From mboxrd@z Thu Jan 1 00:00:00 1970 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 47A753207; Tue, 15 Jul 2025 00:21:34 +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=1752538895; cv=none; b=Y4BGGh0QRUPx7AWv6gLTwXyu/FMbpImncuvhm7D5FkI2c7CMdemScohQox0r6AwlRQi/6Uojhp7BzrSrjQRHMUFaaFYQk1d25dzRjyJvZ8vo1UO1wEoGgkzELUv4RHsZYQj+xtIrW7+6TLQhgdNFiK3SFvR6HrB/Px5xBXZ3ZgA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752538895; c=relaxed/simple; bh=ggcEC9bbWrHlmXqb/IZkagM/1dITGxzsZ7d7NZy45XA=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=rkd6UtqH9qwiTm6HkHrqcZf2N2lqBfCceYjzqIjZpB3nep/fOPEC7pjkWPND3NCj9BnULGlXvCJnZB4E8T+RqTf+byDibUKdmPqkUhuJUrbt2vPSBA2pP4eKfkdqutZpHrgT1X7gGMsIKYAhxNK0NGtIvwuF7OCf/rjJxxYtgMM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cbwfmwSy; 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="cbwfmwSy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DF290C4CEED; Tue, 15 Jul 2025 00:21:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752538894; bh=ggcEC9bbWrHlmXqb/IZkagM/1dITGxzsZ7d7NZy45XA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=cbwfmwSy95HmlSWI4uiy/mtiUWFaeu/uH7ad9AQ4TACV7HMBT0oaevtd6abttH333 Le8jxJFr/1McYBGAH3q9PI6W0fxrP4PIOl8fA49YokMeLF4ahnaXk0n8tnE5khdFXl FSPnuQDjOpQgn00x8nn0TLS5ydHbfc69JXWsYVeiZBp6r22sqyxTFHkBvksFKwc1yA 4Q/1jX8bf32gzrSR6LZTEbe0cYIoonR8H2wvCdxrdzbZixmXOfOAAJWX7zCvyHiytS J5k8Q3FR46+0gtrqVv8VxFGTOEaYy6vKEX9gs/HYrkj0SFvg7uxl5ZBvYOUDBA/v0T dANMPu5y9fwzQ== Date: Tue, 15 Jul 2025 09:21:30 +0900 From: Masami Hiramatsu (Google) To: Mike Rapoport Cc: Andrew Morton , Andy Lutomirski , Borislav Petkov , Christophe Leroy , Daniel Gomez , Dave Hansen , Ingo Molnar , "Liam R. Howlett" , Luis Chamberlain , Mark Rutland , Masami Hiramatsu , "H. Peter Anvin" , Peter Zijlstra , Petr Pavlu , Sami Tolvanen , Steven Rostedt , Thomas Gleixner , Yann Ylavic , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v3 7/8] x86/kprobes: enable EXECMEM_ROX_CACHE for kprobes allocations Message-Id: <20250715092130.0b4eda67c5db02e815e478b2@kernel.org> In-Reply-To: <20250713071730.4117334-8-rppt@kernel.org> References: <20250713071730.4117334-1-rppt@kernel.org> <20250713071730.4117334-8-rppt@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sun, 13 Jul 2025 10:17:29 +0300 Mike Rapoport wrote: > From: "Mike Rapoport (Microsoft)" > > x86::alloc_insn_page() always allocates ROX memory. > > Instead of overriding this method, add EXECMEM_KPROBES entry in > execmem_info with pgprot set to PAGE_KERNEL_ROX and use ROX cache when > configuration and CPU features allow it. > Looks good to me. Acked-by: Masami Hiramatsu (Google) Thanks! > Acked-by: Peter Zijlstra (Intel) > Signed-off-by: Mike Rapoport (Microsoft) > --- > arch/x86/kernel/kprobes/core.c | 18 ------------------ > arch/x86/mm/init.c | 9 ++++++++- > 2 files changed, 8 insertions(+), 19 deletions(-) > > diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c > index 47cb8eb138ba..6079d15dab8c 100644 > --- a/arch/x86/kernel/kprobes/core.c > +++ b/arch/x86/kernel/kprobes/core.c > @@ -481,24 +481,6 @@ static int prepare_singlestep(kprobe_opcode_t *buf, struct kprobe *p, > return len; > } > > -/* Make page to RO mode when allocate it */ > -void *alloc_insn_page(void) > -{ > - void *page; > - > - page = execmem_alloc(EXECMEM_KPROBES, PAGE_SIZE); > - if (!page) > - return NULL; > - > - /* > - * TODO: Once additional kernel code protection mechanisms are set, ensure > - * that the page was not maliciously altered and it is still zeroed. > - */ > - set_memory_rox((unsigned long)page, 1); > - > - return 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/arch/x86/mm/init.c b/arch/x86/mm/init.c > index dbc63f0d538f..442fafd8ff52 100644 > --- a/arch/x86/mm/init.c > +++ b/arch/x86/mm/init.c > @@ -1098,7 +1098,14 @@ struct execmem_info __init *execmem_arch_setup(void) > .pgprot = pgprot, > .alignment = MODULE_ALIGN, > }, > - [EXECMEM_KPROBES ... EXECMEM_BPF] = { > + [EXECMEM_KPROBES] = { > + .flags = flags, > + .start = start, > + .end = MODULES_END, > + .pgprot = PAGE_KERNEL_ROX, > + .alignment = MODULE_ALIGN, > + }, > + [EXECMEM_FTRACE ... EXECMEM_BPF] = { > .flags = EXECMEM_KASAN_SHADOW, > .start = start, > .end = MODULES_END, > -- > 2.47.2 > -- Masami Hiramatsu (Google)