From be907e4960755592d7960dc0bfb072a9431e5e1c Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Tue, 30 Dec 2003 01:00:38 -0800 Subject: [PATCH] [PATCH] call_usermodehelper retval fix The reworked firmware loader in the DVB patches needs the fix to the call_usermodehelper() return value. From: Rusty Russell MODULE_ALIAS_BLOCK() and MODULE_ALIAS_CHAR() define aliases of form "XXX--", so we should probe for modules using this form. Unfortunately in 2.4, block aliases were "XXX-" and char aliases were of both forms. Ideally, all modules would now be using MODULE_ALIAS() macros to define their aliases, and the old configuration files wouldn't matter as much. Unfortunately, this hasn't happened, so we make request_module() return the exit status of modprobe, and then do fallback when probing for char and block devices. (Kudos to Chris Wright, I stole his kernel_thread flags). --- drivers/block/genhd.c | 4 +++- fs/char_dev.c | 4 +++- include/linux/kmod.h | 2 ++ kernel/kmod.c | 17 +++++++++++------ 4 files changed, 19 insertions(+), 8 deletions(-) diff --git a/drivers/block/genhd.c b/drivers/block/genhd.c index d50419e1e7d1b..06a7d4ea0d1bd 100644 --- a/drivers/block/genhd.c +++ b/drivers/block/genhd.c @@ -296,7 +296,9 @@ extern int blk_dev_init(void); static struct kobject *base_probe(dev_t dev, int *part, void *data) { - request_module("block-major-%d", MAJOR(dev)); + if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0) + /* Make old-style 2.4 aliases work */ + request_module("block-major-%d", MAJOR(dev)); return NULL; } diff --git a/fs/char_dev.c b/fs/char_dev.c index 5f4ab3ac12964..50ab4cf8e8e16 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -434,7 +434,9 @@ void cdev_init(struct cdev *cdev, struct file_operations *fops) static struct kobject *base_probe(dev_t dev, int *part, void *data) { - request_module("char-major-%d-%d", MAJOR(dev), MINOR(dev)); + if (request_module("char-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0) + /* Make old-style 2.4 aliases work */ + request_module("char-major-%d", MAJOR(dev)); return NULL; } diff --git a/include/linux/kmod.h b/include/linux/kmod.h index 8412faeea0f7e..7c5af18df9d11 100644 --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -24,6 +24,8 @@ #include #ifdef CONFIG_KMOD +/* modprobe exit status on success, -ve on error. Return value + * usually useless though. */ extern int request_module(const char * name, ...) __attribute__ ((format (printf, 1, 2))); #else static inline int request_module(const char * name, ...) { return -ENOSYS; } diff --git a/kernel/kmod.c b/kernel/kmod.c index 2c74533c0b963..ed2c9a76f66b6 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -182,16 +182,21 @@ static int wait_for_helper(void *data) { struct subprocess_info *sub_info = data; pid_t pid; + struct k_sigaction sa; + + /* Install a handler: if SIGCLD isn't handled sys_wait4 won't + * populate the status, but will return -ECHILD. */ + sa.sa.sa_handler = SIG_IGN; + sa.sa.sa_flags = 0; + siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); + do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); + allow_signal(SIGCHLD); - sub_info->retval = 0; pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD); if (pid < 0) sub_info->retval = pid; else - /* We don't have a SIGCHLD signal handler, so this - * always returns -ECHILD, but the important thing is - * that it blocks. */ - sys_wait4(pid, NULL, 0, NULL); + sys_wait4(pid, &sub_info->retval, 0, NULL); complete(sub_info->complete); return 0; @@ -210,7 +215,7 @@ static void __call_usermodehelper(void *data) * until that is done. */ if (sub_info->wait) pid = kernel_thread(wait_for_helper, sub_info, - CLONE_KERNEL | SIGCHLD); + CLONE_FS | CLONE_FILES | SIGCHLD); else pid = kernel_thread(____call_usermodehelper, sub_info, CLONE_VFORK | SIGCHLD); -- 2.53.0