67 lines
2.2 KiB
Diff
67 lines
2.2 KiB
Diff
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From: Rusty Russell <rusty@rustcorp.com.au>
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Date: Fri, 28 Sep 2012 05:01:03 +0000 (+0930)
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Subject: module: fix symbol waiting when module fails before init
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X-Git-Tag: v3.7-rc1~2^2~33
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X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=6f13909f4fe9652f1
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module: fix symbol waiting when module fails before init
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We use resolve_symbol_wait(), which blocks if the module containing
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the symbol is still loading. However:
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1) The module_wq we use is only woken after calling the modules' init
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function, but there are other failure paths after the module is
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placed in the linked list where we need to do the same thing.
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2) wake_up() only wakes one waiter, and our waitqueue is shared by all
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modules, so we need to wake them all.
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3) wake_up_all() doesn't imply a memory barrier: I feel happier calling
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it after we've grabbed and dropped the module_mutex, not just after
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the state assignment.
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Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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---
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diff --git a/kernel/module.c b/kernel/module.c
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index 7f2ee45f..63cf6e7 100644
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--- a/kernel/module.c
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+++ b/kernel/module.c
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@@ -2959,7 +2959,7 @@ static struct module *load_module(void __user *umod,
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/* Unlink carefully: kallsyms could be walking list. */
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list_del_rcu(&mod->list);
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module_bug_cleanup(mod);
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-
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+ wake_up_all(&module_wq);
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ddebug:
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dynamic_debug_remove(info.debug);
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unlock:
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@@ -3034,7 +3034,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
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blocking_notifier_call_chain(&module_notify_list,
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MODULE_STATE_GOING, mod);
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free_module(mod);
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- wake_up(&module_wq);
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+ wake_up_all(&module_wq);
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return ret;
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}
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if (ret > 0) {
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@@ -3046,9 +3046,8 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
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dump_stack();
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}
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- /* Now it's a first class citizen! Wake up anyone waiting for it. */
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+ /* Now it's a first class citizen! */
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mod->state = MODULE_STATE_LIVE;
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- wake_up(&module_wq);
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blocking_notifier_call_chain(&module_notify_list,
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MODULE_STATE_LIVE, mod);
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@@ -3071,6 +3070,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
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mod->init_ro_size = 0;
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mod->init_text_size = 0;
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mutex_unlock(&module_mutex);
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+ wake_up_all(&module_wq);
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return 0;
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}
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