From patchwork Sat Oct 26 04:37:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13852047 X-Patchwork-Delegate: bpf@iogearbox.net 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 23BF516C854; Sat, 26 Oct 2024 04:38:08 +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=1729917489; cv=none; b=UmPJ/QRKtQPjblEJHZthRS2GhMlV/OvuaEaWbMw4LY2IcZoQZKRVtwIZn2bgqKHgn8WPGUsOiWgmdDYwoy/geUWTr13US0/GFRytlUeHF4VwoWhj5hhJ00YSgUd5dQluLXzyNRKQKN3vn+Hy9fq89WYB3lTmKjC18GROlOYsGVg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729917489; c=relaxed/simple; bh=l9kF/l0bqD0+3Tk9MUinu/zNZdO/QVH0/GjbJr01A9c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qBUNw0DE5PxkPSfs2tOG8miQMm+TzCOTRWCtHgukJQAz5txsxZiRj0zcF/XifXCRLwzkBbnOeN41rH6I9ahO+Vh3dcvIWEHfXTqZv3e+hNcNoITs1LrDwMLD7KAbQFRsE0y1r30dqCYf6eEUhou9db+lI2b2mNTgYEXHVs+w74A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=t2wQLo0b; 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="t2wQLo0b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B54BFC4CEC6; Sat, 26 Oct 2024 04:38:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729917488; bh=l9kF/l0bqD0+3Tk9MUinu/zNZdO/QVH0/GjbJr01A9c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t2wQLo0baeUwBI8lECjXBEPCyXzpnqWdLMAHanmZuQFVYNlq1+d6YYtflvkrbtPpq qstxdxOVRRZ4c3B2R4P+7hr7iOUHxdHuqL3mRyqczr2hQHHRyLSoGof2Q0mi0dha7w SvXRNiTV2nhtHExN8bervVmUUx+gZJmAGNPe5JkmyHZej+7M/gCB66VR6bqrfRS64h qujVaf4CIWWEhbkdocG+ZurCP8N10zXqw8TcgINNCDs/PtGwaG9w0q/1/2kP7qFn7I /dnbl8rNcUe28Lx9Wmr4zOrKRXi/2zbuXHU4wivrnWMt9RPkw8GLayZ5cdf5sXZ72/ yE15hUBnxfwGQ== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Alexei Starovoitov , Jiri Olsa , Alan Maguire , Mark Rutland , linux-arch@vger.kernel.org, Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Paul Walmsley , Palmer Dabbelt , Albert Ou , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Arnd Bergmann , Masami Hiramatsu , Mathieu Desnoyers Subject: [PATCH v18 12/17] fprobe: Add fprobe_header encoding feature Date: Sat, 26 Oct 2024 13:37:59 +0900 Message-ID: <172991747946.443985.11014834036464028393.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <172991731968.443985.4558065903004844780.stgit@devnote2> References: <172991731968.443985.4558065903004844780.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Masami Hiramatsu (Google) Fprobe store its data structure address and size on the fgraph return stack by __fprobe_header. But most 64bit architecture can combine those to one unsigned long value because 4 MSB in the kernel address are the same. With this encoding, fprobe can consume less space on ret_stack. This introduces asm/fprobe.h to define arch dependent encode/decode macros. Note that since fprobe depends on CONFIG_HAVE_FUNCTION_GRAPH_FREGS, currently only arm64, loongarch, riscv, s390 and x86 are supported. Signed-off-by: Masami Hiramatsu (Google) Cc: Catalin Marinas Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Arnd Bergmann Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: Mathieu Desnoyers --- arch/arm64/include/asm/fprobe.h | 7 +++++++ arch/loongarch/include/asm/fprobe.h | 5 +++++ arch/riscv/include/asm/fprobe.h | 9 +++++++++ arch/s390/include/asm/fprobe.h | 10 ++++++++++ arch/x86/include/asm/fprobe.h | 9 +++++++++ include/asm-generic/fprobe.h | 33 +++++++++++++++++++++++++++++++++ kernel/trace/fprobe.c | 29 +++++++++++++++++++++++++++++ 7 files changed, 102 insertions(+) create mode 100644 arch/arm64/include/asm/fprobe.h create mode 100644 arch/loongarch/include/asm/fprobe.h create mode 100644 arch/riscv/include/asm/fprobe.h create mode 100644 arch/s390/include/asm/fprobe.h create mode 100644 arch/x86/include/asm/fprobe.h create mode 100644 include/asm-generic/fprobe.h diff --git a/arch/arm64/include/asm/fprobe.h b/arch/arm64/include/asm/fprobe.h new file mode 100644 index 000000000000..bbf254db878d --- /dev/null +++ b/arch/arm64/include/asm/fprobe.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_ARM64_FPROBE_H +#define _ASM_ARM64_FPROBE_H + +#include + +#endif /* _ASM_ARM64_FPROBE_H */ \ No newline at end of file diff --git a/arch/loongarch/include/asm/fprobe.h b/arch/loongarch/include/asm/fprobe.h new file mode 100644 index 000000000000..68156a66873c --- /dev/null +++ b/arch/loongarch/include/asm/fprobe.h @@ -0,0 +1,5 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_LOONGARCH_FPROBE_H +#define _ASM_LOONGARCH_FPROBE_H + +#endif /* _ASM_LOONGARCH_FPROBE_H */ \ No newline at end of file diff --git a/arch/riscv/include/asm/fprobe.h b/arch/riscv/include/asm/fprobe.h new file mode 100644 index 000000000000..51fc2ef3eda1 --- /dev/null +++ b/arch/riscv/include/asm/fprobe.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_RISCV_FPROBE_H +#define _ASM_RISCV_FPROBE_H + +#ifdef CONFIG_64BIT +#include +#endif + +#endif /* _ASM_RISCV_FPROBE_H */ \ No newline at end of file diff --git a/arch/s390/include/asm/fprobe.h b/arch/s390/include/asm/fprobe.h new file mode 100644 index 000000000000..84b94ba6e3a4 --- /dev/null +++ b/arch/s390/include/asm/fprobe.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_S390_FPROBE_H +#define _ASM_S390_FPROBE_H + +#include + +#undef FPROBE_HEADER_MSB_PATTERN +#define FPROBE_HEADER_MSB_PATTERN 0 + +#endif /* _ASM_S390_FPROBE_H */ \ No newline at end of file diff --git a/arch/x86/include/asm/fprobe.h b/arch/x86/include/asm/fprobe.h new file mode 100644 index 000000000000..c863518bef90 --- /dev/null +++ b/arch/x86/include/asm/fprobe.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_FPROBE_H +#define _ASM_X86_FPROBE_H + +#ifdef CONFIG_64BIT +#include +#endif + +#endif /* _ASM_X86_FPROBE_H */ \ No newline at end of file diff --git a/include/asm-generic/fprobe.h b/include/asm-generic/fprobe.h new file mode 100644 index 000000000000..00f480748a1d --- /dev/null +++ b/include/asm-generic/fprobe.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/include/asm-generic/fprobe.h + */ +#ifndef __ASM_GENERIC_FPROBE_H__ +#define __ASM_GENERIC_FPROBE_H__ + +#include + +#define ARCH_HAVE_ENCODE_FPROBE_HEADER + +#define FPROBE_HEADER_MSB_SIZE_SHIFT (BITS_PER_LONG - FPROBE_DATA_SIZE_BITS) +#define FPROBE_HEADER_MSB_MASK \ + GENMASK(FPROBE_HEADER_MSB_SIZE_SHIFT - 1, 0) +#define FPROBE_HEADER_MSB_PATTERN \ + GENMASK(BITS_PER_LONG - 1, FPROBE_HEADER_MSB_SIZE_SHIFT) + +#define arch_fprobe_header_encodable(fp) \ + (((unsigned long)(fp) & ~FPROBE_HEADER_MSB_MASK) == \ + FPROBE_HEADER_MSB_PATTERN) + +#define arch_encode_fprobe_header(fp, size) \ + ((unsigned long)(fp) & FPROBE_HEADER_MSB_MASK) | \ + ((unsigned long)(size) << FPROBE_HEADER_MSB_SIZE_SHIFT) + +#define arch_decode_fprobe_header_size(val) \ + ((unsigned long)(val) >> FPROBE_HEADER_MSB_SIZE_SHIFT) + +#define arch_decode_fprobe_header_fp(val) \ + (struct fprobe *)(((unsigned long)(val) & FPROBE_HEADER_MSB_MASK) | \ + FPROBE_HEADER_MSB_PATTERN) + +#endif /* __ASM_GENERIC_FPROBE_H__ */ \ No newline at end of file diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index ed9c1d79426a..949963f1f17a 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -13,6 +13,8 @@ #include #include +#include + #include "trace.h" #define FPROBE_IP_HASH_BITS 8 @@ -143,6 +145,31 @@ static int del_fprobe_hash(struct fprobe *fp) return 0; } +#ifdef ARCH_HAVE_ENCODE_FPROBE_HEADER + +/* The arch should encode fprobe_header info into one unsigned long */ +#define FPROBE_HEADER_SIZE_IN_LONG 1 + +static inline bool write_fprobe_header(unsigned long *stack, + struct fprobe *fp, unsigned int size_words) +{ + if (WARN_ON_ONCE(size_words > MAX_FPROBE_DATA_SIZE_WORD || + !arch_fprobe_header_encodable(fp))) + return false; + + *stack = arch_encode_fprobe_header(fp, size_words); + return true; +} + +static inline void read_fprobe_header(unsigned long *stack, + struct fprobe **fp, unsigned int *size_words) +{ + *fp = arch_decode_fprobe_header_fp(*stack); + *size_words = arch_decode_fprobe_header_size(*stack); +} + +#else + /* Generic fprobe_header */ struct __fprobe_header { struct fprobe *fp; @@ -173,6 +200,8 @@ static inline void read_fprobe_header(unsigned long *stack, *size_words = fph->size_words; } +#endif + /* * fprobe shadow stack management: * Since fprobe shares a single fgraph_ops, it needs to share the stack entry