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From: Brandon Williams <bmwill@google.com>
To: git@vger.kernel.org
Cc: Brandon Williams <bmwill@google.com>
Subject: [PATCH 2/5] run-command: prepare argv before forking
Date: Mon, 10 Apr 2017 16:49:16 -0700	[thread overview]
Message-ID: <20170410234919.34586-3-bmwill@google.com> (raw)
In-Reply-To: <20170410234919.34586-1-bmwill@google.com>

In order to avoid allocation between 'fork()' and 'exec()' the argv
array used in the exec call is prepared prior to forking the process.

Signed-off-by: Brandon Williams <bmwill@google.com>
---
 run-command.c | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/run-command.c b/run-command.c
index 682bc3ca5..2514b54bc 100644
--- a/run-command.c
+++ b/run-command.c
@@ -226,18 +226,6 @@ static const char **prepare_shell_cmd(struct argv_array *out, const char **argv)
 }
 
 #ifndef GIT_WINDOWS_NATIVE
-static int execv_shell_cmd(const char **argv)
-{
-	struct argv_array nargv = ARGV_ARRAY_INIT;
-	prepare_shell_cmd(&nargv, argv);
-	trace_argv_printf(nargv.argv, "trace: exec:");
-	sane_execvpe(nargv.argv[0], (char **)nargv.argv, NULL);
-	argv_array_clear(&nargv);
-	return -1;
-}
-#endif
-
-#ifndef GIT_WINDOWS_NATIVE
 static int child_notifier = -1;
 
 static void notify_parent(void)
@@ -377,9 +365,20 @@ int start_command(struct child_process *cmd)
 #ifndef GIT_WINDOWS_NATIVE
 {
 	int notify_pipe[2];
+	struct argv_array argv = ARGV_ARRAY_INIT;
+
 	if (pipe(notify_pipe))
 		notify_pipe[0] = notify_pipe[1] = -1;
 
+	if (cmd->git_cmd) {
+		argv_array_push(&argv, "git");
+		argv_array_pushv(&argv, cmd->argv);
+	} else if (cmd->use_shell) {
+		prepare_shell_cmd(&argv, cmd->argv);
+	} else {
+		argv_array_pushv(&argv, cmd->argv);
+	}
+
 	cmd->pid = fork();
 	failed_errno = errno;
 	if (!cmd->pid) {
@@ -442,12 +441,9 @@ int start_command(struct child_process *cmd)
 					unsetenv(*cmd->env);
 			}
 		}
-		if (cmd->git_cmd)
-			execv_git_cmd(cmd->argv);
-		else if (cmd->use_shell)
-			execv_shell_cmd(cmd->argv);
-		else
-			sane_execvpe(cmd->argv[0], (char *const*) cmd->argv, NULL);
+
+		sane_execvpe(argv.argv[0], (char *const*) argv.argv, NULL);
+
 		if (errno == ENOENT) {
 			if (!cmd->silent_exec_failure)
 				error("cannot run %s: %s", cmd->argv[0],
@@ -480,6 +476,8 @@ int start_command(struct child_process *cmd)
 		cmd->pid = -1;
 	}
 	close(notify_pipe[0]);
+
+	argv_array_clear(&argv);
 }
 #else
 {
-- 
2.12.2.715.g7642488e1d-goog


  parent reply	other threads:[~2017-04-10 23:49 UTC|newest]

Thread overview: 140+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-10 23:49 [PATCH 0/5] forking and threading Brandon Williams
2017-04-10 23:49 ` [PATCH 1/5] run-command: convert sane_execvp to sane_execvpe Brandon Williams
2017-04-12 19:22   ` Brandon Williams
2017-04-10 23:49 ` Brandon Williams [this message]
2017-04-10 23:49 ` [PATCH 3/5] run-command: allocate child_err before forking Brandon Williams
2017-04-10 23:49 ` [PATCH 4/5] run-command: prepare child environment " Brandon Williams
2017-04-11  0:58   ` Jonathan Nieder
2017-04-11 17:27     ` Brandon Williams
2017-04-11 17:30       ` Jonathan Nieder
2017-04-10 23:49 ` [PATCH 5/5] run-command: add note about forking and threading Brandon Williams
2017-04-11  0:26   ` Jonathan Nieder
2017-04-11  0:53     ` Eric Wong
2017-04-11 17:33       ` Jonathan Nieder
2017-04-11 17:34       ` Brandon Williams
2017-04-11 17:40         ` Eric Wong
2017-04-11  7:05 ` [PATCH 6/5] run-command: avoid potential dangers in forked child Eric Wong
2017-04-11 16:29   ` Brandon Williams
2017-04-11 16:59     ` Eric Wong
2017-04-11 17:17       ` Brandon Williams
2017-04-11 17:37 ` [PATCH 0/5] forking and threading Jonathan Nieder
2017-04-11 17:54   ` Brandon Williams
2017-04-13 18:32 ` [PATCH v2 0/6] " Brandon Williams
2017-04-13 18:32   ` [PATCH v2 1/6] t5550: use write_script to generate post-update hook Brandon Williams
2017-04-13 20:43     ` Jonathan Nieder
2017-04-13 20:59       ` Eric Wong
2017-04-13 21:35         ` Brandon Williams
2017-04-13 21:39           ` Eric Wong
2017-04-13 18:32   ` [PATCH v2 2/6] run-command: prepare command before forking Brandon Williams
2017-04-13 21:14     ` Jonathan Nieder
2017-04-13 22:41       ` Brandon Williams
2017-04-13 18:32   ` [PATCH v2 3/6] run-command: prepare child environment " Brandon Williams
2017-04-13 18:32   ` [PATCH v2 4/6] run-command: don't die in child when duping /dev/null Brandon Williams
2017-04-13 19:29     ` Eric Wong
2017-04-13 19:43       ` Brandon Williams
2017-04-13 18:32   ` [PATCH v2 5/6] run-command: eliminate calls to error handling functions in child Brandon Williams
2017-04-13 18:32   ` [PATCH v2 6/6] run-command: add note about forking and threading Brandon Williams
2017-04-13 20:50   ` [PATCH v2 0/6] " Jonathan Nieder
2017-04-13 23:44     ` Brandon Williams
2017-04-13 21:14   ` [PATCH 7/6] run-command: block signals between fork and execve Eric Wong
2017-04-13 23:37     ` Brandon Williams
2017-04-14  2:42     ` Brandon Williams
2017-04-14  5:26       ` Eric Wong
2017-04-14  5:35         ` Eric Wong
2017-04-14 16:58   ` [PATCH v3 00/10] forking and threading Brandon Williams
2017-04-14 16:58     ` [PATCH v3 01/10] t5550: use write_script to generate post-update hook Brandon Williams
2017-04-14 16:58     ` [PATCH v3 02/10] t0061: run_command executes scripts without a #! line Brandon Williams
2017-04-14 16:58     ` [PATCH v3 03/10] run-command: prepare command before forking Brandon Williams
2017-04-14 16:58     ` [PATCH v3 04/10] run-command: use the async-signal-safe execv instead of execvp Brandon Williams
2017-04-14 16:58     ` [PATCH v3 05/10] run-command: prepare child environment before forking Brandon Williams
2017-04-14 16:58     ` [PATCH v3 06/10] run-command: don't die in child when duping /dev/null Brandon Williams
2017-04-14 19:38       ` Eric Wong
2017-04-14 20:19         ` Brandon Williams
2017-04-14 16:58     ` [PATCH v3 07/10] run-command: eliminate calls to error handling functions in child Brandon Williams
2017-04-14 18:50       ` Eric Wong
2017-04-14 20:22         ` Brandon Williams
2017-04-14 16:59     ` [PATCH v3 08/10] run-command: handle dup2 and close errors " Brandon Williams
2017-04-14 16:59     ` [PATCH v3 09/10] run-command: add note about forking and threading Brandon Williams
2017-04-14 16:59     ` [PATCH v3 10/10] run-command: block signals between fork and execve Brandon Williams
2017-04-14 20:24       ` Brandon Williams
2017-04-14 21:35         ` Eric Wong
2017-04-17 22:08     ` [PATCH v4 00/10] forking and threading Brandon Williams
2017-04-17 22:08       ` [PATCH v4 01/10] t5550: use write_script to generate post-update hook Brandon Williams
2017-04-17 22:08       ` [PATCH v4 02/10] t0061: run_command executes scripts without a #! line Brandon Williams
2017-04-17 22:08       ` [PATCH v4 03/10] run-command: prepare command before forking Brandon Williams
2017-04-17 22:08       ` [PATCH v4 04/10] run-command: use the async-signal-safe execv instead of execvp Brandon Williams
2017-04-17 22:08       ` [PATCH v4 05/10] run-command: prepare child environment before forking Brandon Williams
2017-04-18  0:26         ` Eric Wong
2017-04-18 21:02           ` Brandon Williams
2017-04-17 22:08       ` [PATCH v4 06/10] run-command: don't die in child when duping /dev/null Brandon Williams
2017-04-17 22:08       ` [PATCH v4 07/10] run-command: eliminate calls to error handling functions in child Brandon Williams
2017-04-17 22:08       ` [PATCH v4 08/10] run-command: handle dup2 and close errors " Brandon Williams
2017-04-17 22:08       ` [PATCH v4 09/10] run-command: add note about forking and threading Brandon Williams
2017-04-17 22:08       ` [PATCH v4 10/10] run-command: block signals between fork and execve Brandon Williams
2017-04-18 23:17       ` [PATCH v5 00/11] forking and threading Brandon Williams
2017-04-18 23:17         ` [PATCH v5 01/11] t5550: use write_script to generate post-update hook Brandon Williams
2017-04-18 23:17         ` [PATCH v5 02/11] t0061: run_command executes scripts without a #! line Brandon Williams
2017-04-19  5:43           ` Johannes Sixt
2017-04-19  6:21             ` Johannes Sixt
2017-04-19 15:56               ` Brandon Williams
2017-04-19 18:18                 ` Johannes Sixt
2017-04-20 10:47                 ` Johannes Schindelin
2017-04-20 17:02                   ` Brandon Williams
2017-04-20 20:24                     ` Johannes Schindelin
2017-04-20 20:49                       ` Brandon Williams
2017-04-18 23:17         ` [PATCH v5 03/11] run-command: prepare command before forking Brandon Williams
2017-04-18 23:17         ` [PATCH v5 04/11] run-command: use the async-signal-safe execv instead of execvp Brandon Williams
2017-04-18 23:17         ` [PATCH v5 05/11] string-list: add string_list_remove function Brandon Williams
2017-04-18 23:31           ` Stefan Beller
2017-04-18 23:36             ` Brandon Williams
2017-04-18 23:40               ` Stefan Beller
2017-04-18 23:18         ` [PATCH v5 06/11] run-command: prepare child environment before forking Brandon Williams
2017-04-18 23:18         ` [PATCH v5 07/11] run-command: don't die in child when duping /dev/null Brandon Williams
2017-04-18 23:18         ` [PATCH v5 08/11] run-command: eliminate calls to error handling functions in child Brandon Williams
2017-04-18 23:18         ` [PATCH v5 09/11] run-command: handle dup2 and close errors " Brandon Williams
2017-04-18 23:18         ` [PATCH v5 10/11] run-command: add note about forking and threading Brandon Williams
2017-04-18 23:18         ` [PATCH v5 11/11] run-command: block signals between fork and execve Brandon Williams
2017-04-19  6:00           ` Johannes Sixt
2017-04-19  7:48             ` Eric Wong
2017-04-19 16:10               ` Brandon Williams
2017-04-19 23:13         ` [PATCH v6 00/11] forking and threading Brandon Williams
2017-04-19 23:13           ` [PATCH v6 01/11] t5550: use write_script to generate post-update hook Brandon Williams
2017-04-19 23:13           ` [PATCH v6 02/11] t0061: run_command executes scripts without a #! line Brandon Williams
2017-04-20 10:49             ` Johannes Schindelin
2017-04-20 16:58               ` Brandon Williams
2017-04-19 23:13           ` [PATCH v6 03/11] run-command: prepare command before forking Brandon Williams
2017-04-19 23:13           ` [PATCH v6 04/11] run-command: use the async-signal-safe execv instead of execvp Brandon Williams
2017-05-17  2:15             ` Junio C Hamano
2017-05-17  2:26               ` Jeff King
2017-05-17  2:28                 ` Jeff King
2017-05-17  3:41                 ` Junio C Hamano
2017-05-17 14:52                 ` Brandon Williams
2017-04-19 23:13           ` [PATCH v6 05/11] string-list: add string_list_remove function Brandon Williams
2017-04-19 23:13           ` [PATCH v6 06/11] run-command: prepare child environment before forking Brandon Williams
2017-04-19 23:13           ` [PATCH v6 07/11] run-command: don't die in child when duping /dev/null Brandon Williams
2017-04-19 23:13           ` [PATCH v6 08/11] run-command: eliminate calls to error handling functions in child Brandon Williams
2017-04-19 23:13           ` [PATCH v6 09/11] run-command: handle dup2 and close errors " Brandon Williams
2017-04-19 23:13           ` [PATCH v6 10/11] run-command: add note about forking and threading Brandon Williams
2017-04-19 23:13           ` [PATCH v6 11/11] run-command: block signals between fork and execve Brandon Williams
2017-04-24 22:37           ` [PATCH v6 00/11] forking and threading Brandon Williams
2017-04-24 23:50             ` [PATCH v6 12/11] run-command: don't try to execute directories Brandon Williams
2017-04-25  0:17               ` Jonathan Nieder
2017-04-25  1:58                 ` Junio C Hamano
2017-04-25  2:51                   ` Jonathan Nieder
2017-04-25  2:56                 ` Jeff King
2017-04-25  1:47               ` Junio C Hamano
2017-04-25  2:57               ` Jonathan Nieder
2017-04-25 17:54               ` [PATCH v7 1/2] exec_cmd: expose is_executable function Brandon Williams
2017-04-25 17:54                 ` [PATCH v7 2/2] run-command: don't try to execute directories Brandon Williams
2017-04-25 18:51                   ` Jonathan Nieder
2017-04-25 19:32                     ` Brandon Williams
2017-04-25 18:04                 ` [PATCH v7 1/2] exec_cmd: expose is_executable function Jonathan Nieder
2017-04-25 18:18                 ` Johannes Sixt
2017-04-25 18:38                   ` Brandon Williams
2017-04-25 23:46                 ` [PATCH v8 1/2] run-command: " Brandon Williams
2017-04-25 23:47                   ` [PATCH v8 2/2] run-command: restrict PATH search to executable files Brandon Williams
2017-04-25 23:50                     ` Jonathan Nieder
2017-04-26  1:44                     ` Junio C Hamano
2017-04-26 17:10                       ` [PATCH v9 " Brandon Williams
2017-04-27  0:33                         ` Junio C Hamano
2017-04-25 23:48                   ` [PATCH v8 1/2] run-command: expose is_executable function Jonathan Nieder

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