From bed831f9a251968272dae10a83b512c7db256ef0 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 27 May 2015 11:09:35 +0930 Subject: [PATCH] module, jump_label: Fix module locking As per the module core lockdep annotations in the coming patch: [ 18.034047] ---[ end trace 9294429076a9c673 ]--- [ 18.047760] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 [ 18.059228] ffffffff817d8676 ffff880036683c38 ffffffff8157e98b 0000000000000001 [ 18.067541] 0000000000000000 ffff880036683c78 ffffffff8105fbc7 ffff880036683c68 [ 18.075851] ffffffffa0046b08 0000000000000000 ffffffffa0046d00 ffffffffa0046cc8 [ 18.084173] Call Trace: [ 18.086906] [] dump_stack+0x4f/0x7b [ 18.092649] [] warn_slowpath_common+0x97/0xe0 [ 18.099361] [] warn_slowpath_null+0x1a/0x20 [ 18.105880] [] __module_address+0x1d2/0x1e0 [ 18.112400] [] jump_label_module_notify+0x143/0x1e0 [ 18.119710] [] notifier_call_chain+0x4f/0x70 [ 18.126326] [] __blocking_notifier_call_chain+0x5e/0x90 [ 18.134009] [] blocking_notifier_call_chain+0x16/0x20 [ 18.141490] [] load_module+0x1b50/0x2660 [ 18.147720] [] SyS_init_module+0xce/0x100 [ 18.154045] [] system_call_fastpath+0x12/0x17 [ 18.160748] ---[ end trace 9294429076a9c674 ]--- Jump labels is not doing it right; fix this. Cc: Rusty Russell Cc: Jason Baron Acked-by: Paul E. McKenney Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Rusty Russell --- kernel/jump_label.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 9019f15deab2..52ebaca1b9fc 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -302,7 +302,7 @@ static int jump_label_add_module(struct module *mod) continue; key = iterk; - if (__module_address(iter->key) == mod) { + if (within_module(iter->key, mod)) { /* * Set key->entries to iter, but preserve JUMP_LABEL_TRUE_BRANCH. */ @@ -339,7 +339,7 @@ static void jump_label_del_module(struct module *mod) key = (struct static_key *)(unsigned long)iter->key; - if (__module_address(iter->key) == mod) + if (within_module(iter->key, mod)) continue; prev = &key->next; @@ -443,14 +443,16 @@ static void jump_label_update(struct static_key *key, int enable) { struct jump_entry *stop = __stop___jump_table; struct jump_entry *entry = jump_label_get_entries(key); - #ifdef CONFIG_MODULES - struct module *mod = __module_address((unsigned long)key); + struct module *mod; __jump_label_mod_update(key, enable); + preempt_disable(); + mod = __module_address((unsigned long)key); if (mod) stop = mod->jump_entries + mod->num_jump_entries; + preempt_enable(); #endif /* if there are no users, entry can be NULL */ if (entry) -- 2.34.1