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 2437E151CE8; Tue, 20 Feb 2024 21:13:38 +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=1708463618; cv=none; b=hIF3mdNnIbqDloDf1ytfkB09CVYqqcTGsbAmjM6WoSbxZcE21Z98xzfl1QCSagcrBn9Sxr0TLZv7vjHVrYD5ZoZQAve35UdJiaCgtGBRmb0Bi0aQ2yIn3F2TOKjUFSzjKMDtgjLmN/Up4APDDH1firQ63N7TBG4jf+4gaUusvu4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708463618; c=relaxed/simple; bh=FNJmbmkZABeentB1LMuka0sAUC6kJtUeR38Sk/SwGr8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SeGO9p1x8zA+0Auc9uURsmRDb6s8A/tZEKu1/Mn6VJuctsHfwmfrHS+/BKHJ8hF6AWfMD9VKsV6iNImrLhzyyLyBHI1TfSMRdEj+D0p8JIzwJWRtjbAO566FhwDtfxc0SZyTcrWYdvRUxbHquiHc9J/F8AFzPuRo7ExaQHZCSDE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lS+ZyOZJ; 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="lS+ZyOZJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98183C433C7; Tue, 20 Feb 2024 21:13:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708463618; bh=FNJmbmkZABeentB1LMuka0sAUC6kJtUeR38Sk/SwGr8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lS+ZyOZJVKUkEwgdhBQHZNURc/LPwfk+gdtWHDqRbEqg0BvMxOu02vpv1Hcp815QO cWz4DlQfwyu1JuTFbajcFmgnKTwOjxnlivhjOea6ZA/DFbnaZAOQAk1IAvJnNW+Wu9 0AnNxBbXVdrZoHWNpzQwi2ME7Ck3ROD96BozQcgc= 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 6.6 100/331] powerpc/kasan: Limit KASAN thread size increase to 32KB Date: Tue, 20 Feb 2024 21:53:36 +0100 Message-ID: <20240220205640.725006471@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240220205637.572693592@linuxfoundation.org> References: <20240220205637.572693592@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 6.6-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 bf5dde1a4114..15c5691dd218 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