From patchwork Fri Jun 16 08:50:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 13282260 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 703F6EB64D8 for ; Fri, 16 Jun 2023 08:51:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343887AbjFPIve (ORCPT ); Fri, 16 Jun 2023 04:51:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343839AbjFPIvZ (ORCPT ); Fri, 16 Jun 2023 04:51:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B205E2D7E; Fri, 16 Jun 2023 01:51:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 308B26312F; Fri, 16 Jun 2023 08:51:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0ABD5C433C0; Fri, 16 Jun 2023 08:51:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686905478; bh=sDQNKYFwURAYEmF9xoW+gjLSz1JkAE0kb/4vtxjtP3o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PQo52LFvhgtb7nkBC+Gp0z2cnnoeV+/2RUXKacnrlcYavYEV4p/+zLAIw4RUmENAq 9I7bf0FA/F2x7W6yYFFMEHHlLAx0JKqOTqJ5qL0E8Q/X9mNTnS8vUX1TxoZ7iuuVk7 xSXDT8Xkqao0xtz1XU9/dV0eMEe48G8lp7qqpvBgVYF4/T9Al+QBY2ig4Rh21/FGVT 2CHNNsLJJQ4m4YlL9HprLlv+MlQ5uuxN8sn+a7bIWFrttePY5MWKLYRAPx4ILBdnMI 1WmZudC0s8ssYH4lEDrkic7fu8vn3p57mOisRaq8YcrsCrCSf3PPuqo+QlLGoCE++y ObDOjuChZwyNw== From: Mike Rapoport To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Catalin Marinas , Christophe Leroy , "David S. Miller" , Dinh Nguyen , Heiko Carstens , Helge Deller , Huacai Chen , Kent Overstreet , Luis Chamberlain , Mark Rutland , Michael Ellerman , Mike Rapoport , Nadav Amit , "Naveen N. Rao" , Palmer Dabbelt , Puranjay Mohan , Rick Edgecombe , Russell King , Song Liu , Steven Rostedt , Thomas Bogendoerfer , Thomas Gleixner , Will Deacon , bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev, netdev@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org Subject: [PATCH v2 02/12] mm: introduce execmem_text_alloc() and jit_text_alloc() Date: Fri, 16 Jun 2023 11:50:28 +0300 Message-Id: <20230616085038.4121892-3-rppt@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20230616085038.4121892-1-rppt@kernel.org> References: <20230616085038.4121892-1-rppt@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org From: "Mike Rapoport (IBM)" module_alloc() is used everywhere as a mean to allocate memory for code. Beside being semantically wrong, this unnecessarily ties all subsystems that need to allocate code, such as ftrace, kprobes and BPF to modules and puts the burden of code allocation to the modules code. Several architectures override module_alloc() because of various constraints where the executable memory can be located and this causes additional obstacles for improvements of code allocation. Start splitting code allocation from modules by introducing execmem_text_alloc(), execmem_free(), jit_text_alloc(), jit_free() APIs. Initially, execmem_text_alloc() and jit_text_alloc() are wrappers for module_alloc() and execmem_free() and jit_free() are replacements of module_memfree() to allow updating all call sites to use the new APIs. The intention semantics for new allocation APIs: * execmem_text_alloc() should be used to allocate memory that must reside close to the kernel image, like loadable kernel modules and generated code that is restricted by relative addressing. * jit_text_alloc() should be used to allocate memory for generated code when there are no restrictions for the code placement. For architectures that require that any code is within certain distance from the kernel image, jit_text_alloc() will be essentially aliased to execmem_text_alloc(). The names execmem_text_alloc() and jit_text_alloc() emphasize that the allocated memory is for executable code, the allocations of the associated data, like data sections of a module will use execmem_data_alloc() interface that will be added later. Signed-off-by: Mike Rapoport (IBM) Reviewed-by: Kent Overstreet Acked-by: Song Liu --- arch/powerpc/kernel/kprobes.c | 4 +-- arch/s390/kernel/ftrace.c | 4 +-- arch/s390/kernel/kprobes.c | 4 +-- arch/s390/kernel/module.c | 5 +-- arch/sparc/net/bpf_jit_comp_32.c | 8 ++--- arch/x86/kernel/ftrace.c | 6 ++-- arch/x86/kernel/kprobes/core.c | 4 +-- include/linux/execmem.h | 52 ++++++++++++++++++++++++++++++++ include/linux/moduleloader.h | 3 -- kernel/bpf/core.c | 14 ++++----- kernel/kprobes.c | 8 ++--- kernel/module/Kconfig | 1 + kernel/module/main.c | 25 +++++---------- mm/Kconfig | 3 ++ mm/Makefile | 1 + mm/execmem.c | 36 ++++++++++++++++++++++ 16 files changed, 130 insertions(+), 48 deletions(-) create mode 100644 include/linux/execmem.h create mode 100644 mm/execmem.c diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index b20ee72e873a..5db8df5e3657 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -19,8 +19,8 @@ #include #include #include -#include #include +#include #include #include #include @@ -130,7 +130,7 @@ void *alloc_insn_page(void) { void *page; - page = module_alloc(PAGE_SIZE); + page = jit_text_alloc(PAGE_SIZE); if (!page) return NULL; diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index c46381ea04ec..65343f944101 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -7,13 +7,13 @@ * Author(s): Martin Schwidefsky */ -#include #include #include #include #include #include #include +#include #include #include #include @@ -220,7 +220,7 @@ static int __init ftrace_plt_init(void) { const char *start, *end; - ftrace_plt = module_alloc(PAGE_SIZE); + ftrace_plt = execmem_text_alloc(PAGE_SIZE); if (!ftrace_plt) panic("cannot allocate ftrace plt\n"); diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index d4b863ed0aa7..459cd5141346 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -9,7 +9,6 @@ #define pr_fmt(fmt) "kprobes: " fmt -#include #include #include #include @@ -21,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -38,7 +38,7 @@ void *alloc_insn_page(void) { void *page; - page = module_alloc(PAGE_SIZE); + page = execmem_text_alloc(PAGE_SIZE); if (!page) return NULL; set_memory_rox((unsigned long)page, 1); diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c index f1b35dcdf3eb..4a844683dc76 100644 --- a/arch/s390/kernel/module.c +++ b/arch/s390/kernel/module.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -76,7 +77,7 @@ void *module_alloc(unsigned long size) #ifdef CONFIG_FUNCTION_TRACER void module_arch_cleanup(struct module *mod) { - module_memfree(mod->arch.trampolines_start); + execmem_free(mod->arch.trampolines_start); } #endif @@ -509,7 +510,7 @@ static int module_alloc_ftrace_hotpatch_trampolines(struct module *me, size = FTRACE_HOTPATCH_TRAMPOLINES_SIZE(s->sh_size); numpages = DIV_ROUND_UP(size, PAGE_SIZE); - start = module_alloc(numpages * PAGE_SIZE); + start = execmem_text_alloc(numpages * PAGE_SIZE); if (!start) return -ENOMEM; set_memory_rox((unsigned long)start, numpages); diff --git a/arch/sparc/net/bpf_jit_comp_32.c b/arch/sparc/net/bpf_jit_comp_32.c index a74e5004c6c8..4261832a9882 100644 --- a/arch/sparc/net/bpf_jit_comp_32.c +++ b/arch/sparc/net/bpf_jit_comp_32.c @@ -1,10 +1,10 @@ // SPDX-License-Identifier: GPL-2.0 -#include #include #include #include #include #include +#include #include #include @@ -713,7 +713,7 @@ cond_branch: f_offset = addrs[i + filter[i].jf]; if (unlikely(proglen + ilen > oldproglen)) { pr_err("bpb_jit_compile fatal error\n"); kfree(addrs); - module_memfree(image); + execmem_free(image); return; } memcpy(image + proglen, temp, ilen); @@ -736,7 +736,7 @@ cond_branch: f_offset = addrs[i + filter[i].jf]; break; } if (proglen == oldproglen) { - image = module_alloc(proglen); + image = execmem_text_alloc(proglen); if (!image) goto out; } @@ -758,7 +758,7 @@ cond_branch: f_offset = addrs[i + filter[i].jf]; void bpf_jit_free(struct bpf_prog *fp) { if (fp->jited) - module_memfree(fp->bpf_func); + execmem_free(fp->bpf_func); bpf_prog_unlock_free(fp); } diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 5e7ead52cfdb..f77c63bb3203 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -25,6 +25,7 @@ #include #include #include +#include #include @@ -261,15 +262,14 @@ void arch_ftrace_update_code(int command) #ifdef CONFIG_X86_64 #ifdef CONFIG_MODULES -#include /* Module allocation simplifies allocating memory for code */ static inline void *alloc_tramp(unsigned long size) { - return module_alloc(size); + return execmem_text_alloc(size); } static inline void tramp_free(void *tramp) { - module_memfree(tramp); + execmem_free(tramp); } #else /* Trampolines can only be created if modules are supported */ diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index f7f6042eb7e6..9294e11d0fb4 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -40,11 +40,11 @@ #include #include #include -#include #include #include #include #include +#include #include #include @@ -414,7 +414,7 @@ void *alloc_insn_page(void) { void *page; - page = module_alloc(PAGE_SIZE); + page = execmem_text_alloc(PAGE_SIZE); if (!page) return NULL; diff --git a/include/linux/execmem.h b/include/linux/execmem.h new file mode 100644 index 000000000000..0d4e5a6985f8 --- /dev/null +++ b/include/linux/execmem.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_EXECMEM_ALLOC_H +#define _LINUX_EXECMEM_ALLOC_H + +#include + +/** + * execmem_text_alloc - allocate executable memory + * @size: how many bytes of memory are required + * + * Allocates memory that will contain executable code, either generated or + * loaded from kernel modules. + * + * The memory will have protections defined by architecture for executable + * regions. + * + * The allocated memory will reside in an area that does not impose + * restrictions on the addressing modes. + * + * Return: a pointer to the allocated memory or %NULL + */ +void *execmem_text_alloc(size_t size); + +/** + * execmem_free - free executable memory + * @ptr: pointer to the memory that should be freed + */ +void execmem_free(void *ptr); + +/** + * jit_text_alloc - allocate executable memory + * @size: how many bytes of memory are required. + * + * Allocates memory that will contain generated executable code. + * + * The memory will have protections defined by architecture for executable + * regions. + * + * The allocated memory will reside in an area that might impose + * restrictions on the addressing modes depending on the architecture + * + * Return: a pointer to the allocated memory or %NULL + */ +void *jit_text_alloc(size_t size); + +/** + * jit_free - free generated executable memory + * @ptr: pointer to the memory that should be freed + */ +void jit_free(void *ptr); + +#endif /* _LINUX_EXECMEM_ALLOC_H */ diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h index 03be088fb439..b3374342f7af 100644 --- a/include/linux/moduleloader.h +++ b/include/linux/moduleloader.h @@ -29,9 +29,6 @@ unsigned int arch_mod_section_prepend(struct module *mod, unsigned int section); sections. Returns NULL on failure. */ void *module_alloc(unsigned long size); -/* Free memory returned from module_alloc. */ -void module_memfree(void *module_region); - /* Determines if the section name is an init section (that is only used during * module loading). */ diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 7421487422d4..ecb58fa6696c 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -22,7 +22,6 @@ #include #include #include -#include #include #include #include @@ -37,6 +36,7 @@ #include #include #include +#include #include #include @@ -860,7 +860,7 @@ static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_ins GFP_KERNEL); if (!pack) return NULL; - pack->ptr = module_alloc(BPF_PROG_PACK_SIZE); + pack->ptr = jit_text_alloc(BPF_PROG_PACK_SIZE); if (!pack->ptr) { kfree(pack); return NULL; @@ -884,7 +884,7 @@ void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns) mutex_lock(&pack_mutex); if (size > BPF_PROG_PACK_SIZE) { size = round_up(size, PAGE_SIZE); - ptr = module_alloc(size); + ptr = jit_text_alloc(size); if (ptr) { bpf_fill_ill_insns(ptr, size); set_vm_flush_reset_perms(ptr); @@ -922,7 +922,7 @@ void bpf_prog_pack_free(struct bpf_binary_header *hdr) mutex_lock(&pack_mutex); if (hdr->size > BPF_PROG_PACK_SIZE) { - module_memfree(hdr); + jit_free(hdr); goto out; } @@ -946,7 +946,7 @@ void bpf_prog_pack_free(struct bpf_binary_header *hdr) if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0, BPF_PROG_CHUNK_COUNT, 0) == 0) { list_del(&pack->list); - module_memfree(pack->ptr); + jit_free(pack->ptr); kfree(pack); } out: @@ -997,12 +997,12 @@ void bpf_jit_uncharge_modmem(u32 size) void *__weak bpf_jit_alloc_exec(unsigned long size) { - return module_alloc(size); + return jit_text_alloc(size); } void __weak bpf_jit_free_exec(void *addr) { - module_memfree(addr); + jit_free(addr); } struct bpf_binary_header * diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 00e177de91cc..37c928d5deaf 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -26,7 +26,6 @@ #include #include #include -#include #include #include #include @@ -39,6 +38,7 @@ #include #include #include +#include #include #include @@ -113,17 +113,17 @@ enum kprobe_slot_state { void __weak *alloc_insn_page(void) { /* - * Use module_alloc() so this page is within +/- 2GB of where the + * Use jit_text_alloc() so this page is within +/- 2GB of where the * kernel image and loaded module images reside. This is required * for most of the architectures. * (e.g. x86-64 needs this to handle the %rip-relative fixups.) */ - return module_alloc(PAGE_SIZE); + return jit_text_alloc(PAGE_SIZE); } static void free_insn_page(void *page) { - module_memfree(page); + jit_free(page); } struct kprobe_insn_cache kprobe_insn_slots = { diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig index 33a2e991f608..813e116bdee6 100644 --- a/kernel/module/Kconfig +++ b/kernel/module/Kconfig @@ -2,6 +2,7 @@ menuconfig MODULES bool "Enable loadable module support" modules + select EXECMEM help Kernel modules are small pieces of compiled code which can be inserted in the running kernel, rather than being diff --git a/kernel/module/main.c b/kernel/module/main.c index 044aa2c9e3cb..43810a3bdb81 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -57,6 +57,7 @@ #include #include #include +#include #include #include "internal.h" @@ -1186,16 +1187,6 @@ resolve_symbol_wait(struct module *mod, return ksym; } -void __weak module_memfree(void *module_region) -{ - /* - * This memory may be RO, and freeing RO memory in an interrupt is not - * supported by vmalloc. - */ - WARN_ON(in_interrupt()); - vfree(module_region); -} - void __weak module_arch_cleanup(struct module *mod) { } @@ -1214,7 +1205,7 @@ static void *module_memory_alloc(unsigned int size, enum mod_mem_type type) { if (mod_mem_use_vmalloc(type)) return vzalloc(size); - return module_alloc(size); + return execmem_text_alloc(size); } static void module_memory_free(void *ptr, enum mod_mem_type type) @@ -1222,7 +1213,7 @@ static void module_memory_free(void *ptr, enum mod_mem_type type) if (mod_mem_use_vmalloc(type)) vfree(ptr); else - module_memfree(ptr); + execmem_free(ptr); } static void free_mod_mem(struct module *mod) @@ -2478,9 +2469,9 @@ static void do_free_init(struct work_struct *w) llist_for_each_safe(pos, n, list) { initfree = container_of(pos, struct mod_initfree, node); - module_memfree(initfree->init_text); - module_memfree(initfree->init_data); - module_memfree(initfree->init_rodata); + execmem_free(initfree->init_text); + execmem_free(initfree->init_data); + execmem_free(initfree->init_rodata); kfree(initfree); } } @@ -2583,10 +2574,10 @@ static noinline int do_init_module(struct module *mod) * We want to free module_init, but be aware that kallsyms may be * walking this with preempt disabled. In all the failure paths, we * call synchronize_rcu(), but we don't want to slow down the success - * path. module_memfree() cannot be called in an interrupt, so do the + * path. execmem_free() cannot be called in an interrupt, so do the * work and call synchronize_rcu() in a work queue. * - * Note that module_alloc() on most architectures creates W+X page + * Note that execmem_text_alloc() on most architectures creates W+X page * mappings which won't be cleaned up until do_free_init() runs. Any * code such as mark_rodata_ro() which depends on those mappings to * be cleaned up needs to sync with the queued work - ie diff --git a/mm/Kconfig b/mm/Kconfig index 7672a22647b4..3d2826940c4a 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1206,6 +1206,9 @@ config PER_VMA_LOCK This feature allows locking each virtual memory area separately when handling page faults instead of taking mmap_lock. +config EXECMEM + bool + source "mm/damon/Kconfig" endmenu diff --git a/mm/Makefile b/mm/Makefile index e29afc890cde..1c25d1b5ffef 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -137,3 +137,4 @@ obj-$(CONFIG_IO_MAPPING) += io-mapping.o obj-$(CONFIG_HAVE_BOOTMEM_INFO_NODE) += bootmem_info.o obj-$(CONFIG_GENERIC_IOREMAP) += ioremap.o obj-$(CONFIG_SHRINKER_DEBUG) += shrinker_debug.o +obj-$(CONFIG_EXECMEM) += execmem.o diff --git a/mm/execmem.c b/mm/execmem.c new file mode 100644 index 000000000000..eac26234eb38 --- /dev/null +++ b/mm/execmem.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include + +static void *execmem_alloc(size_t size) +{ + return module_alloc(size); +} + +void *execmem_text_alloc(size_t size) +{ + return execmem_alloc(size); +} + +void execmem_free(void *ptr) +{ + /* + * This memory may be RO, and freeing RO memory in an interrupt is not + * supported by vmalloc. + */ + WARN_ON(in_interrupt()); + vfree(ptr); +} + +void *jit_text_alloc(size_t size) +{ + return execmem_alloc(size); +} + +void jit_free(void *ptr) +{ + execmem_free(ptr); +}