From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 81342151CDF; Tue, 20 Feb 2024 21:01:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708462869; cv=none; b=DU18S47IJwYLKILBqYDcnWk2XJD9L8X1GC5P6Q/2AbDelLu8LggTPLdn2xXu6SwAHNY9e+FBQPVQ3XuZ9MgSyr9L0K1VnilvkX37a6G5PCn26NcErHc2zvYrVZWsDDdLePZODJtg6RJgoanW5KnYxgseSOocZybTqwvFbuGQ47c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708462869; c=relaxed/simple; bh=Xx3NyURWlUovmXX+ouWS2Kz1NgT7OmOxLNibTczDMiI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PJ6rOrxDgNKuQmHk4XpbJ0GflfUrS/nR4mllG/g7pkba7+DH4kyZhb6jkhxFMLsZ7eQXU6ECebOM6by5RWUVEPad14IoEGwLi42ykKpSCFlN5n9KckQTvYilI+4WOoz0VFvLnNhhkTX3xwfSElM0sYwubPTX6QcfxJNV29ksGHo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fzoZX644; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="fzoZX644" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9E8EC43390; Tue, 20 Feb 2024 21:01:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708462869; bh=Xx3NyURWlUovmXX+ouWS2Kz1NgT7OmOxLNibTczDMiI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fzoZX644VG4o7BTiI6chh7vVSzY4JvX3YfKJZjADNkEBLTA2b+HQXvNvoQ1psBoWz KWzeVDdD4GawfzGHlfPTTlrBv+1da056Con33prPuxnlpGGHTugvwdbAiFBAnVkTt0 8WZ08qHI5xhPE9TxsLMwA+ZqWuj3mjC1rOtBjMO8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Spoorthy , Benjamin Gray , Michael Ellerman , Sasha Levin Subject: [PATCH 6.1 062/197] powerpc/kasan: Limit KASAN thread size increase to 32KB Date: Tue, 20 Feb 2024 21:50:21 +0100 Message-ID: <20240220204842.938914265@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240220204841.073267068@linuxfoundation.org> References: <20240220204841.073267068@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Ellerman [ Upstream commit f1acb109505d983779bbb7e20a1ee6244d2b5736 ] KASAN is seen to increase stack usage, to the point that it was reported to lead to stack overflow on some 32-bit machines (see link). To avoid overflows the stack size was doubled for KASAN builds in commit 3e8635fb2e07 ("powerpc/kasan: Force thread size increase with KASAN"). However with a 32KB stack size to begin with, the doubling leads to a 64KB stack, which causes build errors: arch/powerpc/kernel/switch.S:249: Error: operand out of range (0x000000000000fe50 is not between 0xffffffffffff8000 and 0x0000000000007fff) Although the asm could be reworked, in practice a 32KB stack seems sufficient even for KASAN builds - the additional usage seems to be in the 2-3KB range for a 64-bit KASAN build. So only increase the stack for KASAN if the stack size is < 32KB. Fixes: 18f14afe2816 ("powerpc/64s: Increase default stack size to 32KB") Reported-by: Spoorthy Reported-by: Benjamin Gray Reviewed-by: Benjamin Gray Link: https://lore.kernel.org/linuxppc-dev/bug-207129-206035@https.bugzilla.kernel.org%2F/ Signed-off-by: Michael Ellerman Link: https://msgid.link/20240212064244.3924505-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/thread_info.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index af58f1ed3952..c4b798aa6ce8 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -14,7 +14,7 @@ #ifdef __KERNEL__ -#ifdef CONFIG_KASAN +#if defined(CONFIG_KASAN) && CONFIG_THREAD_SHIFT < 15 #define MIN_THREAD_SHIFT (CONFIG_THREAD_SHIFT + 1) #else #define MIN_THREAD_SHIFT CONFIG_THREAD_SHIFT -- 2.43.0