diff options
| -rw-r--r-- | include/linux/kmod.h | 51 | ||||
| -rw-r--r-- | kernel/kmod.c | 51 | ||||
| -rw-r--r-- | kernel/sys.c | 6 |
3 files changed, 73 insertions, 35 deletions
diff --git a/include/linux/kmod.h b/include/linux/kmod.h index facb27fe7de..f9edf63e90e 100644 --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -23,6 +23,7 @@ #include <linux/stddef.h> #include <linux/errno.h> #include <linux/compiler.h> +#include <linux/workqueue.h> #define KMOD_PATH_LEN 256 @@ -45,7 +46,27 @@ static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; struct key; struct file; -struct subprocess_info; + +enum umh_wait { + UMH_NO_WAIT = -1, /* don't wait at all */ + UMH_WAIT_EXEC = 0, /* wait for the exec, but not the process */ + UMH_WAIT_PROC = 1, /* wait for the process to complete */ +}; + +struct subprocess_info { + struct work_struct work; + struct completion *complete; + struct cred *cred; + char *path; + char **argv; + char **envp; + enum umh_wait wait; + int retval; + struct file *stdin; + int (*init)(struct subprocess_info *info); + void (*cleanup)(struct subprocess_info *info); + void *data; +}; /* Allocate a subprocess_info structure */ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, @@ -56,14 +77,10 @@ void call_usermodehelper_setkeys(struct subprocess_info *info, struct key *session_keyring); int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info, struct file **filp); -void call_usermodehelper_setcleanup(struct subprocess_info *info, - void (*cleanup)(char **argv, char **envp)); - -enum umh_wait { - UMH_NO_WAIT = -1, /* don't wait at all */ - UMH_WAIT_EXEC = 0, /* wait for the exec, but not the process */ - UMH_WAIT_PROC = 1, /* wait for the process to complete */ -}; +void call_usermodehelper_setfns(struct subprocess_info *info, + int (*init)(struct subprocess_info *info), + void (*cleanup)(struct subprocess_info *info), + void *data); /* Actually execute the sub-process */ int call_usermodehelper_exec(struct subprocess_info *info, enum umh_wait wait); @@ -73,18 +90,32 @@ int call_usermodehelper_exec(struct subprocess_info *info, enum umh_wait wait); void call_usermodehelper_freeinfo(struct subprocess_info *info); static inline int -call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait) +call_usermodehelper_fns(char *path, char **argv, char **envp, + enum umh_wait wait, + int (*init)(struct subprocess_info *info), + void (*cleanup)(struct subprocess_info *), void *data) { struct subprocess_info *info; gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL; info = call_usermodehelper_setup(path, argv, envp, gfp_mask); + if (info == NULL) return -ENOMEM; + + call_usermodehelper_setfns(info, init, cleanup, data); + return call_usermodehelper_exec(info, wait); } static inline int +call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait) +{ + return call_usermodehelper_fns(path, argv, envp, wait, + NULL, NULL, NULL); +} + +static inline int call_usermodehelper_keys(char *path, char **argv, char **envp, struct key *session_keyring, enum umh_wait wait) { diff --git a/kernel/kmod.c b/kernel/kmod.c index bf0e231d970..531ef62cf53 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -116,27 +116,16 @@ int __request_module(bool wait, const char *fmt, ...) trace_module_request(module_name, wait, _RET_IP_); - ret = call_usermodehelper(modprobe_path, argv, envp, - wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC); + ret = call_usermodehelper_fns(modprobe_path, argv, envp, + wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC, + NULL, NULL, NULL); + atomic_dec(&kmod_concurrent); return ret; } EXPORT_SYMBOL(__request_module); #endif /* CONFIG_MODULES */ -struct subprocess_info { - struct work_struct work; - struct completion *complete; - struct cred *cred; - char *path; - char **argv; - char **envp; - enum umh_wait wait; - int retval; - struct file *stdin; - void (*cleanup)(char **argv, char **envp); -}; - /* * This is the task which runs the usermode application */ @@ -184,9 +173,16 @@ static int ____call_usermodehelper(void *data) */ set_user_nice(current, 0); + if (sub_info->init) { + retval = sub_info->init(sub_info); + if (retval) + goto fail; + } + retval = kernel_execve(sub_info->path, sub_info->argv, sub_info->envp); /* Exec failed? */ +fail: sub_info->retval = retval; do_exit(0); } @@ -194,7 +190,7 @@ static int ____call_usermodehelper(void *data) void call_usermodehelper_freeinfo(struct subprocess_info *info) { if (info->cleanup) - (*info->cleanup)(info->argv, info->envp); + (*info->cleanup)(info); if (info->cred) put_cred(info->cred); kfree(info); @@ -406,21 +402,31 @@ void call_usermodehelper_setkeys(struct subprocess_info *info, EXPORT_SYMBOL(call_usermodehelper_setkeys); /** - * call_usermodehelper_setcleanup - set a cleanup function + * call_usermodehelper_setfns - set a cleanup/init function * @info: a subprocess_info returned by call_usermodehelper_setup * @cleanup: a cleanup function + * @init: an init function + * @data: arbitrary context sensitive data + * + * The init function is used to customize the helper process prior to + * exec. A non-zero return code causes the process to error out, exit, + * and return the failure to the calling process * - * The cleanup function is just befor ethe subprocess_info is about to + * The cleanup function is just before ethe subprocess_info is about to * be freed. This can be used for freeing the argv and envp. The * Function must be runnable in either a process context or the * context in which call_usermodehelper_exec is called. */ -void call_usermodehelper_setcleanup(struct subprocess_info *info, - void (*cleanup)(char **argv, char **envp)) +void call_usermodehelper_setfns(struct subprocess_info *info, + int (*init)(struct subprocess_info *info), + void (*cleanup)(struct subprocess_info *info), + void *data) { info->cleanup = cleanup; + info->init = init; + info->data = data; } -EXPORT_SYMBOL(call_usermodehelper_setcleanup); +EXPORT_SYMBOL(call_usermodehelper_setfns); /** * call_usermodehelper_stdinpipe - set up a pipe to be used for stdin @@ -515,7 +521,8 @@ int call_usermodehelper_pipe(char *path, char **argv, char **envp, struct subprocess_info *sub_info; int ret; - sub_info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL); + sub_info = call_usermodehelper_setup(path, argv, envp, + GFP_KERNEL); if (sub_info == NULL) return -ENOMEM; diff --git a/kernel/sys.c b/kernel/sys.c index 0d36d889c74..e83ddbbaf89 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1632,9 +1632,9 @@ SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; -static void argv_cleanup(char **argv, char **envp) +static void argv_cleanup(struct subprocess_info *info) { - argv_free(argv); + argv_free(info->argv); } /** @@ -1668,7 +1668,7 @@ int orderly_poweroff(bool force) goto out; } - call_usermodehelper_setcleanup(info, argv_cleanup); + call_usermodehelper_setfns(info, NULL, argv_cleanup, NULL); ret = call_usermodehelper_exec(info, UMH_NO_WAIT); |