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https://github.com/rd-stuffs/msm-4.14.git
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9b78c1da60
If firmware is requested asynchronously, by calling request_firmware_nowait(), there is no reason to fail the request (and warn the user) when the system is (presumably temporarily) unready to handle it (because user space is not available yet or frozen). For this reason, introduce an alternative routine for read-locking umhelper_sem, usermodehelper_read_lock_wait(), that will wait for usermodehelper_disabled to be unset (possibly with a timeout) and make request_firmware_work_func() use it instead of usermodehelper_read_trylock(). Accordingly, modify request_firmware() so that it uses usermodehelper_read_trylock() to acquire umhelper_sem and remove the code related to that lock from _request_firmware(). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org
122 lines
3.9 KiB
C
122 lines
3.9 KiB
C
#ifndef __LINUX_KMOD_H__
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#define __LINUX_KMOD_H__
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/*
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* include/linux/kmod.h
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/gfp.h>
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#include <linux/stddef.h>
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#include <linux/errno.h>
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#include <linux/compiler.h>
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#include <linux/workqueue.h>
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#include <linux/sysctl.h>
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#define KMOD_PATH_LEN 256
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#ifdef CONFIG_MODULES
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extern char modprobe_path[]; /* for sysctl */
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/* modprobe exit status on success, -ve on error. Return value
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* usually useless though. */
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extern __printf(2, 3)
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int __request_module(bool wait, const char *name, ...);
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#define request_module(mod...) __request_module(true, mod)
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#define request_module_nowait(mod...) __request_module(false, mod)
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#define try_then_request_module(x, mod...) \
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((x) ?: (__request_module(true, mod), (x)))
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#else
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static inline int request_module(const char *name, ...) { return -ENOSYS; }
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static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
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#define try_then_request_module(x, mod...) (x)
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#endif
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struct cred;
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struct file;
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#define UMH_NO_WAIT 0 /* don't wait at all */
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#define UMH_WAIT_EXEC 1 /* wait for the exec, but not the process */
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#define UMH_WAIT_PROC 2 /* wait for the process to complete */
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#define UMH_KILLABLE 4 /* wait for EXEC/PROC killable */
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struct subprocess_info {
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struct work_struct work;
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struct completion *complete;
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char *path;
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char **argv;
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char **envp;
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int wait;
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int retval;
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int (*init)(struct subprocess_info *info, struct cred *new);
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void (*cleanup)(struct subprocess_info *info);
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void *data;
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};
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/* Allocate a subprocess_info structure */
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struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
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char **envp, gfp_t gfp_mask);
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/* Set various pieces of state into the subprocess_info structure */
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void call_usermodehelper_setfns(struct subprocess_info *info,
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int (*init)(struct subprocess_info *info, struct cred *new),
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void (*cleanup)(struct subprocess_info *info),
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void *data);
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/* Actually execute the sub-process */
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int call_usermodehelper_exec(struct subprocess_info *info, int wait);
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/* Free the subprocess_info. This is only needed if you're not going
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to call call_usermodehelper_exec */
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void call_usermodehelper_freeinfo(struct subprocess_info *info);
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static inline int
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call_usermodehelper_fns(char *path, char **argv, char **envp, int wait,
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int (*init)(struct subprocess_info *info, struct cred *new),
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void (*cleanup)(struct subprocess_info *), void *data)
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{
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struct subprocess_info *info;
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gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
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info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
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if (info == NULL)
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return -ENOMEM;
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call_usermodehelper_setfns(info, init, cleanup, data);
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return call_usermodehelper_exec(info, wait);
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}
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static inline int
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call_usermodehelper(char *path, char **argv, char **envp, int wait)
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{
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return call_usermodehelper_fns(path, argv, envp, wait,
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NULL, NULL, NULL);
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}
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extern struct ctl_table usermodehelper_table[];
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extern void usermodehelper_init(void);
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extern int usermodehelper_disable(void);
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extern void usermodehelper_enable(void);
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extern int usermodehelper_read_trylock(void);
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extern long usermodehelper_read_lock_wait(long timeout);
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extern void usermodehelper_read_unlock(void);
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#endif /* __LINUX_KMOD_H__ */
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