x86/percpu: Do not use this_cpu_read_stable_8() for 32-bit targets

Browse source

this_cpu_read_stable() macro uses __pcpu_size_call_return()
that unconditionally calls this_cpu_read_stable_8() also for
32-bit targets. This usage is ivalid as it will result in the
generation of 64-bit MOVQ instruction on 32-bit targets via
percpu_stable_op() macro.

Since there is no generic support for this_cpu_read_stable_8() for
32-bit targets, the patch defines this_cpu_read_stable_8() to
BUILD_BUG() when CONFIG_X86_64 is not defined. This way, we are
sure that this_cpu_read_stable_8() won't actually be used for
32-bit targets, but it is still defined to prevent build failure.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240324212014.310189-1-ubizjak@gmail.com

...

This commit is contained in:

Uros Bizjak 2024-03-24 22:19:45 +01:00 • committed by Ingo Molnar

parent 4e5b0e8003

commit b90169b42a

1 changed files with 9 additions and 4 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

13

arch/x86/include/asm/percpu.h

View file