[PATCH] LoongArch: Support pointer guard on LoongArch32

[mengqinggang]

Ping.


在 2026/8/10 16:44, mengqinggang 写道:
> LoongArch32 Reduced has no rotri.d/rotri.w instructions.
> Use slli.w/srli.w/or to synthesize the rotation on LoongArch32
> and LoongArch32 Reduced.
>
> Reported-by: Haiyong Sun <sunhaiyong@loongson.cn>
> ---
>   sysdeps/loongarch/__longjmp.S                 |  4 +-
>   sysdeps/loongarch/setjmp.S                    |  4 +-
>   .../sysv/linux/loongarch/pointer_guard-asm.h  | 44 +++++++++++++------
>   3 files changed, 34 insertions(+), 18 deletions(-)
>
> diff --git a/sysdeps/loongarch/__longjmp.S b/sysdeps/loongarch/__longjmp.S
> index 191f03320a..302cb6894a 100644
> --- a/sysdeps/loongarch/__longjmp.S
> +++ b/sysdeps/loongarch/__longjmp.S
> @@ -23,9 +23,9 @@
>   ENTRY (__longjmp)
>   #ifdef PTR_MANGLE
>   	REG_L t0, a0, 0*SZREG
> -	PTR_DEMANGLE (ra, t0, t1)
> +	PTR_DEMANGLE (ra, t0, t1, t2)
>   	REG_L t0, a0, 1*SZREG
> -	PTR_DEMANGLE2 (sp, t0, t1)
> +	PTR_DEMANGLE2 (sp, t0, t1, t2)
>   #else
>   	REG_L ra, a0, 0*SZREG
>   	REG_L sp, a0, 1*SZREG
> diff --git a/sysdeps/loongarch/setjmp.S b/sysdeps/loongarch/setjmp.S
> index 591e0d2709..58c1ee02b2 100644
> --- a/sysdeps/loongarch/setjmp.S
> +++ b/sysdeps/loongarch/setjmp.S
> @@ -31,9 +31,9 @@ END (setjmp)
>   
>   ENTRY (__sigsetjmp)
>   #ifdef PTR_MANGLE
> -	PTR_MANGLE (t0, ra, t1)
> +	PTR_MANGLE (t0, ra, t1, t2)
>   	REG_S t0, a0, 0*SZREG
> -	PTR_MANGLE2 (t0, sp, t1)
> +	PTR_MANGLE2 (t0, sp, t1, t2)
>   	REG_S t0, a0, 1*SZREG
>   #else
>   	REG_S ra, a0, 0*SZREG
> diff --git a/sysdeps/unix/sysv/linux/loongarch/pointer_guard-asm.h b/sysdeps/unix/sysv/linux/loongarch/pointer_guard-asm.h
> index 24e27e4092..006b713f9c 100644
> --- a/sysdeps/unix/sysv/linux/loongarch/pointer_guard-asm.h
> +++ b/sysdeps/unix/sysv/linux/loongarch/pointer_guard-asm.h
> @@ -24,24 +24,40 @@
>         || (!defined SHARED && (IS_IN (libc) \
>         || IS_IN (libpthread))))
>   #  define PTR_MANGLE_LOAD(guard) \
> -  LOAD_LOCAL (guard, __pointer_chk_guard_local);
> +	LOAD_LOCAL (guard, __pointer_chk_guard_local);
>   # else
>   #  define PTR_MANGLE_LOAD(guard) \
> -  LOAD_GLOBAL (guard, __pointer_chk_guard);
> +	LOAD_GLOBAL (guard, __pointer_chk_guard);
>   # endif
> -# define PTR_MANGLE(dst, src, guard) \
> -  PTR_MANGLE_LOAD (guard); \
> -  PTR_MANGLE2 (dst, src, guard);
> -# define PTR_DEMANGLE(dst, src, guard) \
> -  PTR_MANGLE_LOAD (guard); \
> -  PTR_DEMANGLE2 (dst, src, guard);
> +
> +# define PTR_MANGLE(dst, src, guard, tmp) \
> +	PTR_MANGLE_LOAD (guard); \
> +	PTR_MANGLE2 (dst, src, guard, tmp);
> +# define PTR_DEMANGLE(dst, src, guard, tmp) \
> +	PTR_MANGLE_LOAD (guard); \
> +	PTR_DEMANGLE2 (dst, src, guard, tmp);
> +
> +# if __loongarch_grlen == 64
>   /* Use PTR_MANGLE2 for efficiency if guard is already loaded.  */
> -# define PTR_MANGLE2(dst, src, guard) \
> -  xor  dst, src, guard; \
> -  rotri.d  dst, dst, 47;
> -# define PTR_DEMANGLE2(dst, src, guard) \
> -  rotri.d  src, src, 17; \
> -  xor  dst, src, guard;
> +#  define PTR_MANGLE2(dst, src, guard, tmp) \
> +	xor	  tmp, src, guard; \
> +	rotri.d	  dst, tmp, 47;
> +#  define PTR_DEMANGLE2(dst, src, guard, tmp) \
> +	rotri.d	  tmp, src, 17; \
> +	xor	  dst, tmp, guard;
> +# elif __loongarch_grlen == 32 /* __loongarch_grlen == 64 */
> +#  define PTR_MANGLE2(dst, src, guard, tmp) \
> +	xor	  tmp, src, guard; \
> +	slli.w	  dst, tmp, 9; \
> +	srli.w	  tmp, tmp, 23; \
> +	or	  dst, dst, tmp;
> +#  define PTR_DEMANGLE2(dst, src, guard, tmp) \
> +	srli.w	  tmp, src, 9; \
> +	slli.w	  src, src, 23; \
> +	or	  tmp, tmp, src; \
> +	xor	  dst, tmp, guard;
> +# endif /* __loongarch_grlen == 64 */
> +
>   #endif
>   
>   #endif /* POINTER_GUARD_ASM_H */