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authorMark Rutland <mark.rutland@arm.com>2017-02-02 17:32:15 +0000
committerWill Deacon <will.deacon@arm.com>2017-02-02 18:34:38 +0000
commit965861d66fad6ce07bd5c5ecbe6514bc50b8fc11 (patch)
tree5ef91fe1935cb720a522f61c16c6cd34f5f53a05 /arch
parentarm64: fix erroneous __raw_read_system_reg() cases (diff)
downloadlinux-dev-965861d66fad6ce07bd5c5ecbe6514bc50b8fc11.tar.xz
linux-dev-965861d66fad6ce07bd5c5ecbe6514bc50b8fc11.zip
arm64: ensure __raw_read_system_reg() is self-consistent
We recently discovered that __raw_read_system_reg() erroneously mapped sysreg IDs to the wrong registers. To ensure that we don't get hit by a similar issue in future, this patch makes __raw_read_system_reg() use a macro for each case statement, ensuring that each case reads the correct register. To ensure that this patch hasn't introduced an issue, I've binary-diffed the object files before and after this patch. No code or data sections differ (though some debug section differ due to line numbering changing). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/kernel/cpufeature.c64
1 files changed, 34 insertions, 30 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 0688b9a3adeb..1ee5357d0c6a 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -645,6 +645,9 @@ u64 read_system_reg(u32 id)
return regp->sys_val;
}
+#define read_sysreg_case(r) \
+ case r: return read_sysreg_s(r)
+
/*
* __raw_read_system_reg() - Used by a STARTING cpu before cpuinfo is populated.
* Read the system register on the current CPU
@@ -652,36 +655,37 @@ u64 read_system_reg(u32 id)
static u64 __raw_read_system_reg(u32 sys_id)
{
switch (sys_id) {
- case SYS_ID_PFR0_EL1: return read_cpuid(ID_PFR0_EL1);
- case SYS_ID_PFR1_EL1: return read_cpuid(ID_PFR1_EL1);
- case SYS_ID_DFR0_EL1: return read_cpuid(ID_DFR0_EL1);
- case SYS_ID_MMFR0_EL1: return read_cpuid(ID_MMFR0_EL1);
- case SYS_ID_MMFR1_EL1: return read_cpuid(ID_MMFR1_EL1);
- case SYS_ID_MMFR2_EL1: return read_cpuid(ID_MMFR2_EL1);
- case SYS_ID_MMFR3_EL1: return read_cpuid(ID_MMFR3_EL1);
- case SYS_ID_ISAR0_EL1: return read_cpuid(ID_ISAR0_EL1);
- case SYS_ID_ISAR1_EL1: return read_cpuid(ID_ISAR1_EL1);
- case SYS_ID_ISAR2_EL1: return read_cpuid(ID_ISAR2_EL1);
- case SYS_ID_ISAR3_EL1: return read_cpuid(ID_ISAR3_EL1);
- case SYS_ID_ISAR4_EL1: return read_cpuid(ID_ISAR4_EL1);
- case SYS_ID_ISAR5_EL1: return read_cpuid(ID_ISAR5_EL1);
- case SYS_MVFR0_EL1: return read_cpuid(MVFR0_EL1);
- case SYS_MVFR1_EL1: return read_cpuid(MVFR1_EL1);
- case SYS_MVFR2_EL1: return read_cpuid(MVFR2_EL1);
-
- case SYS_ID_AA64PFR0_EL1: return read_cpuid(ID_AA64PFR0_EL1);
- case SYS_ID_AA64PFR1_EL1: return read_cpuid(ID_AA64PFR1_EL1);
- case SYS_ID_AA64DFR0_EL1: return read_cpuid(ID_AA64DFR0_EL1);
- case SYS_ID_AA64DFR1_EL1: return read_cpuid(ID_AA64DFR1_EL1);
- case SYS_ID_AA64MMFR0_EL1: return read_cpuid(ID_AA64MMFR0_EL1);
- case SYS_ID_AA64MMFR1_EL1: return read_cpuid(ID_AA64MMFR1_EL1);
- case SYS_ID_AA64MMFR2_EL1: return read_cpuid(ID_AA64MMFR2_EL1);
- case SYS_ID_AA64ISAR0_EL1: return read_cpuid(ID_AA64ISAR0_EL1);
- case SYS_ID_AA64ISAR1_EL1: return read_cpuid(ID_AA64ISAR1_EL1);
-
- case SYS_CNTFRQ_EL0: return read_cpuid(CNTFRQ_EL0);
- case SYS_CTR_EL0: return read_cpuid(CTR_EL0);
- case SYS_DCZID_EL0: return read_cpuid(DCZID_EL0);
+ read_sysreg_case(SYS_ID_PFR0_EL1);
+ read_sysreg_case(SYS_ID_PFR1_EL1);
+ read_sysreg_case(SYS_ID_DFR0_EL1);
+ read_sysreg_case(SYS_ID_MMFR0_EL1);
+ read_sysreg_case(SYS_ID_MMFR1_EL1);
+ read_sysreg_case(SYS_ID_MMFR2_EL1);
+ read_sysreg_case(SYS_ID_MMFR3_EL1);
+ read_sysreg_case(SYS_ID_ISAR0_EL1);
+ read_sysreg_case(SYS_ID_ISAR1_EL1);
+ read_sysreg_case(SYS_ID_ISAR2_EL1);
+ read_sysreg_case(SYS_ID_ISAR3_EL1);
+ read_sysreg_case(SYS_ID_ISAR4_EL1);
+ read_sysreg_case(SYS_ID_ISAR5_EL1);
+ read_sysreg_case(SYS_MVFR0_EL1);
+ read_sysreg_case(SYS_MVFR1_EL1);
+ read_sysreg_case(SYS_MVFR2_EL1);
+
+ read_sysreg_case(SYS_ID_AA64PFR0_EL1);
+ read_sysreg_case(SYS_ID_AA64PFR1_EL1);
+ read_sysreg_case(SYS_ID_AA64DFR0_EL1);
+ read_sysreg_case(SYS_ID_AA64DFR1_EL1);
+ read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
+ read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
+ read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
+ read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
+ read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
+
+ read_sysreg_case(SYS_CNTFRQ_EL0);
+ read_sysreg_case(SYS_CTR_EL0);
+ read_sysreg_case(SYS_DCZID_EL0);
+
default:
BUG();
return 0;