From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794063485; b=grjWEt5vsDP+b06BHB7TUJ7i3HjfjmXmTYYcnBBvCi4UGpq3lqjTOmUzXKyJJs6YF+zY nxk/X89yknC9Q/3Gl/Enjloqwp4QBkACdG+CLmTdM6jVu7FHXPxY5X8zRuVZ5QE8WncKy 4Dr8ZbpdotrC7uCoJa5SO6M55id/GbOiga+iXkdFjWIb1isaco+b5gSZiOhExm2sfV/XN sDkwDWbaPoBTxFQdKX7R/qNSBolVeVCQ8FEdkjpCFD+M0yQZfhZuyhmba7XOxW5rSue4C 9YMBvfK/xa4dPINZkm3s2+3iAW3lz9RCXJ7Ylg8bieEHvxFmDmDI1RqS2yoU0RSVVYQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063485; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=FvFfh+ttCLhrWAoiLyj2i3wQScvclyBBGbuQwI4bwrI=; b=WwMjamjqVV4ohFL8Ann1aON09x2lTETLqjnvbVg1nC9MJDOIx3rtw5OJ04fpf5uwO2a3 Zqme4VrHcSoJy2J8dNu5Wd4WI5xMccOadeSB6XSgCP+KmSMTHgXD/LrNPWZhQZQ98jHOD ig5zOhfS55n7+cIfxKcvgEYArDAnmfKJr9F1UNgOeL1EmjULRzNZqcBdmsUOeidExdP13 ug4H1ynBx9nap+5duaodVtfu//6cClPEb36dx+Fns1ADCB/Laqa8zMD2TdOfrqlanvCoC ODS8xZRNhYdicANHdBS8Ok1kevnpR7eKEC6bC4Ii7LEvJK42T+beDhUCwa0blDYNCnw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=vE6214u0; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7EC63606A9EF; Sat, 7 Nov 2026 14:58:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=vE6214u0 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 226F01F008A7; Sat, 7 Nov 2026 14:58:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063484; bh=FvFfh+ttCLhrWAoiLyj2i3wQScvclyBBGbuQwI4bwrI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=vE6214u0mG8vn27FgRYaJ+aR8gQ9Yf+rqMYeF0wJIJqciv9tEg2YfIRQ7bj+TQ/wg 9fyN2Dp3YNA4WlLL6JmoNnyMX1xkkDnNwNAdFheE4CO7UnY56faZCCAhCwMW3qWsLx zM3D+ppA12Z3cVRFF95Ps8Uxilt+kiHfee9FWbo0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Matt Turner , Magnus Lindholm , Sasha Levin Subject: [PATCH 6.18 631/869] alpha: invalidate the local context in flush_tlb_mm() Date: Sat, 7 Nov 2026 08:55:13 -0500 Message-ID: <20261107134914.370348518@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Magnus Lindholm [ Upstream commit 721bb7a129771f0ff9cef1dd5abfc106ef65feba ] flush_tlb_mm() has the same caller-CPU omission that was fixed in flush_tlb_page(): when the target mm is not the calling CPU's active_mm nothing happens locally, and smp_call_function() handles only the other CPUs, so this CPU may later reuse the old ASN together with the translations it still holds. The active_mm test itself is left alone here. That path calls flush_tlb_current(), which loads a fresh context through __load_new_mm_context() rather than issuing a targeted tbi() against whatever ASN happens to be loaded, so it does not depend on which context is current. The uniprocessor implementation in asm/tlbflush.h already has the missing branch. Counted over a fork-heavy run, flush_tlb_mm() was entered with the mm not this CPU's active_mm 2934 times, and 632 times while otherwise idle. The proposed Alpha hugetlb support routes hugetlb invalidations through flush_tlb_range(), which calls this function. Unmapping or migrating a hugetlb folio from another context will also need this local invalidate. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reviewed-by: Matt Turner Signed-off-by: Magnus Lindholm Link: https://lore.kernel.org/r/20261010142533.974797-8-linmag7@gmail.com Signed-off-by: Magnus Lindholm Signed-off-by: Sasha Levin --- arch/alpha/kernel/smp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index a5a42ae4a7d80..988e397b0b8a7 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -649,6 +649,9 @@ flush_tlb_mm(struct mm_struct *mm) preempt_enable(); return; } + } else { + /* smp_call_function() does not call back into this CPU. */ + flush_tlb_other(mm); } smp_call_function(ipi_flush_tlb_mm, mm, 1); -- 2.53.0