From: "Rafael J. Wysocki" rafael.j.wysocki@intel.com
stable inclusion from stable-v5.10.210 commit ac4dcccbe9106a5cec483d2ffa7f628b95340a07 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I97NIA CVE: CVE-2023-52498
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 7d4b5d7a37bdd63a5a3371b988744b060d5bb86f upstream.
In preparation for subsequent changes, introduce a specialized variant of async_schedule_dev() that will not invoke the argument function synchronously when it cannot be scheduled for asynchronous execution.
The new function, async_schedule_dev_nocall(), will be used for fixing possible deadlocks in the system-wide power management core code.
Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Reviewed-by: Stanislaw Gruszka stanislaw.gruszka@linux.intel.com for the series. Tested-by: Youngmin Nam youngmin.nam@samsung.com Reviewed-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- include/linux/async.h | 2 ++ kernel/async.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+)
diff --git a/include/linux/async.h b/include/linux/async.h index 0a17cd27f348..d5496a520a38 100644 --- a/include/linux/async.h +++ b/include/linux/async.h @@ -90,6 +90,8 @@ async_schedule_dev(async_func_t func, struct device *dev) return async_schedule_node(func, dev, dev_to_node(dev)); }
+bool async_schedule_dev_nocall(async_func_t func, struct device *dev); + /** * async_schedule_dev_domain - A device specific version of async_schedule_domain * @func: function to execute asynchronously diff --git a/kernel/async.c b/kernel/async.c index dfa4ed15cc42..5dba7461fc75 100644 --- a/kernel/async.c +++ b/kernel/async.c @@ -243,6 +243,35 @@ async_cookie_t async_schedule_node(async_func_t func, void *data, int node) } EXPORT_SYMBOL_GPL(async_schedule_node);
+/** + * async_schedule_dev_nocall - A simplified variant of async_schedule_dev() + * @func: function to execute asynchronously + * @dev: device argument to be passed to function + * + * @dev is used as both the argument for the function and to provide NUMA + * context for where to run the function. + * + * If the asynchronous execution of @func is scheduled successfully, return + * true. Otherwise, do nothing and return false, unlike async_schedule_dev() + * that will run the function synchronously then. + */ +bool async_schedule_dev_nocall(async_func_t func, struct device *dev) +{ + struct async_entry *entry; + + entry = kzalloc(sizeof(struct async_entry), GFP_KERNEL); + + /* Give up if there is no memory or too much work. */ + if (!entry || atomic_read(&entry_count) > MAX_WORK) { + kfree(entry); + return false; + } + + __async_schedule_node_domain(func, dev, dev_to_node(dev), + &async_dfl_domain, entry); + return true; +} + /** * async_synchronize_full - synchronize all asynchronous function calls *