kernel/git - git - PowerEL Git System

Author	SHA1	Message	Date
Brandon Williams	940283101c	run-command: restrict PATH search to executable files In some situations run-command will incorrectly try (and fail) to execute a directory instead of an executable file. This was observed by having a directory called "ssh" in $PATH before the real ssh and trying to use ssh protoccol, reslting in the following: $ git ls-remote ssh://url fatal: cannot exec 'ssh': Permission denied It ends up being worse and run-command will even try to execute a non-executable file if it preceeds the executable version of a file on the PATH. For example, if PATH=~/bin1:~/bin2:~/bin3 and there exists a directory 'git-hello' in 'bin1', a non-executable file 'git-hello' in bin2 and an executable file 'git-hello' (which prints "Hello World!") in bin3 the following will occur: $ git hello fatal: cannot exec 'git-hello': Permission denied This is due to only checking 'access()' when locating an executable in PATH, which doesn't distinguish between files and directories. Instead use 'is_executable()' which check that the path is to a regular, executable file. Now run-command won't try to execute the directory or non-executable file 'git-hello': $ git hello Hello World! which matches what execvp(3) would have done when asked to execute git-hello with such a $PATH. Reported-by: Brian Hatfield <bhatfield@google.com> Signed-off-by: Brandon Williams <bmwill@google.com> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	8 years ago
Brandon Williams	c2d3119d7b	t0061: run_command executes scripts without a #! line Add a test to 't0061-run-command.sh' to ensure that run_command can continue to execute scripts which don't include a '#!' line. As shell scripts are not natively executable on Windows, we use a workaround to check "#!" when running scripts from Git. As this test requires the platform (not with Git's help) to run scripts without "#!", skipt it on Windows. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	8 years ago
Stefan Beller	c553c72eed	run-command: add an asynchronous parallel child processor This allows to run external commands in parallel with ordered output on stderr. If we run external commands in parallel we cannot pipe the output directly to the our stdout/err as it would mix up. So each process's output will flow through a pipe, which we buffer. One subprocess can be directly piped to out stdout/err for a low latency feedback to the user. Example: Let's assume we have 5 submodules A,B,C,D,E and each fetch takes a different amount of time as the different submodules vary in size, then the output of fetches in sequential order might look like this: time --> output: \|---A---\| \|-B-\| \|-------C-------\| \|-D-\| \|-E-\| When we schedule these submodules into maximal two parallel processes, a schedule and sample output over time may look like this: process 1: \|---A---\| \|-D-\| \|-E-\| process 2: \|-B-\| \|-------C-------\| output: \|---A---\|B\|---C-------\|DE So A will be perceived as it would run normally in the single child version. As B has finished by the time A is done, we can dump its whole progress buffer on stderr, such that it looks like it finished in no time. Once that is done, C is determined to be the visible child and its progress will be reported in real time. So this way of output is really good for human consumption, as it only changes the timing, not the actual output. For machine consumption the output needs to be prepared in the tasks, by either having a prefix per line or per block to indicate whose tasks output is displayed, because the output order may not follow the original sequential ordering: \|----A----\| \|--B--\| \|-C-\| will be scheduled to be all parallel: process 1: \|----A----\| process 2: \|--B--\| process 3: \|-C-\| output: \|----A----\|CB This happens because C finished before B did, so it will be queued for output before B. To detect when a child has finished executing, we check interleaved with other actions (such as checking the liveliness of children or starting new processes) whether the stderr pipe still exists. Once a child closed its stderr stream, we assume it is terminating very soon, and use `finish_command()` from the single external process execution interface to collect the exit status. By maintaining the strong assumption of stderr being open until the very end of a child process, we can avoid other hassle such as an implementation using `waitpid(-1)`, which is not implemented in Windows. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	9 years ago
Junio C Hamano	eae69530ae	tests: correct misuses of POSIXPERM POSIXPERM requires that a later call to stat(2) (hence "ls -l") faithfully reproduces what an earlier chmod(2) did. Some filesystems cannot satisify this. SANITY requires that a file or a directory is indeed accessible (or inaccessible) when its permission bits would say it ought to be accessible (or inaccessible). Running tests as root would lose this prerequisite for obvious reasons. Fix a few tests that misuse POSIXPERM. t0061-run-command.sh has two uses of POSIXPERM. - One checks that an attempt to execute a file that is marked as unexecutable results in a failure with EACCES; I do not think having root-ness or any other capability that busts the filesystem permission mode bits will make you run an unexecutable file, so this should be left as-is. The test does not have anything to do with SANITY. - The other one expects 'git nitfol' runs the alias when an alias.nitfol is defined and a directory on the PATH is marked as unreadable and unsearchable. I _think_ the test tries to reject the alternative expectation that we want to refuse to run the alias because it would break "no alias may mask a command" rule if a file 'git-nitfol' exists in the unreadable directory but we cannot even determine if that is the case. Under !SANITY that busts the permission bits, this test no longer checks that, so it must be protected with SANITY. t1509-root-worktree.sh expects to be run on a / that is writable by the user and sees if Git behaves "sensibly" when /.git is the repository to govern a worktree that is the whole filesystem, and also if Git behaves "sensibly" when / itself is a bare repository with refs, objects, and friends (I find the definition of "behaves sensibly" under these conditions hard to fathom, but it is a different matter). The implementation of the test is very much problematic. - It requires POSIXPERM, but it does not do chmod or checks modes in any way. - It runs "rm /*" and "rm -fr /refs /objects ..." in one of the tests, and also does "cd / && git init --bare". If done on a live system that takes advantages of the "feature" being tested, these obviously will clobber the system. But there is no guard against such a breakage. - It uses "test $UID = 0" to see rootness, which now should be spelled "! test_have_prereq NOT_ROOT" Signed-off-by: Junio C Hamano <gitster@pobox.com>	10 years ago
Jeff King	38f865c27d	run-command: treat inaccessible directories as ENOENT When execvp reports EACCES, it can be one of two things: 1. We found a file to execute, but did not have permissions to do so. 2. We did not have permissions to look in some directory in the $PATH. In the former case, we want to consider this a permissions problem and report it to the user as such (since getting this for something like "git foo" is likely a configuration error). In the latter case, there is a good chance that the inaccessible directory does not contain anything of interest. Reporting "permission denied" is confusing to the user (and prevents our usual "did you mean...?" lookup). It also prevents git from trying alias lookup, since we do so only when an external command does not exist (not when it exists but has an error). This patch detects EACCES from execvp, checks whether we are in case (2), and if so converts errno to ENOENT. This behavior matches that of "bash" (but not of simpler shells that use execvp more directly, like "dash"). Test stolen from Junio. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	13 years ago
Jonathan Nieder	c0f19bf3b9	tests: check error message from run_command In git versions starting at v1.7.5-rc0~29^2 until v1.7.5-rc3~2 (Revert "run-command: prettify -D_FORTIFY_SOURCE workaround", 2011-04-18) fixed it, the run_command facility would write a truncated error message when the command is present but cannot be executed for some other reason. For example, if I add a 'hello' command to git: $ echo 'echo hello' >git-hello $ chmod +x git-hello $ PATH=.:$PATH git hello hello and make it non-executable, this is what I normally get: $ chmod -x git-hello $ git hello fatal: cannot exec 'git-hello': Permission denied But with the problematic versions, we get disturbing output: $ PATH=.:$PATH git hello fatal: $ Add some tests to make sure it doesn't happen again. The hello-script used in these tests uses cat instead of echo because on Windows the bash spawned by git converts LF to CRLF in text written by echo while the bash running tests does not, causing the test to fail if "echo" is used. Thanks to Hannes for noticing. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Improved-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	14 years ago
Johannes Sixt	2b541bf8be	start_command: detect execvp failures early Previously, failures during execvp could be detected only by finish_command. However, in some situations it is beneficial for the parent process to know earlier that the child process will not run. The idea to use a pipe to signal failures to the parent process and the test case were lifted from patches by Ilari Liusvaara. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago