Commit 9d1869f0 authored by Breno Leitao's avatar Breno Leitao Committed by Will Deacon
Browse files

arm64: remove CONFIG_VMAP_STACK checks from entry code 



With VMAP_STACK now always enabled on arm64, remove all CONFIG_VMAP_STACK
conditionals from entry handling in arch/arm64/kernel/entry-common.c and
arch/arm64/kernel/entry.S.

This change unconditionally includes the bad stack handling and overflow
detection logic, simplifying the code and reflecting the mandatory use of
VMAP_STACK for all arm64 kernel builds.

Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Acked-by: default avatarArd Biesheuvel <ardb@kernel.org>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-8-8de98ca0f91c@debian.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 3e72b9e9

arch/arm64/kernel/entry-common.c

+0 −2
Original line number Diff line number Diff line
@@ -977,7 +977,6 @@ UNHANDLED(el0t, 32, fiq) 
UNHANDLED(el0t, 32, error)

#endif /* CONFIG_COMPAT */



#ifdef CONFIG_VMAP_STACK

asmlinkage void noinstr __noreturn handle_bad_stack(struct pt_regs *regs)

{

	unsigned long esr = read_sysreg(esr_el1);
@@ -986,7 +985,6 @@ asmlinkage void noinstr __noreturn handle_bad_stack(struct pt_regs *regs) 
	arm64_enter_nmi(regs);

	panic_bad_stack(regs, esr, far);

}

#endif /* CONFIG_VMAP_STACK */



#ifdef CONFIG_ARM_SDE_INTERFACE

asmlinkage noinstr unsigned long

arch/arm64/kernel/entry.S

+0 −6
Original line number Diff line number Diff line
@@ -55,7 +55,6 @@ 
	.endif



	sub	sp, sp, #PT_REGS_SIZE

#ifdef CONFIG_VMAP_STACK

	/*

	 * Test whether the SP has overflowed, without corrupting a GPR.

	 * Task and IRQ stacks are aligned so that SP & (1 << THREAD_SHIFT)
@@ -97,7 +96,6 @@ 
	/* We were already on the overflow stack. Restore sp/x0 and carry on. */

	sub	sp, sp, x0

	mrs	x0, tpidrro_el0

#endif

	b	el\el\ht\()_\regsize\()_\label

.org .Lventry_start\@ + 128	// Did we overflow the ventry slot?

	.endm
@@ -540,7 +538,6 @@ SYM_CODE_START(vectors) 
	kernel_ventry	0, t, 32, error		// Error 32-bit EL0

SYM_CODE_END(vectors)



#ifdef CONFIG_VMAP_STACK

SYM_CODE_START_LOCAL(__bad_stack)

	/*

	 * We detected an overflow in kernel_ventry, which switched to the
@@ -568,7 +565,6 @@ SYM_CODE_START_LOCAL(__bad_stack) 
	bl	handle_bad_stack

	ASM_BUG()

SYM_CODE_END(__bad_stack)

#endif /* CONFIG_VMAP_STACK */





	.macro entry_handler el:req, ht:req, regsize:req, label:req
@@ -1003,7 +999,6 @@ SYM_CODE_START(__sdei_asm_handler) 
1:	adr_this_cpu dst=x5, sym=sdei_active_critical_event, tmp=x6

2:	str	x19, [x5]



#ifdef CONFIG_VMAP_STACK

	/*

	 * entry.S may have been using sp as a scratch register, find whether

	 * this is a normal or critical event and switch to the appropriate
@@ -1016,7 +1011,6 @@ SYM_CODE_START(__sdei_asm_handler) 
2:	mov	x6, #SDEI_STACK_SIZE

	add	x5, x5, x6

	mov	sp, x5

#endif



#ifdef CONFIG_SHADOW_CALL_STACK

	/* Use a separate shadow call stack for normal and critical events */