Re: [PATCH] random: vDSO: Redefine PAGE_SIZE and PAGE_MASK

From
Vincenzo Frascino <vincenzo.frascino@arm.com>
Date
2024-08-29 15:34:56
Also in
linux-arch, lkml
Reply to
Christophe Leroy, 2024-08-29
...

quoted
quoted
Without linux/array_size.h:

   VDSO32C arch/powerpc/kernel/vdso/vgetrandom-32.o
In file included from <command-line>:
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c: In function
'__cvdso_getrandom_data':
/home/chleroy/linux-powerpc/lib/vdso/getrandom.c:89:40: error: implicit
If this is the case, those headers should be defined for the powerpc
implementation only. The generic implementation should be interpreted as the
minimum common denominator in between all the architectures for what concerns
the headers.
Sorry, I disagree. You can't rely on necessary headers being included indirectly
by other arch specific headers. getrandom.c uses ARRAY_SIZE(), it must include
the header that defines ARRAY_SIZE().

At the moment, on x86 you get linux/array.h by change through the following
chain, that the reason why the build doesn't break:

In file included from ./include/linux/kernel.h:16,
                 from ./include/linux/cpumask.h:11,
                 from ./arch/x86/include/asm/cpumask.h:5,
                 from ./arch/x86/include/asm/msr.h:11,
                 from ./arch/x86/include/asm/vdso/gettimeofday.h:19,
                 from ./include/vdso/datapage.h:164,
                 from arch/x86/entry/vdso/../../../../lib/vdso/getrandom.c:9,

From my point of view you can't expect such a chain from each architecture.
--->8---
I can't see which header provides you with min_t() or ARRAY_SIZE().
Good point, this needs to be addressed by my patch, I will extend it, do some
more testing and post it again next week.

--->8---


As I explained in my other email (snippet above), my patch should address the
cases of ARRAY_SIZE() and min_t() which are directly used by getrandom.c. My
comment here refers to the cases not directly used by getrandom.c or the Generic
vDSO library more in general (if any).

Hope this clarifies.
Christophe
-- 
Regards,
Vincenzo
Thread (21 messages) 21 messages, 5 authors, last reply 2024-08-29
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