Re: [PATCH 6.6 000/113] 6.6.91-rc2 review

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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").

Pawan, any hints on what should be done here instead?

thanks,

greg k-h