* Jiri Slaby ([email protected]) wrote:
> On 27. 01. 25, 17:05, Uros Bizjak wrote:
> > This patch declares percpu variables in __seg_gs/__seg_fs named AS
> > and keeps them named AS qualified until they are dereferenced with
> > percpu accessor. This approach enables various compiler check
> > for cross-namespace variable assignments.
> >
> > Signed-off-by: Uros Bizjak <[email protected]>
> > Acked-by: Nadav Amit <[email protected]>
> > Cc: Dennis Zhou <[email protected]>
> > Cc: Tejun Heo <[email protected]>
> > Cc: Christoph Lameter <[email protected]>
> > Cc: Thomas Gleixner <[email protected]>
> > Cc: Ingo Molnar <[email protected]>
> > Cc: Borislav Petkov <[email protected]>
> > Cc: Dave Hansen <[email protected]>
> > Cc: "H. Peter Anvin" <[email protected]>
> > Cc: Linus Torvalds <[email protected]>
> > Cc: Andy Lutomirski <[email protected]>
> > Cc: Brian Gerst <[email protected]>
> > Cc: Peter Zijlstra <[email protected]>
> > ---
> > arch/x86/include/asm/percpu.h | 15 ++++++++++++---
> > 1 file changed, 12 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
> > index 27f668660abe..474d648bca9a 100644
> > --- a/arch/x86/include/asm/percpu.h
> > +++ b/arch/x86/include/asm/percpu.h
> > @@ -95,9 +95,18 @@
> > #endif /* CONFIG_SMP */
> > -#define __my_cpu_type(var) typeof(var) __percpu_seg_override
> > -#define __my_cpu_ptr(ptr) (__my_cpu_type(*(ptr))*)(__force uintptr_t)(ptr)
> > -#define __my_cpu_var(var) (*__my_cpu_ptr(&(var)))
> > +#if defined(CONFIG_USE_X86_SEG_SUPPORT) && defined(USE_TYPEOF_UNQUAL)
> > +# define __my_cpu_type(var) typeof(var)
> > +# define __my_cpu_ptr(ptr) (ptr)
> > +# define __my_cpu_var(var) (var)
> > +
> > +# define __percpu_qual __percpu_seg_override
> > +#else
> > +# define __my_cpu_type(var) typeof(var) __percpu_seg_override
> > +# define __my_cpu_ptr(ptr) (__my_cpu_type(*(ptr))*)(__force uintptr_t)(ptr)
> > +# define __my_cpu_var(var) (*__my_cpu_ptr(&(var)))
> > +#endif
> > +
>
> Another issue with this is this causes all modules in 6.15 are 2-4 times
> (compressed size) bigger:
Oh, is that why config-all kernel is too big?
Dave
> $ ll /usr/lib/modules/*-[0-9]-default/kernel/drivers/atm/atmtcp.ko.zst
> > -rw-r--r--. 1 root root 10325 May 13 11:49
> /usr/lib/modules/6.14.6-2-default/kernel/drivers/atm/atmtcp.ko.zst
> > -rw-r--r--. 1 root root 39677 Jun 2 09:13
> /usr/lib/modules/6.15.0-1-default/kernel/drivers/atm/atmtcp.ko.zst
>
> It's due to larger .BTF section:
> .BTF PROGBITS 0000000000000000 [-00003080-]
> [- 00000000000011a8-] {+00003100+}
> {+ 0000000000012cf8+} 0000000000000000 0 0 1
>
> There are a lot of new BTF types defined in each module like:
> +attribute_group STRUCT
> +backing_dev_info STRUCT
> +bdi_writeback STRUCT
> +bin_attribute STRUCT
> +bio_end_io_t TYPEDEF
> +bio_list STRUCT
> +bio_set STRUCT
> +bio STRUCT
> +bio_vec STRUCT
>
> Reverting this gives me back to normal sizes.
>
> Any ideas?
>
> FTR downstream report:
> https://bugzilla.suse.com/show_bug.cgi?id=1244135
>
> thanks,
> --
> js
> suse labs
>
>
--
-----Open up your eyes, open up your mind, open up your code -------
/ Dr. David Alan Gilbert | Running GNU/Linux | Happy \
\ dave @ treblig.org | | In Hex /
\ _________________________|_____ http://www.treblig.org |_______/
