The "run-command" API implementation has been made more robust
against dead-locking in a threaded environment.
* bw/forking-and-threading:
usage.c: drop set_error_handle()
run-command: restrict PATH search to executable files
run-command: expose is_executable function
run-command: block signals between fork and execve
run-command: add note about forking and threading
run-command: handle dup2 and close errors in child
run-command: eliminate calls to error handling functions in child
run-command: don't die in child when duping /dev/null
run-command: prepare child environment before forking
string-list: add string_list_remove function
run-command: use the async-signal-safe execv instead of execvp
run-command: prepare command before forking
t0061: run_command executes scripts without a #! line
t5550: use write_script to generate post-update hook
The set_error_handle() function was introduced by 3b331e926
(vreportf: report to arbitrary filehandles, 2015-08-11) so
that run-command could send post-fork, pre-exec errors to
the parent's original stderr.
That use went away in 79319b194 (run-command: eliminate
calls to error handling functions in child, 2017-04-19),
which pushes all of the error reporting to the parent.
This leaves no callers of set_error_handle(). As we're not
likely to add any new ones, let's drop it.
Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There's a convention in Git's code base to write assertions
as:
if (...some_bad_thing...)
die("BUG: the terrible thing happened");
with the idea that users should never see a "BUG:" message
(but if they, it at least gives a clue what happened). We
use die() here because it's convenient, but there are a few
draw-backs:
1. Without parsing the messages, it's hard for callers to
distinguish BUG assertions from regular errors.
For instance, it would be nice if the test suite could
check that we don't hit any assertions, but
test_must_fail will pass BUG deaths as OK.
2. It would be useful to add more debugging features to
BUG assertions, like file/line numbers or dumping core.
3. The die() handler can be replaced, and might not
actually exit the whole program (e.g., it may just
pthread_exit()). This is convenient for normal errors,
but for an assertion failure (which is supposed to
never happen), we're probably better off taking down
the whole process as quickly and cleanly as possible.
We could address these by checking in die() whether the
error message starts with "BUG", and behaving appropriately.
But there's little advantage at that point to sharing the
die() code, and only downsides (e.g., we can't change the
BUG() interface independently). Moreover, converting all of
the existing BUG calls reveals that the test suite does
indeed trigger a few of them.
Instead, this patch introduces a new BUG() function, which
prints an error before dying via SIGABRT. This gives us test
suite checking and core dumps. The function is actually a
macro (when supported) so that we can show the file/line
number.
We can convert die("BUG") invocations to BUG() in further
patches, dealing with any test fallouts individually.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
gethostname(2) may not NUL terminate the buffer if hostname does
not fit; unfortunately there is no easy way to see if our buffer
was too small, but at least this will make sure we will not end up
using garbage past the end of the buffer.
* dt/xgethostname-nul-termination:
xgethostname: handle long hostnames
use HOST_NAME_MAX to size buffers for gethostname(2)
If the full hostname doesn't fit in the buffer supplied to
gethostname, POSIX does not specify whether the buffer will be
null-terminated, so to be safe, we should do it ourselves. Introduce
new function, xgethostname, which ensures that there is always a \0
at the end of the buffer.
Signed-off-by: David Turner <dturner@twosigma.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
POSIX limits the length of host names to HOST_NAME_MAX. Export the
fallback definition from daemon.c and use this constant to make all
buffers used with gethostname(2) big enough for any possible result
and a terminating NUL.
Inspired-by: David Turner <dturner@twosigma.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: David Turner <dturner@twosigma.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up.
* jk/pack-name-cleanups:
index-pack: make pointer-alias fallbacks safer
replace snprintf with odb_pack_name()
odb_pack_keep(): stop generating keepfile name
sha1_file.c: make pack-name helper globally accessible
move odb_* declarations out of git-compat-util.h
These functions were originally conceived as wrapper
functions similar to xmkstemp(). They were later moved by
463db9b10 (wrapper: move odb_* to environment.c,
2010-11-06). The more appropriate place for a declaration is
in cache.h.
While we're at it, let's add some basic docstrings.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The last call to the mkstemps() function was removed in commit 659488326
("wrapper.c: delete dead function git_mkstemps()", 22-04-2016). In order
to support platforms without mkstemps(), this functionality was provided,
along with a Makefile build variable (NO_MKSTEMPS), by the gitmkstemps()
function. Remove the dead code, along with the defunct build machinery.
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a macro for exchanging the values of variables. It allows users
to avoid repetition and takes care of the temporary variable for them.
It also makes sure that the storage sizes of its two parameters are the
same. Its memcpy(1) calls are optimized away by current compilers.
Also add a conservative semantic patch for transforming only swaps of
variables of the same type.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add the macro QSORT_S, a convenient wrapper for qsort_s() that infers
the size of the array elements and dies on error.
Basically all possible errors are programming mistakes (passing NULL as
base of a non-empty array, passing NULL as comparison function,
out-of-bounds accesses), so terminating the program should be acceptable
for most callers.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function qsort_s() was introduced with C11 Annex K; it provides the
ability to pass a context pointer to the comparison function, supports
the convention of using a NULL pointer for an empty array and performs a
few safety checks.
Add an implementation based on compat/qsort.c for platforms that lack a
native standards-compliant qsort_s() (i.e. basically everyone). It
doesn't perform the full range of possible checks: It uses size_t
instead of rsize_t and doesn't check nmemb and size against RSIZE_MAX
because we probably don't have the restricted size type defined. For
the same reason it returns int instead of errno_t.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 3f2e2297b9 (add an extra level of indirection to
main(), 2016-07-01) added a declaration to git-compat-util.h,
but it was accidentally placed after the final #endif that
guards against multiple inclusions.
This doesn't have any actual impact on the code, since it's
not incorrect to repeat a function declaration in C. But
it's a bad habit, and makes it more likely for somebody else
to make the same mistake. It also defeats gcc's optimization
to avoid opening header files whose contents are completely
guarded.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allocate and copy directly in FLEXPTR_ALLOC_MEM and remove the now
unused helper function xalloc_flex(). The resulting code is shorter
and the offset arithmetic is a bit simpler.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Calculating offsets involving a NULL pointer is undefined. It works in
practice (for now?), but we should not rely on it. Allocate first and
then simply refer to the flexible array member by its name instead of
performing pointer arithmetic up front. The resulting code is slightly
shorter, easier to read and doesn't rely on undefined behaviour.
NB: The cast to a (non-const) void pointer is necessary to keep support
for flexible array members declared as const.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We call "qsort(array, nelem, sizeof(array[0]), fn)", and most of
the time third parameter is redundant. A new QSORT() macro lets us
omit it.
* rs/qsort:
show-branch: use QSORT
use QSORT, part 2
coccicheck: use --all-includes by default
remove unnecessary check before QSORT
use QSORT
add QSORT
Some codepaths in "git diff" used regexec(3) on a buffer that was
mmap(2)ed, which may not have a terminating NUL, leading to a read
beyond the end of the mapped region. This was fixed by introducing
a regexec_buf() helper that takes a <ptr,len> pair with REG_STARTEND
extension.
* js/regexec-buf:
regex: use regexec_buf()
regex: add regexec_buf() that can work on a non NUL-terminated string
regex: -G<pattern> feeds a non NUL-terminated string to regexec() and fails
Add the macro QSORT, a convenient wrapper for qsort(3) that infers the
size of the array elements and supports the convention of initializing
empty arrays with a NULL pointer, which we use in some places.
Calling qsort(3) directly with a NULL pointer is undefined -- even with
an element count of zero -- and allows the compiler to optimize away any
following NULL checks. Using the macro avoids such surprises.
Add a semantic patch as well to demonstrate the macro's usage and to
automate the transformation of trivial cases.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some codepaths in "git diff" used regexec(3) on a buffer that was
mmap(2)ed, which may not have a terminating NUL, leading to a read
beyond the end of the mapped region. This was fixed by introducing
a regexec_buf() helper that takes a <ptr,len> pair with REG_STARTEND
extension.
* js/regexec-buf:
regex: use regexec_buf()
regex: add regexec_buf() that can work on a non NUL-terminated string
regex: -G<pattern> feeds a non NUL-terminated string to regexec() and fails
Add COPY_ARRAY, a safe and convenient helper for copying arrays,
complementing ALLOC_ARRAY and REALLOC_ARRAY. Users just specify source,
destination and the number of elements; the size of an element is
inferred automatically.
It checks if the multiplication of size and element count overflows.
The inferred size is passed first to st_mult, which allows the division
there to be done at compilation time.
As a basic type safety check it makes sure the sizes of source and
destination elements are the same. That's evaluated at compilation time
as well.
COPY_ARRAY is safe to use with NULL as source pointer iff 0 elements are
to be copied. That convention is used in some cases for initializing
arrays. Raw memcpy(3) does not support it -- compilers are allowed to
assume that only valid pointers are passed to it and can optimize away
NULL checks after such a call.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We just introduced a test that demonstrates that our sloppy use of
regexec() on a mmap()ed area can result in incorrect results or even
hard crashes.
So what we need to fix this is a function that calls regexec() on a
length-delimited, rather than a NUL-terminated, string.
Happily, there is an extension to regexec() introduced by the NetBSD
project and present in all major regex implementation including
Linux', MacOSX' and the one Git includes in compat/regex/: by using
the (non-POSIX) REG_STARTEND flag, it is possible to tell the
regexec() function that it should only look at the offsets between
pmatch[0].rm_so and pmatch[0].rm_eo.
That is exactly what we need.
Since support for REG_STARTEND is so widespread by now, let's just
introduce a helper function that always uses it, and tell people
on a platform whose regex library does not support it to use the
one from our compat/regex/ directory.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git am" has been taught to make an internal call to "git apply"'s
innards without spawning the latter as a separate process.
* cc/apply-am: (41 commits)
builtin/am: use apply API in run_apply()
apply: learn to use a different index file
apply: pass apply state to build_fake_ancestor()
apply: refactor `git apply` option parsing
apply: change error_routine when silent
usage: add get_error_routine() and get_warn_routine()
usage: add set_warn_routine()
apply: don't print on stdout in verbosity_silent mode
apply: make it possible to silently apply
apply: use error_errno() where possible
apply: make some parsing functions static again
apply: move libified code from builtin/apply.c to apply.{c,h}
apply: rename and move opt constants to apply.h
builtin/apply: rename option parsing functions
builtin/apply: make create_one_file() return -1 on error
builtin/apply: make try_create_file() return -1 on error
builtin/apply: make write_out_results() return -1 on error
builtin/apply: make write_out_one_result() return -1 on error
builtin/apply: make create_file() return -1 on error
builtin/apply: make add_index_file() return -1 on error
...
Let's make it possible to get the current error_routine and warn_routine,
so that we can store them before using set_error_routine() or
set_warn_routine() to use new ones.
This way we will be able put back the original routines, when we are done
with using new ones.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are already set_die_routine() and set_error_routine(),
so let's add set_warn_routine() as this will be needed in a
following commit.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move our implementation of strdup(3) out of compat/nedmalloc/ and
allow it to be used independently from USE_NED_ALLOCATOR. The
original nedmalloc doesn't come with strdup() and doesn't need it.
Only _users_ of nedmalloc need it, which was added when we imported
it to our compat/ hierarchy.
This reduces the difference of our copy of nedmalloc from the
original, making it easier to update, and allows for easier testing
and reusing of our version of strdup().
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit e208f9c (make error()'s constant return value more
visible, 2012-12-15) introduced some macro trickery to make
the constant return from error() more visible to callers,
which in turn can help gcc produce better warnings (and
possibly even better code).
Later, fd1d672 (usage.c: add warning_errno() and
error_errno(), 2016-05-08) introduced another variant, and
subsequent commits converted some uses of error() to
error_errno(), losing the magic from e208f9c for those
sites.
As a result, compiling vcs-svn/svndiff.c with "gcc -O3"
produces -Wmaybe-uninitialized false positives (at least
with gcc 6.2.0). Let's give error_errno() the same
treatment, which silences these warnings.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The tempfile (hence its user lockfile) API lets the caller to open
a file descriptor to a temporary file, write into it and then
finalize it by first closing the filehandle and then either
removing or renaming the temporary file. When the process spawns a
subprocess after obtaining the file descriptor, and if the
subprocess has not exited when the attempt to remove or rename is
made, the last step fails on Windows, because the subprocess has
the file descriptor still open. Open tempfile with O_CLOEXEC flag
to avoid this (on Windows, this is mapped to O_NOINHERIT).
* bw/mingw-avoid-inheriting-fd-to-lockfile:
mingw: ensure temporary file handles are not inherited by child processes
t6026-merge-attr: child processes must not inherit index.lock handles
When the index is locked and child processes inherit the handle to
said lock and the parent process wants to remove the lock before the
child process exits, on Windows there is a problem: it won't work
because files cannot be deleted if a process holds a handle on them.
The symptom:
Rename from 'xxx/.git/index.lock' to 'xxx/.git/index' failed.
Should I try again? (y/n)
Spawning child processes with bInheritHandles==FALSE would not work
because no file handles would be inherited, not even the hStdXxx
handles in STARTUPINFO (stdin/stdout/stderr).
Opening every file with O_NOINHERIT does not work, either, as e.g.
git-upload-pack expects inherited file handles.
This leaves us with the only way out: creating temp files with the
O_NOINHERIT flag. This flag is Windows-specific, however. For our
purposes, it is equivalent to O_CLOEXEC (which does not exist on
Windows), so let's just open temporary files with the O_CLOEXEC flag and
map that flag to O_NOINHERIT on Windows.
As Eric Wong pointed out, we need to be careful to handle the case where
the Linux headers used to compile Git support O_CLOEXEC but the Linux
kernel used to run Git does not: it returns an EINVAL.
This fixes the test that we just introduced to demonstrate the problem.
Signed-off-by: Ben Wijen <ben@wijen.net>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This section is about "The FLEXPTR_* variants", so use FLEXPTR_ALLOC_STR
in the example.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are certain house-keeping tasks that need to be performed at
the very beginning of any Git program, and programs that are not
built-in commands had to do them exactly the same way as "git"
potty does. It was easy to make mistakes in one-off standalone
programs (like test helpers). A common "main()" function that
calls cmd_main() of individual program has been introduced to
make it harder to make mistakes.
* jk/common-main:
mingw: declare main()'s argv as const
common-main: call git_setup_gettext()
common-main: call restore_sigpipe_to_default()
common-main: call sanitize_stdfds()
common-main: call git_extract_argv0_path()
add an extra level of indirection to main()
The output coloring scheme learned two new attributes, italic and
strike, in addition to existing bold, reverse, etc.
* jk/ansi-color:
color: support strike-through attribute
color: support "italic" attribute
color: allow "no-" for negating attributes
color: refactor parse_attr
add skip_prefix_mem helper
doc: refactor description of color format
color: fix max-size comment
There are certain startup tasks that we expect every git
process to do. In some cases this is just to improve the
quality of the program (e.g., setting up gettext()). In
others it is a requirement for using certain functions in
libgit.a (e.g., system_path() expects that you have called
git_extract_argv0_path()).
Most commands are builtins and are covered by the git.c
version of main(). However, there are still a few external
commands that use their own main(). Each of these has to
remember to include the correct startup sequence, and we are
not always consistent.
Rather than just fix the inconsistencies, let's make this
harder to get wrong by providing a common main() that can
run this standard startup.
We basically have two options to do this:
- the compat/mingw.h file already does something like this by
adding a #define that replaces the definition of main with a
wrapper that calls mingw_startup().
The upside is that the code in each program doesn't need
to be changed at all; it's rewritten on the fly by the
preprocessor.
The downside is that it may make debugging of the startup
sequence a bit more confusing, as the preprocessor is
quietly inserting new code.
- the builtin functions are all of the form cmd_foo(),
and git.c's main() calls them.
This is much more explicit, which may make things more
obvious to somebody reading the code. It's also more
flexible (because of course we have to figure out _which_
cmd_foo() to call).
The downside is that each of the builtins must define
cmd_foo(), instead of just main().
This patch chooses the latter option, preferring the more
explicit approach, even though it is more invasive. We
introduce a new file common-main.c, with the "real" main. It
expects to call cmd_main() from whatever other objects it is
linked against.
We link common-main.o against anything that links against
libgit.a, since we know that such programs will need to do
this setup. Note that common-main.o can't actually go inside
libgit.a, as the linker would not pick up its main()
function automatically (it has no callers).
The rest of the patch is just adjusting all of the various
external programs (mostly in t/helper) to use cmd_main().
I've provided a global declaration for cmd_main(), which
means that all of the programs also need to match its
signature. In particular, many functions need to switch to
"const char **" instead of "char **" for argv. This effect
ripples out to a few other variables and functions, as well.
This makes the patch even more invasive, but the end result
is much better. We should be treating argv strings as const
anyway, and now all programs conform to the same signature
(which also matches the way builtins are defined).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The skip_prefix function has been very useful for
simplifying pointer arithmetic and avoiding repeated magic
numbers, but we have no equivalent for length-limited
buffers. So we're stuck with:
if (3 <= len && skip_prefix(buf, "foo", &buf))
len -= 3;
That's not that complicated, but it needs to use magic
numbers for the length of the prefix (or else write out
strlen("foo"), repeating the string). By using a helper, we
can get the string length behind the scenes (and often at
compile time for string literals).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code for warning_errno/die_errno has been refactored and a new
error_errno() reporting helper is introduced.
* nd/error-errno: (41 commits)
wrapper.c: use warning_errno()
vcs-svn: use error_errno()
upload-pack.c: use error_errno()
unpack-trees.c: use error_errno()
transport-helper.c: use error_errno()
sha1_file.c: use {error,die,warning}_errno()
server-info.c: use error_errno()
sequencer.c: use error_errno()
run-command.c: use error_errno()
rerere.c: use error_errno() and warning_errno()
reachable.c: use error_errno()
mailmap.c: use error_errno()
ident.c: use warning_errno()
http.c: use error_errno() and warning_errno()
grep.c: use error_errno()
gpg-interface.c: use error_errno()
fast-import.c: use error_errno()
entry.c: use error_errno()
editor.c: use error_errno()
diff-no-index.c: use error_errno()
...
Similar to die_errno(), these functions will append strerror()
automatically.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Upcoming OpenSSL 1.1.0 will break compilation b updating a few APIs
we use in imap-send, which has been adjusted for the change.
* ky/imap-send-openssl-1.1.0:
configure: remove checking for HMAC_CTX_cleanup
imap-send: avoid deprecated TLSv1_method()
imap-send: check NULL return of SSL_CTX_new()
imap-send: use HMAC() function provided by OpenSSL
Upcoming OpenSSL 1.1.0 will break compilation b updating a few APIs
we use in imap-send, which has been adjusted for the change.
* ky/imap-send-openssl-1.1.0:
configure: remove checking for HMAC_CTX_cleanup
imap-send: avoid deprecated TLSv1_method()
imap-send: check NULL return of SSL_CTX_new()
imap-send: use HMAC() function provided by OpenSSL
