random: vDSO: minimize and simplify header includes

Depending on the architecture, building a 32-bit vDSO on a 64-bit kernel
is problematic when some system headers are included.

Minimise the amount of headers by moving needed items, such as
__{get,put}_unaligned_t, into dedicated common headers and in general
use more specific headers, similar to what was done in commit
8165b57bca21 ("linux/const.h: Extract common header for vDSO") and
commit 8c59ab839f52 ("lib/vdso: Enable common headers").

On some architectures this results in missing PAGE_SIZE, as was
described by commit 8b3843ae3634 ("vdso/datapage: Quick fix - use
asm/page-def.h for ARM64"), so define this if necessary, in the same way
as done prior by commit cffaefd15a8f ("vdso: Use CONFIG_PAGE_SHIFT in
vdso/datapage.h").

Removing linux/time64.h leads to missing 'struct timespec64' in
x86's asm/pvclock.h. Add a forward declaration of that struct in
that file.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index 0c92db84469d..6e4f8fae3ce9 100644
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -5,6 +5,7 @@
 #include <asm/clocksource.h>
 #include <asm/pvclock-abi.h>
 
+struct timespec64;
 /* some helper functions for xen and kvm pv clock sources */
 u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
 u64 pvclock_clocksource_read_nowd(struct pvclock_vcpu_time_info *src);