Builtins (including variable assignments without command word), function
calls and redirected compound commands need to restore file descriptors
to their original state after execution. This is handled by allocating a
redirtab structure. These mallocs and frees show up heavily in pmcstat.
Only allocate a redirtab if there are actually redirections and maintain a
count of how many levels of REDIR_PUSH there are without redirtabs.
A simple loop without external programs like
sh -c 'i=0; w=$(printf %0100d 7); while [ "$i" -lt 1000000 ]; do
i=$((i+1)); done'
is over 25% faster on an amd64 bhyve VM.
Forbid (temporary or permanent) modifications of the strings in NARG nodes
during expansion.
Tilde expansion now needs to copy the username for the terminating '\0'.
Per POSIX, 'cd -' should use the OLDPWD shell variable, not internal state.
This variable is normally exported.
Also, if OLDPWD is not set, fail 'cd -' instead of changing to the current
directory.
Some variables like PATH call a function when modified. Make sure to call
this also when leaving a function where such a variable was made local.
Make sure to restore local variables before shellparam, so getopts state is
not clobbered.
Redirect 'cd -' output to /dev/null since POSIX requires it to write the new
directory name even if not interactive, but we currently only write it if
interactive.
Command substitutions containing a single simple command and here-document
expansion are performed in a subshell environment, but may not fork. Any
modified state of the shell environment should be restored afterward.
The state that OPTIND=1 had been done was not saved and restored here.
Note that the other parts of shellparam need not be saved and restored,
since they are not modified in these situations (a fork is done before such
modifications).
With the new expand.c code, the intermediate representation passed to the
pathname generation code only contains CTLESC, not CTLQUOTEMARK.
CTLQUOTEMARK now only occurs in the text of NARG nodes (output of the
parser).
This avoids the need to add and remove CTLESC bytes if pathname generation
will not be performed (set -f).
Side effect: the order of operations is slightly different: pathname
generation in ${$+* $(CMD)} will not see filesystem changes from CMD.
This simplifies the code and should be faster in some cases.
Side effect: the order of operations is different so that the value of IFS
used when IFS is modified during expansion (${IFS:=...}, ${IFS=...} or
$((...IFS=...))) may be different. Note that this order is highly unportable
between shells.
netbsd-tests.test.mk (r289151)
- Eliminate explicit OBJTOP/SRCTOP setting
- Convert all ad hoc NetBSD test integration over to netbsd-tests.test.mk
- Remove unnecessary TESTSDIR setting
- Use SRCTOP where possible for clarity
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Divison
This simplifies the code (e.g. allowing use of qsort(3) instead of a
hand-rolled mergesort) and should have better cache properties.
The waste of unused args arrays after resizes is approximately the same as
the savings from getting rid of the next pointers.
At the same time, remove a piece of global state and move some duplicated
code into a function.
Shell syntax is too complicated to detect command substitution and unquoted
operators reliably without implementing much of sh's parser. Therefore, have
sh do this detection.
While changing sh's support anyway, also read input from a pipe instead of
arguments to avoid {ARG_MAX} limits and improve privacy, and output count
and length using 16 instead of 8 digits.
The basic concept is:
execl("/bin/sh", "sh", "-c", "freebsd_wordexp ${1:+\"$1\"} -f "$2",
"", flags & WRDE_NOCMD ? "-p" : "", <pipe with words>);
The WRDE_BADCHAR error is still implemented in libc. POSIX requires us to
fail strings containing unquoted braces with code WRDE_BADCHAR. Since this
is normally not a syntax error in sh, there is still a need for checking
code in libc, we_check().
The new we_check() is an optimistic check that all the characters
<newline> | & ; < > ( ) { }
are quoted. To avoid duplicating too much sh logic, such characters are
permitted when quoting characters are seen, even if the quoting characters
may themselves be quoted. This code reports all WRDE_BADCHAR errors; bad
characters that get past it and are a syntax error in sh return WRDE_SYNTAX.
Although many implementations of WRDE_NOCMD erroneously allow some command
substitutions (and ours even documented this), there appears to be code that
relies on its security (codesearch.debian.net shows quite a few uses).
Passing untrusted data to wordexp() still exposes a denial of service
possibility and a fairly large attack surface.
Reviewed by: wblock (man page only)
MFC after: 2 weeks
Relnotes: yes
Security: fixes command execution with wordexp(untrusted, WRDE_NOCMD)
POSIX requires this to prevent entering function definitions in history but
this implementation does nothing except retain the option's value. In ksh88,
function definitions were usually entered in the history file, even when
they came from ~/.profile and the $ENV file, to allow displaying their
definitions.
This is also the first option that does not have a letter.
The initial check for a matching ] was incorrect if a ] may be consumed by a
[:class:]. The subsequent loop assumed that there must be a ].
Remove the initial check and make the loop cope with a missing ].
Found with afl-fuzz.
MFC after: 1 week
An invalid substitution like ${var@} does not cause a parse error but is
stored in the intermediate representation, to be written as part of the
error message. If there is a CTL* byte in the stored part, this confuses
some code such as the code to skip an unused alternative such as in
${var-alternative}.
To keep things simple, do not store CTL* bytes.
Found with afl-fuzz.
MFC after: 1 week
The negative value was not expected and generated the low 8 bits as a byte,
which may be an invalid character encoding.
The final shift in creating the negative value was undefined as well.
Make the temporary variable unsigned to fix this.
Fix shifts of possibly negative numbers found with ubsan and avoid signed
integer overflow when hashing an extremely long command name.
MFC after: 1 week
Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.
Still need to add real targets under targets/ to build packages.
Differential Revision: D2796
Reviewed by: brooks imp
interactive.
I added the interactive check in r208881 to be safe, but in actual use
(scripts in set -m mode) passing along SIGINT seems best.
Discussed with: bdrewery
The parser considered 'trap exit INT' to reset the default for both EXIT and
INT. This beahvior is not POSIX compliant. This was avoided if a value was
specified for 'exit', but then disallows exiting with the signal received. A
possible workaround is using ' exit'.
However POSIX does allow this type of behavior if the parameters are all
integers. Fix the handling for this and clarify its support in the manpage
since it is specifically allowed by POSIX.
Differential Revision: https://reviews.freebsd.org/D2325
Reviewed by: jilles
MFC after: 2 weeks
