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authorPeter Zijlstra <peterz@infradead.org>2020-12-16 12:21:36 +0100
committerPeter Zijlstra <peterz@infradead.org>2020-12-18 16:53:12 +0100
commit55d2eba8e7cd439c11cdb204898c2d384227629b (patch)
tree14afa4f82d3d0c604a7d724850babc5259526fcf /kernel
parent2c85ebc57b3e1817b6ce1a6b703928e113a90442 (diff)
downloadlinux-55d2eba8e7cd439c11cdb204898c2d384227629b.tar.bz2
jump_label: Fix usage in module __init
When the static_key is part of the module, and the module calls static_key_inc/enable() from it's __init section *AND* has a static_branch_*() user in that very same __init section, things go wobbly. If the static_key lives outside the module, jump_label_add_module() would append this module's sites to the key and jump_label_update() would take the static_key_linked() branch and all would be fine. If all the sites are outside of __init, then everything will be fine too. However, when all is aligned just as described above, jump_label_update() calls __jump_label_update(.init = false) and we'll not update sites in __init text. Fixes: 19483677684b ("jump_label: Annotate entries that operate on __init code earlier") Reported-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Jessica Yu <jeyu@kernel.org> Link: https://lkml.kernel.org/r/20201216135435.GV3092@hirez.programming.kicks-ass.net
Diffstat (limited to 'kernel')
-rw-r--r--kernel/jump_label.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 015ef903ce8c..c6a39d662935 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -793,6 +793,7 @@ int jump_label_text_reserved(void *start, void *end)
static void jump_label_update(struct static_key *key)
{
struct jump_entry *stop = __stop___jump_table;
+ bool init = system_state < SYSTEM_RUNNING;
struct jump_entry *entry;
#ifdef CONFIG_MODULES
struct module *mod;
@@ -804,15 +805,16 @@ static void jump_label_update(struct static_key *key)
preempt_disable();
mod = __module_address((unsigned long)key);
- if (mod)
+ if (mod) {
stop = mod->jump_entries + mod->num_jump_entries;
+ init = mod->state == MODULE_STATE_COMING;
+ }
preempt_enable();
#endif
entry = static_key_entries(key);
/* if there are no users, entry can be NULL */
if (entry)
- __jump_label_update(key, entry, stop,
- system_state < SYSTEM_RUNNING);
+ __jump_label_update(key, entry, stop, init);
}
#ifdef CONFIG_STATIC_KEYS_SELFTEST