The commit is pushed to "branch-rh7-3.10.0-693.17.1.vz7.45.x-ovz" and will
appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-693.17.1.vz7.45.8
------>
commit 4c026c8c44ec29538ff88a7a3a329751f2174400
Author: Pavel Tikhomirov <[email protected]>
Date: Thu Mar 22 13:55:05 2018 +0300
ve/kthread: pass ve to __call_usermodehelper_exec
These is a preparation to fix race between call_usermodehelper_by and
ve_umh_worker, for these we need to put the action of queueing work and
the action of checking that ve is running under ve->op_sem critical
section, but at the same time these lock must be released just after
queueing. Thus provide ve->op_sem to __call_usermodehelper_exec through
arguments, as we already pass ve->ve_umh_worker there, it is reasonable
to just pass ve istead of these two.
https://jira.sw.ru/browse/PSBM-82490
Signed-off-by: Pavel Tikhomirov <[email protected]>
Reviewed-by: Kirill Tkhai <[email protected]>
---
include/linux/kmod.h | 6 +++---
kernel/kmod.c | 39 +++++++++++++++++++--------------------
2 files changed, 22 insertions(+), 23 deletions(-)
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index f9c18741d1a4..9bd5776b1302 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -72,10 +72,10 @@ struct subprocess_info {
};
extern int
-call_usermodehelper_by(struct kthread_worker *worker,
- char *path, char **argv, char **envp, int wait,
+call_usermodehelper_by(char *path, char **argv, char **envp, int wait,
int (*init)(struct subprocess_info *info, struct cred
*new),
- void (*cleanup)(struct subprocess_info *), void *data);
+ void (*cleanup)(struct subprocess_info *), void *data,
+ struct ve_struct *ve);
extern int
call_usermodehelper(char *path, char **argv, char **envp, int wait);
diff --git a/kernel/kmod.c b/kernel/kmod.c
index bb7671bc0177..9c37e8b3ab01 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -78,8 +78,8 @@ static void free_modprobe_argv(struct subprocess_info *info)
kfree(info->argv);
}
-static int __call_usermodehelper_exec(struct kthread_worker *worker,
- struct subprocess_info *sub_info, int wait);
+static int __call_usermodehelper_exec(struct subprocess_info *sub_info,
+ int wait, struct ve_struct *ve);
static int call_modprobe(char *module_name, int wait, int blacklist)
{
@@ -118,7 +118,7 @@ static int call_modprobe(char *module_name, int wait, int
blacklist)
* We enter to this function with the right permittions, so
* it's possible to directly call __call_usermodehelper_exec()
*/
- return __call_usermodehelper_exec(&khelper_worker, info, wait |
UMH_KILLABLE);
+ return __call_usermodehelper_exec(info, wait | UMH_KILLABLE, NULL);
free_module_name:
kfree(module_name);
@@ -874,9 +874,11 @@ EXPORT_SYMBOL(call_usermodehelper_setup);
* asynchronously if wait is not set, and runs as a child of keventd.
* (ie. it runs with full root capabilities).
*/
-static int __call_usermodehelper_exec(struct kthread_worker *worker,
- struct subprocess_info *sub_info, int wait)
+static int __call_usermodehelper_exec(struct subprocess_info *sub_info,
+ int wait, struct ve_struct *ve)
{
+ struct kthread_worker *worker = ve ? &ve->ve_umh_worker
+ : &khelper_worker;
DECLARE_COMPLETION_ONSTACK(done);
int retval = 0;
@@ -937,7 +939,7 @@ int call_usermodehelper_exec(struct subprocess_info
*sub_info, int wait)
if (!ve_is_super(get_exec_env()))
return -EPERM;
- return __call_usermodehelper_exec(&khelper_worker, sub_info, wait);
+ return __call_usermodehelper_exec(sub_info, wait, NULL);
}
EXPORT_SYMBOL(call_usermodehelper_exec);
@@ -956,8 +958,8 @@ EXPORT_SYMBOL(call_usermodehelper_exec);
*/
int call_usermodehelper(char *path, char **argv, char **envp, int wait)
{
- return call_usermodehelper_by(&khelper_worker, path, argv, envp,
- wait, NULL, NULL, NULL);
+ return call_usermodehelper_by(path, argv, envp,
+ wait, NULL, NULL, NULL, NULL);
}
EXPORT_SYMBOL(call_usermodehelper);
@@ -968,17 +970,14 @@ int call_usermodehelper_fns_ve(struct ve_struct *ve,
void (*cleanup)(struct subprocess_info *), void *data)
{
int err;
- struct kthread_worker *khelper;
ve = get_ve(ve);
if (!ve)
return -EFAULT;
- khelper = ve_is_super(ve) ? &khelper_worker : &ve->ve_umh_worker;
-
if (ve_is_super(ve) || (get_exec_env() == ve)) {
- err = call_usermodehelper_by(khelper, path, argv, envp, wait,
init,
- cleanup, data);
+ err = call_usermodehelper_by(path, argv, envp, wait, init,
cleanup,
+ data, ve_is_super(ve) ? NULL : ve);
goto out_put;
}
@@ -994,8 +993,8 @@ int call_usermodehelper_fns_ve(struct ve_struct *ve,
if (!ve->is_running)
goto out;
- err = call_usermodehelper_by(khelper, path, argv, envp, wait, init,
- cleanup, data);
+ err = call_usermodehelper_by(path, argv, envp, wait, init,
+ cleanup, data, ve);
out:
up_read(&ve->op_sem);
@@ -1006,15 +1005,15 @@ int call_usermodehelper_fns_ve(struct ve_struct *ve,
EXPORT_SYMBOL(call_usermodehelper_fns_ve);
#endif
-int call_usermodehelper_by(struct kthread_worker *worker,
- char *path, char **argv, char **envp, int wait,
+int call_usermodehelper_by(char *path, char **argv, char **envp, int wait,
int (*init)(struct subprocess_info *info, struct cred *new),
- void (*cleanup)(struct subprocess_info *), void *data)
+ void (*cleanup)(struct subprocess_info *), void *data,
+ struct ve_struct *ve)
{
struct subprocess_info *info;
gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
- if (worker == &khelper_worker && !ve_is_super(get_exec_env()))
+ if (!ve && !ve_is_super(get_exec_env()))
return -EPERM;
info = call_usermodehelper_setup(path, argv, envp, gfp_mask,
@@ -1022,7 +1021,7 @@ int call_usermodehelper_by(struct kthread_worker *worker,
if (info == NULL)
return -ENOMEM;
- return __call_usermodehelper_exec(worker, info, wait);
+ return __call_usermodehelper_exec(info, wait, ve);
}
EXPORT_SYMBOL(call_usermodehelper_by);
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