Re: [PATCH v5 10/22] powerpc/syscall: Use is_compat_task()

Nicholas Piggin
2021-02-09T01:30:05Z

Excerpts from Christophe Leroy's message of February 9, 2021 1:10 am:
> Instead of hard comparing task flags with _TIF_32BIT, use
> is_compat_task(). The advantage is that it returns 0 on PPC32
> allthough _TIF_32BIT is always set.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

> ---
> arch/powerpc/kernel/interrupt.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
> index 2dac4d2bb1cf..46fd195ca659 100644
> --- a/arch/powerpc/kernel/interrupt.c
> +++ b/arch/powerpc/kernel/interrupt.c
> @@ -2,6 +2,8 @@
>
> #include <linux/context_tracking.h>
> #include <linux/err.h>
> +#include <linux/compat.h>
> +
> #include <asm/asm-prototypes.h>
> #include <asm/kup.h>
> #include <asm/cputime.h>
> @@ -118,7 +120,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
> /* May be faster to do array_index_nospec? */
> barrier_nospec();
>
> - if (unlikely(is_32bit_task())) {
> + if (unlikely(is_compat_task())) {
> f = (void *)compat_sys_call_table[r0];
>
> r3 &= 0x00000000ffffffffULL;
> --
> 2.25.0
>
>