From patchwork Sun Jul 30 08:27:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nam Cao X-Patchwork-Id: 13333366 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6FDFAC04E69 for ; Sun, 30 Jul 2023 08:27:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ul4V8xObkqgLFb2hzqb2JLZ2oD7nJegYSjqLymEMWXY=; b=jm3vRP3K5WhYO7 srl3fCx2KrsyDjxImM/c5PV7Y1E6j+CXv79cTGZrKABFPF0VQIQC7GNedYPEfkBN2nV131bQPWpwp zdEIYIZ9ODD+Uzcg84BnpV0C+1tigjZm2uhU1AtRYSUXtYBXsSVYFaPU8OMDgXradejTqcdZccMhy 0ij6NFV0jukcS1pPG+p/GAsxxkmhrd6pQHZZvdR6ZCRHBLHNAKkMLQJ3l4hc9Poxij7edAOBKfsLz 6oye2EJ7QCxZk4SGqxZSQvmpq4u+WEcR0MolzlQruhI7DJ8b2M3Ofr09/XCgMuQa5erIIuKeZuoja ES0fd7HO7Nnn4kzEAHxQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qQ1m3-00AXgL-2b; Sun, 30 Jul 2023 08:27:35 +0000 Received: from mail-ej1-x62d.google.com ([2a00:1450:4864:20::62d]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qQ1lv-00AXc0-1c for linux-riscv@lists.infradead.org; Sun, 30 Jul 2023 08:27:30 +0000 Received: by mail-ej1-x62d.google.com with SMTP id a640c23a62f3a-9922d6f003cso565355766b.0 for ; Sun, 30 Jul 2023 01:27:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690705643; x=1691310443; 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=SimULQDdjpxXsYNdrfirKLk/fw8zuGv/egec0Yb7dzM=; b=Ka3V4bKaipjHIdFwBaUbvZopzCCe7cVlYdzQdNIAY9n6AyuDohH4211nmO3bbJ0Xdg Ur0LWW2k9uEXsnlWhaBWI0p2ybgnV00QpSTvbZoPhQyCNx5Ir2Woi0bFudpmb52ynpJk ePutJ+JeE0YVQuiJqkllHi9DbdxxTNI/m496ybuqV8txe4ucnSZICAFThXnLkkFYCJSh AEs+Yk+Uc5uz7+wFWgWiACGxsPKVM4q3vMD4/CcOk09PU+Z5e8Fvk1hCzwcZs1xhryaZ DnrVUhkNKibdML6rONMM386r/39VektrRLvv11bmJNfTHI65A5OEAsow8Mdnttalrr+O 5LiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690705643; x=1691310443; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=SimULQDdjpxXsYNdrfirKLk/fw8zuGv/egec0Yb7dzM=; b=VwH8i0PZN3P+46oE+MrUfjjUaMPmli3e6nmX76BWE/9p2x/L+Fsc7ZR4zQDC9wiPLn plPH8KS87B+Yg2qJzF3i5LEv+Uw0hXfiQ4Merq1ZWVFAn2EuYpomkUknwJDFTL7WWyHj 58IPtHDaI2AtJRAVo58MKquRw9T+X3OPVybk9mG6GOeFjPwn/YMDBM4iAg1yS+YSHjxW 0OWVk2HyzlsSEzslJNeZvEAfpctT7OfYCs5faJPYYpmGWlah/WtHtb/fiLQGnk1iQ4VE QIJYhv/hzB+m9hRhaHR5/aFUobo9wBBeOGZSNfsUJ80tDK6yahMgazMBrb6iA8JPUZ79 StuA== X-Gm-Message-State: ABy/qLbyMKCgvI52RShCyZ0OsolhEORVRYPmSJEFXjGpNihPci3Jk/28 6mELpUAggSvEg0XR4TPOyC8= X-Google-Smtp-Source: APBJJlHuYaRULyZJssvkHmCmmwoVNjfNhvOm5DYln4RYnWRjLUMNsD8+TP8VgT1J4/gKJsVzi0knqw== X-Received: by 2002:a17:906:530e:b0:993:6845:89d6 with SMTP id h14-20020a170906530e00b00993684589d6mr4470426ejo.47.1690705643484; Sun, 30 Jul 2023 01:27:23 -0700 (PDT) Received: from nam-dell (ip-217-105-46-58.ip.prioritytelecom.net. [217.105.46.58]) by smtp.gmail.com with ESMTPSA id n16-20020a1709067b5000b009927a49ba94sm4333519ejo.169.2023.07.30.01.27.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 30 Jul 2023 01:27:23 -0700 (PDT) From: Nam Cao To: Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Nam Cao Subject: [PATCH 3/3] riscv: kprobes: simulate c.beqz and c.bnez Date: Sun, 30 Jul 2023 10:27:09 +0200 Message-Id: <1d879dba4e4ee9a82e27625d6483b5c9cfed684f.1690704360.git.namcaov@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230730_012727_543760_D2AC119E X-CRM114-Status: GOOD ( 13.85 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org kprobes currently rejects instruction c.beqz and c.bnez. Implement them. Signed-off-by: Nam Cao Reviewed-by: Charlie Jenkins --- arch/riscv/kernel/probes/decode-insn.c | 4 +-- arch/riscv/kernel/probes/simulate-insn.c | 44 ++++++++++++++++++++++++ arch/riscv/kernel/probes/simulate-insn.h | 2 ++ 3 files changed, 48 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/probes/decode-insn.c b/arch/riscv/kernel/probes/decode-insn.c index 6dba23a55ac7..65d9590bfb9f 100644 --- a/arch/riscv/kernel/probes/decode-insn.c +++ b/arch/riscv/kernel/probes/decode-insn.c @@ -30,13 +30,13 @@ riscv_probe_decode_insn(probe_opcode_t *addr, struct arch_probe_insn *api) */ #ifdef CONFIG_RISCV_ISA_C RISCV_INSN_REJECTED(c_jal, insn); - RISCV_INSN_REJECTED(c_beqz, insn); - RISCV_INSN_REJECTED(c_bnez, insn); RISCV_INSN_REJECTED(c_ebreak, insn); RISCV_INSN_SET_SIMULATE(c_j, insn); RISCV_INSN_SET_SIMULATE(c_jr, insn); RISCV_INSN_SET_SIMULATE(c_jalr, insn); + RISCV_INSN_SET_SIMULATE(c_beqz, insn); + RISCV_INSN_SET_SIMULATE(c_bnez, insn); #endif RISCV_INSN_SET_SIMULATE(jal, insn); diff --git a/arch/riscv/kernel/probes/simulate-insn.c b/arch/riscv/kernel/probes/simulate-insn.c index 1ead6f4951f9..d3099d67816d 100644 --- a/arch/riscv/kernel/probes/simulate-insn.c +++ b/arch/riscv/kernel/probes/simulate-insn.c @@ -249,3 +249,47 @@ bool __kprobes simulate_c_jalr(u32 opcode, unsigned long addr, struct pt_regs *r { return simulate_c_jr_jalr(opcode, addr, regs, true); } + +static bool __kprobes simulate_c_bnez_beqz(u32 opcode, unsigned long addr, struct pt_regs *regs, + bool is_bnez) +{ + /* + * 15 13 12 10 9 7 6 2 1 0 + * | funct3 | offset[8|4:3] | rs1' | offset[7:6|2:1|5] | op | + * 3 3 3 5 2 + */ + + s32 offset; + u32 rs1; + unsigned long rs1_val; + + rs1 = 0x8 | ((opcode >> 7) & 0x7); + + if (!rv_insn_reg_get_val(regs, rs1, &rs1_val)) + return false; + + if ((rs1_val != 0 && is_bnez) || (rs1_val == 0 && !is_bnez)) { + offset = ((opcode >> 3) & 0x3) << 1; + offset |= ((opcode >> 10) & 0x3) << 3; + offset |= ((opcode >> 2) & 0x1) << 5; + offset |= ((opcode >> 5) & 0x3) << 6; + offset |= ((opcode >> 12) & 0x1) << 8; + offset = sign_extend32(offset, 8); + } else { + offset = 2; + } + + instruction_pointer_set(regs, addr + offset); + + return true; +} + +bool __kprobes simulate_c_bnez(u32 opcode, unsigned long addr, struct pt_regs *regs) +{ + return simulate_c_bnez_beqz(opcode, addr, regs, true); +} + +bool __kprobes simulate_c_beqz(u32 opcode, unsigned long addr, struct pt_regs *regs) +{ + return simulate_c_bnez_beqz(opcode, addr, regs, false); +} diff --git a/arch/riscv/kernel/probes/simulate-insn.h b/arch/riscv/kernel/probes/simulate-insn.h index 472a1948ec4f..44ebbc444db9 100644 --- a/arch/riscv/kernel/probes/simulate-insn.h +++ b/arch/riscv/kernel/probes/simulate-insn.h @@ -27,5 +27,7 @@ bool simulate_jalr(u32 opcode, unsigned long addr, struct pt_regs *regs); bool simulate_c_j(u32 opcode, unsigned long addr, struct pt_regs *regs); bool simulate_c_jr(u32 opcode, unsigned long addr, struct pt_regs *regs); bool simulate_c_jalr(u32 opcode, unsigned long addr, struct pt_regs *regs); +bool simulate_c_bnez(u32 opcode, unsigned long addr, struct pt_regs *regs); +bool simulate_c_beqz(u32 opcode, unsigned long addr, struct pt_regs *regs); #endif /* _RISCV_KERNEL_PROBES_SIMULATE_INSN_H */