From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 22D9A606A33E for ; Mon, 2 Nov 2026 13:02:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=kKwoqK/z; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=TjAx56T7 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: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=L806xsiGlwO13TAwrjN8i31kZe6YvPSlLcIj0vmc54w=; b=kKwoqK/zyeE1OA wo5j62WT+FseweTC4fRcQWZzTsb2/y779DwCXquSbfB1Difj7XoBwFLcaBdO2aDb0NzleU2FLyugm MYYV9FMNg88zyz/2SbgDNuk7Y2SLRneS4tLCSOmlXiKJtdSn0C5aaq9kReWLIoeBDrSaJd/dHtn02 w3Wss2vdNP5Ta5mPyI7tS5ii/Ujd4EKnlBW8x9GSLE/aOIO6yLgmM0O8hFGq4d29eg3Y5nOfngQ/q k1ZWV5Khix/V4J68LI1nRUmWlEu4fG1hvsrvk1vZc5YZp0h6Blyu3zm6mtoeSestk+w+uCftPeEOa PYkK5JMRkzcA1jm25Rvg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xNrg6-0000000GXwm-1N8N; Mon, 02 Nov 2026 13:02:22 +0000 Received: from out-92.mta0.migadu.com ([2001:41d0:1004:224b::5c] helo=mta0.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xNrg3-0000000GXt5-1QwS for linux-arm-kernel@lists.infradead.org; Mon, 02 Nov 2026 13:02:20 +0000 X-Envelope-To: linux-arm-kernel@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=CBH6n7O8BP/HoFkIHe06UxiI77aEmPLQp99OnnXWeHY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793624533; v=1; x=1794229333; b=TjAx56T7pLXnuPa7R0RTirXIC9JVUa5pjHj0na8JD9eN/L8lGgpXvIVDx7vbE6wuCeX0Y67r sBTcJ3ODe9528XLhf/EkggfVJdLTpxNiFFdd6bRU4CH+fJi1wqTGNmOIfrg0grgZwfayhAi+dop b2gxLjHpwWRzIAKodRKg0Am0= X-Envelope-To: linux-arm-kernel@lists.infradead.org Received: by smtp.migadu.com with ESMTPS id a4c58a5f30d34fbb; Mon, 02 Nov 2026 13:02:13 +0000 X-Mizu-Trace-ID: a4c58a5f30d34fbb X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton Cc: Will Deacon , Catalin Marinas , Joey Gouly , Mark Rutland , Suzuki K Poulose , Raghavendra Rao Ananta , Sascha Bischoff , Thomas Gleixner , Sebastian Ene , =?UTF-8?q?Bart=C5=82omiej=20Grzesik?= , Mostafa Saleh , Vincent Donnefort , Vladimir Murzin , Zenghui Yu , Zenghui Yu , Steffen Eiden , Radu Rendec , Fuad Tabba , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 05/13] irqchip/gic-v3-its: Compute the wait target under the ITS lock Date: Mon, 2 Nov 2026 13:01:25 +0000 Message-ID: <20261102130133.3684226-6-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261102130133.3684226-1-fuad.tabba@linux.dev> References: <20261102130133.3684226-1-fuad.tabba@linux.dev> X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261102_050219_522326_B6A2B8BC X-CRM114-Status: GOOD ( 14.06 ) X-Spam-Score: -2.1 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 its_wait_for_range_completion() converts the posted command pointer into a queue offset against its->cmd_base, after the caller has dropped its->lock. That's fine while cmd_base never changes, but the protected KVM takeover in a later patch switches cmd_base to a copy of the queue under the lock, and a wait racing with it would compute its target against the wrong base. Compute the offset in its_post_commands(), under the lock, and pass it to the wait instead of the pointer. No functional change intended. Signed-off-by: Fuad Tabba --- drivers/irqchip/irq-gic-v3-its.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 8cc1bd8e7835b..f06da58cccf3d 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -1144,13 +1144,13 @@ static struct its_cmd_block *its_allocate_entry(struct its_node *its) return cmd; } -static struct its_cmd_block *its_post_commands(struct its_node *its) +static u64 its_post_commands(struct its_node *its) { u64 wr = its_cmd_ptr_to_offset(its, its->cmd_write); writel_relaxed(wr, its->base + GITS_CWRITER); - return its->cmd_write; + return wr; } static void its_flush_cmd(struct its_node *its, struct its_cmd_block *cmd) @@ -1167,13 +1167,12 @@ static void its_flush_cmd(struct its_node *its, struct its_cmd_block *cmd) static int its_wait_for_range_completion(struct its_node *its, u64 prev_idx, - struct its_cmd_block *to) + u64 to_idx) { - u64 rd_idx, to_idx, linear_idx; + u64 rd_idx, linear_idx; u32 count = 1000000; /* 1s! */ /* Linearize to_idx if the command set has wrapped around */ - to_idx = its_cmd_ptr_to_offset(its, to); if (to_idx < prev_idx) to_idx += ITS_CMD_QUEUE_SZ; @@ -1216,10 +1215,10 @@ void name(struct its_node *its, \ buildtype builder, \ struct its_cmd_desc *desc) \ { \ - struct its_cmd_block *cmd, *sync_cmd, *next_cmd; \ + struct its_cmd_block *cmd, *sync_cmd; \ synctype *sync_obj; \ unsigned long flags; \ - u64 rd_idx; \ + u64 rd_idx, wr_idx; \ \ raw_spin_lock_irqsave(&its->lock, flags); \ \ @@ -1242,10 +1241,10 @@ void name(struct its_node *its, \ \ post: \ rd_idx = readl_relaxed(its->base + GITS_CREADR); \ - next_cmd = its_post_commands(its); \ + wr_idx = its_post_commands(its); \ raw_spin_unlock_irqrestore(&its->lock, flags); \ \ - if (its_wait_for_range_completion(its, rd_idx, next_cmd)) \ + if (its_wait_for_range_completion(its, rd_idx, wr_idx)) \ pr_err_ratelimited("ITS cmd %ps failed\n", builder); \ } -- 2.47.3