Commit bb8e93a2 authored by Mark Rutland's avatar Mark Rutland Committed by Will Deacon
Browse files

arm64: entry: convert SError handlers to C 



For various reasons we'd like to convert the bulk of arm64's exception
triage logic to C. As a step towards that, this patch converts the EL1
and EL0 SError triage logic to C.

Separate C functions are added for the native and compat cases so that
in subsequent patches we can handle native/compat differences in C.

There should be no functional change as a result of this patch.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarJoey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-4-mark.rutland@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent f7c706f0

arch/arm64/include/asm/exception.h

+4 −0
Original line number Diff line number Diff line
@@ -32,8 +32,11 @@ static inline u32 disr_to_esr(u64 disr) 
}



asmlinkage void el1_sync_handler(struct pt_regs *regs);

asmlinkage void el1_error_handler(struct pt_regs *regs);

asmlinkage void el0_sync_handler(struct pt_regs *regs);

asmlinkage void el0_error_handler(struct pt_regs *regs);

asmlinkage void el0_sync_compat_handler(struct pt_regs *regs);

asmlinkage void el0_error_compat_handler(struct pt_regs *regs);



asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs);

asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs);
@@ -57,4 +60,5 @@ void do_cp15instr(unsigned int esr, struct pt_regs *regs); 
void do_el0_svc(struct pt_regs *regs);

void do_el0_svc_compat(struct pt_regs *regs);

void do_ptrauth_fault(struct pt_regs *regs, unsigned int esr);

void do_serror(struct pt_regs *regs, unsigned int esr);

#endif	/* __ASM_EXCEPTION_H */

arch/arm64/kernel/entry-common.c

+32 −0
Original line number Diff line number Diff line
@@ -279,6 +279,16 @@ asmlinkage void noinstr el1_sync_handler(struct pt_regs *regs) 
	}

}



asmlinkage void noinstr el1_error_handler(struct pt_regs *regs)

{

	unsigned long esr = read_sysreg(esr_el1);



	local_daif_restore(DAIF_ERRCTX);

	arm64_enter_nmi(regs);

	do_serror(regs, esr);

	arm64_exit_nmi(regs);

}



asmlinkage void noinstr enter_from_user_mode(void)

{

	lockdep_hardirqs_off(CALLER_ADDR0);
@@ -468,6 +478,23 @@ asmlinkage void noinstr el0_sync_handler(struct pt_regs *regs) 
	}

}



static void __el0_error_handler_common(struct pt_regs *regs)

{

	unsigned long esr = read_sysreg(esr_el1);



	enter_from_user_mode();

	local_daif_restore(DAIF_ERRCTX);

	arm64_enter_nmi(regs);

	do_serror(regs, esr);

	arm64_exit_nmi(regs);

	local_daif_restore(DAIF_PROCCTX);

}



asmlinkage void noinstr el0_error_handler(struct pt_regs *regs)

{

	__el0_error_handler_common(regs);

}



#ifdef CONFIG_COMPAT

static void noinstr el0_cp15(struct pt_regs *regs, unsigned long esr)

{
@@ -526,4 +553,9 @@ asmlinkage void noinstr el0_sync_compat_handler(struct pt_regs *regs) 
		el0_inv(regs, esr);

	}

}



asmlinkage void noinstr el0_error_compat_handler(struct pt_regs *regs)

{

	__el0_error_handler_common(regs);

}

#endif /* CONFIG_COMPAT */

arch/arm64/kernel/entry.S

+5 −11
Original line number Diff line number Diff line
@@ -757,7 +757,9 @@ SYM_CODE_END(el0_fiq_compat) 


SYM_CODE_START_LOCAL_NOALIGN(el0_error_compat)

	kernel_entry 0, 32

	b	el0_error_naked

	mov	x0, sp

	bl	el0_error_compat_handler

	b	ret_to_user

SYM_CODE_END(el0_error_compat)

#endif
@@ -778,23 +780,15 @@ SYM_CODE_END(el0_fiq) 


SYM_CODE_START_LOCAL(el1_error)

	kernel_entry 1

	mrs	x1, esr_el1

	enable_dbg

	mov	x0, sp

	bl	do_serror

	bl	el1_error_handler

	kernel_exit 1

SYM_CODE_END(el1_error)



SYM_CODE_START_LOCAL(el0_error)

	kernel_entry 0

el0_error_naked:

	mrs	x25, esr_el1

	user_exit_irqoff

	enable_dbg

	mov	x0, sp

	mov	x1, x25

	bl	do_serror

	enable_daif

	bl	el0_error_handler

	b	ret_to_user

SYM_CODE_END(el0_error)

arch/arm64/kernel/traps.c

+1 −5
Original line number Diff line number Diff line
@@ -869,15 +869,11 @@ bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned int esr) 
	}

}



asmlinkage void noinstr do_serror(struct pt_regs *regs, unsigned int esr)

void do_serror(struct pt_regs *regs, unsigned int esr)

{

	arm64_enter_nmi(regs);



	/* non-RAS errors are not containable */

	if (!arm64_is_ras_serror(esr) || arm64_is_fatal_ras_serror(regs, esr))

		arm64_serror_panic(regs, esr);



	arm64_exit_nmi(regs);

}



/* GENERIC_BUG traps */