[PATCH] LoongArch: Don't define __ARCH_WANT_NEW_STAT for LA32

[PATCH] LoongArch: Don't define __ARCH_WANT_NEW_STAT for LA32

[Xi Ruoyao]

While on LA64 we had added __ARCH_WANT_NEW_STAT back for technological
aesthetics reason, on LA32 the newstat family suffers Y2038 issue and it
should not be used at all, as the commit 82b355d161c9 ("y2038: Remove
newstat family from default syscall set") has already pointed out.

Fixes: 14338e631afd ("LoongArch: Adjust system call for 32BIT/64BIT")
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
---
 arch/loongarch/include/asm/unistd.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/loongarch/include/asm/unistd.h b/arch/loongarch/include/asm/unistd.h
index e2c0f3d86c7b..4a7e4a6b6627 100644
--- a/arch/loongarch/include/asm/unistd.h
+++ b/arch/loongarch/include/asm/unistd.h
@@ -8,7 +8,10 @@
 
 #include <uapi/asm/unistd.h>
 
+#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
 #define __ARCH_WANT_NEW_STAT
+#endif
+
 #define __ARCH_WANT_SYS_CLONE
 
 #define NR_syscalls (__NR_syscalls)
-- 
2.52.0

Re: [PATCH] LoongArch: Don't define __ARCH_WANT_NEW_STAT for LA32

[Jiaxun Yang]

On Mon, 15 Dec 2025, at 11:34 AM, Xi Ruoyao wrote:
> While on LA64 we had added __ARCH_WANT_NEW_STAT back for technological
> aesthetics reason, on LA32 the newstat family suffers Y2038 issue and it
> should not be used at all, as the commit 82b355d161c9 ("y2038: Remove
> newstat family from default syscall set") has already pointed out.
>
> Fixes: 14338e631afd ("LoongArch: Adjust system call for 32BIT/64BIT")
> Signed-off-by: Xi Ruoyao <xry111@xry111.site>

That makes sense, we certainly don't want any y2038 syscall.

Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>

Thanks!

> ---
>  arch/loongarch/include/asm/unistd.h | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/arch/loongarch/include/asm/unistd.h 
> b/arch/loongarch/include/asm/unistd.h
> index e2c0f3d86c7b..4a7e4a6b6627 100644
> --- a/arch/loongarch/include/asm/unistd.h
> +++ b/arch/loongarch/include/asm/unistd.h
> @@ -8,7 +8,10 @@
> 
>  #include <uapi/asm/unistd.h>
> 
> +#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
>  #define __ARCH_WANT_NEW_STAT
> +#endif
> +
>  #define __ARCH_WANT_SYS_CLONE
> 
>  #define NR_syscalls (__NR_syscalls)
> -- 
> 2.52.0

-- 
- Jiaxun

Re: [PATCH] LoongArch: Don't define __ARCH_WANT_NEW_STAT for LA32

[Arnd Bergmann]

On Mon, Dec 15, 2025, at 04:34, Xi Ruoyao wrote:
> While on LA64 we had added __ARCH_WANT_NEW_STAT back for technological
> aesthetics reason, on LA32 the newstat family suffers Y2038 issue and it
> should not be used at all, as the commit 82b355d161c9 ("y2038: Remove
> newstat family from default syscall set") has already pointed out.
>
> Fixes: 14338e631afd ("LoongArch: Adjust system call for 32BIT/64BIT")
> Signed-off-by: Xi Ruoyao <xry111@xry111.site>

The patch looks good to me.

Note that unlike the referenced 82b355d161c9 patch, this is no
longer needed for correctness, since modern kernels generate
the asm/unistd.h from the syscall.tbl based on 
arch/loongarch/kernel/Makefile.syscalls, which leaves out the
references to newstat.

The patch is still useful of course, but only to slightly reduce
the size of the kernel image by eliminating dead code.

     Arnd

Ping: [PATCH] LoongArch: Don't define __ARCH_WANT_NEW_STAT for LA32

[Xi Ruoyao]

Ping.

On Mon, 2025-12-15 at 11:34 +0800, Xi Ruoyao wrote:
> While on LA64 we had added __ARCH_WANT_NEW_STAT back for technological
> aesthetics reason, on LA32 the newstat family suffers Y2038 issue and it
> should not be used at all, as the commit 82b355d161c9 ("y2038: Remove
> newstat family from default syscall set") has already pointed out.
> 
> Fixes: 14338e631afd ("LoongArch: Adjust system call for 32BIT/64BIT")
> Signed-off-by: Xi Ruoyao <xry111@xry111.site>
> ---
>  arch/loongarch/include/asm/unistd.h | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/loongarch/include/asm/unistd.h b/arch/loongarch/include/asm/unistd.h
> index e2c0f3d86c7b..4a7e4a6b6627 100644
> --- a/arch/loongarch/include/asm/unistd.h
> +++ b/arch/loongarch/include/asm/unistd.h
> @@ -8,7 +8,10 @@
>  
>  #include <uapi/asm/unistd.h>
>  
> +#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
>  #define __ARCH_WANT_NEW_STAT
> +#endif
> +
>  #define __ARCH_WANT_SYS_CLONE
>  
>  #define NR_syscalls (__NR_syscalls)

-- 
Xi Ruoyao <xry111@xry111.site>