Upstream commit
Date: Wed, 14 Dec 2022 02:06:05 +0100
parser: Invalid redirections are run-time, not syntax errors
This fixes a long-standing bug where
echo 'echo >&a' | sh
errors out with
sh: 2: Syntax error: Bad fd number
despite the error being on line 1
This patch makes the error
sh: 1: Bad fd number: a
as expected
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Thu, 28 May 2020 21:31:45 +1000
redir: Retry open64 on EINTR
It is possible for open64 to block on named pipes, and therefore
it can be interrupted by signals and return EINTR. We should only
let it fail with EINTR if real signals are pending (i.e., it should
not fail on SIGCHLD if SIGCHLD has not been trapped).
This patch adds a new helper sh_open to retry the open64 call if
necessary. It also calls sh_error when appropriate.
Fixes: 3800d4934391 ("[JOBS] Fix dowait signal race")
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Sun, 3 Mar 2019 21:57:50 +0800
eval: Reset handler when entering a subshell
As it is a subshell can execute code that is only meant for the
parent shell when it executes a longjmp that is caught by something
like evalcommand. This patch fixes it by resetting the handler
when entering a subshell.
function old new delta
evalsubshell 169 183 +14
evalpipe 342 356 +14
argstr 1406 1416 +10
ash_main 1236 1226 -10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/1 up/down: 65/-10) Total: 28 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Wed, 6 Jan 2021 15:45:12 +1100
jobs: Block signals during tcsetpgrp
Harald van Dijk <harald@gigawatt.nl> wrote:
> On 19/12/2020 22:21, Steffen Nurpmeso wrote:
>> Steffen Nurpmeso wrote in
>> <20201219172838.1B-WB%steffen@sdaoden.eu>:
>> |Long story short, after falsely accusing BSD make of not working
>>
>> After dinner i shortened it a bit more, and attach it again, ok?
>> It is terrible, but now less redundant than before.
>> Sorry for being so terse, that problem crosses my head for about
>> a week, and i was totally mislead and if you bang your head
>> against the wall so many hours bugs or misbehaviours in a handful
>> of other programs is not the expected outcome.
>
> I think a minimal test case is simply
>
> all:
> $(SHELL) -c 'trap "echo TTOU" TTOU; set -m; echo all good'
>
> unless I accidentally oversimplified.
>
> The SIGTTOU is caused by setjobctl's xtcsetpgrp(fd, pgrp) call to make
> its newly started process group the foreground process group when job
> control is enabled, where xtcsetpgrp is a wrapper for tcsetpgrp. (That's
> in dash, the other variants may have some small differences.) tcsetpgrp
> has this little bit in its specification:
>
> Attempts to use tcsetpgrp() from a process which is a member of
> a background process group on a fildes associated with its con‐
> trolling terminal shall cause the process group to be sent a
> SIGTTOU signal. If the calling thread is blocking SIGTTOU sig‐
> nals or the process is ignoring SIGTTOU signals, the process
> shall be allowed to perform the operation, and no signal is
> sent.
>
> Ordinarily, when job control is enabled, SIGTTOU is ignored. However,
> when a trap action is specified for SIGTTOU, the signal is not ignored,
> and there is no blocking in place either, so the tcsetpgrp() call is not
> allowed.
>
> The lowest impact change to make here, the one that otherwise preserves
> the existing shell behaviour, is to block signals before calling
> tcsetpgrp and unblocking them afterwards. This ensures SIGTTOU does not
> get raised here, but also ensures that if SIGTTOU is sent to the shell
> for another reason, there is no window where it gets silently ignored.
>
> Another way to fix this is by not trying to make the shell start a new
> process group, or at least not make it the foreground process group.
> Most other shells appear to not try to do this.
This patch implements the blocking of SIGTTOU (and everything else)
while we call tcsetpgrp.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Sat, 19 May 2018 02:39:56 +0800
eval: Add vfork support
This patch adds basic vfork support for the case of a simple command.
Upstream commit:
Date: Tue, 12 Jan 2021 17:11:19 +1100
jobs: Always reset SIGINT/SIGQUIT handlers
On Fri, Jan 08, 2021 at 08:55:41PM +0000, Harald van Dijk wrote:
> On 18/05/2018 19:39, Herbert Xu wrote:
> > This patch adds basic vfork support for the case of a simple command.
> > ... @@ -879,17 +892,30 @@ forkchild(struct job *jp, union node *n, int
> > mode)
> > }
> > }
> > if (!oldlvl && iflag) {
> > - setsignal(SIGINT);
> > - setsignal(SIGQUIT);
> > + if (mode != FORK_BG) {
> > + setsignal(SIGINT);
> > + setsignal(SIGQUIT);
> > + }
> > setsignal(SIGTERM);
> > }
> > +
> > + if (lvforked)
> > + return;
> > +
> > for (jp = curjob; jp; jp = jp->prev_job)
> > freejob(jp);
> > }
>
> This leaves SIGQUIT ignored in background jobs in interactive shells.
>
> ENV= dash -ic 'dash -c "kill -QUIT \$\$; echo huh" & wait'
>
> As of dash 0.5.11, this prints "huh". Before, the subprocess process killed
> itself before it could print anything. Other shells do not leave SIGQUIT
> ignored.
>
> (In a few other shells, this also prints "huh", but in those other shells,
> that is because the inner shell chooses to ignore SIGQUIT, not because the
> outer shell leaves it ignored.)
Thanks for catching this. I have no idea how that got in there
and it makes no sense whatsoever. This patch removes the if
conditional.
Fixes: e94a964e7dd0 ("eval: Add vfork support")
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Comparing code with dash is more difficult with these differences.
(We didn't know back then that dash will be revived...)
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Tue, 6 Dec 2022 16:49:14 +0800
eval: Always set exitstatus in evaltree
There is no harm in setting exitstatus unconditionally in evaltree.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Mon Feb 25 12:49:20 2019 +0800
options: Do not set commandname in procargs
We set commandname in procargs when we don't have to. This results
in a duplicated output of arg0 when an error occurs.
function old new delta
ash_main 1256 1236 -20
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
The rationale here is that unsetting HISTFILE in /etc/profile
does not "stick": if it's unset, the default one is set later
(after /etc/profile is executed) by the shell.
But setting (and exporting, so it is inherited by all
(grand)child shells) an empty one works.
function old new delta
save_history 296 316 +20
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Make the read built-in more compatible with bash:
- Return an exit code of 142 on timeout.
- When the timeout expires before a newline is detected in the
input bash captures the partial input. This behaviour is new
since bash version 4.4. BusyBox shells had the pre-4.4 behaviour
where the input was lost.
Update the tests to suit and fix a couple of compiler errors in
the testsuite.
function old new delta
builtin_read 154 174 +20
readcmd 213 228 +15
shell_builtin_read 1364 1370 +6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 41/0) Total: 41 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream commit:
Date: Fri, 5 Apr 2024 17:55:46 +0800
exec: Check executable bit when searching path
Andrej Shadura <andrew.shadura@collabora.co.uk> wrote:
...
> https://bugs.debian.org/874264
> -------- Forwarded Message --------
> Subject: dash: 'command -v' mistakenly returns a shell script whose
> executable is not set
> Date: Mon, 04 Sep 2017 10:45:48 -0400
> From: Norman Ramsey <nr@cs.tufts.edu>
> To: Debian Bug Tracking System <submit@bugs.debian.org>
...
> I tracked a build bug in s-nail to a problem with dash. Symptom:
> building s-nail tries to run /home/nr/bin/clang, a script whose
> executable bit is not set. We tracked the problem to the result of
> running `command -v clang` with /bin/sh:
...
This is inherited from NetBSD. There is even a commented-out
block of code that tried to fix this.
Anyway, we now have faccessat so we can simply use it.
function old new delta
test_exec - 125 +125
find_command 911 918 +7
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/0 up/down: 132/0) Total: 132 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Commit 64f70cc755 (Add --login support) added code in options()
to handle the bash-compatible '--login' option. In doing so it
committed BusyBox ash to silently accepting all other long
options.
Restore compatibility with other ash variants by rejecting unknown
long options.
function old new delta
options 589 624 +35
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
dash has accepted a patch to remove the first argument of findvar().
It's commit e85e972 (var: move hashvar() calls into findvar()).
Apply the same change to BusyBox ash.
function old new delta
findvar 35 40 +5
mklocal 268 261 -7
exportcmd 164 157 -7
setvareq 319 310 -9
lookupvar 150 141 -9
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/4 up/down: 5/-32) Total: -27 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
"echo text >&0000000000002" works as you would expect,
"echo text >&9999999999" properly fails instead of creating a file
named "9999999999".
function old new delta
expredir 219 232 +13
readtoken1 3045 3053 +8
parsefname 204 201 -3
isdigit_str9 45 - -45
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 2/1 up/down: 21/-48) Total: -27 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
With very large fd#, the error code path is different
from one for closed but small fd#.
Make it not abort if we are interactive:
$ echo text >&99 # this wasn't buggy
ash: dup2(9,1): Bad file descriptor
$ echo text >&9999 # this was
ash: fcntl(1,F_DUPFD,10000): Invalid argument
function old new delta
.rodata 105637 105661 +24
dup2_or_raise 35 38 +3
redirect 1084 1044 -40
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 27/-40) Total: -13 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Commit 549deab5a (ash: move parse-time quote flag detection to
run-time) did away with the need to distinguish between backquotes
inside and outside quotes. This left a gap among the control
characters used in argument strings. Removing this gap saves a
few bytes.
function old new delta
.rodata 167346 167338 -8
cmdputs 399 388 -11
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-19) Total: -19 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
An alias expansion immediately followed by '<' and a newline is
parsed incorrectly:
~ $ alias x='echo yo'
~ $ x<
yo
~ $
sh: syntax error: unexpected newline
The echo is executed and an error is printed on the next command
submission. In dash the echo isn't executed and the error is
reported immediately:
$ alias x='echo yo'
$ x<
dash: 3: Syntax error: newline unexpected
$
The difference between BusyBox and dash is that BusyBox supports
bash-style process substitution and output redirection. These
require checking for '<(', '>(' and '&>' in readtoken1().
In the case above, when the end of the alias is found, the '<' and
the following newline are both read to check for '<('. Since
there's no match both characters are pushed back.
The next input is obtained by reading the expansion of the alias.
Once this string is exhausted the next call to __pgetc() calls
preadbuffer() which pops the string, reverts to the previous input
and recursively calls __pgetc(). This request is satisified from
the pungetc buffer. But the first __pgetc() doesn't know this:
it sees the character has come from preadbuffer() so it (incorrectly)
updates the pungetc buffer.
Resolve the issue by moving the code to pop the string and fetch
the next character up from preadbuffer() into __pgetc().
function old new delta
pgetc 28 589 +561
__pgetc 607 - -607
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/0 up/down: 561/-607) Total: -46 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
When I planned to print the command in read_line_input, I found that after
the system started, the command printed for the first time was always
garbled.
After analysis, it is found that in the init() function of ash, the
variable basepf.buf is not initialized after applying for memory, resulting
in garbled initial data. Then assign it to the global variable
g_parsefile->buf in ash.c, and then pass g_parsefile->buf to the parameter
command of the function read_line_input in the function preadfd(), and
finally cause it to be garbled when the command is printed by
read_line_input.
The call stack is as follows:
#0 read_line_input (st=0xb6fff220, prompt=0xb6ffc910 "\\[\\033[32m\\]\\h \\w\\[\\033[m\\] \\$ ", command=command@entry=0xb6ffc230 "P\325\377\266P\325\377\266", maxsize=maxsize@entry=1024) at libbb/lineedit.c:2461
#1 0x0043ef8c in preadfd () at shell/ash.c:10812
#2 preadbuffer () at shell/ash.c:10914
#3 pgetc () at shell/ash.c:10997
#4 0x00440c20 in pgetc_eatbnl () at shell/ash.c:11039
#5 0x00440cbc in xxreadtoken () at shell/ash.c:13157
#6 0x00440f40 in readtoken () at shell/ash.c:13268
#7 0x00441234 in list (nlflag=nlflag@entry=1) at shell/ash.c:11782
#8 0x004420e8 in parsecmd (interact=<optimized out>) at shell/ash.c:13344
#9 0x00442c34 in cmdloop (top=top@entry=1) at shell/ash.c:13549
#10 0x00444e4c in ash_main (argc=<optimized out>, argv=0x444e4c <ash_main+1328>) at shell/ash.c:14747
#11 0x00407954 in run_applet_no_and_exit (applet_no=9, name=<optimized out>, argv=0xbefffd34) at libbb/appletlib.c:1024
#12 0x00407b68 in run_applet_and_exit (name=0xbefffe56 "ash", argv=0x9) at libbb/appletlib.c:1047
#13 0x00407f88 in main (argc=<optimized out>, argv=0xbefffd34) at libbb/appletlib.c:1181
Fixes: 82dd14a510 ("ash: use CONFIG_FEATURE_EDITING_MAX_LEN")
Signed-off-by: zhuyan <zhuyan34@huawei.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Has a few annoying problems:
* sleepcmd() -> sleep_main(), the parsing of bad arguments exits the shell.
* sleep_for_duration() in sleep_main() has to be interruptible for
^C traps to work, which may be a problem for other users
of sleep_for_duration().
* BUT, if sleep_for_duration() is interruptible, then SIGCHLD interrupts it
as well (try "/bin/sleep 1 & sleep 10").
* sleep_main() must not allocate anything as ^C in ash longjmp's.
(currently, allocations are only on error paths, in message printing).
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Commit daa66ed6 fixed a number of use-after-free bugs in bash pattern
substitution, however one "unguarded" STPUTC remained, which is fixed here.
function old new delta
subevalvar 1564 1576 +12
Signed-off-by: Karsten Sperling <ksperling@apple.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Since commit 9e2a5668f (ash,hush: allow builtins to be tab-completed,
closes 7532) ash and hush have supported tab completion of builtins.
Other shells, bash and ksh for example, also support tab completion
of functions and aliases.
Add such support to ash and hush.
function old new delta
ash_command_name - 92 +92
hush_command_name - 63 +63
ash_builtin_name 17 - -17
hush_builtin_name 38 - -38
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 0/0 up/down: 169/-55) Total: 100 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Avi Halachmi <avihpit@yahoo.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
We can just clear mailtime_hash to zero and have the same effect.
function old new delta
changemail 8 11 +3
mail_var_path_changed 1 - -1
cmdloop 398 382 -16
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/1 up/down: 3/-17) Total: -14 bytes
text data bss dec hex filename
1054786 559 5020 1060365 102e0d busybox_old
1054773 559 5020 1060352 102e00 busybox_unstripped
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
padvance() exit condition is return value < 0, not == 0.
After MAIL changing twice, the logic erroneously
concluded that "you have new mail".
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Mea culpa, in "Do not allocate stack string in padvance" commit
(I left an extraneous "break" statement).
function old new delta
cmdloop 329 398 +69
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
