| Message ID | 20211101045421.2215822-1-reijiw@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: arm64_ftr_reg->name may not be a human-readable string | expand |
On Mon, 01 Nov 2021 04:54:21 +0000, Reiji Watanabe <reijiw@google.com> wrote: > > 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@google.com> > --- > arch/arm64/kernel/cpufeature.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 6ec7036ef7e1..7553c98f379f 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; Seems reasonable to me. Acked-by: Marc Zyngier <maz@kernel.org> M.
On Sun, Oct 31, 2021 at 9:54 PM Reiji Watanabe <reijiw@google.com> wrote: > > 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@google.com> Reviewed-by: Oliver Upton <oupton@google.com>
On Sun, 31 Oct 2021 21:54:21 -0700, Reiji Watanabe wrote: > 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). > > [...] Applied to arm64 (for-next/core), thanks! [1/1] arm64: arm64_ftr_reg->name may not be a human-readable string https://git.kernel.org/arm64/c/b0f364414a23 Cheers,
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 6ec7036ef7e1..7553c98f379f 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;
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@google.com> --- arch/arm64/kernel/cpufeature.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)