lib/vdso: Allow architectures to provide the vdso data pointer

Browse source

On powerpc, __arch_get_vdso_data() clobbers the link register, requiring
the caller to save it.

As the parent function already has to set a stack frame and saves the link
register before calling the C vdso function, retrieving the vdso data
pointer there is less overhead.

Split out the functional code from the __cvdso.*() interfaces into new
static functions which can either be called from the existing interfaces
with the vdso data pointer supplied via __arch_get_vdso_data() or directly
from ASM code.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/abf97996602ef07223fec30c005df78e5ed41b2e.1580399657.git.christophe.leroy@c-s.fr
Link: https://lkml.kernel.org/r/20200207124403.965789141@linutronix.de

...

This commit is contained in:

Christophe Leroy 2020-02-07 13:39:04 +01:00 • committed by Thomas Gleixner

parent 8345228ccf

commit e876f0b69d

1 changed files with 56 additions and 16 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

74

lib/vdso/gettimeofday.c

View file