Re: linux-next: build failure after merge of the vfs tree

[Al Viro]

On Tue, Jan 05, 2021 at 09:36:16AM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the vfs tree, today's linux-next build (x86_64 allmodconfig)
> failed like this:
> 
> In file included from arch/x86/include/asm/elf.h:8,
>                  from include/linux/elf.h:6,
>                  from include/linux/elfcore-compat.h:5,
>                  from fs/compat_binfmt_elf.c:17:
> fs/binfmt_elf.c: In function 'fill_thread_core_info':
> arch/x86/include/asm/elfcore-compat.h:23:20: error: 'TIF_X32' undeclared (first use in this function)
>    23 |  (test_thread_flag(TIF_X32) \
>       |                    ^~~~~~~
> include/linux/thread_info.h:116:45: note: in definition of macro 'test_thread_flag'
>   116 |  test_ti_thread_flag(current_thread_info(), flag)
>       |                                             ^~~~
> fs/binfmt_elf.c:1744:5: note: in expansion of macro 'PRSTATUS_SIZE'
>  1744 |     PRSTATUS_SIZE, &t->prstatus);
>       |     ^~~~~~~~~~~~~
> arch/x86/include/asm/elfcore-compat.h:23:20: note: each undeclared identifier is reported only once for each function it appears in
>    23 |  (test_thread_flag(TIF_X32) \
>       |                    ^~~~~~~
> include/linux/thread_info.h:116:45: note: in definition of macro 'test_thread_flag'
>   116 |  test_ti_thread_flag(current_thread_info(), flag)
>       |                                             ^~~~
> fs/binfmt_elf.c:1744:5: note: in expansion of macro 'PRSTATUS_SIZE'
>  1744 |     PRSTATUS_SIZE, &t->prstatus);
>       |     ^~~~~~~~~~~~~
> 
> Caused by commit
> 
>   5a9b7f382248 ("binfmt_elf: partially sanitize PRSTATUS_SIZE and SET_PR_FPVALID")
> 
> or maybe commit
> 
>   9866fcab1c65 ("[elfcore-compat][amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properly")

Arrgh...  It's 8d71d2bf6efe ("x86: Reclaim TIF_IA32 and TIF_X32") in mainline, actually.
Mea culpa ;-/