Re: [PATCH v3 14/23] ARM: drop arm_fixup_vectors()

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hi,

On 1/8/26 4:50 PM, Sascha Hauer wrote:
> Add the missing "ax" flag for the exception table. With this the jumps
> in the exception table are correctly relocated and we no longer have to
> fix them up during runtime. Remove the now unnecessary
> arm_fixup_vectors().

Splendid!

> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

Cheers,
Ahmad

> ---
>  arch/arm/cpu/exceptions_32.S       | 54 +++++---------------------------------
>  arch/arm/cpu/interrupts_32.c       |  5 +---
>  arch/arm/cpu/mmu_32.c              |  2 --
>  arch/arm/cpu/no-mmu.c              |  2 --
>  arch/arm/include/asm/barebox-arm.h |  4 ---
>  5 files changed, 8 insertions(+), 59 deletions(-)
> 
> diff --git a/arch/arm/cpu/exceptions_32.S b/arch/arm/cpu/exceptions_32.S
> index dc3d42663cbedd37947e27d449eb4ac8c3d8c3f1..68eb696fc7b78924156172a8867d3c9ed1dce588 100644
> --- a/arch/arm/cpu/exceptions_32.S
> +++ b/arch/arm/cpu/exceptions_32.S
> @@ -127,58 +127,18 @@ fiq:
>  	bad_save_user_regs
>  	bl 	do_fiq
>  
> -#ifdef CONFIG_ARM_EXCEPTIONS
> -/*
> - * With relocatable binary support the runtime exception vectors do not match
> - * the addresses in the binary. We have to fix them up during runtime
> - */
> -ENTRY(arm_fixup_vectors)
> -	ldr	r0, =undefined_instruction
> -	ldr	r1, =_undefined_instruction
> -	str	r0, [r1]
> -	ldr	r0, =software_interrupt
> -	ldr	r1, =_software_interrupt
> -	str	r0, [r1]
> -	ldr	r0, =prefetch_abort
> -	ldr	r1, =_prefetch_abort
> -	str	r0, [r1]
> -	ldr	r0, =data_abort
> -	ldr	r1, =_data_abort
> -	str	r0, [r1]
> -	ldr	r0, =irq
> -	ldr	r1, =_irq
> -	str	r0, [r1]
> -	ldr	r0, =fiq
> -	ldr	r1, =_fiq
> -	str	r0, [r1]
> -	bx	lr
> -ENDPROC(arm_fixup_vectors)
> -#endif
> -
> -.section .text_exceptions
> +.section .text_exceptions, "ax"
>  .globl extable
>  extable:
>  1:	b 1b				/* barebox_arm_reset_vector */
>  #ifdef CONFIG_ARM_EXCEPTIONS
> -	ldr pc, _undefined_instruction	/* undefined instruction */
> -	ldr pc, _software_interrupt	/* software interrupt (SWI) */
> -	ldr pc, _prefetch_abort		/* prefetch abort */
> -	ldr pc, _data_abort		/* data abort */
> +	ldr pc, =undefined_instruction	/* undefined instruction */
> +	ldr pc, =software_interrupt	/* software interrupt (SWI) */
> +	ldr pc, =prefetch_abort		/* prefetch abort */
> +	ldr pc, =data_abort		/* data abort */
>  1:	b 1b				/* (reserved) */
> -	ldr pc, _irq			/* irq (interrupt) */
> -	ldr pc, _fiq			/* fiq (fast interrupt) */
> -.globl _undefined_instruction
> -_undefined_instruction: .word undefined_instruction
> -.globl _software_interrupt
> -_software_interrupt: .word software_interrupt
> -.globl _prefetch_abort
> -_prefetch_abort: .word prefetch_abort
> -.globl _data_abort
> -_data_abort: .word data_abort
> -.globl _irq
> -_irq: .word irq
> -.globl _fiq
> -_fiq: .word fiq
> +	ldr pc, =irq			/* irq (interrupt) */
> +	ldr pc, =fiq			/* fiq (fast interrupt) */
>  #else
>  1:	b 1b				/* undefined instruction */
>  1:	b 1b				/* software interrupt (SWI) */
> diff --git a/arch/arm/cpu/interrupts_32.c b/arch/arm/cpu/interrupts_32.c
> index 0b88db10fe487378fe08018701bc672f63139fc1..af2231f2a78059f7dc6b4a786a384fb870e9f14c 100644
> --- a/arch/arm/cpu/interrupts_32.c
> +++ b/arch/arm/cpu/interrupts_32.c
> @@ -231,10 +231,8 @@ static __maybe_unused int arm_init_vectors(void)
>  	 * First try to use the vectors where they actually are, works
>  	 * on ARMv7 and later.
>  	 */
> -	if (!set_vector_table((unsigned long)__exceptions_start)) {
> -		arm_fixup_vectors();
> +	if (!set_vector_table((unsigned long)__exceptions_start))
>  		return 0;
> -	}
>  
>  	/*
>  	 * Next try high vectors at 0xffff0000.
> @@ -265,6 +263,5 @@ void arm_pbl_init_exceptions(void)
>  		return;
>  
>  	set_vbar((unsigned long)__exceptions_start);
> -	arm_fixup_vectors();
>  }
>  #endif
> diff --git a/arch/arm/cpu/mmu_32.c b/arch/arm/cpu/mmu_32.c
> index 981202b789befbd04e212f48490aebb41dfb6b98..1d2ead9160cf3b921c2900d4edaad0d465f636d9 100644
> --- a/arch/arm/cpu/mmu_32.c
> +++ b/arch/arm/cpu/mmu_32.c
> @@ -534,8 +534,6 @@ void create_vector_table(unsigned long adr)
>  			      get_pte_flags(MAP_CACHED), true);
>  	}
>  
> -	arm_fixup_vectors();
> -
>  	memset(vectors, 0, PAGE_SIZE);
>  	memcpy(vectors, __exceptions_start, __exceptions_stop - __exceptions_start);
>  }
> diff --git a/arch/arm/cpu/no-mmu.c b/arch/arm/cpu/no-mmu.c
> index c4ef5d1f9d55136d606c244309dbeeb8fd988784..8e00cffebfd9193a45f5b5ab1863e4e6b13464d8 100644
> --- a/arch/arm/cpu/no-mmu.c
> +++ b/arch/arm/cpu/no-mmu.c
> @@ -58,8 +58,6 @@ static int nommu_v7_vectors_init(void)
>  	cr &= ~CR_V;
>  	set_cr(cr);
>  
> -	arm_fixup_vectors();
> -
>  	vectors = xmemalign(PAGE_SIZE, PAGE_SIZE);
>  	memset(vectors, 0, PAGE_SIZE);
>  	memcpy(vectors, __exceptions_start, __exceptions_size);
> diff --git a/arch/arm/include/asm/barebox-arm.h b/arch/arm/include/asm/barebox-arm.h
> index e1d89d5684d36f003ba8da3651ae86bda1d9b34c..99f82311945ceb0d06ef9e36ba34a9be54f1ae8e 100644
> --- a/arch/arm/include/asm/barebox-arm.h
> +++ b/arch/arm/include/asm/barebox-arm.h
> @@ -45,12 +45,8 @@ unsigned long arm_mem_membase_get(void);
>  unsigned long arm_mem_endmem_get(void);
>  
>  #ifdef CONFIG_ARM_EXCEPTIONS
> -void arm_fixup_vectors(void);
>  ulong arm_get_vector_table(void);
>  #else
> -static inline void arm_fixup_vectors(void)
> -{
> -}
>  static inline ulong arm_get_vector_table(void)
>  {
>  	return ~0;
> 

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