Re: [GIT PULL] x86/mm changes for v6.8

From: Ingo Molnar
Date: Tue Jan 09 2024 - 03:37:56 EST



* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Mon, 8 Jan 2024 at 03:35, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> >
> > - Robustify pfn_to_kaddr()
> >
> > - Improve the __untagged_addr() code: RIP-relative addresses are fine these days
> > and generate better code, and update misleading/outdated comments as well.
>
> This does not even compile for me.
>
> arch/x86/include/asm/uaccess_64.h: In function ‘__untagged_addr’:
> arch/x86/include/asm/uaccess_64.h:25:28: error: implicit declaration
> of function ‘__my_cpu_var’; did you mean ‘put_cpu_var’?
> [-Werror=implicit-function-declaration]
>
> WTH?
>
> Maybe this has worked in your tree by mistake because there was some
> branch dependency that just happened to work out because you had
> merged things in a different order.
>
> But that would very much not be ok regardless. Those branches should
> be tested independently, and clearly they were not.

Sorry about that and agreed. Indeed the build failure was hidden by another
branch, and while I did test-build and test-boot the x86/mm branch before
sending it out, but my test config didn't have CONFIG_ADDRESS_MASKING=y ...
which ... masked the build failure. The bots that do per-tree testing
didn't catch this either.

I've now sorted it out in our trees, will send the new x86/mm in a few days.

Thanks,

Ingo