From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta1.migadu.com (out-189.mta1.migadu.com [95.215.58.189]) (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 8840C3BCD23 for ; Mon, 8 Jun 2026 10:09:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780913373; cv=none; b=kwhQH+pnpCZEttbUicxzlGPj6V9CKtQi9puVfektYVW7UYrHCD6WZ+BOo1SVf9GBPxf25rLJomudQjp7emXg7DhRAiLv9kFPFtgq0OeA0REt1wABewY1pbPIi8WfW4jFxqYTV/gyKMxiXlHXpMSB0LbsaHeDx9ccm1ymgp8OfxE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780913373; c=relaxed/simple; bh=cbS69o5iESsfbUbRgcNuv3uKnv/pE5hU4jIiUR0Ij9M=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Osjb6xcPIf+4m+VNsrxfXuZTPzL5g97/hFQ3Qjk5vx/blJmapyvUgws9y/kX9m2Ex9nCEOh+JokwlakQs4gmwf6KB+0aVzHrHx9Phlw5UnLtgU5hN9bG47seXSKLaVpYgU5SjeSnVgkN0vdZEA7UYpGOgki94GdPp8NPX+U5pyM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=wMgA5fHm; arc=none smtp.client-ip=95.215.58.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="wMgA5fHm" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1780913369; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/3FyhKq1xd5fu9klCT0mfTqjvkusYJv3Ps48W8w3NkU=; b=wMgA5fHmLOPGoKNYg1bO1roOJO2R7WfPejr3DyihFpw/wy9LFPAgCM9VKBzE7L3xEKDlOm jbUW2YpjYtPi7RqilWMGCPezDD7ygawkdwpeIvfXfHZqEYxbM09Eg/9TAlScUdELnZ9+t4 mlMj+raA7Jm6lenGImO4hITCL/QCi6A= From: George Guo To: chenhuacai@kernel.org, jpoimboe@kernel.org, peterz@infradead.org, jikos@kernel.org, mbenes@suse.cz, pmladek@suse.com Cc: kernel@xen0n.name, joe.lawrence@redhat.com, rostedt@goodmis.org, ardb@kernel.org, nathan@kernel.org, nick.desaulniers+lkml@gmail.com, yangtiezhu@loongson.cn, jiaxun.yang@flygoat.com, liukexin@kylinos.cn, guodongtai@kylinos.cn, xry111@xry111.site, wangyuli@aosc.io, loongarch@lists.linux.dev, live-patching@vger.kernel.org, llvm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/8] LoongArch: Mark special sections for KLP support Date: Mon, 8 Jun 2026 18:08:46 +0800 Message-Id: <20260608100852.325413-3-dongtai.guo@linux.dev> In-Reply-To: <20260608100852.325413-1-dongtai.guo@linux.dev> References: <20260608100852.325413-1-dongtai.guo@linux.dev> Precedence: bulk X-Mailing-List: live-patching@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: George Guo objtool needs to split the kernel's special sections into per-entry symbols when generating livepatch modules. Mark them so it can: - .altinstructions and __ex_table are read-only, so set an explicit entry size via SHF_MERGE (ALT_INSTR_SIZE / EXTABLE_SIZE). - __bug_table and __jump_table are writable. SHF_MERGE cannot be combined with SHF_WRITE (Clang rejects it), so annotate each entry with ANNOTATE_DATA_SPECIAL instead, mirroring x86/arm64. Co-developed-by: Kexin Liu Signed-off-by: Kexin Liu Signed-off-by: George Guo --- arch/loongarch/include/asm/alternative-asm.h | 5 +++-- arch/loongarch/include/asm/alternative.h | 6 ++++-- arch/loongarch/include/asm/asm-extable.h | 10 ++++++++-- arch/loongarch/include/asm/bug.h | 1 + arch/loongarch/include/asm/jump_label.h | 2 ++ arch/loongarch/kernel/asm-offsets.c | 20 ++++++++++++++++++++ 6 files changed, 38 insertions(+), 6 deletions(-) diff --git a/arch/loongarch/include/asm/alternative-asm.h b/arch/loongarch/include/asm/alternative-asm.h index 7dc29bd9b2f0..d940d9d2c0e1 100644 --- a/arch/loongarch/include/asm/alternative-asm.h +++ b/arch/loongarch/include/asm/alternative-asm.h @@ -5,6 +5,7 @@ #ifdef __ASSEMBLER__ #include +#include /* * Issue one struct alt_instr descriptor entry (need to put it into @@ -33,7 +34,7 @@ .fill - (((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)) / 4, 4, 0x03400000 142 : - .pushsection .altinstructions, "a" + .pushsection .altinstructions, "aM", @progbits, ALT_INSTR_SIZE altinstruction_entry 140b, 143f, \feature, 142b-140b, 144f-143f .popsection @@ -63,7 +64,7 @@ (alt_max_short(new_len1, new_len2) - (old_len)) / 4, 4, 0x03400000 142 : - .pushsection .altinstructions, "a" + .pushsection .altinstructions, "aM", @progbits, ALT_INSTR_SIZE altinstruction_entry 140b, 143f, \feature1, 142b-140b, 144f-143f, 142b-141b altinstruction_entry 140b, 144f, \feature2, 142b-140b, 145f-144f, 142b-141b .popsection diff --git a/arch/loongarch/include/asm/alternative.h b/arch/loongarch/include/asm/alternative.h index b5bae21fb3c8..8f7712ed2f4e 100644 --- a/arch/loongarch/include/asm/alternative.h +++ b/arch/loongarch/include/asm/alternative.h @@ -70,7 +70,8 @@ extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); /* alternative assembly primitive: */ #define ALTERNATIVE(oldinstr, newinstr, feature) \ OLDINSTR(oldinstr, 1) \ - ".pushsection .altinstructions,\"a\"\n" \ + ".pushsection .altinstructions, \"aM\", @progbits, " \ + __stringify(ALT_INSTR_SIZE) "\n" \ ALTINSTR_ENTRY(feature, 1) \ ".popsection\n" \ ".subsection 1\n" \ @@ -79,7 +80,8 @@ extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); #define ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2)\ OLDINSTR_2(oldinstr, 1, 2) \ - ".pushsection .altinstructions,\"a\"\n" \ + ".pushsection .altinstructions, \"aM\", @progbits, " \ + __stringify(ALT_INSTR_SIZE) "\n" \ ALTINSTR_ENTRY(feature1, 1) \ ALTINSTR_ENTRY(feature2, 2) \ ".popsection\n" \ diff --git a/arch/loongarch/include/asm/asm-extable.h b/arch/loongarch/include/asm/asm-extable.h index d60bdf2e6377..2d7eef7c0b39 100644 --- a/arch/loongarch/include/asm/asm-extable.h +++ b/arch/loongarch/include/asm/asm-extable.h @@ -7,10 +7,15 @@ #define EX_TYPE_UACCESS_ERR_ZERO 2 #define EX_TYPE_BPF 3 +#ifndef COMPILE_OFFSETS +#include +#endif + #ifdef __ASSEMBLER__ #define __ASM_EXTABLE_RAW(insn, fixup, type, data) \ - .pushsection __ex_table, "a"; \ + .pushsection __ex_table, "aM", @progbits, \ + EXTABLE_SIZE; \ .balign 4; \ .long ((insn) - .); \ .long ((fixup) - .); \ @@ -29,7 +34,8 @@ #include #define __ASM_EXTABLE_RAW(insn, fixup, type, data) \ - ".pushsection __ex_table, \"a\"\n" \ + ".pushsection __ex_table, \"aM\", @progbits, "\ + __stringify(EXTABLE_SIZE) "\n" \ ".balign 4\n" \ ".long ((" insn ") - .)\n" \ ".long ((" fixup ") - .)\n" \ diff --git a/arch/loongarch/include/asm/bug.h b/arch/loongarch/include/asm/bug.h index d090a5bec5eb..14e3acbaad8d 100644 --- a/arch/loongarch/include/asm/bug.h +++ b/arch/loongarch/include/asm/bug.h @@ -25,6 +25,7 @@ #define __BUG_ENTRY(cond_str, flags) \ .pushsection __bug_table, "aw"; \ .align 2; \ + __ANNOTATE_DATA_SPECIAL; \ 10000: .long 10001f - .; \ _BUGVERBOSE_LOCATION(WARN_CONDITION_STR(cond_str) __FILE__, __LINE__) \ .short flags; \ diff --git a/arch/loongarch/include/asm/jump_label.h b/arch/loongarch/include/asm/jump_label.h index 7ef4ae3abf08..d20f0fa24b6b 100644 --- a/arch/loongarch/include/asm/jump_label.h +++ b/arch/loongarch/include/asm/jump_label.h @@ -12,6 +12,7 @@ #include #include #include +#include #define HAVE_JUMP_LABEL_BATCH @@ -27,6 +28,7 @@ #define JUMP_TABLE_ENTRY(key, label) \ ".pushsection __jump_table, \"aw\" \n\t" \ ".align " __stringify(PTRLOG) " \n\t" \ + ANNOTATE_DATA_SPECIAL "\n\t" \ ".long 1b - ., " label " - . \n\t" \ JUMP_LABEL_TYPE key " - . \n\t" \ ".popsection \n\t" diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/asm-offsets.c index 2cc953f113ac..470323aa022c 100644 --- a/arch/loongarch/kernel/asm-offsets.c +++ b/arch/loongarch/kernel/asm-offsets.c @@ -18,6 +18,8 @@ #include #include #include +#include +#include static void __used output_ptreg_defines(void) { @@ -323,3 +325,21 @@ static void __used output_vdso_defines(void) DEFINE(__VDSO_PAGES, VDSO_NR_PAGES); BLANK(); } + +static void __used output_extable_defines(void) +{ + COMMENT("LoongArch exception table entry offsets."); + + DEFINE(EXTABLE_SIZE, sizeof(struct exception_table_entry)); + BLANK(); +} + +static void __used output_alt_instr_defines(void) +{ + COMMENT("LoongArch alternative instructions offsets."); + + DEFINE(ALT_INSTR_SIZE, sizeof(struct alt_instr)); + BLANK(); +} + + -- 2.25.1