From patchwork Mon Mar 25 21:15:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 13602988 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B2C4A6D1D7; Mon, 25 Mar 2024 21:15:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711401348; cv=none; b=OalQK7JoiydCjupoi6kCutgUJCNVgaf6GkNfRSUgf8tlePDhROvhRqEQkvTOBXqliotJMfLuWy8Xz3l4DkHFgO+wcYLODV2Pl/hS/glLK9pDf74gx0bzSdAd6EC2SBtFVNzTTq3gSK67qAYpJiEjdW+bta5dggVKH7ogDsd40MY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711401348; c=relaxed/simple; bh=FCy4kecgMkVWhP91pvNt2LYQchl8jV2Rw34VjcQRizs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SdxPUEa4LyDU2PlMokEoj3xXSPMoXUa4mY+tF63bzmol8E0iynvPae2JkHuAGy2W/TyJWIaNFPrJWqwUHBW9sVXKoGhXcufCI2U6PMPI+9iYdzrWOmef+oAcSONVulmXhG45QIAeE4FHTJ2FOEiLE9scH/0fakdhCaewqd+6SlI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NchMrmQi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NchMrmQi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0480FC433C7; Mon, 25 Mar 2024 21:15:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711401348; bh=FCy4kecgMkVWhP91pvNt2LYQchl8jV2Rw34VjcQRizs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NchMrmQiBENlvmGRvleESEVVL2psV2IrWvXzjxJfpZFA85NIuoOtMMd0K5nmPEcM1 JENAHtSKx69ElaZydFCDk0E6hv0n4elRsuomj7LyU+M+gRWTBV8mjQTilvWhu9Yqg9 2w0UDfQvU+Ikt71kuoLJzYe8T9Oy9cpxTBEYIYoNugcYt/ob/qU3pml9MTJ/6nrS+q kmzS6FtCXBNZbTpL7JC8Ld70eps+pfgWS+2VnwXu98hDZnPS7T3XU65F2VzAKgmjKX VhM6NVJJURLtS8QuevXfFdr0VuRZiEpSwS8rmMQsM3YEt+fQa8swQKJYu0u0IOKNqt 6vxQ49Scs1TUw== From: Jarkko Sakkinen To: linux-riscv@lists.infradead.org Cc: Jarkko Sakkinen , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-kernel@vger.kernel.org, Luis Chamberlain , linux-modules@vger.kernel.org, "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" , Masami Hiramatsu Subject: [PATCH v4 2/2] arch/riscv: Enable kprobes when CONFIG_MODULES=n Date: Mon, 25 Mar 2024 23:15:35 +0200 Message-ID: <20240325211535.25142-2-jarkko@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240325211535.25142-1-jarkko@kernel.org> References: <20240325211535.25142-1-jarkko@kernel.org> Precedence: bulk X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Tacing with kprobes while running a monolithic kernel is currently impossible due the kernel module allocator dependency. Address the issue by implementing textmem API for RISC-V. Link: https://www.sochub.fi # for power on testing new SoC's with a minimal stack Link: https://lore.kernel.org/all/20220608000014.3054333-1-jarkko@profian.com/ # continuation Signed-off-by: Jarkko Sakkinen --- v4: - Include linux/execmem.h. v3: - Architecture independent parts have been split to separate patches. - Do not change arch/riscv/kernel/module.c as it is out of scope for this patch set now. v2: - Better late than never right? :-) - Focus only to RISC-V for now to make the patch more digestable. This is the arch where I use the patch on a daily basis to help with QA. - Introduce HAVE_KPROBES_ALLOC flag to help with more gradual migration. --- arch/riscv/Kconfig | 1 + arch/riscv/kernel/Makefile | 3 +++ arch/riscv/kernel/execmem.c | 22 ++++++++++++++++++++++ kernel/kprobes.c | 2 +- 4 files changed, 27 insertions(+), 1 deletion(-) create mode 100644 arch/riscv/kernel/execmem.c diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index e3142ce531a0..499512fb17ff 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -132,6 +132,7 @@ config RISCV select HAVE_KPROBES if !XIP_KERNEL select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL select HAVE_KRETPROBES if !XIP_KERNEL + select HAVE_ALLOC_EXECMEM if !XIP_KERNEL # https://github.com/ClangBuiltLinux/linux/issues/1881 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD select HAVE_MOVE_PMD diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 604d6bf7e476..337797f10d3e 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -73,6 +73,9 @@ obj-$(CONFIG_SMP) += cpu_ops.o obj-$(CONFIG_RISCV_BOOT_SPINWAIT) += cpu_ops_spinwait.o obj-$(CONFIG_MODULES) += module.o +ifeq ($(CONFIG_ALLOC_EXECMEM),y) +obj-y += execmem.o +endif obj-$(CONFIG_MODULE_SECTIONS) += module-sections.o obj-$(CONFIG_CPU_PM) += suspend_entry.o suspend.o diff --git a/arch/riscv/kernel/execmem.c b/arch/riscv/kernel/execmem.c new file mode 100644 index 000000000000..3e52522ead32 --- /dev/null +++ b/arch/riscv/kernel/execmem.c @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include +#include +#include +#include + +void *alloc_execmem(unsigned long size, gfp_t /* gfp */) +{ + return __vmalloc_node_range(size, 1, MODULES_VADDR, + MODULES_END, GFP_KERNEL, + PAGE_KERNEL, 0, NUMA_NO_NODE, + __builtin_return_address(0)); +} + +void free_execmem(void *region) +{ + if (in_interrupt()) + pr_warn("In interrupt context: vmalloc may not work.\n"); + + vfree(region); +} diff --git a/kernel/kprobes.c b/kernel/kprobes.c index a1a547723c3c..87fd8c14a938 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -119,7 +119,7 @@ void __weak *alloc_insn_page(void) * for most of the architectures. * (e.g. x86-64 needs this to handle the %rip-relative fixups.) */ - return alloc_execmem(PAGE_SIZE); + return alloc_execmem(PAGE_SIZE, GFP_KERNEL); } static void free_insn_page(void *page)