely lost to history as it's been there since
1995 or before. My testing says that removing it doesn't break
anything. If that turns out to be wrong, then the breakage will
have to be fixed in a correct way instead.
Attempting to use array subscript expansion with variables that
aren't set currently causes a spurious syntax error (in ksh93u+ and
older commits the reproducer crashes):
$ ksh -c 'echo ${foo[${bar}..${baz}]}' # Shouldn't print anything
ksh: : arithmetic syntax error
src/cmd/ksh93/sh/macro.c:
- Backport a parser bugfix from ksh93v- 2012-08-24 that avoids
setting mp->dotdot until the copyto() function's loop is
finished.
src/cmd/ksh93/tests/arrays.sh:
- Add regression tests for this bug.
On Cygwin, ksh does not execute scripts without a #! path in a fork
of the ksh process as it does on other systems. Reproducer (run
from ksh):
$ cat test.sh
echo "${BASH_VERSION:-not bash}"
echo "${.sh.version}"
$ chmod +x test.sh
$ ./test.sh
4.4.12(3)-release
./test.sh: line 2: ${.sh.version}: bad substitution
The script was executed in bash instead of ksh.
After this fix, the output on Cygwin is like ksh on other systems:
not bash
Version AJM 93u+m/1.1.0-alpha+dev 2022-01-26
This also fixes a number of regression test failures, as quite a
few tests create and execute temp scripts without a hashbang path.
Analysis: On Cygwin, execve(2) happily executes shell scripts
without a #! path with /bin/sh (which is bash --posix). However,
ksh relies on execve(2) executing binaries or #! only, as it uses
an ENOEXEC failure to decide whether to fork and execute a #!-less
shell script with a reinitialized copy of itself via exscript().
src/cmd/ksh93/sh/path.c: path_spawn():
- Look at the magic first two bytes of the file; if it is "MZ"
(Mark Zbikowski, originator of the .exe format) or "#!", continue
as normal, otherwise simulate an ENOEXEC failure from execve(2)
which will cause ksh to fall back on #!-less script execution.
Notable changes:
src/cmd/ksh93/include/fault.h:
- Get rid of the superflous sh pointer argument in the
sh_pushcontext() and sh_popcontext() macros. (re: 2d3ec8b6)
src/cmd/ksh93/tests/io.sh:
- Tweak a process substitution test to allow up to a second for
unused process substitution processes to disappear. On the Alpine
Linux console (at least the musl libc version), this is needed to
avoid a test failure as long as no GUI is active. As soon as you
start X11, this phenomenon disappears, even on the console. Very
strange, but also very probably not ksh's fault.
src/cmd/ksh93/tests/shtests:
- Instead of just SIGCONT and SIGPIPE, set all signals to default,
just to be sure to avoid spurious test failures due to signals
that were ignored on entry. (It made no difference to the
aforementioned Alpine Linux test failure, so ignored signals had
nothing to do with that -- but still a good idea.)
.github/workflows/ci.yml:
- On the GitHub CI runs, when testing with SHOPTs disabled, disable
SHOPT_SPAWN as well, which tests that everything still works
correctly with the regular fork(2) method.
COPYRIGHT:
- Remove duplicate of BSD license.
src/cmd/ksh93/sh.1:
- Add a new section on history expansion mostly adapted from the
"History substitution" section from the tcsh(1) man page. This
has the standard BSD license which is already in the COPYRIGHT
file. Inapplicable stuff was removed, some new stuff added.
src/cmd/ksh93/edit/hexpand.c,
src/cmd/ksh93/sh/io.c:
- Set '#' as the default history comment character as on bash;
no longer disable it by default.
- Add the 'a' modifier as a synonym for 'g', as on bash.
- Remove pointless static keyword from np variable; since the
value from previous calls is never used it can just be local.
- Use NV_NOADD flag with nv_open() to avoid pointlessly creating
the node if the variable doesn't exist yet.
- Fix a bug in history expansion where the 'p' modifier had no
effect if the 'histverify' option is on.
Reproducer:
$ set -H -o histv
$ true a b c
$ !!:p
$ true a b c▁ <= instead of printed, the line is re-edited
Expected:
$ set -H -o histv
$ true a b c
$ !!:p
true a b c
$ ▁
This is fixed by making 'p' remove the HIST_EVENT bit from the
returned flag bits in hist_expand(), leaving only the HIST_PRINT
flag, then adding special handling for this case to slowread()
in io.c (print the line, then instead of executing it, continue
and read the next line).
src/lib/libast/features/standards:
- Do not emit #defines for the typ u_long test which is only used
as a heuristic in subsequent tests in this file. (Note that 'set'
can set and unset any iffe command-line --option at runtime.)
- Remove definition of _ISOC99_SOURCE macro. This is another old
GNU thing; feature_test_macros(7) says invoking the compiler with
the option -std=c99 has the same effect. But modern GCC has C11
with GNU extensions as the default, which is fine. If a
particular standard is desired, pass a -std=... flag in $CC.
src/cmd/ksh93/features/rlimits:
- Remove overlooked Linux *64* types/functions hackery.
After defining standards macros it caused a build failure
on at least one version of Void Linux (but not 5.15.14_1).
Thanks to @JohnoKing for the report.
src/cmd/ksh93/sh/subshell.c,
src/lib/libdll/dllnext.c:
- Remove now-redundant local definitions of _GNU_SOURCE and
__EXTENSIONS__ macros.
src/cmd/ksh93/tests/builtins.sh:
- Fix broken sed invocation (re: 41829efa).
The more notable ones are:
src/lib/libast/features/standards:
- Do not redefine _GNU_SOURCE and _FILE_OFFSET_BITS if already
defined from $CCFLAGS. Thanks to @hyanias for the heads-up.
(re: 289dd46c)
src/cmd/ksh93/data/builtins.c,
src/cmd/ksh93/include/shell.h,
src/cmd/ksh93/sh/args.c,
src/cmd/ksh93/sh/name.c:
- Remove -T test code activation option. It was basically unused.
The only thing it did was intentionally introduce a memory leak
in table_unset() if the 4th bit in the option argument was set.
A search in ast-open-history reveals a few more trivial test uses
that were later deleted, but nothing interesting.
src/cmd/ksh93/tests/{basic,path}.sh:
- Skip a couple of tests on AIX avoid hangs, at least one of which
is not ksh's fault. Thanks to @HansH111 for the report.
src/cmd/ksh93/tests/builtins.sh:
- Change one awk use to a more portable sed invocation to placate
systems with ancient awk commands, such as AIX. (re: de795e1f)
These are minor things I accumulated over the last month or so.
Notable changes:
src/lib/libast/features/api,
src/lib/libast/misc/state.c,
src/lib/libast/comp/conf.tab,
src/cmd/ksh93/include/defs.h:
- Bump internal libast version to 20220101L. We've made a few
additions to the API, at least pathicase (see 71934570, ca3ec200)
and astconf_long (see c2ac69b2), so this should have been done
already. This also updates '/opt/ast/bin/getconf _AST_VERSION'.
- Use AST_VERSION instead of outdated _AST_VERSION.
- In state.c, use AST_VERSION instead of hardcoding the version.
src/cmd/ksh93/sh/xec.c:
- Remove 'restorefd' variable, unused as of 42becab6.
- Remove 'cmdrecurse' function and SH_RUNPROG macro; this was once
used by a few libcmd commands, but ast-open-archive reveals it's
unused as of ast 1999-12-25.
src/cmd/ksh93/sh/*.c:
- Where available, use e_dot instead of "." for consistency; it is
defined as an extern so we might as well use it.
src/cmd/ksh93/tests/*.sh:
- When reporting signal names in fails, include the SIG prefix.
- Fix a broken process hang test in subshell.sh.
src/lib/libast/man/sfdisc.3:
- Removed. The interfaces described here never made it out of AT&T;
they do not exist in any libast version in ast-open-archive.
Resolves: https://github.com/ksh93/ksh/issues/426
This fixes one of the ASan failures in the variables.sh regression
tests. Explanation from <https://github.com/att/ast/issues/1268>:
> The problem is caused by this block of code freeing the Namfun_t*
> (via the call to chktfree()):
> 307bc3ed/src/cmd/ksh93/sh/nvdisc.c (L570-L577)
>> 570 else
>> 571 {
>> 572 struct blocked *bp;
>> 573 action = vp->disc[type];
>> 574 vp->disc[type] = 0;
>> 575 if(!(bp=block_info(np,(struct blocked*)0)) || !isblocked(bp,UNASSIGN))
>> 576 chktfree(np,vp);
>> 577 }
> That invalidates the value stored in vp which is dereferenced here:
> 307bc3ed/src/cmd/ksh93/sh/nvdisc.c (L411-L421)
>> 419 unblock(bp,type);
>> 420 if(!vp->disc[type])
>> 421 chktfree(np,vp);
ksh2020 commit:
df1e8165
src/cmd/ksh93/sh/nvdisc.c:
- Block nv_setdisc from freeing the memory associated with the vp pointer.
In the times(3) fallback for the time keyword (which can be enabled
in xec.c by undefining _lib_getrusage and timeofday), ksh will
print the obtained time incorrectly if TIMEFORMAT is set to use a
precision level of three:
$ TIMEFORMAT=$'\nreal\t%3lR'
$ time sleep .080
real 0m00.008s # Should be '00.080s'
This commit corrects that issue by using 10^precision to get the
correct fractional scaling. Note that the fallback still doesn't
support a true precision level of three (times(3) alone doesn't
support it), so this in effect pads a zero to the end of the output
when the precision level is three.
Additional change to tests/builtins.sh:
- While fixing the above issue I found out that ksh93v- broke
support for passing microseconds to the sleep builtin in the form
of <num>U. I've added a regression test for that bug to ensure it
isn't backported to ksh93u+m by accident.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
If neither gmacs/emacs nor vi are active, the multiline mode should
not be enabled even if the multiline option is on. Doing so can
cause inconsistent behaviour, particularly in multibyte locales
where, if the shell is compiled with SHOPT_RAWONLY (as is default),
the no-editor mode is actually handled by vi.c.
Also, the new --histreedit and --histverify options only work in
the emacs or vi editors, or in no-editor mode when handled by vi.
Which means they cannot ever work if neither emacs or vi were
compiled in (i.e. SHOPT_ESH and SHOPT_VSH were both disabled).
In that case, there's no point in compiling in those options.
Come to think of it, the same applies to the multiline option.
All changed files:
- Update SHOPT_ESH/SHOPT_VSH preprocessor directives as per above.
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/include/shell.h:
- Move definitions of history expansion-related options to shell.h,
which is where all the other shell options are defined.
The referenced commit introduced a bug that caused command
substitutions to hang, writing infinite zero bytes, when
redirecting standard output on a built-in comand that forks the
command substitution subshell.
The bug was caused by removing the fork when redirecting standard
output in a non-permanent manner. However, simply reintroducing the
fork causes multiple regressions that we had fixed in the meantime.
Thankfully, it looks like this forking workaround is only necessary
when redirecting the output of built-ins. It appears that moving
workaround from io.c to the built-ins handling code in sh_exec() in
xec.c, right before calling sh_redirect(), allows reintroducing the
forking workaround for non-permanent redirections without causing
other regressions.
It would be better if the underlying cause of the hang were fixed
so the workaround becomes unnecessary, but I don't think that is
going to happen any time soon (AT&T didn't manage, either).
src/cmd/ksh93/sh/io.c: sh_redirect():
- Remove forking workaround for redirecting stdout in a comsub.
src/cmd/ksh93/sh/xec.c: sh_exec(): TCOM: built-ins handling code:
- Reimplement the workaround here.
Resolves: https://github.com/ksh93/ksh/issues/416
On Haiku:
# /bin/cat <(echo hi) # no redirection
cat: /tmp/ksh.f29pd8f: No such file or directory
Whereas this works fine:
# /bin/cat < <(echo hi) # with redirection
hi
# /opt/ast/bin/cat <(echo hi) # no redirection; use built-in
hi
Haiku does not have /dev/fd, so uses the FIFO (named pipe) fallback
mechanism. See also: c3eac977
Analysis: In the TFORK part of sh_exec(), forked branch (child),
the FIFO (sh.fifo) is unlinked immediately after opening it. This
is not a problem if the process substitution is used in combination
with a redirection, but if not, then the FIFO is passed on to the
command as a file name argument. This creates a race condition: ksh
was counting on the external 'cat' command opening the FIFO before
the child could unlink it. Whether that race is won depends on
operating system implementation details. When invoking an external
command on Haiku, the race is lost.
src/cmd/ksh93/sh/xec.c: sh_exec(): TFORK: child branch:
- Delay unlinking the FIFO until after executing the process
substitution, when we're about to exit from the child process.
This commit makes various different improvements to the documentation:
- sh.1: Backported (with changes) mandoc warning fixes from ksh2020
for the ksh93(1) man page: <https://github.com/att/ast/pull/1406>
- Removed unnecessary spaces at the end of lines to fix a few other
mandoc warnings.
- Fixed various typos and capitalization errors in the documentation.
- ANNOUNCE: Document the addition of the ${.sh.pid} variable
(re: 9de65210).
- libast/man/str*: Update the man pages for the libast str* functions
to improve how accurately each function is described.
- ksh93/README: Update regression test/compatibility notes to include
OpenBSD 7.0, FreeBSD 13.0 and WSL running Ubuntu 20.04.
- Change a few places to store the return value from strlen in a
size_t variable rather than signed int.
- comp/setlocale.c: To avoid confusion of two separate variables named
lang, the function local variable has been renamed to langidx.
This commit implements the build fixes required to get ksh running on
Haiku. Note that while ksh does compile, it has a ton of regression test
failures on Haiku.
src/cmd/ksh93/data/signals.c,
src/lib/libast/features/signal.c:
- Add support for the SIGKILLTHR signal, which is supported by BeOS and
Haiku.
- SIGINFO was missing an entry in the libast feature test, so add one
(re: 658bba74).
src/cmd/ksh93/RELEASE:
- Add an entry noting that ksh now compiles on Haiku, albeit with many
regression test failures.
src/cmd/ksh93/{include/terminal.h,sh/path.c}:
- Silence compiler warnings on Haiku.
src/lib/libast/features/mmap:
- The mmap feature test freezes on Haiku, so modify the test to fail
immediately on that OS.
src/lib/libast/misc/signal.c:
- Avoid redefining the signal definition on Haiku to fix a compiler
error.
src/lib/libast/features/nl_types:
- For some reason the nl_item typedef on Haiku doesn't work correctly.
Work around that by creating the nl_item type in the libast nl_types
feature test.
This combines 20 cleanup commits from the dev branch.
All changed files:
- Clean up pointer defererences to sh.
- Remove shp arguments from functions.
Other notable changes:
src/cmd/ksh93/include/shell.h,
src/cmd/ksh93/sh/init.c:
- On second thought, get rid of the function version of
sh_getinterp() as libshell ABI compatibility is moot. We've
already been breaking that by reordering the sh struct, so there
is no way it's going to work without recompiling.
src/cmd/ksh93/sh/name.c:
- De-obfuscate the relationship between nv_scan() and scanfilter().
The former just calls the latter as a static function, there's no
need to do that via a function pointer and void* type conversions.
src/cmd/ksh93/bltins/typeset.c,
src/cmd/ksh93/sh/name.c,
src/cmd/ksh93/sh/nvdisc.c:
- 'struct adata' and 'struct tdata', defined as local struct types
in these files, need to have their first three fields in common,
the first being a pointer to sh. This is because scanfilter() in
name.c accesses these fields via a type conversion. So the sh
field needed to be removed in all three at the same time.
TODO: de-obfuscate: good practice definition via a header file.
src/cmd/ksh93/sh/path.c:
- Naming consistency: reserve the path_ function name prefix for
externs and rename statics with that prefix.
- The default path was sometimes referred to as the standard path.
To use one term, rename std_path to defpath and onstdpath() to
ondefpath().
- De-obfuscate SHOPT_PFSH conditional code by only calling
pf_execve() (was path_pfexecve()) if that is compiled in.
src/cmd/ksh93/include/streval.h,
src/cmd/ksh93/sh/streval.c:
- Rename extern strval() to arith_strval() for consistency.
src/cmd/ksh93/sh/string.c:
- Remove outdated/incorrect isxdigit() fallback; '#ifnded isxdigit'
is not a correct test as isxdigit() is specified as a function.
Plus, it's part of C89/C90 which we now require. (re: ac8991e5)
src/cmd/ksh93/sh/suid_exec.c:
- Replace an incorrect reference to shgd->current_pid with
getpid(); it cannot work as (contrary to its misleading directory
placement) suid_exec is an independent libast program with no
link to ksh or libshell at all. However, no one noticed because
this was in fallback code for ancient systems without
setreuid(2). Since that standard function was specified in POSIX
Issue 4 Version 2 from 1994, we should remove that fallback code
sometime as part of another obsolete code cleanup operation to
avoid further bit rot. (re: 843b546c)
src/cmd/ksh93/bltins/print.c: genformat():
- Remove preformat[] which was always empty and had no effect.
src/cmd/ksh93/shell.3:
- Minor copy-edit.
- Remove documentation for nonexistent sh.infile_name. A search
through ast-open-archive[*] reveals this never existed at all.
- Document sh.savexit (== $?).
src/cmd/ksh93/shell.3,
src/cmd/ksh93/include/shell.h,
src/cmd/ksh93/sh/init.c:
- Remove sh.gd/shgd; this is now unused and was never documented
or exposed in the shell.h public interface.
- sh_sigcheck() was documented in shell.3 as taking no arguments
whereas in the actual code it took a shp argument. I decided to
go with the documentation.
- That leaves sh_parse() as the only documented function that still
takes an shp argument. I'm just going to go ahead and remove it
for consistency, reverting sh_parse() to its pre-2003 spec.
- Remove undocumented/unused sh_bltin_tree() function which simply
returned sh.bltin_tree.
- Bump SH_VERSION to 20220106.
(nmake makefiles) defined this macro:
__OBSOLETE__ == $("6 months ago":@F=%(%Y0101)T)
This was used to automatically disable code after a period between
6 and 18 months, on 1st Jan of each year, in preprocessor
directives like:
#if __OBSOLETE__ < 20080101
// obsolete code here
#endif
However, when compiling without nmake (as we do), this __OBSOLETE__
macro is not defined at all. And undefined macros evaluate to zero
in arithmetic comparisons, so all that obsolete code has been
getting compiled. Thankfully it doesn't seem to have done any harm,
but all that code was supposed to expire between 2008 and 2014.
src/lib/libast/disc/sfstrtmp.c:
- Removed. Was supposed to be a stub #if __OBSOLETE__ >= 20070101.
src/lib/libast/include/ast.h:
- Remove unused fmtbasell() macro (/* until 2014-01-01 */).
Other changed files:
- Remove __OBSOLETE__d code.
This fixes the use after free issue that caused typeset -m to crash on
older versions of OpenBSD and under ASan. The problem that was causing
the failure was that the ap pointer wasn't set to null after the memory
associated with it was freed. This commit backports a bugfix from
ksh93v- 2013-06-28 that sets ap to null before freeing the associated
memory and adds a check that makes sure ap is still a valid pointer
before calling array_unscope().
tests/types.sh changes:
- Avoid redirecting stderr to /dev/null, as this test shouldn't print
anything to stderr.
- Apply error message improvement from
https://github.com/ksh93/ksh/issues/231#issue-834252084.
tests/arrays.sh change:
- Apply error message improvement from
https://github.com/ksh93/ksh/issues/229#issue-834240645 (re: 7c7fde75).
Resolves: https://github.com/ksh93/ksh/issues/231
This backports a ksh2020 fix for an ASan heap-use-after-free error in
arrays.sh. The arrays regression tests were failing under ASan because
the ap pointer was used after the memory allocated to it was freed by
_nv_unset(). ksh2020 commit:
f1e5119e31
This upstreams the patch to init.c that is necessary to build dtksh
(graphical extensions for CDE, see <https://cdesktopenv.sf.net/>).
It has no effect when building regular ksh. Upstreaming it avoids
the need to keep updating it when changes to init.c are made.
As observed previously (see 3654ee73, 7e6bbf85, 79d19458), the ksh
93u+ codebase on which we rebased development was in a transition:
AT&T evidently wanted to make it possible to have several shell
interpreter states in the same process, which in theory would have
made it possible to start a complete new shell (not just a
subshell) without forking a new process.
This required transitioning from accessing the 'sh' state struct
directly to accessing it via pointers (usually but not always
called 'shp'), introducing a lot of bug-prone passing around of
those pointers via function arguments and other state structs.
Some of the original 'sh' struct was separated into a 'struct
shared' called 'shgd' a.k.a. 'sh.gd' (global data) instead; these
were global state variables that were going to be shared between
the different main shell environments sharing a process. Yet, for
some reason, that struct was allocated dynamically once at init
time, requiring yet another pointer to access it. <shrug>
None of this ever worked, because that transition was incomplete.
It was much further along in the ksh 93v- beta, but I don't think
it actually worked there either (not very much really did). So,
starting a new shell has always required starting a new process.
So, now that it's clear what they were trying to do, should we try
to make it work? I'm going to go with a firm "no" on that question.
Even non-forking (virtual) subshells, something quite a bit less
ambitious, were already an unmitigated nightmare of bugs. In 93u+m
we fixed a load of bugs related to those, but I'm sure there are
still many left. At the very least there are multiple memory leaks.
I think the ambition to go even further and have complete shells
running separate programs share a process, particularly given the
brittle and buggy state of the existing codebase, is evidence that
the AT&T team, in the final years, had well and truly lost the
ability to think "wait a minute, aren't we in over our heads here,
and why are we doing this again? Is this *actually* a feasible and
useful idea?"
In my view, having entirely separate programs share a process is a
*terrible*, horrible, no-good idea that takes us back to the bad
old days before Unix, when kernels and CPUs were unable to enforce
any memory access restrictions. Programmers are imperfect. If
you're going to run a new program, you need the kernel to enforce
the separation between programs, or you're just asking for memory
corruption and security holes. And that separation is enforced by
starting a new program in a new process. That's what processes are
*for*. And if you need *that* to be radically performance-optimised
then you're probably doing it wrong anyway.
(By the way, I would still argue the same for subshells, even after
we fixed many bugs in virtual subshells. But forking all subshells
would in fact cause many scripts to slow down, and the community
would surely revolt. <sigh> Maybe I should make it a shell option
instead, so scripts can 'set -o subfork' for reliability.)
It is also unclear how they were going to make something like
'ulimit' work, which can only work in a separate process. There
was no sign of a mechanism to fork a separate program's shell
mid-execution like there is for subshells (sh_subfork()).
Anyway... I had already changed some code here and there to access
the sh state struct directly, but as of this commit I'm beginning
to properly undo this exercise in pointlessness. From now on, we're
exercising pointerlessness instead.
I'll do this in stages to make any problems introduced more
traceable. Stage 0 restores the full 'sh' state struct to its
former static glory and reverts 'shgd' as a separate entity.
src/cmd/ksh93/sh/defs.c,
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/include/shell.h
src/cmd/ksh93/Mamfile::
- Move 'struct sh_scoped' and 'struct limits' from defs.h to
shell.h as the sh struct will need their complete definitions.
- Get rid of 'struct shared' (shgd) in defs.h; its members are
folded back into their original place, the main Shell_t struct
(sh) in shell.h. There are no name conflicts.
- Get rid of the _SH_PRIVATE macro in defs.h. The members it
defines are now defined normally in the main Shell_t struct (sh)
in shell.h.
- To make this possible, move <history.h> and "fault.h" includes
from defs.h to shell.h and update the Mamfile accordingly.
- Turn sh_getinterp() and shgd into macros that resolve to (&sh).
This will allow the compiler to optimise out many pointer
dereferences already.
- Keep extern sh_getinterp() for libshell ABI compatibility.
src/cmd/ksh93/sh/init.c:
- sh_init(): Do not calloc (sh_newof) the sh or shgd structs.
- sh_getinterp(): Keep function for libshell ABI compat.
This commit backports a bugfix from ksh2020 to fix an ASan
heap-buffer-overflow error in one of the regression tests. See:
c57f7398https://github.com/att/ast/issues/1261
This explanation comes from the linked issue:
> The poplevel() in this block of code is called when lp->lexd.lex_max
> is zero:
> bd94eb56/src/cmd/ksh93/sh/lex.c (L921-L925)
> Since poplevel() first decrements lp->lexd.lex_max then uses it as
> an index into lp->lexd.lex_match this causes the word before the
> start of that buffer to be accessed. The buffer is allocated here:
> bd94eb56/src/cmd/ksh93/sh/lex.c (L2210-L2218)
src/cmd/ksh93/sh/lex.c:
- Avoid calling poplevel() twice when handling syntax errors.
Depending on the OS, the heredoc.sh regression tests, and possibly
others, still crashed with the -x option (xtrace) on.
Analysis: The lexer crashes in lex_advance(). Something has caused
an inconsistent lexer state, and it happened earlier on, so the
backtrace is useless for figuring out where that happened.
But I think I've found it. It's the sh_mactry() call here:
src/cmd/ksh93/sh/xec.c, lines 2800 to 2807 in f7213f03
2800: if(!(cp=nv_getval(sh_scoped(shp,PS4NOD))))
2801: cp = "+ ";
2802: else
2803: {
2804: sh_offoption(SH_XTRACE);
2805: cp = sh_mactry(shp,cp);
2806: sh_onoption(SH_XTRACE);
2807: }
sh_mactry() needs to parse the contents of $PS4 to perform
expansions and command substitutions in it, which involves the
lexer. If that happens in a here-document, the lexer is in the C
function call stack, in the middle of parsing the here-document.
Result: inconsistent lexer state. Solution: save and restore lexer
state in sh_mactry().
After this commit, all regression tests should pass with the
'-x'/'--xtrace' option in use, with no errors or crashes.
Note for backporters: this fix depends both on on d7cada7b and on
the consistency fix for the Lex_t type's size applied in a7ed5d9f.
src/cmd/ksh93/include/shlex.h:
- Cosmetic fix: remove a copied & pasted backslash. (re: a7ed5d9f)
src/cmd/ksh93/sh/macro.c: sh_mactry():
- Save and restore the lexer state before letting sh_mactrim()
indirectly parse and execute code.
src/cmd/ksh93/tests/*.sh:
- Turn off xtrace in various command substitutions that contain
2>&1 redirections, so that the xtrace output is not caught by
the command substitutions, causing tests to fail incorrectly.
- Turn off xtrace for a few code blocks with 2>&1 redirections,
stopping xtrace output from being written to standard output.
Resolves: https://github.com/ksh93/ksh/issues/306 (again)
On some systems (at least Linux and macOS):
1. Run on a command line: t=$(sleep 10|while :; do :; done)
2. Press Ctrl+C in the first 10 seconds.
3. Execute any other command substitution. The shell crashes.
Analysis: Something in the job_wait() call in the sh_subshell()
restore routine may be interrupted by a signal such as SIGINT on
Linux and macOS. Exactly what that interruptible thing is remains
to be determined. In any case, since job_wait() was invoked after
sh_popcontext(), interrupting it caused the sh_subshell() restore
routine to be aborted, resulting in an inconsistent state of the
shell. The fix is to sh_popcontext() at a later stage instead.
src/cmd/ksh93/sh/subshell.c: sh_subshell():
- Rename struct checkpt buff to checkpoint because it's clearer.
- Move the sh_popcontext() call to near the end, just after
decreasing the subshell level counters and restoring the global
subshell data struct to its parent. This seems like a logical
place for it and could allow other things to be interrupted, too.
- Get rid of the if(shp->subshell) because it is known that the
value is > 0 at this point.
- The short exit routine run if the subshell forked now needs a new
sh_popcontext() call, because this is handled before restoring
the virtual subshell state.
- While we're here, do a little more detransitioning from all those
pointless shp pointers.
Fixes: https://github.com/ksh93/ksh/issues/397
The sh_close() function fails to set errno to EBADF when passed a
negative (invalid) file descriptor. This commit fixes the issue
by setting errno if the file descriptor is a negative value
(backported from ksh93v- 2012-08-24).
This takes another step towards cleaning up the build system. We
now do not even pretend to be theoretically compatible with
pre-1989 K&R C compilers or with C++ compilers. In practice, this
had already been broken for many years due to bit rot.
Commit 46593a89 already removed the license handling enormity that
depended on proto, so now we can cleanly remove it altogether. But
we do need to leave some backwards compatibility stubs to keep the
build system compatible with older AST code; it should remain
possible to build older ksh versions with the current build system
(the bin/ and src/cmd/INIT/ directories) for testing purposes.
So as of now there is no more __MANGLE__d rubbish in your generated
header files. This is only about a quarter of a century overdue...
This commit also includes a huge amount of code cleanup to remove
thousands of unused K&R C fallbacks and other cruft, particularly
in libast. This code base should now be a little easier to
understand for people who are familiar with a modern(ish) C
standard.
ratz is now also removed; this was a standalone and simplified 2005
version of gunzip. As of 6137b99a, none of our code uses it, even
theoretically. And the real g(un)zip is now everywhere.
src/cmd/INIT/proto.c, src/cmd/INIT/ratz.c:
- Removed.
COPYRIGHT:
- Remove zlib license; this only applied to ratz.
bin/package, src/cmd/INIT/package.sh:
- Related cleanups.
- Unset LC_ALL before invoking a new shell, respecting the user's
locale again and avoiding multibyte character corruption on the
command line.
src/cmd/INIT/proto.sh:
- Add stub for backwards compatibility with Mamfiles that depend on
proto. It does nothing but pass input without modification and is
now installed as the new arch/*/bin/proto by src/cmd/INIT/Mamfile.
src/cmd/INIT/iffe.sh:
- Ignore the proto-related -e (--package) and -p (--prototyped)
options; keep parsing them for backwards compatibility.
- Trim the macros passed to every test to their standard C
versions, removing K&R C and C++ versions. These are now
considered to be for backwards compatibility only.
src/cmd/INIT/iffe.tst:
- Remove proto(1) mangling code.
By the way, iffe can be regression-tested as follows:
$ bin/package use # set up environment in a child shell
$ regress src/cmd/INIT/iffe.tst
$ exit # leave package environment
src/cmd/INIT/make.probe, src/cmd/INIT/probe.win32:
- Remove code to handle C++.
src/lib/libast/features/common:
- As in iffe.sh above, trim macros designed for compatibility with
C++ and ancient C compilers to their standard C versions and
comment that they are for backwards compatibility with AST code.
This is needed to keep all the old ast and ksh code compiling.
src/cmd/ksh93/sh/init.c,
src/cmd/ksh93/sh/name.c:
- Clarify libshell ABI compatibility function versions of macros.
A "proto workaround" comment in the original code mislead me into
thinking this had something to do with the removed proto(1), but
it's unrelated. Call the workaround macro BYPASS_MACRO instead.
src/cmd/ksh93/include/defs.h:
- sh_sigcheck() macro: allow &sh as an argument: parenthesise shp.
src/cmd/ksh93/sh/nvtype.c:
- Remove unused nv_mkstruct() function. (re: d0a5cab1)
**/features/*:
- Remove obsolete iffe 'set prototyped' option.
**/Mamfile:
- Remove all references to the ast/prototyped.h header.
- Remove all use of the proto command. Simply copy instead.
*** 850-ish source files: ***
- Remove all '#pragma prototyped' directives.
- Remove all C++ compat code conditional upon defined(__cplusplus).
- Remove all use of the _ARG_ macro, which on standard C expands to
its argument:
#define _ARG_(x) x
(on K&R C, it expanded to nothing)
- Remove all use of _BEGIN_EXTERNS_ and _END_EXTERNS_ macros (empty
on standard C; this was for C++ compatibility)
- Reduce all #if __STD_C (standard code) #else (K&R code) #endif
blocks to the standard code only, without use of the macro.
- Same for _STD_ macro which seems to have had the same function.
- Change all instances of 'Void_t' to standard 'void'.
