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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 D9CAAC433FE for ; Wed, 22 Sep 2021 17:00:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB3E36105A for ; Wed, 22 Sep 2021 17:00:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236741AbhIVRCB (ORCPT ); Wed, 22 Sep 2021 13:02:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236727AbhIVRB6 (ORCPT ); Wed, 22 Sep 2021 13:01:58 -0400 Received: from mail-pf1-x430.google.com (mail-pf1-x430.google.com [IPv6:2607:f8b0:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B085C061574; Wed, 22 Sep 2021 10:00:28 -0700 (PDT) Received: by mail-pf1-x430.google.com with SMTP id g14so3287676pfm.1; Wed, 22 Sep 2021 10:00:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=quAjGgUTPRretr+n9tLcFkF+/sLuVYJsTUhZuBzshIM=; b=W4JWq30ih97bVAP8dBqiBIFuQ+dMDp5LwK/5Ksy9UDvtdkvkIqLDwCbLfHT5XRiRo6 0ZmmjD+pyz+suYzxl+++cuTHckbtSeZN8TqgqLhYiWvNYnnz4KY1k7AcVhZrHQ54w1Xn MFJXd3PBZzbYng03+xXhXqXY2pkdgebow19dCXuwxeKc8ozCy+z5t5KK03djInfzbG+I secg0Uzi3aIC7Z/qINMASlOzRq8Hg/n9Dls2vASIm9IEgege/8GBc4lqck3qmd2uYZmx dcRHImpc1+b24Ims40vptaZLXl9Us/F7ji82wM4IYB5Ps1dbl+GCPobRziHV1WJLnE6w Es9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=quAjGgUTPRretr+n9tLcFkF+/sLuVYJsTUhZuBzshIM=; b=ubhL6UxlqluRP1qljebzsVtDeAZ/ZiiD9BHGnouq96+US5p5Qryn9Vq2rpzY10l1Jq YBqa+MJqebbHgy+tMp4SsgKiwPXfK+IYHlK9ElxH1AAuAp2DvG6rss8jdmQSo1paSvdN 5axuhznMrGsj1l6x+HZxK4+4lGcHgTLuez0pqTfNkf2CDq0+zG7xCri4XU/56sC4204Q QThxOsHuh68iBj2BwFpdtmuGYK8Fw62/QSJsUocCHyeIKS1UODQ6vZ71HqVCr9HgGGVe iB1UyQu3Lb/R+Ky78gMtK43KSOLDcoiZEb9rRfrKcAzp8FDA1k+UxbUYqF9wGfGSUcn5 qfHQ== X-Gm-Message-State: AOAM533bpcEWRhxwCSufsWmMzrQpfJ/DGRPYXOqWvDK2F0BeD1LnQNDb +m4Ir8hbt5JJWSmsH+q0U7hn+F6k/rM= X-Google-Smtp-Source: ABdhPJyZ72JOjAdjYXI0r1hPhgs55ih6qVqDUNKH4uQXvcBxtp1jvv5okY9dU2Hgeh7w8YYPFHCYaQ== X-Received: by 2002:a63:935a:: with SMTP id w26mr634794pgm.314.1632330027603; Wed, 22 Sep 2021 10:00:27 -0700 (PDT) Received: from fainelli-desktop.igp.broadcom.net ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id j23sm3196336pfr.208.2021.09.22.10.00.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Sep 2021 10:00:27 -0700 (PDT) From: Florian Fainelli To: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, Greg Kroah-Hartman , Sasha Levin , Alex Sverdlin , Russell King , Florian Fainelli , Steven Rostedt , Ingo Molnar , Russell King , linux-arm-kernel@lists.infradead.org (moderated list:ARM PORT) Subject: [PATCH stable 5.10 v2 3/4] ARM: 9079/1: ftrace: Add MODULE_PLTS support Date: Wed, 22 Sep 2021 09:59:57 -0700 Message-Id: <20210922165958.189843-4-f.fainelli@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210922165958.189843-1-f.fainelli@gmail.com> References: <20210922165958.189843-1-f.fainelli@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alex Sverdlin commit 79f32b221b18c15a98507b101ef4beb52444cc6f upstream Teach ftrace_make_call() and ftrace_make_nop() about PLTs. Teach PLT code about FTRACE and all its callbacks. Otherwise the following might happen: ------------[ cut here ]------------ WARNING: CPU: 14 PID: 2265 at .../arch/arm/kernel/insn.c:14 __arm_gen_branch+0x83/0x8c() ... Hardware name: LSI Axxia AXM55XX [] (unwind_backtrace) from [] (show_stack+0x11/0x14) [] (show_stack) from [] (dump_stack+0x81/0xa8) [] (dump_stack) from [] (warn_slowpath_common+0x69/0x90) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x17/0x1c) [] (warn_slowpath_null) from [] (__arm_gen_branch+0x83/0x8c) [] (__arm_gen_branch) from [] (ftrace_make_nop+0xf/0x24) [] (ftrace_make_nop) from [] (ftrace_process_locs+0x27b/0x3e8) [] (ftrace_process_locs) from [] (load_module+0x11e9/0x1a44) [] (load_module) from [] (SyS_finit_module+0x59/0x84) [] (SyS_finit_module) from [] (ret_fast_syscall+0x1/0x18) ---[ end trace e1b64ced7a89adcc ]--- ------------[ cut here ]------------ WARNING: CPU: 14 PID: 2265 at .../kernel/trace/ftrace.c:1979 ftrace_bug+0x1b1/0x234() ... Hardware name: LSI Axxia AXM55XX [] (unwind_backtrace) from [] (show_stack+0x11/0x14) [] (show_stack) from [] (dump_stack+0x81/0xa8) [] (dump_stack) from [] (warn_slowpath_common+0x69/0x90) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x17/0x1c) [] (warn_slowpath_null) from [] (ftrace_bug+0x1b1/0x234) [] (ftrace_bug) from [] (ftrace_process_locs+0x285/0x3e8) [] (ftrace_process_locs) from [] (load_module+0x11e9/0x1a44) [] (load_module) from [] (SyS_finit_module+0x59/0x84) [] (SyS_finit_module) from [] (ret_fast_syscall+0x1/0x18) ---[ end trace e1b64ced7a89adcd ]--- ftrace failed to modify [] 0xe9ef7006 actual: 02:f0:3b:fa ftrace record flags: 0 (0) expected tramp: c0314265 Signed-off-by: Alexander Sverdlin Signed-off-by: Russell King Signed-off-by: Florian Fainelli --- arch/arm/include/asm/ftrace.h | 3 +++ arch/arm/include/asm/module.h | 1 + arch/arm/kernel/ftrace.c | 46 +++++++++++++++++++++++++++++------ arch/arm/kernel/module-plts.c | 44 ++++++++++++++++++++++++++++++--- 4 files changed, 82 insertions(+), 12 deletions(-) diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h index 48ec1d0337da..a4dbac07e4ef 100644 --- a/arch/arm/include/asm/ftrace.h +++ b/arch/arm/include/asm/ftrace.h @@ -15,6 +15,9 @@ extern void __gnu_mcount_nc(void); #ifdef CONFIG_DYNAMIC_FTRACE struct dyn_arch_ftrace { +#ifdef CONFIG_ARM_MODULE_PLTS + struct module *mod; +#endif }; static inline unsigned long ftrace_call_adjust(unsigned long addr) diff --git a/arch/arm/include/asm/module.h b/arch/arm/include/asm/module.h index 09b9ad55b83d..cfffae67c04e 100644 --- a/arch/arm/include/asm/module.h +++ b/arch/arm/include/asm/module.h @@ -30,6 +30,7 @@ struct plt_entries { struct mod_plt_sec { struct elf32_shdr *plt; + struct plt_entries *plt_ent; int plt_count; }; diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index 61de8172a044..3c83b5d29697 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -68,9 +68,10 @@ int ftrace_arch_code_modify_post_process(void) return 0; } -static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr) +static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr, + bool warn) { - return arm_gen_branch_link(pc, addr, true); + return arm_gen_branch_link(pc, addr, warn); } static int ftrace_modify_code(unsigned long pc, unsigned long old, @@ -104,14 +105,14 @@ int ftrace_update_ftrace_func(ftrace_func_t func) int ret; pc = (unsigned long)&ftrace_call; - new = ftrace_call_replace(pc, (unsigned long)func); + new = ftrace_call_replace(pc, (unsigned long)func, true); ret = ftrace_modify_code(pc, 0, new, false); #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS if (!ret) { pc = (unsigned long)&ftrace_regs_call; - new = ftrace_call_replace(pc, (unsigned long)func); + new = ftrace_call_replace(pc, (unsigned long)func, true); ret = ftrace_modify_code(pc, 0, new, false); } @@ -124,10 +125,22 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { unsigned long new, old; unsigned long ip = rec->ip; + unsigned long aaddr = adjust_address(rec, addr); + struct module *mod = NULL; + +#ifdef CONFIG_ARM_MODULE_PLTS + mod = rec->arch.mod; +#endif old = ftrace_nop_replace(rec); - new = ftrace_call_replace(ip, adjust_address(rec, addr)); + new = ftrace_call_replace(ip, aaddr, !mod); +#ifdef CONFIG_ARM_MODULE_PLTS + if (!new && mod) { + aaddr = get_module_plt(mod, ip, aaddr); + new = ftrace_call_replace(ip, aaddr, true); + } +#endif return ftrace_modify_code(rec->ip, old, new, true); } @@ -140,9 +153,9 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long new, old; unsigned long ip = rec->ip; - old = ftrace_call_replace(ip, adjust_address(rec, old_addr)); + old = ftrace_call_replace(ip, adjust_address(rec, old_addr), true); - new = ftrace_call_replace(ip, adjust_address(rec, addr)); + new = ftrace_call_replace(ip, adjust_address(rec, addr), true); return ftrace_modify_code(rec->ip, old, new, true); } @@ -152,12 +165,29 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { + unsigned long aaddr = adjust_address(rec, addr); unsigned long ip = rec->ip; unsigned long old; unsigned long new; int ret; - old = ftrace_call_replace(ip, adjust_address(rec, addr)); +#ifdef CONFIG_ARM_MODULE_PLTS + /* mod is only supplied during module loading */ + if (!mod) + mod = rec->arch.mod; + else + rec->arch.mod = mod; +#endif + + old = ftrace_call_replace(ip, aaddr, + !IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || !mod); +#ifdef CONFIG_ARM_MODULE_PLTS + if (!old && mod) { + aaddr = get_module_plt(mod, ip, aaddr); + old = ftrace_call_replace(ip, aaddr, true); + } +#endif + new = ftrace_nop_replace(rec); ret = ftrace_modify_code(ip, old, new, true); diff --git a/arch/arm/kernel/module-plts.c b/arch/arm/kernel/module-plts.c index d330e9ec2de3..a0524ad84e4d 100644 --- a/arch/arm/kernel/module-plts.c +++ b/arch/arm/kernel/module-plts.c @@ -4,6 +4,7 @@ */ #include +#include #include #include #include @@ -20,19 +21,52 @@ (PLT_ENT_STRIDE - 8)) #endif +static const u32 fixed_plts[] = { +#ifdef CONFIG_FUNCTION_TRACER + FTRACE_ADDR, + MCOUNT_ADDR, +#endif +}; + static bool in_init(const struct module *mod, unsigned long loc) { return loc - (u32)mod->init_layout.base < mod->init_layout.size; } +static void prealloc_fixed(struct mod_plt_sec *pltsec, struct plt_entries *plt) +{ + int i; + + if (!ARRAY_SIZE(fixed_plts) || pltsec->plt_count) + return; + pltsec->plt_count = ARRAY_SIZE(fixed_plts); + + for (i = 0; i < ARRAY_SIZE(plt->ldr); ++i) + plt->ldr[i] = PLT_ENT_LDR; + + BUILD_BUG_ON(sizeof(fixed_plts) > sizeof(plt->lit)); + memcpy(plt->lit, fixed_plts, sizeof(fixed_plts)); +} + u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val) { struct mod_plt_sec *pltsec = !in_init(mod, loc) ? &mod->arch.core : &mod->arch.init; + struct plt_entries *plt; + int idx; + + /* cache the address, ELF header is available only during module load */ + if (!pltsec->plt_ent) + pltsec->plt_ent = (struct plt_entries *)pltsec->plt->sh_addr; + plt = pltsec->plt_ent; - struct plt_entries *plt = (struct plt_entries *)pltsec->plt->sh_addr; - int idx = 0; + prealloc_fixed(pltsec, plt); + + for (idx = 0; idx < ARRAY_SIZE(fixed_plts); ++idx) + if (plt->lit[idx] == val) + return (u32)&plt->ldr[idx]; + idx = 0; /* * Look for an existing entry pointing to 'val'. Given that the * relocations are sorted, this will be the last entry we allocated. @@ -180,8 +214,8 @@ static unsigned int count_plts(const Elf32_Sym *syms, Elf32_Addr base, int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod) { - unsigned long core_plts = 0; - unsigned long init_plts = 0; + unsigned long core_plts = ARRAY_SIZE(fixed_plts); + unsigned long init_plts = ARRAY_SIZE(fixed_plts); Elf32_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum; Elf32_Sym *syms = NULL; @@ -236,6 +270,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, mod->arch.core.plt->sh_size = round_up(core_plts * PLT_ENT_SIZE, sizeof(struct plt_entries)); mod->arch.core.plt_count = 0; + mod->arch.core.plt_ent = NULL; mod->arch.init.plt->sh_type = SHT_NOBITS; mod->arch.init.plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC; @@ -243,6 +278,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, mod->arch.init.plt->sh_size = round_up(init_plts * PLT_ENT_SIZE, sizeof(struct plt_entries)); mod->arch.init.plt_count = 0; + mod->arch.init.plt_ent = NULL; pr_debug("%s: plt=%x, init.plt=%x\n", __func__, mod->arch.core.plt->sh_size, mod->arch.init.plt->sh_size); -- 2.25.1