From 898b374af6f71041bd3bceebe257e564f3f1d458 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Wed, 26 May 2010 14:42:59 -0700 Subject: exec: replace call_usermodehelper_pipe with use of umh init function and resolve limit The first patch in this series introduced an init function to the call_usermodehelper api so that processes could be customized by caller. This patch takes advantage of that fact, by customizing the helper in do_coredump to create the pipe and set its core limit to one (for our recusrsion check). This lets us clean up the previous uglyness in the usermodehelper internals and factor call_usermodehelper out entirely. While I'm at it, we can also modify the helper setup to look for a core limit value of 1 rather than zero for our recursion check Signed-off-by: Neil Horman Reviewed-by: Oleg Nesterov Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kmod.c | 82 ----------------------------------------------------------- 1 file changed, 82 deletions(-) (limited to 'kernel') diff --git a/kernel/kmod.c b/kernel/kmod.c index 531ef62..d154454 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -147,23 +147,6 @@ static int ____call_usermodehelper(void *data) commit_creds(sub_info->cred); sub_info->cred = NULL; - /* Install input pipe when needed */ - if (sub_info->stdin) { - struct files_struct *f = current->files; - struct fdtable *fdt; - /* no races because files should be private here */ - sys_close(0); - fd_install(0, sub_info->stdin); - spin_lock(&f->file_lock); - fdt = files_fdtable(f); - FD_SET(0, fdt->open_fds); - FD_CLR(0, fdt->close_on_exec); - spin_unlock(&f->file_lock); - - /* and disallow core files too */ - current->signal->rlim[RLIMIT_CORE] = (struct rlimit){0, 0}; - } - /* We can run anywhere, unlike our parent keventd(). */ set_cpus_allowed_ptr(current, cpu_all_mask); @@ -429,35 +412,6 @@ void call_usermodehelper_setfns(struct subprocess_info *info, EXPORT_SYMBOL(call_usermodehelper_setfns); /** - * call_usermodehelper_stdinpipe - set up a pipe to be used for stdin - * @sub_info: a subprocess_info returned by call_usermodehelper_setup - * @filp: set to the write-end of a pipe - * - * This constructs a pipe, and sets the read end to be the stdin of the - * subprocess, and returns the write-end in *@filp. - */ -int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info, - struct file **filp) -{ - struct file *f; - - f = create_write_pipe(0); - if (IS_ERR(f)) - return PTR_ERR(f); - *filp = f; - - f = create_read_pipe(f, 0); - if (IS_ERR(f)) { - free_write_pipe(*filp); - return PTR_ERR(f); - } - sub_info->stdin = f; - - return 0; -} -EXPORT_SYMBOL(call_usermodehelper_stdinpipe); - -/** * call_usermodehelper_exec - start a usermode application * @sub_info: information about the subprocessa * @wait: wait for the application to finish and return status. @@ -504,42 +458,6 @@ unlock: } EXPORT_SYMBOL(call_usermodehelper_exec); -/** - * call_usermodehelper_pipe - call a usermode helper process with a pipe stdin - * @path: path to usermode executable - * @argv: arg vector for process - * @envp: environment for process - * @filp: set to the write-end of a pipe - * - * This is a simple wrapper which executes a usermode-helper function - * with a pipe as stdin. It is implemented entirely in terms of - * lower-level call_usermodehelper_* functions. - */ -int call_usermodehelper_pipe(char *path, char **argv, char **envp, - struct file **filp) -{ - struct subprocess_info *sub_info; - int ret; - - sub_info = call_usermodehelper_setup(path, argv, envp, - GFP_KERNEL); - if (sub_info == NULL) - return -ENOMEM; - - ret = call_usermodehelper_stdinpipe(sub_info, filp); - if (ret < 0) { - call_usermodehelper_freeinfo(sub_info); - return ret; - } - - ret = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC); - if (ret < 0) /* Failed to execute helper, close pipe */ - filp_close(*filp, NULL); - - return ret; -} -EXPORT_SYMBOL(call_usermodehelper_pipe); - void __init usermodehelper_init(void) { khelper_wq = create_singlethread_workqueue("khelper"); -- cgit v1.1