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smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wz+6uRX0; 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="wz+6uRX0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2F26C4CEE4; Mon, 19 May 2025 15:27:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1747668453; bh=t+V18x9K5U3txXXfD8+PUaO/b5cpwqu1b7n9tWAOFPM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=wz+6uRX0un26SiQI4WLnR7eoKrHilQeIdCP3yUyIP5wyq8PMHyQV4mxaxyaiyg+QZ 5fOSpYU9hlHSVPVq/3HXij8x9xlYI69sTdFWSzoMfEDxsDp8mMbVTzfq3aNJZnEWkZ GhB5Nb4pdGlBlGDbZGwm2/nICqffO4CBqxcd4RCM= Date: Mon, 19 May 2025 17:27:30 +0200 From: Greg Kroah-Hartman To: Pawan Gupta Cc: Natanael Copa , Guenter Roeck , Harshit Mogalapalli , stable@vger.kernel.org, patches@lists.linux.dev, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, shuah@kernel.org, patches@kernelci.org, lkft-triage@lists.linaro.org, pavel@denx.de, jonathanh@nvidia.com, f.fainelli@gmail.com, sudipm.mukherjee@gmail.com, srw@sladewatkins.net, rwarsow@gmx.de, conor@kernel.org, hargar@microsoft.com, broonie@kernel.org, Darren Kenny Subject: Re: [PATCH 6.6 000/113] 6.6.91-rc2 review Message-ID: <2025051931-hardy-had-44a3@gregkh> References: <20250514125617.240903002@linuxfoundation.org> <861004b4-e036-4306-b129-252b9cb983c7@oracle.com> <2025051440-sturdily-dragging-3843@gregkh> <9af6afb1-9d91-48ea-a212-bcd6d1a47203@oracle.com> <2025051527-travesty-shape-0e3b@gregkh> <20250515152557.a4q2cqab4uvhnpia@desk> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250515152557.a4q2cqab4uvhnpia@desk> On Thu, May 15, 2025 at 08:25:57AM -0700, Pawan Gupta wrote: > On Thu, May 15, 2025 at 07:35:26AM +0200, Greg Kroah-Hartman wrote: > > On Wed, May 14, 2025 at 01:49:06PM -0700, Guenter Roeck wrote: > > > On 5/14/25 13:33, Harshit Mogalapalli wrote: > > > > Hi Greg, > > > > > > > > On 15/05/25 01:35, Greg Kroah-Hartman wrote: > > > > > On Thu, May 15, 2025 at 12:29:40AM +0530, Harshit Mogalapalli wrote: > > > > > > Hi Greg, > > > > > > On 14/05/25 18:34, Greg Kroah-Hartman wrote: > > > > > > > This is the start of the stable review cycle for the 6.6.91 release. > > > > > > > There are 113 patches in this series, all will be posted as a response > > > > > > > to this one.  If anyone has any issues with these being applied, please > > > > > > > let me know. > > > > > > > > > > > > > > Responses should be made by Fri, 16 May 2025 12:55:38 +0000. > > > > > > > Anything received after that time might be too late. > > > > > > > > > > > > ld: vmlinux.o: in function `patch_retpoline': > > > > > > alternative.c:(.text+0x3b6f1): undefined reference to `module_alloc' > > > > > > make[2]: *** [scripts/Makefile.vmlinux:37: vmlinux] Error 1 > > > > > > > > > > > > We see this build error in 6.6.91-rc2 tag. > > > > > > > > > > What is odd about your .config?  Have a link to it?  I can't duplicate > > > > > it here on my builds. > > > > > > > > > > > > > So this is a config where CONFIG_MODULES is unset(!=y) -- with that we could reproduce it on defconfig + disabling CONFIG_MODULES as well. > > > > > > > > > > Key is the combination of CONFIG_MODULES=n with CONFIG_MITIGATION_ITS=y. > > > > Ah, this is due to the change in its_alloc() for 6.6.y and 6.1.y by the > > call to module_alloc() instead of execmem_alloc() in the backport of > > 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches"). > > Sorry for the trouble. I wish I had a test to catch problems like this. The > standard config targets defconfig, allyesconfig, allnoconfig, etc. do not > expose such issues. The only thing that comes close is randconfig. > > CONFIG_MODULES=n is not a common setting, I wonder how people find such > issues? (trying to figure out how to prevent such issues in future). > > > Pawan, any hints on what should be done here instead? > > Since dynamic thunks are not possible without CONFIG_MODULES, one option is > to adjust the already in 6.6.91-rc2 patch 9f35e331144a (x86/its: Fix build > errors when CONFIG_MODULES=n) to also bring the ITS thunk allocation under > CONFIG_MODULES. > > I am not seeing any issue with below build and boot test: > > #!/bin/bash -ex > > ./scripts/config --disable CONFIG_MODULES > ./scripts/config --disable CONFIG_MITIGATION_ITS > # https://github.com/arighi/virtme-ng > vng -b > vng -- lscpu > > # main test > ./scripts/config --disable CONFIG_MODULES > ./scripts/config --enable CONFIG_MITIGATION_ITS > vng -b > vng -- lscpu > > ./scripts/config --enable CONFIG_MODULES > ./scripts/config --disable CONFIG_MITIGATION_ITS > vng -b > vng -- lscpu > > ./scripts/config --enable CONFIG_MODULES > ./scripts/config --enable CONFIG_MITIGATION_ITS > vng -b > vng -- lscpu > > echo "PASS" > > Similar change is required for 6.1 and 5.15 as well. 6.12 is fine because > it uses execmem_alloc(). > > --- 8< --- > From: Pawan Gupta > Subject: [PATCH 6.6] x86/its: Fix build errors when CONFIG_MODULES=n > > From: Eric Biggers > > commit 9f35e33144ae5377d6a8de86dd3bd4d995c6ac65 upstream. > > Fix several build errors when CONFIG_MODULES=n, including the following: > > ../arch/x86/kernel/alternative.c:195:25: error: incomplete definition of type 'struct module' > 195 | for (int i = 0; i < mod->its_num_pages; i++) { > > [ pawan: backport: Bring ITS dynamic thunk code under CONFIG_MODULES ] > > Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") > Cc: stable@vger.kernel.org > Signed-off-by: Eric Biggers > Acked-by: Dave Hansen > Tested-by: Steven Rostedt (Google) > Reviewed-by: Alexandre Chartre > Signed-off-by: Linus Torvalds > Signed-off-by: Greg Kroah-Hartman > --- > arch/x86/kernel/alternative.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c > index 6085919d3b3e..c6d9a3882ec8 100644 > --- a/arch/x86/kernel/alternative.c > +++ b/arch/x86/kernel/alternative.c > @@ -129,6 +129,7 @@ const unsigned char * const x86_nops[ASM_NOP_MAX+1] = > > #ifdef CONFIG_MITIGATION_ITS > > +#ifdef CONFIG_MODULES > static struct module *its_mod; > static void *its_page; > static unsigned int its_offset; > @@ -244,7 +245,16 @@ static void *its_allocate_thunk(int reg) > return thunk; > } > > -#endif > +#else /* CONFIG_MODULES */ > + > +static void *its_allocate_thunk(int reg) > +{ > + return NULL; > +} > + > +#endif /* CONFIG_MODULES */ > + > +#endif /* CONFIG_MITIGATION_ITS */ > > /* > * Fill the buffer with a single effective instruction of size @len. > -- > 2.34.1 > This looks to still be causing problems, see these two reports of build problems with the latest 6.1 and 6.6 releases with this commit in it: https://lore.kernel.org/r/20250519164717.18738b4e@ncopa-desktop https://lore.kernel.org/r/2f1ae598-0339-4e17-8156-03e8525a213d@roeck-us.net thanks, greg k-h