[PATCH] y2038: uapi: use 64-bit __kernel_old_timespec::tv_nsec on x32

[Thomas Weißschuh]

'struct __kernel_old_timespec' represents the 'native' time ABI of the
kernel. On 32-bit systems it uses 32-bit fields and on 64-bit systems
it uses 64-bit fields.
However the x86 x32 ABI uses the 64-bit time ABI natively.
This is correctly handled for the 'tv_sec' fields, through the typedefs
of '__kernel_old_time_t' -> '__kernel_long_t' -> 'long long'. The same
treatment was missed for 'tv_nsec'.

In practice this might not make much of a difference as the value of
'tv_nsec' will always fit into 32 bits and the missing bits fall
into the padding of the structure.
When introspecting the structure however, a difference can be observed.

Switch to 64-bit tv_nsec on x32.
No other architectures or ABIs are affected.

Fixes: 94c467ddb273 ("y2038: add __kernel_old_timespec and __kernel_old_time_t")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
---
Arnd, can you take this?

I'm not entirely sure if this warrants a stable backport.
---
 include/uapi/linux/time_types.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/uapi/linux/time_types.h b/include/uapi/linux/time_types.h
index bcc0002115d3..03a0d8aaadca 100644
--- a/include/uapi/linux/time_types.h
+++ b/include/uapi/linux/time_types.h
@@ -30,7 +30,7 @@ struct __kernel_old_timeval {
 
 struct __kernel_old_timespec {
 	__kernel_old_time_t	tv_sec;		/* seconds */
-	long			tv_nsec;	/* nanoseconds */
+	__kernel_long_t		tv_nsec;	/* nanoseconds */
 };
 
 struct __kernel_old_itimerval {

---
base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
change-id: 20260224-timespec-x32-0f9c15531320

Best regards,
-- 
Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>