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 05F92D26D6F for ; Fri, 9 Jan 2026 16:17:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=QDtFysfA6XuuTZ/zLbqaNetDzuY1NOgmW5npBz/xxvE=; b=xlELFo/vo92WO1+Hl8v5Ti6I/Q 8JONBZadeeXYmOqtTTzRiHpoVQvCsYca7mWKxHs1ofxbLGPv6xDUtQztG9mxDFt4FDreC2Og/dZzE FrsZpU+m7hw0hPWxHFMqp2lVV0QJt8YGraGHHn5w4skK+19yf4vWR9/t2jNzLGs6rIzrbj07z6K7K eSmDwq1WMAdfZVRvRN3KIV9zclbUdH2es5mbnxOo5NdiJDLoiyVMU+oe5MmVIEX/JxIxgFSCndAZQ p/MK9ea6cxudsSLLXrQ5PejzLtWyiq5mVZTJgeiPauIM9r33HS1mDJd1ww0MKYwLiKaYacXoFqGoi qNB+wCwQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1veFBN-00000002bOC-0c0x; Fri, 09 Jan 2026 16:17:49 +0000 Received: from smtprelay0014.hostedemail.com ([216.40.44.14] helo=relay.hostedemail.com) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1veFBE-00000002bJS-2DUd for linux-arm-kernel@lists.infradead.org; Fri, 09 Jan 2026 16:17:47 +0000 Received: from omf07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 40B7F160333; Fri, 9 Jan 2026 16:17:36 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf07.hostedemail.com (Postfix) with ESMTPA id 7C3552002C; Fri, 9 Jan 2026 16:17:33 +0000 (UTC) Date: Fri, 9 Jan 2026 11:18:04 -0500 From: Steven Rostedt To: Jiri Olsa Cc: Masami Hiramatsu , Will Deacon , Mahe Tardy , Peter Zijlstra , bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, Yonghong Song , Song Liu , Andrii Nakryiko , Mark Rutland Subject: Re: [PATCHv2 bpf-next 1/2] arm64/ftrace,bpf: Fix partial regs after bpf_prog_run Message-ID: <20260109111804.481a6f20@gandalf.local.home> In-Reply-To: <20260109093454.389295-1-jolsa@kernel.org> References: <20260109093454.389295-1-jolsa@kernel.org> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspamout06 X-Rspamd-Queue-Id: 7C3552002C X-Stat-Signature: f8aus8gwt9gwwghji8dnqrqaet4ioy6e X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+dsryzGlYq/IBaVcXmTxW02qO+AtSzCCE= X-HE-Tag: 1767975453-939575 X-HE-Meta: U2FsdGVkX195HTS3PXdoSrXMaKW9jSAqMC2F/Zr2Crpg0MiCloYO/UukNadfj8DBKa27oZ27laPKm/4He9R+NuUHpk6ZGtccKIKcGfY1T9mIju3yta15pVGhCsAjwPOP6oPCBuH/XmjyjXw8274URJ7oA7jwvw5b9EtIk662f2w5s+yFnw8OyJioll9LUPMhshmXpiMGzRVnTS+iMFJgImpS30y4O+Wj1gMyXdQMGCq5Fx+WF0QEa+qLcbzoI456A5q7Jgyv5eEIOt5SDZHm9yUWIjNt/aDsZdfMPQ5ZpY90q7BzwAsiwGprE//EDWLHCDd3z+Ajbnnh14kJleRYrTL+ooQCFoK6kixAZ3n8EeCIvhGQdH0Z/SLDZxU8yTijGfgy/xE9hzqWJAJEcCDEySYDlazdn704J1SZt0Bu7jc= X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260109_081740_678303_F162E75D X-CRM114-Status: GOOD ( 12.82 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 9 Jan 2026 10:34:53 +0100 Jiri Olsa wrote: > Mahe reported issue with bpf_override_return helper not working when > executed from kprobe.multi bpf program on arm. > > The problem is that on arm we use alternate storage for pt_regs object > that is passed to bpf_prog_run and if any register is changed (which > is the case of bpf_override_return) it's not propagated back to actual > pt_regs object. > > Fixing this by introducing and calling ftrace_partial_regs_update function > to propagate the values of changed registers (ip and stack). > > Reported-by: Mahe Tardy > Signed-off-by: Jiri Olsa > --- Reviewed-by: Steven Rostedt (Google) -- Steve