Commit 9dc232a8 authored by Reiji Watanabe's avatar Reiji Watanabe Committed by Will Deacon
Browse files

arm64: arm64_ftr_reg->name may not be a human-readable string 



The id argument of ARM64_FTR_REG_OVERRIDE() is used for two purposes:
one as the system register encoding (used for the sys_id field of
__ftr_reg_entry), and the other as the register name (stringified
and used for the name field of arm64_ftr_reg), which is debug
information. The id argument is supposed to be a macro that
indicates an encoding of the register (eg. SYS_ID_AA64PFR0_EL1, etc).

ARM64_FTR_REG(), which also has the same id argument,
uses ARM64_FTR_REG_OVERRIDE() and passes the id to the macro.
Since the id argument is completely macro-expanded before it is
substituted into a macro body of ARM64_FTR_REG_OVERRIDE(),
the stringified id in the body of ARM64_FTR_REG_OVERRIDE is not
a human-readable register name, but a string of numeric bitwise
operations.

Fix this so that human-readable register names are available as
debug information.

Fixes: 8f266a5d ("arm64: cpufeature: Add global feature override facility")
Signed-off-by: default avatarReiji Watanabe <reijiw@google.com>
Reviewed-by: default avatarOliver Upton <oupton@google.com>
Acked-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211101045421.2215822-1-reijiw@google.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent e6359798

arch/arm64/kernel/cpufeature.c

+7 −3
Original line number Diff line number Diff line
@@ -573,15 +573,19 @@ static const struct arm64_ftr_bits ftr_raz[] = { 
	ARM64_FTR_END,

};



#define ARM64_FTR_REG_OVERRIDE(id, table, ovr) {		\

#define __ARM64_FTR_REG_OVERRIDE(id_str, id, table, ovr) {	\

		.sys_id = id,					\

		.reg = 	&(struct arm64_ftr_reg){		\

			.name = #id,				\

			.name = id_str,				\

			.override = (ovr),			\

			.ftr_bits = &((table)[0]),		\

	}}



#define ARM64_FTR_REG(id, table) ARM64_FTR_REG_OVERRIDE(id, table, &no_override)

#define ARM64_FTR_REG_OVERRIDE(id, table, ovr)	\

	__ARM64_FTR_REG_OVERRIDE(#id, id, table, ovr)



#define ARM64_FTR_REG(id, table)		\

	__ARM64_FTR_REG_OVERRIDE(#id, id, table, &no_override)



struct arm64_ftr_override __ro_after_init id_aa64mmfr1_override;

struct arm64_ftr_override __ro_after_init id_aa64pfr1_override;