This is a note to let you know that I've just added the patch titled arm64: arm64_ftr_reg->name may not be a human-readable string to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm64-arm64_ftr_reg-name-may-not-be-a-human-readable.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5e49ee1da1ca3bb37ecf7d48055bf07b43fbc5a4 Author: Reiji Watanabe <reijiw@xxxxxxxxxx> Date: Sun Oct 31 21:54:21 2021 -0700 arm64: arm64_ftr_reg->name may not be a human-readable string [ Upstream commit 9dc232a8ab18bb20f1dcb03c8e049e3607f3ed15 ] 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: 8f266a5d878a ("arm64: cpufeature: Add global feature override facility") Signed-off-by: Reiji Watanabe <reijiw@xxxxxxxxxx> Reviewed-by: Oliver Upton <oupton@xxxxxxxxxx> Acked-by: Marc Zyngier <maz@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211101045421.2215822-1-reijiw@xxxxxxxxxx Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 6ec7036ef7e18..7553c98f379fc 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -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;