KVM: x86/speculation: Disable Fill buffer clear within guests

[mirror_ubuntu-jammy-kernel.git] / kernel / module.c

diff --git a/kernel/module.c b/kernel/module.c
index 5c26a76e800b579a1e450b1aab962da2df7fc0d6..83991c2d5af9eab1104e7fb5aac0cb62b1d6f4f8 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3683,12 +3683,6 @@ static noinline int do_init_module(struct module *mod)
        }
        freeinit->module_init = mod->init_layout.base;
 
-       /*
-        * We want to find out whether @mod uses async during init.  Clear
-        * PF_USED_ASYNC.  async_schedule*() will set it.
-        */
-       current->flags &= ~PF_USED_ASYNC;
-
        do_mod_ctors(mod);
        /* Start the module */
        if (mod->init != NULL)
@@ -3714,22 +3708,13 @@ static noinline int do_init_module(struct module *mod)
 
        /*
         * We need to finish all async code before the module init sequence
-        * is done.  This has potential to deadlock.  For example, a newly
-        * detected block device can trigger request_module() of the
-        * default iosched from async probing task.  Once userland helper
-        * reaches here, async_synchronize_full() will wait on the async
-        * task waiting on request_module() and deadlock.
-        *
-        * This deadlock is avoided by perfomring async_synchronize_full()
-        * iff module init queued any async jobs.  This isn't a full
-        * solution as it will deadlock the same if module loading from
-        * async jobs nests more than once; however, due to the various
-        * constraints, this hack seems to be the best option for now.
-        * Please refer to the following thread for details.
+        * is done. This has potential to deadlock if synchronous module
+        * loading is requested from async (which is not allowed!).
         *
-        * http://thread.gmane.org/gmane.linux.kernel/1420814
+        * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
+        * request_module() from async workers") for more details.
         */
-       if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
+       if (!mod->async_probe_requested)
                async_synchronize_full();
 
        ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +