From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C32AC433E7 for ; Tue, 1 Sep 2020 14:49:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 716CC2220B for ; Tue, 1 Sep 2020 14:49:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="MZkOHEZz"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="SFZyZRLA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728565AbgIAOt3 (ORCPT ); Tue, 1 Sep 2020 10:49:29 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:39618 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727852AbgIALs3 (ORCPT ); Tue, 1 Sep 2020 07:48:29 -0400 Date: Tue, 01 Sep 2020 11:48:02 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1598960883; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=z7agiW4QyJ/KwxkgyxmE/KuLGl4OhPxpu3gpLz1BoIY=; b=MZkOHEZzQNDCf58BRRdAf2ICd30/zCDUVPbzTWy2a19zbNCaz9ZWa9PtCYbXUfKXfDH+Ds QtNlST16BFzyV0vl283P6W6/lskQXeYUL4Mq7jRz0gPvIk0pvJa8TqOGbUKSbKkWZwKSq2 j4qL+S4zcIovMEWbg1ExAM/8qQ6h3WQP2fjH2mEDugF/x2+2lneIuwlApE9mJszeOzMbes qWIhvKMKJMI/P4vXsaX9DQF9tpOm4GWpFk90+VavxPNBeQZPUsU7eRd3e9H+83SqA+8AA8 eurvyvaOtLujbAi7phUz7AcRIu4tuYrTq05fD2vwa1U85gL9XS5Amn0z4ChhYA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1598960883; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=z7agiW4QyJ/KwxkgyxmE/KuLGl4OhPxpu3gpLz1BoIY=; b=SFZyZRLAxBezvWumwK2Gu/vUnAAVXw4zrfZqP7VVWxlR2yhL59omwop5CAi3E4pr4UeWl/ CyY/Qx/2ekuC23Bg== From: "tip-bot2 for Peter Zijlstra" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: core/static_call] static_call: Allow early init Cc: "Peter Zijlstra (Intel)" , Ingo Molnar , "Steven Rostedt (VMware)" , x86 , LKML In-Reply-To: <20200818135805.220737930@infradead.org> References: <20200818135805.220737930@infradead.org> MIME-Version: 1.0 Message-ID: <159896088285.20229.7006009162500635991.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the core/static_call branch of tip: Commit-ID: a945c8345ec0decb2f1a7f19a8c5e60bcb1dd1eb Gitweb: https://git.kernel.org/tip/a945c8345ec0decb2f1a7f19a8c5e60bcb1dd1eb Author: Peter Zijlstra AuthorDate: Tue, 18 Aug 2020 15:57:51 +02:00 Committer: Ingo Molnar CommitterDate: Tue, 01 Sep 2020 09:58:06 +02:00 static_call: Allow early init In order to use static_call() to wire up x86_pmu, we need to initialize earlier, specifically before memory allocation works; copy some of the tricks from jump_label to enable this. Primarily we overload key->next to store a sites pointer when there are no modules, this avoids having to use kmalloc() to initialize the sites and allows us to run much earlier. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Steven Rostedt (VMware) Link: https://lore.kernel.org/r/20200818135805.220737930@infradead.org --- arch/x86/kernel/setup.c | 2 +- arch/x86/kernel/static_call.c | 5 +- include/linux/static_call.h | 15 ++++++- kernel/static_call.c | 70 ++++++++++++++++++++++++++++++++-- 4 files changed, 85 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 3511736..799a6de 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -19,6 +19,7 @@ #include #include #include +#include #include @@ -849,6 +850,7 @@ void __init setup_arch(char **cmdline_p) early_cpu_init(); arch_init_ideal_nops(); jump_label_init(); + static_call_init(); early_ioremap_init(); setup_olpc_ofw_pgd(); diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c index 55140d8..ca9a380 100644 --- a/arch/x86/kernel/static_call.c +++ b/arch/x86/kernel/static_call.c @@ -11,7 +11,7 @@ enum insn_type { RET = 3, /* tramp / site cond-tail-call */ }; -static void __static_call_transform(void *insn, enum insn_type type, void *func) +static void __ref __static_call_transform(void *insn, enum insn_type type, void *func) { int size = CALL_INSN_SIZE; const void *code; @@ -38,6 +38,9 @@ static void __static_call_transform(void *insn, enum insn_type type, void *func) if (memcmp(insn, code, size) == 0) return; + if (unlikely(system_state == SYSTEM_BOOTING)) + return text_poke_early(insn, code, size); + text_poke_bp(insn, code, size, NULL); } diff --git a/include/linux/static_call.h b/include/linux/static_call.h index 519bd66..bfa2ba3 100644 --- a/include/linux/static_call.h +++ b/include/linux/static_call.h @@ -136,6 +136,8 @@ extern void arch_static_call_transform(void *site, void *tramp, void *func, bool #ifdef CONFIG_HAVE_STATIC_CALL_INLINE +extern void __init static_call_init(void); + struct static_call_mod { struct static_call_mod *next; struct module *mod; /* for vmlinux, mod == NULL */ @@ -144,7 +146,12 @@ struct static_call_mod { struct static_call_key { void *func; - struct static_call_mod *mods; + union { + /* bit 0: 0 = mods, 1 = sites */ + unsigned long type; + struct static_call_mod *mods; + struct static_call_site *sites; + }; }; extern void __static_call_update(struct static_call_key *key, void *tramp, void *func); @@ -155,7 +162,7 @@ extern int static_call_text_reserved(void *start, void *end); DECLARE_STATIC_CALL(name, _func); \ struct static_call_key STATIC_CALL_KEY(name) = { \ .func = _func, \ - .mods = NULL, \ + .type = 1, \ }; \ ARCH_DEFINE_STATIC_CALL_TRAMP(name, _func) @@ -180,6 +187,8 @@ extern int static_call_text_reserved(void *start, void *end); #elif defined(CONFIG_HAVE_STATIC_CALL) +static inline void static_call_init(void) { } + struct static_call_key { void *func; }; @@ -225,6 +234,8 @@ static inline int static_call_text_reserved(void *start, void *end) #else /* Generic implementation */ +static inline void static_call_init(void) { } + struct static_call_key { void *func; }; diff --git a/kernel/static_call.c b/kernel/static_call.c index d98e0e4..f8362b3 100644 --- a/kernel/static_call.c +++ b/kernel/static_call.c @@ -94,10 +94,31 @@ static inline void static_call_sort_entries(struct static_call_site *start, static_call_site_cmp, static_call_site_swap); } +static inline bool static_call_key_has_mods(struct static_call_key *key) +{ + return !(key->type & 1); +} + +static inline struct static_call_mod *static_call_key_next(struct static_call_key *key) +{ + if (!static_call_key_has_mods(key)) + return NULL; + + return key->mods; +} + +static inline struct static_call_site *static_call_key_sites(struct static_call_key *key) +{ + if (static_call_key_has_mods(key)) + return NULL; + + return (struct static_call_site *)(key->type & ~1); +} + void __static_call_update(struct static_call_key *key, void *tramp, void *func) { struct static_call_site *site, *stop; - struct static_call_mod *site_mod; + struct static_call_mod *site_mod, first; cpus_read_lock(); static_call_lock(); @@ -116,13 +137,22 @@ void __static_call_update(struct static_call_key *key, void *tramp, void *func) if (WARN_ON_ONCE(!static_call_initialized)) goto done; - for (site_mod = key->mods; site_mod; site_mod = site_mod->next) { + first = (struct static_call_mod){ + .next = static_call_key_next(key), + .mod = NULL, + .sites = static_call_key_sites(key), + }; + + for (site_mod = &first; site_mod; site_mod = site_mod->next) { struct module *mod = site_mod->mod; if (!site_mod->sites) { /* * This can happen if the static call key is defined in * a module which doesn't use it. + * + * It also happens in the has_mods case, where the + * 'first' entry has no sites associated with it. */ continue; } @@ -192,16 +222,48 @@ static int __static_call_init(struct module *mod, if (key != prev_key) { prev_key = key; + /* + * For vmlinux (!mod) avoid the allocation by storing + * the sites pointer in the key itself. Also see + * __static_call_update()'s @first. + * + * This allows architectures (eg. x86) to call + * static_call_init() before memory allocation works. + */ + if (!mod) { + key->sites = site; + key->type |= 1; + goto do_transform; + } + site_mod = kzalloc(sizeof(*site_mod), GFP_KERNEL); if (!site_mod) return -ENOMEM; + /* + * When the key has a direct sites pointer, extract + * that into an explicit struct static_call_mod, so we + * can have a list of modules. + */ + if (static_call_key_sites(key)) { + site_mod->mod = NULL; + site_mod->next = NULL; + site_mod->sites = static_call_key_sites(key); + + key->mods = site_mod; + + site_mod = kzalloc(sizeof(*site_mod), GFP_KERNEL); + if (!site_mod) + return -ENOMEM; + } + site_mod->mod = mod; site_mod->sites = site; - site_mod->next = key->mods; + site_mod->next = static_call_key_next(key); key->mods = site_mod; } +do_transform: arch_static_call_transform(site_addr, NULL, key->func, static_call_is_tail(site)); } @@ -348,7 +410,7 @@ int static_call_text_reserved(void *start, void *end) return __static_call_mod_text_reserved(start, end); } -static void __init static_call_init(void) +void __init static_call_init(void) { int ret;