From mboxrd@z Thu Jan 1 00:00:00 1970 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 7EF4BC43458 for ; Sun, 28 Jun 2026 08:17:49 +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=433hpgqops+snIIyFUaAE2mOQCwtThuVn8dVjPz5RhY=; b=OLkF/P/4w8Ad17 6U64m75ey5UJTX8ZULOxEk8z3/pJV75EHU5x54KI3ok96IAWxiyIsnY3jnP6tB+jS+zSjOHRgH9d5 DBg2ACI7zVXyh3r8BJd7yw5jOfsBPPLD7LZFb/BtH05izg4s/uKBgl2/0E0ZlzkpBdwyDRjsQUDgz +N7AFbA72CZrQ5RAAGT9l23hdPPHw2yro0t9w5Y8Lp7ucOwsPCMlPjst/8is/Eexxd+KvuH5Cg98P MtUpcZMZciejqvBi5EWislY8n43bQZJb8CrOowd6mNxBu6J66XVWuBDbGXLUNi8vLoeFkgmXhBfdP b36HKOClDAvoHKAh10KQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wdkhs-0000000CyjF-3kBl; Sun, 28 Jun 2026 08:17:36 +0000 Received: from mail-pg1-x52d.google.com ([2607:f8b0:4864:20::52d]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wdkhq-0000000Cyih-1YAV for linux-riscv@lists.infradead.org; Sun, 28 Jun 2026 08:17:35 +0000 Received: by mail-pg1-x52d.google.com with SMTP id 41be03b00d2f7-c964d52321bso224481a12.0 for ; Sun, 28 Jun 2026 01:17:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1782634653; x=1783239453; darn=lists.infradead.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=fS2yJRct07pRe6n4SB8fXurYRNSLUTRVGluVVDIlUMc=; b=RQWMLle6qsz3OuklXYjpVT03Swr925OOK/4CxDxsNrvytuycwPtw88RBrJ00gtm+X5 3/qsp9blsLwU/xtYg+IsHMytxAQfZUmnxhsxp/ioWj39pqSEkBZY5VZfcjACsF4iOZ8v 8D/4sCgr+ULSZC26WPv6PcNJYa2i65QTGVfVPTZrISMYVdeT+9nDan/rAdQYCZILe1we LF8VZv3MbyZRbhiSAqkDjYJPaUHRFg1+SRytMfgLd0FiDYTl9FDIV5+3yucJdk02CMEf 6CEKIVIW9q5JKOG+p31VquCQ12AqRuaiINd/wf5CI9uL1HaC2yAqAoYU6qDZOnxwMfkB TVpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782634653; x=1783239453; 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=fS2yJRct07pRe6n4SB8fXurYRNSLUTRVGluVVDIlUMc=; b=p7Z98Va+falGUPjNMJilQ6R6sP3QuzE3RU/A14QbyW88Nb8QXxdMw8lvPLaOKoIQh4 T+mwF6xh8SfPaDgVDOyYEbm2wNn09rl0WSS1TNw6cJjn3ArYaEfXY0RXLFajLweNVdxb sXsvdzElXltqlb+24YEWrQ5AsS1C9h4y5kBtxqQslsPNA+Qkx/RAhhO3TcYgZ4WBKvNq G6K4ewDKAPdwy6sA7VgsFMpun4xxQ4kGZIIjMTy/tQyawORJ0pYc2houZOS5zi+KNltr iU8MqnNEoIo2JvmNJGvivWFXD1SQ7GHxEgoIsi5vqh19gsH6KJeTZkhmb60YEFYFMGCj Un2A== X-Forwarded-Encrypted: i=1; AFNElJ8uA4kXV3xYCxUEzLDHpiafJbKAcBhx43JRBK6UeapTCJWPP0vCKaiFIrlPHanhomk4+WyQOCV4oeOlAQ==@lists.infradead.org X-Gm-Message-State: AOJu0YxfQzgI3Pi1P3L7NjodnnvMPGthSvL/1TciJrNvD44s/88al/cZ 7f5mofGCc1x+QqGk0HLBRnq5cxwHQvyrhvj/Z1HdKOtc+2vUizgThYf7 X-Gm-Gg: AfdE7ckH142F3d4jILEvZzyOX3qmYyb4X67ebO3O1l0JibgATFv76eeII1GwOUSCZ+B D7yoBHFnO+sGTnj8Qgb3DTZvQPU8I2a73qo/tkI2al9uA8Ea0UTCHNUVOQ1BFQTIvs/sT2dtmZu Be+tHv2JIaEK9MuTzSgdRr99sKibNxIZih7DtTY6ZUJJawZv3StHAwGbE2yFFvHVRX+YfdsqzOK emgcDuk62kpNEfzkWjAr9q0zEEpiLnkSoIHB/OQili/TpnvrhjHOnMdW/aVj+LxRooQ38bBmuIP pmDchfbOZLtjfcQBgKc6UCHVuIBdMedQuvHxdzkYqROj2tn0GWmn7vssOHxqC3V40f3lbyPqnnp MClxeO3weqYl5lwT2/1rEz7Iv8WNnG5ScaT3qPWU5TB6YZEs7Er1Takbz5SJ8PUt6FDYDHdHr2e kXQkAP91qYhDwJxZSd8jIvtdsctv9IJEWnwkT3k5UXhZ9/+3PBul6x6rA= X-Received: by 2002:a05:6a20:7289:b0:3bf:82b4:4b47 with SMTP id adf61e73a8af0-3bf82b44e32mr2761238637.18.1782634653395; Sun, 28 Jun 2026 01:17:33 -0700 (PDT) Received: from computer.goose-salary.ts.net ([2a09:bac5:3b4a:8aa::dd:15]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-c92bd55985asm6020434a12.31.2026.06.28.01.17.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 28 Jun 2026 01:17:33 -0700 (PDT) From: Varun R Mallya To: pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, memxor@gmail.com, bjorn@kernel.org, pulehui@huawei.com Cc: alex@ghiti.fr, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org, emil@etsalapatis.com, puranjay@kernel.org, shuah@kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, varunrmallya@gmail.com Subject: [PATCH bpf-next v2 1/3] riscv: stacktrace: Implement arch_bpf_stack_walk() for BPF Date: Sun, 28 Jun 2026 13:47:08 +0530 Message-ID: <20260628081710.113333-2-varunrmallya@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260628081710.113333-1-varunrmallya@gmail.com> References: <20260628081710.113333-1-varunrmallya@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260628_011734_414212_30441B9A X-CRM114-Status: GOOD ( 13.47 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org This will be used by bpf_throw() to unwind till the program marked as exception boundary and run the callback with the stack of the main program. This is required for supporting BPF exceptions on RISC-V. This depends on the frame pointer unwinder, so it is only built under CONFIG_FRAME_POINTER, else falls back to the weak no-op. Signed-off-by: Varun R Mallya Reviewed-by: Pu Lehui --- arch/riscv/kernel/stacktrace.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c index c7555447149b..64929381bb30 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -5,6 +5,7 @@ */ #include +#include #include #include #include @@ -102,6 +103,36 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, } } +void notrace arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), + void *cookie) +{ + unsigned long fp, sp, pc; + int graph_idx = 0; + + fp = (unsigned long)__builtin_frame_address(0); + sp = current_stack_pointer; + pc = (unsigned long)arch_bpf_stack_walk; + + for (;;) { + struct stackframe *frame; + + if (unlikely(!__kernel_text_address(pc))) + break; + /* pc belongs to the function whose frame pointer is fp */ + if (!consume_fn(cookie, pc, sp, fp)) + break; + if (unlikely(!fp_is_valid(fp, sp))) + break; + + frame = (struct stackframe *)fp - 1; + sp = fp; + fp = READ_ONCE_TASK_STACK(current, frame->fp); + pc = READ_ONCE_TASK_STACK(current, frame->ra); + pc = ftrace_graph_ret_addr(current, &graph_idx, pc, + &frame->ra); + } +} + #else /* !CONFIG_FRAME_POINTER */ void notrace walk_stackframe(struct task_struct *task, -- 2.54.0 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv