From patchwork Wed Apr 3 15:01:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 13616299 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4C778CD128A for ; Wed, 3 Apr 2024 15:02:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=wuSU/QT0MJOA+OWWknWs4r1Fa6gnN6CigTAagor27NM=; b=nQaX3pTjph/7cl S7GaacvqVm/mILdhR7w/Dab3v5HVAOPulFCAHr+kXtCmz+0JB3OM5I+Ois5DR0dS1hwubElFXmV1n yD+J2e0w7gHXDTx0x/qPGlo3vWaVMoJFPyFYurtPr1cLRm040VWBK1zwvJ5Ae2Tx18FHtnRGYyYrm TltOxTWCuJJugxzVsG0pnGWApE1KQnFUDtNBrlrNIWkqyt2fnLhhRU6AOx2PP639Tr0v4EIqQ0Q3e YCIyYwsTxJox8I+OM5V79AkvY9ez59sxGDTQaiT/13FBkXjyOajcpr0YO+IAnB/6D1pLe2x3fMrSu cT/jJOiuuX9OLNuZYppw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rs27x-0000000GbDj-1lBC; Wed, 03 Apr 2024 15:02:13 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rs27t-0000000GbBl-2MgZ for linux-arm-kernel@lists.infradead.org; Wed, 03 Apr 2024 15:02:11 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2C7C21007; Wed, 3 Apr 2024 08:02:40 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7DE443F7B4; Wed, 3 Apr 2024 08:02:07 -0700 (PDT) From: Mark Rutland To: linux-kernel@vger.kernel.org Cc: anil.s.keshavamurthy@intel.com, aou@eecs.berkeley.edu, catalin.marinas@arm.com, davem@davemloft.net, jarkko@kernel.org, linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, mhiramat@kernel.org, naveen.n.rao@linux.ibm.com, palmer@dabbelt.com, paul.walmsley@sifive.com, will@kernel.org Subject: [PATCH v2 3/4] kprobes/treewide: Explicitly override alloc/free functions Date: Wed, 3 Apr 2024 16:01:53 +0100 Message-Id: <20240403150154.667649-4-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240403150154.667649-1-mark.rutland@arm.com> References: <20240403150154.667649-1-mark.rutland@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240403_080209_747551_1F67939E X-CRM114-Status: GOOD ( 21.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Currently architectures can override kprobes_alloc_insn_page(), but kprobes_free_insn_page() is always implemented using module_memfree(), which might not be what an architecture needs, especially as we'd like to make it possible to use kprobes without requiring MODULES. It would be nicer if architectures either: (a) Used only the generic kprobes_alloc_insn_page() and kprobes_free_insn_page(), implicitly depending on MODULES. (b) Provided their own implementation of both kprobes_alloc_insn_page() and kprobes_free_insn_page(), handling the relevant dependencies themselves. This patch applies that split treewide: (a) Architectures using the generic kprobes_free_insn_page() and kprobes_free_insn_page() are left as-is. The __weak annotation is removed from the generic implementations so that accidental overrides/misuse can be detected easily. (b) Architectures which provide their own kprobes_free_insn_page() are given a matching implementation of kprobes_free_insn_page(), and select HAVE_KPROBES_ALLOC. This new Kconfig symbol will allow subsequent patches to relax the dependency on MODULES to (MODULES || HAVE_KPROBES_ALLOC) once other module dependencies in the core kprobes code are cleaned up. Architectures which use module_alloc() are given an implementation using module_memfree() along with an explicit dependency on MODULES. Architectures using __vmalloc_node_range() are given an implementation using vfree(). This loses the warning for in_interrupt(), but vfree() can handle this via vfree_atomic(), so the warning isn't necessary. On riscv, the allocator depends on !XIP_KERNEL, which is already a dependency for HAVE_KPROBES in arch/riscv/Kconfig. As of this patch arm64 and riscv have kprobe allocation functions which do not explicitly depend on MODULES. The core kprobes code still depends on MODULES. Signed-off-by: Mark Rutland Cc: Albert Ou Cc: Anil S Keshavamurthy Cc: Catalin Marinas Cc: David S. Miller Cc: Jarkko Sakkinen Cc: Masami Hiramatsu Cc: Naveen N. Rao Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Will Deacon Reviewed-by: Jarkko Sakkinen --- arch/Kconfig | 3 +++ arch/arm64/Kconfig | 1 + arch/arm64/kernel/probes/kprobes.c | 5 +++++ arch/powerpc/Kconfig | 3 ++- arch/powerpc/kernel/kprobes.c | 5 +++++ arch/riscv/Kconfig | 1 + arch/riscv/kernel/probes/kprobes.c | 5 +++++ arch/s390/Kconfig | 3 ++- arch/s390/kernel/kprobes.c | 5 +++++ arch/x86/Kconfig | 3 ++- arch/x86/kernel/kprobes/core.c | 5 +++++ include/linux/kprobes.h | 1 + kernel/kprobes.c | 6 ++++-- 13 files changed, 41 insertions(+), 5 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index 9f066785bb71d..85bb59f7b8c07 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -206,6 +206,9 @@ config HAVE_IOREMAP_PROT config HAVE_KPROBES bool +config HAVE_KPROBES_ALLOC + bool + config HAVE_KRETPROBES bool diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7b11c98b3e84b..bda7913d6c9b8 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -233,6 +233,7 @@ config ARM64 select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select HAVE_KPROBES + select HAVE_KPROBES_ALLOC select HAVE_KRETPROBES select HAVE_GENERIC_VDSO select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 4b6ab7b1fa211..69d19a390cd48 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -136,6 +136,11 @@ void *kprobes_alloc_insn_page(void) NUMA_NO_NODE, __builtin_return_address(0)); } +void kprobes_free_insn_page(void *page) +{ + vfree(page); +} + /* arm kprobe: install breakpoint in text */ void __kprobes arch_arm_kprobe(struct kprobe *p) { diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 1c4be33736860..13e0fc51dcdcf 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -254,7 +254,8 @@ config PPC select HAVE_KERNEL_LZMA if DEFAULT_UIMAGE select HAVE_KERNEL_LZO if DEFAULT_UIMAGE select HAVE_KERNEL_XZ if PPC_BOOK3S || 44x - select HAVE_KPROBES + select HAVE_KPROBES if MODULES + select HAVE_KPROBES_ALLOC select HAVE_KPROBES_ON_FTRACE select HAVE_KRETPROBES select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if HAVE_OBJTOOL_MCOUNT && (!ARCH_USING_PATCHABLE_FUNCTION_ENTRY || (!CC_IS_GCC || GCC_VERSION >= 110100)) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 0b297718d5de6..d0332aaebab09 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -146,6 +146,11 @@ void *kprobes_alloc_insn_page(void) return NULL; } +void kprobes_free_insn_page(void *page) +{ + module_memfree(page); +} + int arch_prepare_kprobe(struct kprobe *p) { int ret = 0; diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index be09c8836d56b..4e22549a522a5 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -139,6 +139,7 @@ config RISCV select HAVE_GENERIC_VDSO if MMU && 64BIT select HAVE_IRQ_TIME_ACCOUNTING select HAVE_KPROBES if !XIP_KERNEL + select HAVE_KPROBES_ALLOC select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL select HAVE_KRETPROBES if !XIP_KERNEL # https://github.com/ClangBuiltLinux/linux/issues/1881 diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 75201ce721057..37fdfa952d999 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -112,6 +112,11 @@ void *kprobes_alloc_insn_page(void) VM_FLUSH_RESET_PERMS, NUMA_NO_NODE, __builtin_return_address(0)); } + +void kprobes_free_insn_page(void *page) +{ + vfree(page); +} #endif /* install breakpoint in text */ diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 8f01ada6845e3..635eddc3fce80 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -193,7 +193,8 @@ config S390 select HAVE_KERNEL_UNCOMPRESSED select HAVE_KERNEL_XZ select HAVE_KERNEL_ZSTD - select HAVE_KPROBES + select HAVE_KPROBES if MODULES + select HAVE_KPROBES_ALLOC select HAVE_KPROBES_ON_FTRACE select HAVE_KRETPROBES select HAVE_LIVEPATCH diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index 91ca4d501d4ef..a5b142b8eb0f7 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -45,6 +45,11 @@ void *kprobes_alloc_insn_page(void) return page; } +void kprobes_free_insn_page(void *page) +{ + module_memfree(page); +} + static void *alloc_s390_insn_page(void) { if (xchg(&insn_page_in_use, 1) == 1) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 4fff6ed46e902..0810cd0bdeca9 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -240,7 +240,8 @@ config X86 select HAVE_KERNEL_LZO select HAVE_KERNEL_XZ select HAVE_KERNEL_ZSTD - select HAVE_KPROBES + select HAVE_KPROBES if MODULES + select HAVE_KPROBES_ALLOC select HAVE_KPROBES_ON_FTRACE select HAVE_FUNCTION_ERROR_INJECTION select HAVE_KRETPROBES diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 7f01bbbfa9e2a..5f093b94d9b40 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -508,6 +508,11 @@ void *kprobes_alloc_insn_page(void) return page; } +void kprobes_free_insn_page(void *page) +{ + module_memfree(page); +} + /* Kprobe x86 instruction emulation - only regs->ip or IF flag modifiers */ static void kprobe_emulate_ifmodifiers(struct kprobe *p, struct pt_regs *regs) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index ad4b561100f9e..651c807727bea 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -431,6 +431,7 @@ int enable_kprobe(struct kprobe *kp); void dump_kprobe(struct kprobe *kp); void *kprobes_alloc_insn_page(void); +void kprobes_free_insn_page(void *page); void *kprobes_alloc_optinsn_page(void); void kprobes_free_optinsn_page(void *page); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 35adf56430c9b..fa2ee4e59eca2 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -110,7 +110,8 @@ enum kprobe_slot_state { SLOT_USED = 2, }; -void __weak *kprobes_alloc_insn_page(void) +#ifndef CONFIG_HAVE_KPROBES_ALLOC +void *kprobes_alloc_insn_page(void) { /* * Use module_alloc() so this page is within +/- 2GB of where the @@ -121,10 +122,11 @@ void __weak *kprobes_alloc_insn_page(void) return module_alloc(PAGE_SIZE); } -static void kprobes_free_insn_page(void *page) +void kprobes_free_insn_page(void *page) { module_memfree(page); } +#endif struct kprobe_insn_cache kprobe_insn_slots = { .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex),