From nobody Sat Jan 3 06:32:58 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92258E7B611 for ; Wed, 4 Oct 2023 13:10:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242490AbjJDNKh (ORCPT ); Wed, 4 Oct 2023 09:10:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242548AbjJDNKd (ORCPT ); Wed, 4 Oct 2023 09:10:33 -0400 Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67A70C4 for ; Wed, 4 Oct 2023 06:10:29 -0700 (PDT) Received: by mail-wm1-x32b.google.com with SMTP id 5b1f17b1804b1-406553f6976so4704285e9.1 for ; Wed, 04 Oct 2023 06:10:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1696425028; x=1697029828; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=z15iGiezxYK5XcqIfgGulDEdBAkSg8R0+TumWNSNnqo=; b=vbnPtDiZGixJZvl6ozqL0YnBLNX8OsQURI+FOhAuZzPJwKKhNyl+i2uTV8+l4O54fI 8S4U0aCdt0+B8JHCLjprcIvbmTFysRtcaRTuyJcgCqlsgGgJsFxyX4WIbTIeAqWAg1Bp W2+PsRmwHwyKNdAVOg93y7qoOfpjebbDAzDxxRCsipYPxnYb0HwMtyO/6SKMdr8JnAR9 Q5xQ3JUy3jOvG3TbpsRuOTfO2n+ntMT8uYDWpW0sFMc96tsX+3F9XTM2nqOs3CGdkGZ9 MtrS2b5XLLO9QRoiJdtWK8f50JdWzCdnysXajbvRtxVHRFX4zylWeN75eqmOEkAZ85Kd Bq7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696425028; x=1697029828; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=z15iGiezxYK5XcqIfgGulDEdBAkSg8R0+TumWNSNnqo=; b=gCuBjdtqZNhK0K01BqT+60ltDoKdquezhn/g+CqKle/ZruAqbusxOSBNMGktEKnSwA VwXsVCyodK5VsIed/Byswg61nv5of9fqFEbEr+4SaN5tc0zPYEDnxKkjrSnbnNghGjAO RP1WfvmXnYMniZHhwiewULCOhDoEIpptXu9y01vcWvL7zDWpOhqbHuY429M+4pSmr5TU MOKAx//mYSVzvaZim4WBlHccmnhMmIRYtPdF65Ticdt0QJLL0cbBsCo4liCUc0xJz8sn VUP2xkxdEB9VFs2mJBbXBRUAozqMiESeu+CE3akUV+YwHCC2iMFO4UfModaga+s5xav0 2z3w== X-Gm-Message-State: AOJu0Yz/DBBRmE+BoKUBN97N3VAQFo+QL++si9tM1Fl4uzp6yfSPTKVC 0TRQ8FtBLpJPDWPBInd1JCRWRg== X-Google-Smtp-Source: AGHT+IFnbZnW549ZWt1PzlFvEq2ZFwMTlc5GL20gDuzsNXnx6EeJFuLFcPl6tcuFSBDuZ7Gy71wyWw== X-Received: by 2002:a7b:ca59:0:b0:3fe:d637:7b25 with SMTP id m25-20020a7bca59000000b003fed6377b25mr2345430wml.0.1696425027197; Wed, 04 Oct 2023 06:10:27 -0700 (PDT) Received: from carbon-x1.. ([2a01:e0a:999:a3a0:9474:8d75:5115:42cb]) by smtp.gmail.com with ESMTPSA id m10-20020a7bce0a000000b00405953973c3sm1497074wmc.6.2023.10.04.06.10.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Oct 2023 06:10:26 -0700 (PDT) From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] riscv: blacklist assembly symbols for kprobe Date: Wed, 4 Oct 2023 15:10:09 +0200 Message-ID: <20231004131009.409193-1-cleger@rivosinc.com> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Adding kprobes on some assembly functions (mainly exception handling) will result in crashes (either recursive trap or panic). To avoid such errors, add ASM_NOKPROBE() macro which allow adding specific symbols into the __kprobe_blacklist section and use to blacklist the following symbols that showed to be problematic: - handle_exception() - ret_from_exception() - handle_kernel_stack_overflow() Signed-off-by: Cl=C3=A9ment L=C3=A9ger Reviewed-by: Charlie Jenkins --- arch/riscv/include/asm/asm.h | 10 ++++++++++ arch/riscv/kernel/entry.S | 3 +++ 2 files changed, 13 insertions(+) diff --git a/arch/riscv/include/asm/asm.h b/arch/riscv/include/asm/asm.h index 114bbadaef41..9194e334de15 100644 --- a/arch/riscv/include/asm/asm.h +++ b/arch/riscv/include/asm/asm.h @@ -142,6 +142,16 @@ REG_L x31, PT_T6(sp) .endm =20 +/* Annotate a function as being unsuitable for kprobes. */ +#ifdef CONFIG_KPROBES +#define ASM_NOKPROBE(name) \ + .pushsection "_kprobe_blacklist", "aw"; \ + RISCV_PTR name; \ + .popsection +#else +#define ASM_NOKPROBE(name) +#endif + #endif /* __ASSEMBLY__ */ =20 #endif /* _ASM_RISCV_ASM_H */ diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 143a2bb3e697..f24bc4eeedde 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -101,6 +101,7 @@ _save_context: 1: tail do_trap_unknown SYM_CODE_END(handle_exception) +ASM_NOKPROBE(handle_exception) =20 /* * The ret_from_exception must be called with interrupt disabled. Here is = the @@ -167,6 +168,7 @@ SYM_CODE_START_NOALIGN(ret_from_exception) sret #endif SYM_CODE_END(ret_from_exception) +ASM_NOKPROBE(ret_from_exception) =20 #ifdef CONFIG_VMAP_STACK SYM_CODE_START_LOCAL(handle_kernel_stack_overflow) @@ -254,6 +256,7 @@ restore_caller_reg: move a0, sp tail handle_bad_stack SYM_CODE_END(handle_kernel_stack_overflow) +ASM_NOKPROBE(handle_kernel_stack_overflow) #endif =20 SYM_CODE_START(ret_from_fork) --=20 2.42.0