From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f194.google.com (mail-pf1-f194.google.com [209.85.210.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DDBFC315777 for ; Mon, 17 Nov 2025 03:49:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.194 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763351369; cv=none; b=o8DUGEds/SE75mBvD3vbcqqXwPXsGT1RiKFiZKHX7ciCkLtUTLCRvq4mVc2HlS3tLodQmGJ55k6adPmvPJhoMaZK22IT3gSG6VWZQiBVzbZy0aTldaJe7CQVJ6y0XiwS+lPKBfRLhnMvevxmrWoICnhyUmWNfh9td/aknkV/agI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763351369; c=relaxed/simple; bh=yw0+14vG3MTkylBTsNGEjI1rTbbl51z2DrBpLhZnx4s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eTCQR3Kto/bH9pG8Jagj/P7fpewzkerj4dysktPbdusUW1VpgisUxtrafBylRwD/kjykiqHoreADhzrYAJkicqdzD2ccCR8EsVkcH/zPOMbX+uV5cFzcKi2YsD3VYjwFYopkGIc1JT1JmDr0cMeii0vFUQ6bIZium5AXNE3cg/s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=hkPynhKe; arc=none smtp.client-ip=209.85.210.194 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hkPynhKe" Received: by mail-pf1-f194.google.com with SMTP id d2e1a72fcca58-7aad4823079so3368392b3a.0 for ; Sun, 16 Nov 2025 19:49:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1763351366; x=1763956166; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=KRkWsGzjZIg7j77yjUEwdtDGoZTowRE1mWBAeLLFj3U=; b=hkPynhKebPTTFVqZuhGue4sgPwRj245N5SF2dcLva3U/90CsNJu4tsf5DWWoVFevGJ vQ0rEwVYaT+wyu8CvLqLlEdQEfnmVg3tnQLRgrre8Houy4GFeSbsv5UPOMdrF2+nx+7L uV4xTMZ+6uMcKoJnKrKW5JEiQ4ymft5i3P8KrNB0TDAtddCsfWdKsUVO7yCDlif5F6Gg F6WJDsK25MVezlk4pX1BikRIWbG3O8amqRMtjgNdXiDEmbksTPnVsGe63oBcR5KDQuXK Oj+ux5idxqjqokGvAJLqlfO3Wt1Ct1uj7dfUzDfahH8naZhA2iXWGaJscpsVfDB6L7h0 UdzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763351366; x=1763956166; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=KRkWsGzjZIg7j77yjUEwdtDGoZTowRE1mWBAeLLFj3U=; b=g9Lkf2dduwSZKp4/c+triHCNWfj6uzdYPYOkvY8rFnsP4SfRGLhAl94Co2diCWLy+r 9WxApUviEGPQ5XZT9mU43S8fcQpkjy8q5JeWdEPSx4thUI+WLyW37TScvnZLaRj9M+g1 0hj6f2et8iP8/UsMFJ443c1W7zzKiMeysX8r7C3TRiERM7nAdWRXaIy2vrgueyklbd5E wnEKtUTy+ogfGzO5iyNQDO/7ALGR/mjrX45i+WhD9u2mVhci/U8LvwanvfcWEzTaArOr n7aAeQe5maYjCxd8w2EZxbBELUYxsnrGBZKLUoZ8GFvFttNtxvIfEVODE0ZWZzoE7EUO VheA== X-Forwarded-Encrypted: i=1; AJvYcCVZFPN1LiwKirY8UwELAWHTH5XEtKFBpooihs5TWNYHQOO6/3ON4+3teDkNINvQXkAqkIw=@vger.kernel.org X-Gm-Message-State: AOJu0YwzDDBTlZBAGbaAQtcgROzxRpBwmo42WR9HHkVWWGlayVjyw1pT UiFh/uRX5piKqMvE4b4qC8FIuQIWv+PlHM1poESHz9YsJZHd9syajXo+ X-Gm-Gg: ASbGncuSF1KxoxCy2d0oWGOVCPt0nvpoBf+0I0Al0GOQsSiO+5FyB5bmdnEuVhGwauf 9w5shUY+7TRKLTL4zR7H7Xcg1fp8dYxVnoKhSSGTCXbm29Lps9KQuc1KoFWsSoU7AoV6WFVSKta JXGeNKj0LV6jPkbpqQf/ZVuxhkaLAiSOwzqx2MHRfaf+dAMXiszInqTGCzlbV8KvZvVOX8xBuTG KLTxzjCGZBb3UHAlrUthKJEak5sbCBZfKuKoOBIcDJYhlpwDeSIUMai7pCywd+08Br/q6o9xCOG ImY3WavA6Y/XEv0CYs+Swxb77m+AtzCLXcVJWUXo7Lcq70G4YKjqxhUPFILsy0yG+xrhGdx8cDM KMV9TsLKK7Epn3zrftAeKZbvo5ntaWBhL4ASu4Wlh63kRi92m/4P3n7b1ukmI3AjOM3SWjf7Wg8 Hl X-Google-Smtp-Source: AGHT+IEWoo9NvVrwFggEbU1z4T+s2r8capz8djYg6deD4z5HEE79cQawvyH0KkyQkeiQELrp+e/ovQ== X-Received: by 2002:a05:6a20:12ce:b0:34f:b50e:e2e2 with SMTP id adf61e73a8af0-35ba2f6eb18mr12762977637.58.1763351366176; Sun, 16 Nov 2025 19:49:26 -0800 (PST) Received: from 7950hx ([43.129.244.20]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-bc37703a0d9sm10348179a12.31.2025.11.16.19.49.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 16 Nov 2025 19:49:25 -0800 (PST) From: Menglong Dong X-Google-Original-From: Menglong Dong To: ast@kernel.org, rostedt@goodmis.org Cc: daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, mhiramat@kernel.org, mark.rutland@arm.com, mathieu.desnoyers@efficios.com, jiang.biao@linux.dev, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH bpf-next v2 2/6] x86/ftrace: implement DYNAMIC_FTRACE_WITH_JMP Date: Mon, 17 Nov 2025 11:49:02 +0800 Message-ID: <20251117034906.32036-3-dongml2@chinatelecom.cn> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251117034906.32036-1-dongml2@chinatelecom.cn> References: <20251117034906.32036-1-dongml2@chinatelecom.cn> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Implement the DYNAMIC_FTRACE_WITH_JMP for x86_64. In ftrace_call_replace, we will use JMP32_INSN_OPCODE instead of CALL_INSN_OPCODE if the address should use "jmp". Meanwhile, adjust the direct call in the ftrace_regs_caller. The RSB is balanced in the "jmp" mode. Take the function "foo" for example: original_caller: call foo -> foo: call fentry -> fentry: [do ftrace callbacks ] move tramp_addr to stack RET -> tramp_addr tramp_addr: [..] call foo_body -> foo_body: [..] RET -> back to tramp_addr [..] RET -> back to original_caller Signed-off-by: Menglong Dong --- arch/x86/Kconfig | 1 + arch/x86/kernel/ftrace.c | 7 ++++++- arch/x86/kernel/ftrace_64.S | 12 +++++++++++- 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index fa3b616af03a..462250a20311 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -230,6 +230,7 @@ config X86 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 select HAVE_FTRACE_REGS_HAVING_PT_REGS if X86_64 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + select HAVE_DYNAMIC_FTRACE_WITH_JMP if X86_64 select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 select HAVE_EBPF_JIT diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 4450acec9390..0543b57f54ee 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -74,7 +74,12 @@ static const char *ftrace_call_replace(unsigned long ip, unsigned long addr) * No need to translate into a callthunk. The trampoline does * the depth accounting itself. */ - return text_gen_insn(CALL_INSN_OPCODE, (void *)ip, (void *)addr); + if (ftrace_is_jmp(addr)) { + addr = ftrace_jmp_get(addr); + return text_gen_insn(JMP32_INSN_OPCODE, (void *)ip, (void *)addr); + } else { + return text_gen_insn(CALL_INSN_OPCODE, (void *)ip, (void *)addr); + } } static int ftrace_verify_code(unsigned long ip, const char *old_code) diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index 823dbdd0eb41..a132608265f6 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -285,8 +285,18 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL) ANNOTATE_NOENDBR RET +1: + testb $1, %al + jz 2f + andq $0xfffffffffffffffe, %rax + movq %rax, MCOUNT_REG_SIZE+8(%rsp) + restore_mcount_regs + /* Restore flags */ + popfq + RET + /* Swap the flags with orig_rax */ -1: movq MCOUNT_REG_SIZE(%rsp), %rdi +2: movq MCOUNT_REG_SIZE(%rsp), %rdi movq %rdi, MCOUNT_REG_SIZE-8(%rsp) movq %rax, MCOUNT_REG_SIZE(%rsp) -- 2.51.2