From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C3563321D5 for ; Fri, 14 Nov 2025 15:15:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763133335; cv=none; b=LrEbTdZOZoVYJb7JhYWKurohAAlzMJKMDL6whYNu8/+orl4E6/gGwF7BhDhVk7csF4Z7LtXsfZ0SeZ8qANSqjUyhnU58UrCtmcSiDIGELsyu4clYMiuGqC3AOCWdp9AQdvTr0Zv1CMJYoq74tfRuWkwBmadSl9Bvma8CIvQfU2A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763133335; c=relaxed/simple; bh=1IlDDCmLB2DMyjMzK/Tdl0cNptbFgBRDV+MskYp8Re4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ty1yqk4r+Q37NqcP2cSzGDDB2KGo1LAhtkWprbdZf6iiVJ6JGmt/sHLrN8OwH7NqeK9yIEr/HmBRjICDqY5QRdDRDocc30a0IkzuSRbaHOl5Gamy9KCiUOqvMUG73ALaKRvuDXe3MGLmV9pxsmsrRRdbZKS0SG3Q56Pq/PdriKY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=CbCe+QLc; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CbCe+QLc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1763133333; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4ORd+Fn6+m/VKC6BHOBwuPVWzflJh2ADAar+c08WU+E=; b=CbCe+QLcqNZkQv9Ydm7u15a06Uxq4oTUj2rVb6EcNr08HQ20d/9vlCPlT/G/tMYEoBCrq/ tJeE8qiWjACQ+GzioGJk5yeHya4xDWNpJUW+dr7756Oc3o25StRfBbZiXqNadB5YTSVZhZ jyjECHFTyLs5MD6Wh5pNPRFUrZwCoMo= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-13-tXg0QNLVNguk-o74W8HyWg-1; Fri, 14 Nov 2025 10:15:29 -0500 X-MC-Unique: tXg0QNLVNguk-o74W8HyWg-1 X-Mimecast-MFC-AGG-ID: tXg0QNLVNguk-o74W8HyWg_1763133325 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 077A11955F4A; Fri, 14 Nov 2025 15:15:25 +0000 (UTC) Received: from vschneid-thinkpadt14sgen2i.remote.csb (unknown [10.45.226.10]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4BACB1800346; Fri, 14 Nov 2025 15:15:10 +0000 (UTC) From: Valentin Schneider To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, rcu@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Arnaldo Carvalho de Melo , Josh Poimboeuf , Paolo Bonzini , Arnd Bergmann , Frederic Weisbecker , "Paul E. McKenney" , Jason Baron , Steven Rostedt , Ard Biesheuvel , Sami Tolvanen , "David S. Miller" , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , Mathieu Desnoyers , Mel Gorman , Andrew Morton , Masahiro Yamada , Han Shen , Rik van Riel , Jann Horn , Dan Carpenter , Oleg Nesterov , Juri Lelli , Clark Williams , Yair Podemsky , Marcelo Tosatti , Daniel Wagner , Petr Tesarik , Shrikanth Hegde Subject: [PATCH v7 23/31] module: Add MOD_NOINSTR_TEXT mem_type Date: Fri, 14 Nov 2025 16:14:20 +0100 Message-ID: <20251114151428.1064524-3-vschneid@redhat.com> In-Reply-To: <20251114150133.1056710-1-vschneid@redhat.com> References: <20251114150133.1056710-1-vschneid@redhat.com> Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 As pointed out by Sean [1], is_kernel_noinstr_text() will return false for an address contained within a module's .noinstr.text section. A later patch will require checking whether a text address is noinstr, and this can unfortunately be the case of modules - KVM is one such case. A module's .noinstr.text section is already tracked as of commit 66e9b0717102 ("kprobes: Prevent probes in .noinstr.text section") for kprobe blacklisting purposes, but via an ad-hoc mechanism. Add a MOD_NOINSTR_TEXT mem_type, and reorganize __layout_sections() so that it maps all the sections in a single invocation. [1]: http://lore.kernel.org/r/Z4qQL89GZ_gk0vpu@google.com Signed-off-by: Valentin Schneider --- include/linux/module.h | 6 ++-- kernel/kprobes.c | 8 ++--- kernel/module/main.c | 76 ++++++++++++++++++++++++++++++++---------- 3 files changed, 66 insertions(+), 24 deletions(-) diff --git a/include/linux/module.h b/include/linux/module.h index e135cc79aceea..c0911973337c6 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -322,6 +322,7 @@ struct mod_tree_node { enum mod_mem_type { MOD_TEXT = 0, + MOD_NOINSTR_TEXT, MOD_DATA, MOD_RODATA, MOD_RO_AFTER_INIT, @@ -492,8 +493,6 @@ struct module { void __percpu *percpu; unsigned int percpu_size; #endif - void *noinstr_text_start; - unsigned int noinstr_text_size; #ifdef CONFIG_TRACEPOINTS unsigned int num_tracepoints; @@ -622,12 +621,13 @@ static inline bool module_is_coming(struct module *mod) return mod->state == MODULE_STATE_COMING; } -struct module *__module_text_address(unsigned long addr); struct module *__module_address(unsigned long addr); +struct module *__module_text_address(unsigned long addr); bool is_module_address(unsigned long addr); bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr); bool is_module_percpu_address(unsigned long addr); bool is_module_text_address(unsigned long addr); +bool is_module_noinstr_text_address(unsigned long addr); static inline bool within_module_mem_type(unsigned long addr, const struct module *mod, diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ab8f9fc1f0d17..d60560dddec56 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2551,9 +2551,9 @@ static void add_module_kprobe_blacklist(struct module *mod) kprobe_add_area_blacklist(start, end); } - start = (unsigned long)mod->noinstr_text_start; + start = (unsigned long)mod->mem[MOD_NOINSTR_TEXT].base; if (start) { - end = start + mod->noinstr_text_size; + end = start + mod->mem[MOD_NOINSTR_TEXT].size; kprobe_add_area_blacklist(start, end); } } @@ -2574,9 +2574,9 @@ static void remove_module_kprobe_blacklist(struct module *mod) kprobe_remove_area_blacklist(start, end); } - start = (unsigned long)mod->noinstr_text_start; + start = (unsigned long)mod->mem[MOD_NOINSTR_TEXT].base; if (start) { - end = start + mod->noinstr_text_size; + end = start + mod->mem[MOD_NOINSTR_TEXT].size; kprobe_remove_area_blacklist(start, end); } } diff --git a/kernel/module/main.c b/kernel/module/main.c index c66b261849362..1f5bfdbb956a7 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -1653,7 +1653,17 @@ bool module_init_layout_section(const char *sname) return module_init_section(sname); } -static void __layout_sections(struct module *mod, struct load_info *info, bool is_init) +static bool module_noinstr_layout_section(const char *sname) +{ + return strstarts(sname, ".noinstr"); +} + +static bool module_default_layout_section(const char *sname) +{ + return !module_init_layout_section(sname) && !module_noinstr_layout_section(sname); +} + +static void __layout_sections(struct module *mod, struct load_info *info) { unsigned int m, i; @@ -1662,20 +1672,44 @@ static void __layout_sections(struct module *mod, struct load_info *info, bool i * Mask of excluded section header flags } */ static const unsigned long masks[][2] = { + /* Core */ + { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, + { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, + { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, + { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, + { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, + { ARCH_SHF_SMALL | SHF_ALLOC, 0 }, + /* Init */ { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, - { ARCH_SHF_SMALL | SHF_ALLOC, 0 } + { ARCH_SHF_SMALL | SHF_ALLOC, 0 }, }; - static const int core_m_to_mem_type[] = { + static bool (*const section_filter[])(const char *) = { + /* Core */ + module_default_layout_section, + module_noinstr_layout_section, + module_default_layout_section, + module_default_layout_section, + module_default_layout_section, + module_default_layout_section, + /* Init */ + module_init_layout_section, + module_init_layout_section, + module_init_layout_section, + module_init_layout_section, + module_init_layout_section, + }; + static const int mem_type_map[] = { + /* Core */ MOD_TEXT, + MOD_NOINSTR_TEXT, MOD_RODATA, MOD_RO_AFTER_INIT, MOD_DATA, MOD_DATA, - }; - static const int init_m_to_mem_type[] = { + /* Init */ MOD_INIT_TEXT, MOD_INIT_RODATA, MOD_INVALID, @@ -1684,16 +1718,16 @@ static void __layout_sections(struct module *mod, struct load_info *info, bool i }; for (m = 0; m < ARRAY_SIZE(masks); ++m) { - enum mod_mem_type type = is_init ? init_m_to_mem_type[m] : core_m_to_mem_type[m]; + enum mod_mem_type type = mem_type_map[m]; for (i = 0; i < info->hdr->e_shnum; ++i) { Elf_Shdr *s = &info->sechdrs[i]; const char *sname = info->secstrings + s->sh_name; - if ((s->sh_flags & masks[m][0]) != masks[m][0] - || (s->sh_flags & masks[m][1]) - || s->sh_entsize != ~0UL - || is_init != module_init_layout_section(sname)) + if ((s->sh_flags & masks[m][0]) != masks[m][0] || + (s->sh_flags & masks[m][1]) || + s->sh_entsize != ~0UL || + !section_filter[m](sname)) continue; if (WARN_ON_ONCE(type == MOD_INVALID)) @@ -1733,10 +1767,7 @@ static void layout_sections(struct module *mod, struct load_info *info) info->sechdrs[i].sh_entsize = ~0UL; pr_debug("Core section allocation order for %s:\n", mod->name); - __layout_sections(mod, info, false); - - pr_debug("Init section allocation order for %s:\n", mod->name); - __layout_sections(mod, info, true); + __layout_sections(mod, info); } static void module_license_taint_check(struct module *mod, const char *license) @@ -2625,9 +2656,6 @@ static int find_module_sections(struct module *mod, struct load_info *info) } #endif - mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1, - &mod->noinstr_text_size); - #ifdef CONFIG_TRACEPOINTS mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", sizeof(*mod->tracepoints_ptrs), @@ -3872,12 +3900,26 @@ struct module *__module_text_address(unsigned long addr) if (mod) { /* Make sure it's within the text section. */ if (!within_module_mem_type(addr, mod, MOD_TEXT) && + !within_module_mem_type(addr, mod, MOD_NOINSTR_TEXT) && !within_module_mem_type(addr, mod, MOD_INIT_TEXT)) mod = NULL; } return mod; } +bool is_module_noinstr_text_address(unsigned long addr) +{ + scoped_guard(preempt) { + struct module *mod = __module_address(addr); + + /* Make sure it's within the .noinstr.text section. */ + if (mod) + return within_module_mem_type(addr, mod, MOD_NOINSTR_TEXT); + } + + return false; +} + /* Don't grab lock, we're oopsing. */ void print_modules(void) { -- 2.51.0