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static_call: Align static_call_is_init() patching condition
The intent is to avoid writing init code after init (because the text might have been freed). The code is needlessly different between jump_label and static_call and not obviously correct. The existing code relies on the fact that the module loader clears the init layout, such that within_module_init() always fails, while jump_label relies on the module state which is more obvious and matches the kernel logic. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Tested-by: Sumit Garg <sumit.garg@linaro.org> Link: https://lkml.kernel.org/r/20210318113610.636651340@infradead.org
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@ -149,6 +149,7 @@ void __static_call_update(struct static_call_key *key, void *tramp, void *func)
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};
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for (site_mod = &first; site_mod; site_mod = site_mod->next) {
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bool init = system_state < SYSTEM_RUNNING;
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struct module *mod = site_mod->mod;
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if (!site_mod->sites) {
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@ -168,6 +169,7 @@ void __static_call_update(struct static_call_key *key, void *tramp, void *func)
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if (mod) {
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stop = mod->static_call_sites +
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mod->num_static_call_sites;
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init = mod->state == MODULE_STATE_COMING;
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}
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#endif
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@ -175,16 +177,8 @@ void __static_call_update(struct static_call_key *key, void *tramp, void *func)
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site < stop && static_call_key(site) == key; site++) {
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void *site_addr = static_call_addr(site);
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if (static_call_is_init(site)) {
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/*
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* Don't write to call sites which were in
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* initmem and have since been freed.
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*/
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if (!mod && system_state >= SYSTEM_RUNNING)
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continue;
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if (mod && !within_module_init((unsigned long)site_addr, mod))
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continue;
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}
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if (!init && static_call_is_init(site))
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continue;
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if (!kernel_text_address((unsigned long)site_addr)) {
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WARN_ONCE(1, "can't patch static call site at %pS",
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