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| author |   Peter Zijlstra <peterz@infradead.org> | 2020-12-16 12:21:36 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-12-18 16:53:12 +0100 |
| commit | 55d2eba8e7cd439c11cdb204898c2d384227629b (patch) | |
| tree | 14afa4f82d3d0c604a7d724850babc5259526fcf /kernel/jump_label.c | |
| parent | Linux 5.10 (diff) | |
| download | linux-dev-55d2eba8e7cd439c11cdb204898c2d384227629b.tar.xz linux-dev-55d2eba8e7cd439c11cdb204898c2d384227629b.zip | |
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/jump_label.c')
| -rw-r--r-- | kernel/jump_label.c | 8 |
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 |