Without this patch, BusyBox handles bash pattern substitutions without
a terminating '/' character incorrectly.
Consider the following shell script:
_bootstrapver=5.0.211-r0
_referencesdir="/usr/${_bootstrapver/-*}/Sources"
echo $_referencesdir
This should output `/usr/5.0.211/Sources`. However, without this patch
it instead outputs `/usr/5.0.211Sources`. This is due to the fact that
BusyBox expects the bash pattern substitutions to always be terminated
with a '/' (at least in this part of subvareval) and thus reads passed
the substitution itself and consumes the '/' character which is part of
the literal string. If there is no '/' after the substitution then
BusyBox might perform an out-of-bounds read under certain circumstances.
When replacing the bash pattern substitution with `${_bootstrapver/-*/}`,
or with this patch applied, ash outputs the correct value.
Signed-off-by: Sören Tempel <soeren@soeren-tempel.net>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Wed, 29 Apr 2020 00:19:59 +1000
parser: Fix alias expansion after heredoc or newlines
This script should print OK:
alias a="case x in " b=x
a
b) echo BAD;; esac
alias BEGIN={ END=}
BEGIN
cat <<- EOF > /dev/null
$(:)
EOF
END
: <<- EOF &&
$(:)
EOF
BEGIN
echo OK
END
However, because the value of checkkwd is either zeroed when it
shouldn't, or isn't zeroed when it should, dash currently gets
it wrong in every case.
This patch fixes it by saving checkkwd and zeroing it where needed.
function old new delta
readtoken 157 176 +19
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upsteam commit:
Date: Mon, 17 May 2021 15:19:23 +0800
eval: Do not cache value of eflag in evaltree
Patrick Brünn <P.Bruenn@beckhoff.com> wrote:
> Since we are migrating to Debian bullseye, we discovered a new behavior
> with our scripts, which look like this:
>>cleanup() {
>> set +e
>> rmdir ""
>>}
>>set -eu
>>trap 'cleanup' EXIT INT TERM
>>echo 'Hello world!'
>
> With old dash v0.5.10.2 this script would return 0 as we expected it.
> But since commit 62cf6955f8abe875752d7163f6f3adbc7e49ebae it returns
> the last exit code of our cleanup function.
...
Thanks for the report. This is actually a fairly old bug with
set -e that's just been exposed by the exit status change. What's
really happening is that cleanup itself is triggering a set -e
exit incorrectly because evaltree cached the value of eflag prior
to the function call.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Thu, 4 Jun 2020 21:53:55 +1000
eval: Check nflag in evaltree instead of cmdloop
This patch moves the nflag check from cmdloop into evaltree. This
is so that nflag will be in force even if we enter the shell via a
path other than cmdloop, e.g., through sh -c.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Process substitution is a Korn shell feature that's also available
in bash and some other shells. This patch implements process
substitution in ash when ASH_BASH_COMPAT is enabled.
function old new delta
argstr 1386 1522 +136
strtodest - 52 +52
readtoken1 3346 3392 +46
.rodata 183206 183250 +44
unwindredir - 28 +28
cmdloop 365 372 +7
static.spclchars 10 12 +2
cmdputs 380 367 -13
exitreset 86 69 -17
evalcommand 1754 1737 -17
varvalue 675 634 -41
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 5/4 up/down: 315/-88) Total: 227 bytes
text data bss dec hex filename
953967 4219 1904 960090 ea65a busybox_old
954192 4219 1904 960315 ea73b busybox_unstripped
v2: Replace array of file descriptors with a linked list.
Include tests that were unaccountably omitted from v1.
v3: Update linked list code to the intended version.
v4: Change order of conditional code in cmdputs().
v5: Use existing popredir() mechanism to manage file descriptors.
v6: Rebase to latest version of BusyBox ash. Reduce code churn.
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This significantly syncronises ash-signals and hush-signals tests.
function old new delta
process_wait_result 449 450 +1
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
With bash's read builtin it is possible to read from a file (e.g.
device-tree) until the first '\0' character:
IFS= read -r -d '' VARIABLE < file
In busybox ash the -d extension is also implemented, but checking the
read character for '\0' has to be performed after comparing with the
delimiter.
Signed-off-by: Christian Eggers <ceggers@arri.de>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Sun, 11 Nov 2007 15:27:00 +0800
Expand here-documents in the current shell environment
Previously we always expanded here-documents in a subshell. This is
contrary to the POSIX specification and how other shells behave. What's
more this slows down many expansions due to the extra fork (however, it
must be said that it is possible for it speed up certain expansions by
running it simultaneously with the command on two CPUs).
This patch move the expansion into the current shell environment.
Test case:
unset a
cat <<- EOF > /dev/null
${a=NOT}
EOF
echo ${a}BAD
Old result:
BAD
New result:
NOTBAD
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Fri, 1 Jun 2018 18:25:29 +0800
expand: Ensure result is escaped in cvtnum
The minus sign generated from arithmetic expansion is currently
unquoted which causes anomalies when the result is used in where
the quoting matters.
This patch fixes it by explicitly calling memtodest on the result
in cvtnum.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Sat, 19 May 2018 02:39:54 +0800
eval: Fail immediately with redirections errors for simple command
Previously, dash would continue to perform variable expansions
even if a redirection error occured. This patch changes it so
that it fails immediately.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Mon, 29 Apr 2019 19:13:37 +0500
expand: Fix trailing newlines processing in backquote expanding
According to POSIX.1-2008 we should remove newlines only at the end of
the substitution. Newlines-only substitions causes dash to remove
newlines before beggining of the substitution. The following code:
cat <<END
1
$(echo "")
2
END
prints "1<newline>2" instead of expected "1<newline><newline>2".
This patch fixes trailing newlines processing in backquote expanding.
Signed-off-by: Nikolai Merinov <n.merinov@inango-systems.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Mon, 27 May 2019 13:39:37 +0800
parser: Only accept single-digit parameter expansion outside of braces
This patch should fix the problem.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Mon Oct 6 10:39:47 2014 +0800
[BUILTIN] Exit without arguments in a trap should use status outside traps
POSIX now requires that exit without arguments in a trap should
return the last command status prior to executing traps. This
patch implements this behaviour.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Wed, 28 Mar 2018 18:37:51 +0800
expand: Do not quote backslashes in unquoted parameter expansion
Here is a better example:
a="/*/\nullx" b="/*/\null"; printf "%s\n" $a $b
dash currently prints
/*/\nullx
/*/\null
bash prints
/*/\nullx
/dev/null
You may argue the bash behaviour is inconsistent but it actually
makes sense. What happens is that quote removal only applies to
the original token as seen by the shell. It is never applied to
the result of parameter expansion.
Now you may ask why on earth does the second line say "/dev/null"
instead of "/dev/\null". Well that's because it is not the quote
removal step that removed the backslash, but the pathname expansion.
The fact that the /de\v does not become /dev even though it exists
is just the result of the optimisation to avoid unnecessarily
calling stat(2). I have checked POSIX and I don't see anything
that forbids this behaviour.
So going back to dash yes I think we should adopt the bash behaviour
for pathname expansion and keep the existing case semantics.
This patch does exactly that. Note that this patch does not work
unless you have already applied
https://patchwork.kernel.org/patch/10306507/
because otherwise the optimisation mentioned above does not get
detected correctly and we will end up doing quote removal twice.
This patch also updates expmeta to handle naked backslashes at
the end of the pattern which is now possible.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
function old new delta
expmeta 618 653 +35
memtodest 146 147 +1
Tested to work with both ASH_INTERNAL_GLOB on and off.
hush does not handle this correctly.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Fri, 23 Mar 2018 18:58:47 +0800
expand: Fix ghost fields with unquoted $@/$*
You're right. The proper fix to this is to ensure that nulonly
is not set in varvalue for $*. It should only be set for $@ when
it's inside double quotes.
In fact there is another bug while we're playing with $@/$*.
When IFS is set to a non-whitespace character such as :, $*
outside quotes won't remove empty fields as it should.
This patch fixes both problems.
Reported-by: Martijn Dekker <martijn@inlv.org>
Suggested-by: Harald van Dijk <harald@gigawatt.nl>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
function old new delta
argstr 1111 1113 +2
evalvar 571 569 -2
varvalue 579 576 -3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/2 up/down: 2/-5) Total: -3 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Wed, 4 Apr 2018 17:54:01 +0800
eval: Variable assignments on functions are no longer persistent
Dirk Fieldhouse <fieldhouse@gmx.net> wrote:
> In POSIX.1-2017 ("simultaneously IEEE Std 1003.1™-2017 and The Open
> Group Technical Standard Base Specifications, Issue 7")
> <http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_09>,
> we read under '2.9.1 Simple Commands'
>
> "Variable assignments shall be performed as follows:
> ...
> - If the command name is a standard utility implemented as a function
> (see XBD Utility), the effect of variable assignments shall be as if the
> utility was not implemented as a function.
> ...
> - If the command name is a function that is not a standard utility
> implemented as a function, variable assignments shall affect the current
> execution environment during the execution of the function. It is
> unspecified:
>
> * Whether or not the variable assignments persist after the
> completion of the function
>
> * Whether or not the variables gain the export attribute during
> the execution of the function
>
> * Whether or not export attributes gained as a result of the
> variable assignments persist after the completion of the function (if
> variable assignments persist after the completion of the function)"
POSIX used to require the current dash behaviour. However, you're
right that this is no longer the case.
This patch will remove the persistence of the variable assignment.
I have considered the exporting the variables during the function
execution but have decided against it because:
1) It makes the code bigger.
2) dash has never done this in the past.
3) You cannot use this portably anyway.
Reported-by: Dirk Fieldhouse <fieldhouse@gmx.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
function old new delta
evalcommand 1606 1635 +29
evalcase 313 317 +4
evalfun 280 268 -12
pushlocalvars 48 - -48
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 2/1 up/down: 33/-60) Total: -27 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This necessitates switch from libc FILE api to a simple
homegrown replacement.
The change which fixes the bug here is the deleting of
restore_redirected_FILEs();
line. It was prematurely moving (restoring) script fd#3.
The fix is: we don't even _want_ to restore scrit fds,
we are perfectly fine with them being moved.
The only reason we tried to restore them is that FILE api
did not allow moving of FILE->fd.
function old new delta
refill_HFILE_and_getc - 93 +93
hfopen - 90 +90
hfclose - 66 +66
pseudo_exec_argv 591 597 +6
hush_main 1089 1095 +6
builtin_source 209 214 +5
save_fd_on_redirect 197 200 +3
setup_redirects 320 321 +1
fgetc_interactive 235 236 +1
i_peek_and_eat_bkslash_nl 99 97 -2
expand_vars_to_list 1103 1100 -3
restore_redirects 99 52 -47
fclose_and_forget 57 - -57
remember_FILE 63 - -63
------------------------------------------------------------------------------
(add/remove: 3/2 grow/shrink: 6/3 up/down: 271/-172) Total: 99 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
