Commit 7a928b32 authored by Pierre-Clément Tosi's avatar Pierre-Clément Tosi Committed by Oliver Upton
Browse files

arm64: Introduce esr_brk_comment, esr_is_cfi_brk 



As it is already used in two places, move esr_comment() to a header for
re-use, with a clearer name.

Introduce esr_is_cfi_brk() to detect kCFI BRK syndromes, currently used
by early_brk64() but soon to also be used by hypervisor code.

Signed-off-by: default avatarPierre-Clément Tosi <ptosi@google.com>
Acked-by: default avatarWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240610063244.2828978-7-ptosi@google.com


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 3c6eb648

arch/arm64/include/asm/esr.h

+11 −0
Original line number Diff line number Diff line
@@ -379,6 +379,11 @@ 
#ifndef __ASSEMBLY__

#include <asm/types.h>



static inline unsigned long esr_brk_comment(unsigned long esr)

{

	return esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;

}



static inline bool esr_is_data_abort(unsigned long esr)

{

	const unsigned long ec = ESR_ELx_EC(esr);
@@ -386,6 +391,12 @@ static inline bool esr_is_data_abort(unsigned long esr) 
	return ec == ESR_ELx_EC_DABT_LOW || ec == ESR_ELx_EC_DABT_CUR;

}



static inline bool esr_is_cfi_brk(unsigned long esr)

{

	return ESR_ELx_EC(esr) == ESR_ELx_EC_BRK64 &&

	       (esr_brk_comment(esr) & ~CFI_BRK_IMM_MASK) == CFI_BRK_IMM_BASE;

}



static inline bool esr_fsc_is_translation_fault(unsigned long esr)

{

	/* Translation fault, level -1 */

arch/arm64/kernel/debug-monitors.c

+1 −3
Original line number Diff line number Diff line
@@ -312,9 +312,7 @@ static int call_break_hook(struct pt_regs *regs, unsigned long esr) 
	 * entirely not preemptible, and we can use rcu list safely here.

	 */

	list_for_each_entry_rcu(hook, list, node) {

		unsigned long comment = esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;



		if ((comment & ~hook->mask) == hook->imm)

		if ((esr_brk_comment(esr) & ~hook->mask) == hook->imm)

			fn = hook->fn;

	}

arch/arm64/kernel/traps.c

+3 −5
Original line number Diff line number Diff line
@@ -1105,8 +1105,6 @@ static struct break_hook ubsan_break_hook = { 
};

#endif



#define esr_comment(esr) ((esr) & ESR_ELx_BRK64_ISS_COMMENT_MASK)



/*

 * Initial handler for AArch64 BRK exceptions

 * This handler only used until debug_traps_init().
@@ -1115,15 +1113,15 @@ int __init early_brk64(unsigned long addr, unsigned long esr, 
		struct pt_regs *regs)

{

#ifdef CONFIG_CFI_CLANG

	if ((esr_comment(esr) & ~CFI_BRK_IMM_MASK) == CFI_BRK_IMM_BASE)

	if (esr_is_cfi_brk(esr))

		return cfi_handler(regs, esr) != DBG_HOOK_HANDLED;

#endif

#ifdef CONFIG_KASAN_SW_TAGS

	if ((esr_comment(esr) & ~KASAN_BRK_MASK) == KASAN_BRK_IMM)

	if ((esr_brk_comment(esr) & ~KASAN_BRK_MASK) == KASAN_BRK_IMM)

		return kasan_handler(regs, esr) != DBG_HOOK_HANDLED;

#endif

#ifdef CONFIG_UBSAN_TRAP

	if ((esr_comment(esr) & ~UBSAN_BRK_MASK) == UBSAN_BRK_IMM)

	if ((esr_brk_comment(esr) & ~UBSAN_BRK_MASK) == UBSAN_BRK_IMM)

		return ubsan_handler(regs, esr) != DBG_HOOK_HANDLED;

#endif

	return bug_handler(regs, esr) != DBG_HOOK_HANDLED;

arch/arm64/kvm/handle_exit.c

+1 −1
Original line number Diff line number Diff line
@@ -423,7 +423,7 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, 
	if (mode != PSR_MODE_EL2t && mode != PSR_MODE_EL2h) {

		kvm_err("Invalid host exception to nVHE hyp!\n");

	} else if (ESR_ELx_EC(esr) == ESR_ELx_EC_BRK64 &&

		   (esr & ESR_ELx_BRK64_ISS_COMMENT_MASK) == BUG_BRK_IMM) {

		   esr_brk_comment(esr) == BUG_BRK_IMM) {

		const char *file = NULL;

		unsigned int line = 0;