Commit Graph

957 Commits

Author SHA1 Message Date
Ron Yorston
a1b0d3856d ash: add process substitution in bash-compatibility mode
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>
2021-06-05 23:37:19 +02:00
Denys Vlasenko
33745b1fc8 ash: placate -Werror=format-security
"In function 'sprint_status48':
 error: format not a string literal and no format arguments"

function                                             old     new   delta
sprint_status48                                      160     158      -2

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-02-18 13:45:49 +01:00
Denys Vlasenko
2b7c1aa92c ash: match bash behavior for ${empty_var/*/repl}
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-01-09 08:46:54 +01:00
Denys Vlasenko
883cdb79a4 ash: fix ${unset_var/pattern/repl}
function                                             old     new   delta
subevalvar                                          1349    1353      +4

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-01-09 08:27:37 +01:00
Denys Vlasenko
4e039bab37 ash: improve --help
function                                             old     new   delta
packed_usage                                       33504   33499      -5

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-01-04 03:50:38 +01:00
Denys Vlasenko
85158b600d ash: code shrink
function                                             old     new   delta
ash_main                                            1218    1202     -16

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-01-03 12:14:58 +01:00
Denys Vlasenko
3f8ec00b0c ash: make a strdup copy of $HISTFILE for line editing
Otherwise if $HISTFILE is unset or reassigned, bad things can happen.

function                                             old     new   delta
ash_main                                            1210    1218      +8

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-01-03 10:55:39 +01:00
Denys Vlasenko
3c13da3dab libbb: introduce and use xgettimeofday(), do not truncate 64-bit time_t in shells
function                                             old     new   delta
xgettimeofday                                          -      11     +11
get_local_var_value                                  280     281      +1
svlogd_main                                         1323    1322      -1
change_epoch                                          67      66      -1
timestamp_and_log                                    461     458      -3
hwclock_main                                         301     298      -3
fmt_time_bernstein_25                                135     132      -3
step_time                                            331     326      -5
script_main                                         1207    1202      -5
machtime                                              34      28      -6
curtime                                               61      54      -7
ts_main                                              423     415      -8
nmeter_main                                          761     751     -10
gettime1900d                                          67      46     -21
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/12 up/down: 12/-73)           Total: -61 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-12-30 23:48:01 +01:00
Denys Vlasenko
51a471d05d ash: change "clear ungetc counter on syntax errors" fix to match dash
function                                             old     new   delta
ash_main                                            1203    1210      +7
raise_exception                                       39      26     -13
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 7/-13)              Total: -6 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-12-24 00:22:24 +01:00
Denys Vlasenko
93e2a22482 shell: for signal exitcode, use 128 | sig, not 128 + sig - MIPS has signal 128
function                                             old     new   delta
wait_for_child_or_signal                             213     214      +1
refill_HFILE_and_getc                                 89      88      -1
getstatus                                             97      96      -1
builtin_wait                                         339     337      -2
checkjobs                                            187     183      -4
process_wait_result                                  450     444      -6
waitcmd                                              290     281      -9
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/6 up/down: 1/-23)             Total: -22 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-12-23 12:23:21 +01:00
Denys Vlasenko
00eb23b47a bc: do not allocate line editing state until needed
function                                             old     new   delta
xc_read_line                                         324     353     +29
free_line_input_t                                     34      39      +5
xc_vm_init                                           656     640     -16
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 34/-16)             Total: 18 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-12-21 21:36:58 +01:00
Denys Vlasenko
2124c0ec97 ash: clear ungetc counter on syntax errors
function                                             old     new   delta
raise_exception                                       26      39     +13

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-12-19 14:33:02 +01:00
Denys Vlasenko
31df5a3eee ash: reset SIGHUP earlier: allows HUP traps in .profile, closes 13371
function                                             old     new   delta
ash_main                                            1188    1203     +15

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-12-13 16:36:28 +01:00
Denys Vlasenko
965b795b87 decrease paddign: gcc-9.3.1 slaps 32-byte alignment on arrays willy-nilly
text	   data	    bss	    dec	    hex	filename
1021988	    559	   5052	1027599	  fae0f	busybox_old
1021236	    559	   5052	1026847	  fab1f	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-11-30 13:03:03 +01:00
Cristian Ionescu-Idbohrn
ddfdf68ca1 fix warning: label 'out1' defined but not used
Signed-off-by: Cristian Ionescu-Idbohrn <cristian.ionescu-idbohrn@axis.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-11-19 13:14:59 +01:00
Denys Vlasenko
4ac35a30db ash: make interactive ^C break out of PS2 mode
Based on patch by Joachim Nilsson <troglobit@gmail.com>

function                                             old     new   delta
pgetc                                                570     547     -23

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-11-16 13:09:37 +01:00
Denys Vlasenko
a7c065354f shell: update comments on the status of [[ ]] compat
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-10-31 04:32:34 +01:00
Denys Vlasenko
d2241f5902 shell: better support of [[ ]] bashism
Still rather rudimentary for ash

function                                             old     new   delta
binop                                                433     589    +156
check_operator                                        65     101     +36
done_word                                            736     769     +33
test_main                                            405     418     +13
parse_stream                                        2227    2238     +11
ops_texts                                            124     133      +9
ops_table                                             80      86      +6
run_pipe                                            1557    1562      +5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 8/0 up/down: 269/0)             Total: 269 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-10-31 03:34:07 +01:00
Denys Vlasenko
2496616b0a avoid using strok - eliminates use of hidden global variable
function                                             old     new   delta
udhcp_str2optset                                     616     650     +34
setpriv_main                                         950     975     +25
switch_root_main                                     688     706     +18
parse                                                958     970     +12
getopt_main                                          622     628      +6
parse_resolvconf                                     302     306      +4
mpstat_main                                         1139    1142      +3
static.p                                               4       -      -4
cdcmd                                                717     702     -15
strtok                                               148       -    -148
------------------------------------------------------------------------------
(add/remove: 0/3 grow/shrink: 7/1 up/down: 102/-167)          Total: -65 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-10-06 02:36:47 +02:00
Denys Vlasenko
91e11eba6e ash: jobs: Fix waitcmd busy loop
Upstream commit:

    Date: Tue, 2 Jun 2020 23:46:48 +1000
    jobs: Fix waitcmd busy loop

    We need to clear gotsigchld in waitproc because it is used as
    a loop conditional for the waitcmd case.  Without it waitcmd
    may busy loop after a SIGCHLD.

    This patch also changes gotsigchld into a volatile sig_atomic_t
    to prevent compilers from optimising its accesses away.

    Fixes: 6c691b3e5099 ("jobs: Only clear gotsigchld when waiting...")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

This change also incorporates other changes to bring us closer to upstream.

function                                             old     new   delta
dowait                                               553     636     +83

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-09-29 20:35:55 +02:00
Denys Vlasenko
8d5f465a20 ash: jobs: Fix infinite loop in waitproc
Upstream commit:

    Date: Fri, 10 Apr 2020 21:03:09 +1000
    jobs: Fix infinite loop in waitproc

    After we changed the resetting of gotsigchld so that it is only
    done if jp is NULL, we can now get an infinite loop in waitproc
    if gotsigchld is set but there is no outstanding child because
    everything had been waited for previously without gotsigchld being
    zeroed.

    This patch fixes it by always zeroing gotsigchld as we did before.
    The bug that the previous patch was trying to fix is now resolved
    by switching the blocking mode to DOWAIT_NORMAL after the specified
    job has been completed so that we really do wait for all outstanding
    dead children.

    Reported-by: Harald van Dijk <harald@gigawatt.nl>
    Fixes: 6c691b3e5099 ("jobs: Only clear gotsigchld when waiting...")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

function                                             old     new   delta
dowait                                               553     631     +78

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-09-29 20:21:27 +02:00
Denys Vlasenko
777a6357c0 ash: remove a tentative TODO, it's a wrong idea
Upstream tried it, and then reverted by:

    From: Herbert Xu <herbert@gondor.apana.org.au>
    Date: Tue, 26 May 2020 23:19:05 +1000
    parser: Fix double-backslash nl in old-style command sub

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-09-29 20:21:27 +02:00
Denys Vlasenko
67e1529b92 nologin: make it possible to build it as single applet
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-06-24 15:05:22 +02:00
Ron Yorston
9f3b410006 ash,hush: drop pointer check before calls to show_history
show_history() checks that its argument in non-null so there's
no need to repeat the test at call sites.

function                                             old     new   delta
historycmd                                            25      17      -8
builtin_history                                       29      21      -8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-16)             Total: -16 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-04-30 17:30:02 +02:00
Ron Yorston
da7a6dbfa5 ash: fix build failure when command built-in is disabled
Since commit 7eb8eecbb (ash: eval: Add assignment built-in support
again) building BusyBox with the 'command' built-in disabled fails.

parse_command_args() only needs to be called when the 'command'
built-in is run.  Which it won't be if it's disabled.

v2: Avoiding infinite loops is good, too.  Thanks, Harald van Dijk.

Reported-by: Deweloper <deweloper@wp.pl>
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-04-30 16:42:58 +02:00
Denys Vlasenko
1555895b4a ash: expand: Fix multiple issues with EXP_DISCARD in evalvar
Upstream commit:

    Date: Wed, 12 Sep 2018 14:27:16 +0800
    expand: Fix multiple issues with EXP_DISCARD in evalvar

    The commit 3cd538634f71538370f5af239f342aec48b7470b broke parameter
    expansion in multiple ways because the EXP_DISCARD flag wasn't set
    or tested for various cases:

            $ src/dash -c 'var=; echo ${var:+nonempty}'
            nonempty
            $ src/dash -u -c 'unset foo bar; echo ${foo+${bar}}'
            dash: 1: bar: parameter not set
            $ src/dash -c 'foo=bar; echo ${foo=BUG}; echo $foo'
            barBUG
            bar
            $

    This patch fixes them by introducing a new discard variable that
    tracks whether the extra word should be discarded or not when it
    is parsed.

    Reported-by: Martijn Dekker <martijn@inlv.org>
    Fixes: 3cd538634f71 ("expand: Do not reprocess data when...")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
    Reported-by: Martijn Dekker <martijn@inlv.org>
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-24 19:20:51 +01:00
Denys Vlasenko
823318822c ash: expand: Do not reprocess data when expanding words
Upstream patch:

    Date: Wed, 30 May 2018 02:06:03 +0800
    expand: Do not reprocess data when expanding words

    Currently various paths will reprocess data when performing word
    expansion.  For example, expari will skip backwards looking for
    the start of the arithmetic expansion, while evalvar will skip
    unexpanded words manually.

    This is cumbersome and error-prone.  This patch fixes this by
    making word expansions proceed in a linear fashion.  This means
    changing argstr and the various expansion functions such as expari
    and subevalvar to return the next character to be expanded.

    This is inspired by similar code from FreeBSD.  However, we take
    things one step further and completely remove the manual word
    skipping in evalvar.  This is accomplished by introducing a new
    EXP_DISCARD flag that tells argstr to only parse and not produce
    any actual expansions.

    Incidentally, argstr will now always NUL-terminate the expansion
    unless the EXP_WORD flag is set.  This is because all but one
    caller of argstr wants the result to be NUL-termianted.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Also includes two one-line follow-up fixes:

    expand: Eat closing brace for length parameter
            if (subtype == VSLENGTH) {
    +               p++;
                    if (flag & EXP_DISCARD)
    expand: Fix double-decrement in argstr
    -               newloc = expdest - (char *)stackblock() - end;
    +               newloc = q - (char *)stackblock() - end;

and changes in code for bash substring extensions.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-24 19:20:51 +01:00
Ron Yorston
6cda0b04a3 ash: move TRACE statement in evalcommand()
Following recent work on evalcommand() a TRACE statement to report
the status of a forked command was left in the wrong place.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-24 12:52:41 +01:00
Denys Vlasenko
7f19848552 ash: rename some function parameters to match dash
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-24 12:48:33 +01:00
Denys Vlasenko
538ee4102b ash: rename stack_nputstr() back to stnputs() to match dash
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-24 12:47:19 +01:00
Denys Vlasenko
c2058ec98c ash: Expand here-documents in the current shell environment
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>
2020-02-22 20:29:36 +01:00
Denys Vlasenko
c08993f40c ash: parser: Do not push token back before parseheredoc
Upstream commit:

    Date: Mon, 19 Nov 2018 18:43:58 +0800
    parser: Do not push token back before parseheredoc

    When we read the first token in list() we use peektoken instead
    of readtoken as the following code needs to use the same token
    again.  However, this is wrong when we're in a here-document as
    it will clobber the saved token without resetting the tokpushback
    flag.

    This patch fixes it by doing the tokpushback after parseheredoc
    and setting lasttoken again if parseheredoc was called.

    Reported-by: Ron Yorston <rmy@frippery.org>
    Fixes: 7c245aa8ed33 ("[PARSER] Simplify EOF/newline handling in...")
    Fixes: ee5cbe9fd6bc ("[SHELL] Optimize dash -c "command" to avoid a fork")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
    Tested-by: Simon Ser <contact@emersion.fr>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-22 17:26:23 +01:00
Denys Vlasenko
9a1a659707 ash: parser: Fix old-style command substitution here-document crash
Upstream commit:

    Date: Fri, 29 Mar 2019 13:49:59 +0800
    parser: Fix old-style command substitution here-document crash

    ... This is caused by the recent change to
    save/restore here-docment list around command substitutions.  In
    doing so we must finish existing here-documents prior to restoring
    the old here-document list.  This is done for new-style command
    substitutions but not for old-style.

    This patch fixes it by doing it for both.

    Fixes: 51e2d88d6e51 ("parser: Save/restore here-documents in...")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-22 16:39:27 +01:00
Denys Vlasenko
45dd87aac0 ash: expand: Ensure result is escaped in cvtnum
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>
2020-02-21 16:30:44 +01:00
Denys Vlasenko
da2e46dff6 ash: memalloc: Avoid looping in growstackto
Upstream commit:

    Date: Thu, 31 May 2018 01:51:48 +0800
    memalloc: Avoid looping in growstackto

    Currently growstackto will repeatedly call growstackblock until
    the requisite size is obtained.  This is wasteful.  This patch
    changes growstackblock to take a minimum size instead.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-21 15:25:37 +01:00
Denys Vlasenko
f977e004ce ash: eval: Only restore exit status on exit/return
Upstream commit:

    Date: Fri, 14 Dec 2018 13:52:02 +0800
    eval: Only restore exit status on exit/return

    We unconditionally restore the saved status in exitreset, which
    is incorrect as we only want to do it for exitcmd and returncmd.
    This patch fixes the problem by introducing EXEND.

    Reported-by: Martijn Dekker <martijn@inlv.org>
    Fixes: da30b4b78769 ("[BUILTIN] Exit without arguments in a trap...")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-20 16:54:29 +01:00
Denys Vlasenko
cd24a50633 ash: Return without arguments in a trap should use status outside traps
Fixes exitcode_trap4.tests.
Upstream commit:

    Date: Mon, 6 Oct 2014 21:51:26 +0800
    Return without arguments in a trap should use status outside traps

    POSIX now requires that return without arguments in a trap should
    return the last command status prior to executing traps.  This
    patch implements this behaviour.

    Incidentally this also changes the behaviour of return without
    arguments in a loop conditional to use the last exit status in
    the body as opposed to the last command in the conditional when
    there is one.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-20 16:47:01 +01:00
Ron Yorston
d5bfe26c45 ash: return exit status of nofork applets (again)
Since commit d81af7216 (ash: eval: Reap zombies after built-in commands
and functions) if the shell is compiled with SH_STANDALONE and SH_NOFORK
enabled nofork applets potentially return the incorrect status.

The status value returned by evalcommand() in this case is obtained from
exitstatus in a call to waitforjob(NULL).  This overwrites the status
set for nonfork applets.

If this commit seems familiar it's essentially a reversion of commit
5ccb0e92fa (ash: return exit status of nofork applets).  What was correct
in 2016 is wrong in 2020 and vice versa.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-20 10:39:46 +01:00
Denys Vlasenko
ecc85832f8 ash: expand: Merge syntax/quotes in memtodest with flags
Upstream commit:

    Date: Mon, 28 May 2018 00:17:39 +0800
    expand: Merge syntax/quotes in memtodest with flags

    The function arguments syntax and quotes are both derived from
    the expansion flags.  As syntax is only used by memtodest we do
    not need to maintain it outside of the function at all.

    The only place that uses something other than BASESYNTAX or DQSYNTAX
    is exptilde.  However in that case DQSYNTAX has exactly the same
    effect as SQSYNTAX.

    This patch merges these two arguments into a single flags.  The
    macro QUOTES_KEEPNUL has been renamed to EXP_KEEPNUL in order
    to keep the namespace separate.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-20 10:37:30 +01:00
Denys Vlasenko
e2dd2afc8e ash: eval: Always set localvar_stop
Upstream commit:

    Date: Thu, 31 May 2018 01:15:34 +0800
    eval: Always set localvar_stop

    The variable localvar_stop is set iff vlocal is true.  gcc doesn't
    get this so we get a spurious warning.

    This patch fixes this by always calling pushlocalvars with vlocal
    and making it only actually do the push if vlocal is non-zero.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-20 10:37:30 +01:00
Denys Vlasenko
3e729102a8 ash: eval: Replace with listsetvar with mklocal/setvareq
Upstream commit:

    Date: Sat, 19 May 2018 02:39:55 +0800
    eval: Replace with listsetvar with mklocal/setvareq

    This patch replaces listsetvar with mklocal/setvareq.  As we now
    determine special built-in status prior to variable assignment, we
    no longer have to do a second pass listsetvar.  Instead we will
    call setvareq directly instead of mklocal when necessary.

    In order to do this mklocal can now take a flag in order to mark
    a variable for export.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-20 09:36:51 +01:00
Denys Vlasenko
54bef2a8ef ash: eval: Fail immediately with redirections errors for simple command
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>
2020-02-20 09:36:51 +01:00
Denys Vlasenko
7eb8eecbbc ash: eval: Add assignment built-in support again
Upstream commit:

    Date: Sat, 19 May 2018 02:39:52 +0800
    eval: Add assignment built-in support again

    This patch adds assignment built-in support that used to exist
    in dash prior to 0.3.8-15.  This is because it will soon be part
    of POSIX, and the semantics are now much better defined.

    Recognition is done at execution time, so even "command -- export"
    or "var=export; command $var" should work.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-20 09:36:51 +01:00
Denys Vlasenko
23bc562a05 ash,hush: add comment about masked SIGCHLD, handle SIG_IGNed SIGHUP as in bash
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-18 16:46:01 +01:00
Denys Vlasenko
47eb979404 ash: jobs: Only clear gotsigchld when waiting for everything
Upstream commit:

    Date: Sat, 19 May 2018 02:39:41 +0800
    jobs: Only clear gotsigchld when waiting for everything

    The gotsigchld flag is always cleared in dowait but not all callers
    of dowait will wait for everything.  In particular, when jp is set
    we only wait until the set job isn't running anymore.

    This patch fixes this by only clearing gotsigchld if jp is unset.
    It also changes the waitcmd to actually set jp which corresponds
    to the behaviour of bash/ksh93/mksh.

    The only other caller of dowait that doesn't wait for everything
    is the jobless reaper.  This is in fact redundant now that we wait
    after every simple command.  This patch removes it.

    Finally as every caller of dowait needs to wait until either the
    given job is not running, or until all terminated jobs have been
    processed, this patch moves the loop into dowait itself.

    Fixes: 03876c0743a5 ("eval: Reap zombies after built-in...")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-18 15:37:43 +01:00
Denys Vlasenko
97edfc42f1 ash: jobs - Do not block when waiting on SIGCHLD
Upstream comment:

    Date: Mon, 7 May 2018 00:40:34 +0800
    jobs - Do not block when waiting on SIGCHLD

    Because of the nature of SIGCHLD, the process may have already been
    waited on and therefore we must be prepared for the case that wait
    may block.  So ensure that it doesn't by using WNOHANG.

    Furthermore, multiple jobs may have exited when gotsigchld is set.
    Therefore we need to wait until there are no zombies left.

    Lastly, waitforjob needs to be called with interrupts off and
    the original patch broke that.

    Fixes: 03876c0743a5 ("eval: Reap zombies after built-in...")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

While at it, removed INT_ON/OFF in waitforjob() - it must be called
from INT_OFF region anyway.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-18 15:37:22 +01:00
Denys Vlasenko
d81af7216b ash: eval: Reap zombies after built-in commands and functions
Upstream commit:

    Date: Mon, 26 Mar 2018 23:55:50 +0800
    eval: Reap zombies after built-in commands and functions

    Currently dash does not reap dead children after built-in commands
    or functions.  This means that if you construct a loop consisting
    of solely built-in commands and functions, then zombies can hang
    around indefinitely.

    This patch fixes this by reaping when necessary after each built-in
    command and function.

    Reported-by: Denys Vlasenko <vda.linux@googlemail.com>
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-18 14:28:30 +01:00
Denys Vlasenko
22c75924da ash: exec: Never rehash regular built-ins
Upstream commit:

    Date: Sat, 19 May 2018 02:39:51 +0800
    exec: Never rehash regular built-ins

    As regular (including special) built-ins can never be overridden,
    we should never remove them from the hash table.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-17 16:20:05 +01:00
Denys Vlasenko
6c4f87e411 ash: exec: Stricter pathopt parsing
Upstream comment:

    Date: Sat, 19 May 2018 02:39:50 +0800
    exec: Stricter pathopt parsing

    This patch changes the parsing of pathopt.  First of all only
    %builtin and %func (with arbitrary suffixes) will be recognised.
    Any other pathopt will be treated as a normal directory.

    Furthermore, pathopt can now be specified before the directory,
    rather than after it.  In fact, a future version may remove support
    for pathopt suffixes.

    Wherever the pathopt is placed, an optional % may be placed after
    it to terminate the pathopt.

    This is so that it is less likely that a genuine directory containing
    a % sign is parsed as a pathopt.

    Users of padvance outside of exec.c have also been modified:

    1) cd(1) will always treat % characters as part of the path.
    2) chkmail will continue to accept arbitrary pathopt.
    3) find_dot_file will ignore the %builtin pathopt instead of trying
    to do a stat in the accompanying directory (which is usually the
    current directory).

    The patch also removes the clearcmdentry optimisation where we
    attempt to only partially flush the table where possible.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-17 16:02:40 +01:00
Denys Vlasenko
b0d2dc7d62 ash: exec: Do not allocate stack string in padvance
Upstream commit:

    Date: Sat, 19 May 2018 02:39:48 +0800
    exec: Do not allocate stack string in padvance

    Many callers of padvance immediately free the allocated string
    so this patch moves the stalloc call to the caller.  Instead of
    returning the allocated string, padvance now returns the length
    to allocate (this may be longer than the actual string length,
    even including the NUL).  For the case where we would previously
    return NULL, we now return -1.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-17 15:59:44 +01:00
Denys Vlasenko
c55847fedb ash: memalloc: Add growstackto helper
Upstream commit:

    Date: Sat, 19 May 2018 02:39:46 +0800
    memalloc: Add growstackto helper

    This patch adds the growstackto helper which repeatedly calls
    growstackblock until the requested size is reached.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-17 15:59:08 +01:00
Denys Vlasenko
74aaf05170 ash: parser: Save/restore here-documents in command substitution
Upstream comment:

    Date: Sat, 19 May 2018 02:39:42 +0800
    parser: Save/restore here-documents in command substitution

    This patch changes the parsing of here-documents within command
    substitution, both old style and new style.  In particular, the
    original here-document list is saved upon the beginning of parsing
    command substitution and restored when exiting.

    This means that here-documents outside of command substitution
    can no longer be filled by text within it and vice-versa.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-17 12:11:26 +01:00
Denys Vlasenko
afc91faedd ash: mkinit: Split reset into exitreset and reset
Upstream commit:

    Date: Sat, 19 May 2018 02:39:40 +0800
    mkinit: Split reset into exitreset and reset

    Previously reset was called after exitshell.  This was changed
    so that it was called before exitshell because certain state needed
    to be reset in order for the EXIT trap to work.

    However, this caused issues because certain other states (such
    as local variables) should not be reset.  This patch fixes this
    by creating a new function exitreset that is called prior to
    exitshell and moving reset back to its original location.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-17 11:22:59 +01:00
Denys Vlasenko
9ee5892798 ash: expand: Fix trailing newlines processing in backquote expanding
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>
2020-02-17 10:24:32 +01:00
Denys Vlasenko
c2ce888030 ash: parser: Only accept single-digit parameter expansion outside of braces
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>
2020-02-17 10:15:35 +01:00
Denys Vlasenko
3f4847b6d9 ash: shell: Fix clang warnings about "string plus integer"
Upstream commit:

    Date: Sat, 15 Dec 2018 18:49:31 +0100
    shell: Fix clang warnings about "string plus integer"

    Building with clang results in some warnings about integer values being
    added to strings.

    While the code itself is fine and the warnings are indeed harmless,
    fixing them also makes the semantic more explicit: what it is actually
    being increased is the address which points to the start of the string
    in order to skip the initial character when some conditions are met.

    Signed-off-by: Antonio Ospite <ao2@ao2.it>
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:29:31 +01:00
Denys Vlasenko
e368d851e7 ash: eval: Use the correct expansion mode for fd redirection
Upstream comment:

    Date: Mon, 19 Nov 2018 18:00:32 +0800
    eval: Use the correct expansion mode for fd redirection

    It has been reported that

            echo test >&$EMPTY_VARIABLE

    causes dash to segfault.  This is a symptom of the bigger problem
    that dash tries to perform pathname expansion as well as field
    splitting on the word after >& and <&.  This is wrong and this
    patch fixes it to use the same expansions as done on a normal
    redirection.

    Reported-by: Andrej Shadura <andrew.shadura@collabora.co.uk>
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:24:33 +01:00
Denys Vlasenko
4ace385809 ash: expand: Fix skipping of command substitution when trimming in evalvar
Upstream commit:

    Date: Mon, 28 May 2018 17:09:48 +0800
    expand: Fix skipping of command substitution when trimming in evalvar

    When we are trimming an unset variable in evalvar, any embedded
    command substitution that should have been skipped are not.  This
    can cause them to be evaluated later should there be other command
    substitutions in the same input word.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:22:32 +01:00
Denys Vlasenko
226b8a143d ash: main: Print \n upon EOF (CTRL-D) when run interactively
Upstream comment:

    Date: Fri, 7 Sep 2018 10:34:14 +0200
    main: Print \n upon EOF (CTRL-D) when run interactively

    Exiting dash via a ^D instead of with "exit" causes dash to forget to
    print a newline.

        sh-3.1$ sh
        sh-3.1$ ^D
        sh-3.1$ dash
        $ sh-3.1$

    It is more neat and tidy to send a newline similarly to what bash does,
    so it doesn't make the next prompt of the parent shell look ugly.

    Suggested by jidanni.

    Signed-off-by: Gerrit Pape <pape@smarden.org>
    Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
    [reworded the patch description]
    Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>
    Bug-Debian: http://bugs.debian.org/476422
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:16:52 +01:00
Denys Vlasenko
e880b1fea8 ash: expand: Use HOME in tilde expansion when it is empty
Upstream commit:

    Date: Sun, 27 May 2018 17:31:57 +0800
    expand: Use HOME in tilde expansion when it is empty

    Currently if HOME is set to empty tilde expansion will fail, i.e.,
    it will remain as a literal tilde.  This patch changes it to
    return the empty string as required by POSIX.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:16:35 +01:00
Denys Vlasenko
a7b97e367c ash: builtin: Mark more regular built-ins
Upstream commit:

    Date: Sat, 19 May 2018 02:39:49 +0800
    builtin: Mark more regular built-ins

    This patch marks the following built-ins as regular, meaning that
    they cannot be overriden using PATH search:

            hash
            pwd
            type
            ulimit

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:14:45 +01:00
Denys Vlasenko
2bad3a305b ash: jobs: Replace some uses of fmtstr with stpcpy/stpncpy
Upstream commit:

    Date: Sat, 19 May 2018 02:39:45 +0800
    jobs: Replace some uses of fmtstr with stpcpy/stpncpy

    Some uses of fmtstr, particularly the ones without a format string,
    can be replaced with stpcpy or stpncpy.  This patch does that so
    we don't have to introduce unnecessary format strings in order to
    silence compiler warnings.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:14:45 +01:00
Denys Vlasenko
3f7fb2c89a ash: output: Fix fmtstr return value
Upstream commit:

    Date: Sat, 19 May 2018 02:39:44 +0800
    output: Fix fmtstr return value

    The function fmtstr is meant to return the actual length of output
    produced, rather than the untruncated length.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:14:45 +01:00
Denys Vlasenko
970470e235 ash: main: Only set savestatus in exitcmd
Upstream commit:

    Date: Sat, 19 May 2018 02:39:38 +0800
    main: Only set savestatus in exitcmd

    Currently exitcmd sets exitstatus and then savestatus if the latter
    was previously set.  In fact, as exitcmd always raises an exception
    and will either end up in the setjmp call in main() or exitshell(),
    where exitstatus is always replaced by savestatus if set, we only
    need to set savestatus.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:14:45 +01:00
Denys Vlasenko
4ccddc8fb3 ash: [BUILTIN] Exit without arguments in a trap should use status outside traps
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>
2020-02-16 19:14:45 +01:00
Denys Vlasenko
f7eea8c235 ash: parser: Fix incorrect eating of backslash newlines
Keeping up with upstream (in our case, 'before patch' code is not buggy).
Upstream commit:

    Date: Fri, 11 May 2018 23:41:25 +0800
    parser: Fix incorrect eating of backslash newlines

    With the introduction of synstack->syntax, a number of references
    to the syntax variable was missed during the conversion.  This
    causes backslash newlines to be incorrectly removed in single
    quote context.

    This patch also combines these calls into a new helper function
    pgetc_top.

    Fixes: ab1cecb40478 ("parser: Add syntax stack for recursive...")
    Reported-by: Leah Neukirchen <leah@vuxu.org>
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:14:45 +01:00
Denys Vlasenko
acf79f9913 ash: use pgetc_eatbnl() in more places, take 2
Adding previously skipped "readtoken1(pgetc_eatbnl(), DQSYNTAX..." changes
from upstream commit:

    Date:   Thu Mar 8 08:37:11 2018 +0100
    Author: Harald van Dijk <harald@gigawatt.nl>
    parser: use pgetc_eatbnl() in more places

    dash has a pgetc_eatbnl function in parser.c which skips any
    backslash-newline combinations. It's not used everywhere it could be.
    There is also some duplicated backslash-newline handling elsewhere in
    parser.c. Replace most of the calls to pgetc() with calls to
    pgetc_eatbnl() and remove the duplicated backslash-newline handling.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-02-16 19:14:45 +01:00
Ron Yorston
9e2a5668fd ash,hush: allow builtins to be tab-completed, closes 7532
function                                             old     new   delta
complete_cmd_dir_file                                678     830    +152
get_builtin_name                                       -      35     +35
optschanged                                          125     132      +7
hush_main                                           1069    1076      +7
save_command_ps_at_cur_history                        76      78      +2
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 4/0 up/down: 203/0)             Total: 203 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-01-29 15:23:17 +01:00
Ron Yorston
b0c711e64f ash: improve expandstr()
The dash maintainer recently posted a fix for issues with expanding
PS1.  These had already been fixed differently in BusyBox ash.  Borrow
a couple of improvements:

- Use a single call to setjmp() to trap errors in both readtoken1()
  and expandarg().

- In case of error set the prompt to the literal value of PS1 rather
  than the half-digested nonsense in stackblock() which might include
  ugly control characters.

function                                             old     new   delta
expandstr                                            353     300     -53

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-01-29 13:59:45 +01:00
Denys Vlasenko
af7169b4a7 clang/llvm 9 fix - do not eliminate a store to a fake "const"
This is *much* better (9 kbytes better) than dropping "*const"
optimization trick.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-10-25 12:12:22 +02:00
Denys Vlasenko
35e349de3c ash: add a FIXME comment
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-09-05 14:31:49 +02:00
Denys Vlasenko
2f9c124f7d ash: fix set -o to not show "nameless" options
Patch by Martijn Dekker <martijn@inlv.org>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-08-02 16:44:35 +02:00
Ron Yorston
943e81f5db ash: only catch unexpected exceptions in PS1 expansion
Commit d1a2fa2a4 (ash: catch error in arithmetic expansion in PS1)
catches all exceptions raised by expandarg().  Some exceptions, such as
the EXEXIT raised when command expansion is used, are expected:

   export PS1='$(echo "$ ")'

These should be processed normally or the shell hangs at the prompt.

function                                             old     new   delta
expandstr                                            344     353      +9
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 9/0)                 Total: 9 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-31 13:44:32 +02:00
Denys Vlasenko
f3634584d0 ash,hush: show 'c' in $- if run in "sh -c CMD"
function                                             old     new   delta
options                                              552     599     +47
expand_one_var                                      2375    2385     +10
optletters_optnames                                   60      64      +4
hush_main                                           1108    1111      +3
ash_main                                            1150    1152      +2
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/0 up/down: 66/0)               Total: 66 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-06-03 12:21:04 +02:00
Denys Vlasenko
897475ab02 ash: allocate line editing structure only if needed
function                                             old     new   delta
optschanged                                           91     128     +37
historycmd                                            13      17      +4
setcmd                                                80      78      -2
ash_main                                            1167    1150     -17
options                                              576     552     -24
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/3 up/down: 41/-43)             Total: -2 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-06-01 16:35:09 +02:00
Ron Yorston
d1a2fa2a4e ash: catch error in arithmetic expansion in PS1
Setting PS1 to:

   PS1='$((123+))'

causes the shell to enter an infinite error loop:

   sh: arithmetic syntax error

Catch any exception raised by expandarg() in expandstr() and allow
processing to continue.

function                                             old     new   delta
expandstr                                            262     344     +82
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 82/0)               Total: 82 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-19 13:21:34 +02:00
Ron Yorston
48645b8350 ash: prevent error in backquotes in PS1 from exiting shell
Setting PS1 to:

   PS1='`xxx(`'

causes the shell to terminate with the error:

   sh: syntax error: unexpected end of file (expecting ")")

This happens because old-style backquotes require the input to be reread
and thus call setinputstring() a second time.  Prevent the problem by
unwinding all recently opened files in expandstr().

function                                             old     new   delta
unwindfiles                                            -      22     +22
expandstr                                            247     262     +15
forkchild                                            631     625      -6
evalcommand                                         1694    1685      -9
ash_main                                            1346    1336     -10
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/3 up/down: 37/-25)             Total: 12 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-19 13:21:34 +02:00
Ron Yorston
1d37186fe2 ash: add bash-compatible EPOCH variables
Bash 5.0 added the dynamic variable EPOCHSECONDS and EPOCHREALTIME
which return the number of seconds since the Unix Epoch as an
integer or float.  These are useful for logging or tracing.

function                                             old     new   delta
change_epoch                                           -      78     +78
.rodata                                           175167  175235     +68
varinit_data                                         264     312     +48
change_seconds                                         -      24     +24
change_realtime                                        -      24     +24
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 2/0 up/down: 242/0)             Total: 242 bytes
   text	   data	    bss	    dec	    hex	filename
 938508	   4203	   1888	 944599	  e69d7	busybox_old
 938702	   4203	   1888	 944793	  e6a99	busybox_unstripped

v2: Cast tv_sec and tv_usec to unsigned quantities.
    Add brackets to macros.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-16 18:29:52 +02:00
Ron Yorston
d96c69d876 ash: an unset dynamic variable should not be dynamic
Commit b28d4c346 (ash: [VAR] Move unsetvar functionality into setvareq)
dropped the code that caused dynamic variables to lose their special
properties when unset.  Add it back again.

function                                             old     new   delta
setvareq                                             346     360     +14
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 14/0)               Total: 14 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-16 18:29:52 +02:00
Ron Yorston
e48559eae3 ash: distinguish 'wait -n' from other bashisms
Add a specific define to indicate which bash compatibility code
implements 'wait -n'.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-02 13:43:40 +02:00
Denys Vlasenko
966f087ab4 ash: add "wait -n" bashism
function                                             old     new   delta
waitcmd                                              205     288     +83
dowait                                               405     444     +39
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 122/0)             Total: 122 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-03-27 15:52:17 +01:00
Ron Yorston
f55161ad27 ash: eval: avoid leaking memory associated with redirections. Closes 7748
The following constructs result in ever-increasing memory usage:

   while true; do { true; } </dev/null; done
   while true; do ( true; ) </dev/null; done

For comparison, bash displays static memory usage in both cases.

This has been fixed in dash by commit 2bc6caa.  The maintainer
writes:

   I have simplified evaltree so that it simply sets the stack mark
   unconditionally.  This allows us to remove the stack marks in the
   functions called by evaltree.

Closes BusyBox bug 7748.

function                                             old     new   delta
evaltree                                             606     632     +26
evalcommand                                         1724    1696     -28
evalcase                                             382     351     -31
evalfor                                              230     196     -34
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/3 up/down: 26/-93)            Total: -67 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-02-25 18:57:59 +01:00
Denys Vlasenko
b097a84d62 config: update size information
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-12-28 03:20:17 +01:00
Denys Vlasenko
b437df1157 inetd: suppress aliasing warning
function                                             old     new   delta
sigprocmask2                                           -       8      +8
wait_for_child_or_signal                             213     218      +5
dowait                                               424     429      +5
block_CHLD_HUP_ALRM                                   62      59      -3
sigprocmask_SIG_SETMASK                               16       -     -16
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 2/1 up/down: 18/-19)             Total: -1 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-12-08 15:35:24 +01:00
Denys Vlasenko
136fe9bede suppress gcc 8 aliasing warnings
function                                             old     new   delta
sigprocmask_SIG_SETMASK                                -      16     +16
wait_for_child_or_signal                             221     213      -8
dowait                                               432     424      -8

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-12-08 13:49:15 +01:00
Ron Yorston
71df2d3589 hush: allow hush to run embedded scripts
Embedded scripts require a shell to be present in the BusyBox
binary.  Allow either ash or hush to be used for this purpose.
If both are enabled ash takes precedence.

The size of the binary is unchanged in the default configuration:
both ash and hush are present but support for embedded scripts
isn't compiled into hush.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-27 16:13:07 +01:00
Christoph Schulz
03ad7ae081 ash: reset tokpushback before prompting while parsing heredoc
The parser reads from an already freed memory location, thereby causing
unpredictable results, in the following situation:

- ENABLE_ASH_EXPAND_PRMT is enabled
- heredoc is being parsed
- command substitution is used within heredoc

Examples where this bug crops up are (PS2 is set to "> "):

$ cat <<EOF
> `echo abc`
> EOF
-sh: O: not found

$ cat <<EOF
> $(echo abc)
> EOF
-sh: {garbage}: not found

The presumable reason is that setprompt_if() causes a nested expansion when
ENABLE_ASH_EXPAND_PRMT is enabled, therefore leaving "wordtext" in an unusable
state. However, when parseheredoc() is called, "tokpushback" is non-zero, which
causes the next call to xxreadtoken() to return TWORD, causing the caller to
use the invalid "wordtoken" instead of reading the next valid token.

The call chain is:

list()
-> peektoken() [sets tokpushback to 1]
-> parseheredoc()
   -> setprompt_if()
      -> pushstackmark()
      -> expandstr()
         -> readtoken1()
            [sets lasttoken to TWORD, wordtoken points to expanded prompt]
      -> popstackmark() [invalidates wordtoken, leaves lasttoken as is]
   -> readtoken1()
      -> ...parsebackq
         -> list()
            -> andor()
               -> pipeline()
                  -> readtoken()
                     -> xxreadtoken()
                        [tokpushback non-zero, reuse lasttoken and wordtext]

Note that in almost all other contexts, each call to setprompt_if() is preceded
by setting "tokpushback" to zero. One exception is "oldstyle" backquote parsing
in readtoken1(), but there "tokpushback" is reset afterwards. The other
exception is nlprompt(), but this function is only used within readtoken1()
(but in contexts where no nested calls to xxreadtoken() occur) and xxreadtoken()
(where "tokpushback" is guaranteed to be zero).

function                                             old     new   delta
parseheredoc                                         124     131      +7

Signed-off-by: Christoph Schulz <develop@kristov.de>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-20 17:45:52 +01:00
Ron Yorston
3778898f97 Treat custom and applet scripts as applets
BusyBox has support for embedded shell scripts.  Two types can be
distinguished:  custom scripts and scripts implementing applets.

Custom scripts should be placed in the 'embed' directory at build
time.  They are given a default applet configuration and appear
as applets to the user but no further configuration is possible.

Applet scripts are integrated with the BusyBox build system and
are intended to be used to ship standard applets that just happen
to be implemented as scripts.  They can be configured at build time
and appear just like native applets.

Such scripts should be placed in the 'applets_sh' directory.  A stub
C program should be written to provide the usual applet configuration
details and placed in a suitable subsystem directory.  It may be
helpful to have a configuration option to enable any dependencies the
script requires:  see the 'nologin' applet for an example.

function                                             old     new   delta
scripted_main                                          -      41     +41
applet_names                                        2773    2781      +8
applet_main                                         1600    1604      +4
i2cdetect_main                                       672     674      +2
applet_suid                                          100     101      +1
applet_install_loc                                   200     201      +1
applet_flags                                         100     101      +1
packed_usage                                       33180   33179      -1
tryexec                                              159     152      -7
evalcommand                                         1661    1653      -8
script_names                                           9       -      -9
packed_scripts                                       123     114      -9
complete_cmd_dir_file                                826     811     -15
shellexec                                            271     254     -17
find_command                                        1007     990     -17
busybox_main                                         642     624     -18
run_applet_and_exit                                  100      78     -22
find_script_by_name                                   51       -     -51
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 6/9 up/down: 58/-174)          Total: -116 bytes
   text	   data	    bss	    dec	    hex	filename
 950034	    477	   7296	 957807	  e9d6f	busybox_old
 949918	    477	   7296	 957691	  e9cfb	busybox_unstripped

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-17 21:16:33 +01:00
Ron Yorston
e6a63bf683 ash: ensure variables are fully initialised when unset
When a variable is unset by calling setvar(name, NULL, 0) the code
to initialise the new, empty variable fails to initialise the last
character of the string.

Attempts to read the contents of the unset variable will result
in the uninitialised character at the end of the string being
accessed.

For example, running BusyBox under Valgrind and unsetting PATH:

$ valgrind ./busybox_unstripped sh
==21249== Memcheck, a memory error detector
==21249== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==21249== Using Valgrind-3.14.0 and LibVEX; rerun with -h for copyright info
==21249== Command: ./busybox_unstripped sh
==21249==
/data2/git/build_fix_8721 $ unset PATH
/data2/git/build_fix_8721 $ 0
==21249== Conditional jump or move depends on uninitialised value(s)
==21249==    at 0x451371: path_advance (ash.c:2555)
==21249==    by 0x456E22: find_command (ash.c:13407)
==21249==    by 0x458425: evalcommand (ash.c:10139)
==21249==    by 0x454CBC: evaltree (ash.c:9131)
==21249==    by 0x456C80: cmdloop (ash.c:13164)

Closes https://bugs.busybox.net/show_bug.cgi?id=8721

v2: On the dash mailing list Harald van Dijk was kind enough to point
    out a flaw in my reasoning and provide an alternative patch.  Sadly
    his patch adds 2 bytes of bloat.  Using xzalloc to zero the whole
    string gives a bloat of -3 bytes.

function                                             old     new   delta
setvar                                               172     169      -3

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-16 17:28:01 +01:00
Ron Yorston
8767c12774 ash: minor fixes
Ensure that login_sh is initialised in procargs even when running
an embedded script.

The argc argument to ash_main isn't unused when embedded scripts
are present.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-06 08:49:11 +01:00
Denys Vlasenko
b0df5af0fa ash: fix thinko in last commit
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-01 12:50:33 +01:00
Ron Yorston
ca82b5354f ash: in tryexec(), ensure we don't try to run embedded scripts as applets
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-01 11:48:21 +01:00
Ron Yorston
151de441e7 ash: recognize embedded scripts in SH_STANDALONE mode
function                                             old     new   delta
find_script_by_name                                    -      51     +51
shellexec                                            254     271     +17
find_command                                         990    1007     +17
evalcommand                                         1653    1661      +8
doCommands                                          2233    2222     -11
run_applet_and_exit                                  128     100     -28
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 6/4 up/down: 104/-52)            Total: 52 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-01 11:07:26 +01:00
Denys Vlasenko
aa2959c90d claenups for previous commit
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-01 10:28:04 +01:00
Denys Vlasenko
4f2ef4a836 ash: allow shell scripts to be embedded in the binary
To assist in the deployment of shell scripts it may be convenient
to embed them in the BusyBox binary.

'Embed scripts in the binary' takes any files in the directory
'embed', concatenates them with null separators, compresses them
and embeds them in the binary.

When scripts are embedded in the binary, scripts can be run as
'busybox SCRIPT [ARGS]' or by usual (sym)link mechanism.

embed/nologin is provided as an example.

function                                             old     new   delta
packed_scripts                                         -     123    +123
unpack_scripts                                         -      87     +87
ash_main                                            1103    1171     +68
run_applet_and_exit                                   78     128     +50
get_script_content                                     -      32     +32
script_names                                           -      10     +10
expmeta                                              663     659      -4
------------------------------------------------------------------------------
(add/remove: 4/0 grow/shrink: 2/1 up/down: 370/-4)            Total: 366 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-01 10:15:13 +01:00
Denys Vlasenko
eb54ca8be0 ash: expand: Do not quote backslashes in unquoted parameter expansion
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>
2018-08-07 18:58:02 +02:00
Denys Vlasenko
2596f412cd ash: exec: Return 126 on most errors in shellexec
Upstream commit:

    Date: Sat, 19 May 2018 02:39:37 +0800
    exec: Return 126 on most errors in shellexec

    Currently when shellexec fails on most errors the shell will exit
    with exit status 2.  This patch changes it to 126 in order to avoid
    ambiguities with the exit status from a successful exec.

    The errors that result in 127 has also been expanded to include
    ENOTDIR, ENAMETOOLONG and ELOOP.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

function                                             old     new   delta
shellexec                                            245     254      +9

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-08-05 18:11:15 +02:00
Denys Vlasenko
1c5eb88cd8 ash: eval: Restore input files in evalcommand
Upstream commit:

    Date: Tue, 27 Mar 2018 00:39:35 +0800
    eval: Restore input files in evalcommand

    When evalcommand invokes a command that modifies parsefile and
    then bails out without popping the file, we need to ensure the
    input file is restored so that the shell can continue to execute.

    Reported-by: Martijn Dekker <martijn@inlv.org>
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

function                                             old     new   delta
unwindfiles                                            -      20     +20
evalcommand                                         1635    1653     +18
getoptscmd                                           584     595     +11
popallfiles                                           20      10     -10
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/1 up/down: 49/-10)             Total: 39 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-08-05 18:11:15 +02:00
Denys Vlasenko
58eb805c2c ash: parser: Fix parsing of ${}
Upstream commit:

    Date: Tue, 3 Apr 2018 00:40:25 +0800
    parser: Fix parsing of ${}

    dash -c 'echo ${}' should print "Bad subtitution" but instead
    fails with "Syntax error: Missing '}'".  This is caused by us
    reading an extra character beyond the right brace.  This patch
    fixes it so that this construct only fails during expansion rather
    than during parsing.

    Fixes: 3df3edd13389 ("[PARSER] Report substition errors at...")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

function                                             old     new   delta
readtoken1                                          2907    2916      +9

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-08-05 18:11:15 +02:00
Denys Vlasenko
19358cc313 ash,hush: fold shell_builtin_read() way-too-many params into a struct param
function                                             old     new   delta
getoptscmd                                           587     584      -3
readcmd                                              240     224     -16
shell_builtin_read                                  1426    1399     -27
builtin_read                                         210     182     -28
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-74)             Total: -74 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-08-05 18:11:15 +02:00