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| author |   Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2016-07-23 14:42:43 +0530 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2016-08-01 11:15:06 +1000 |
| commit | c812c7d8f1470ac9c8aa6d7e29b56e5845ee05fc (patch) | |
| tree | 9df953d954d85946488f41cbd202865535805eb4 /arch/powerpc | |
| parent | powerpc: Add option to use jump label for mmu_has_feature() (diff) | |
| download | linux-dev-c812c7d8f1470ac9c8aa6d7e29b56e5845ee05fc.tar.xz linux-dev-c812c7d8f1470ac9c8aa6d7e29b56e5845ee05fc.zip | |
powerpc/mm: Catch usage of cpu/mmu_has_feature() before jump label init
This allows us to catch incorrect usage of cpu_has_feature() and
mmu_has_feature() prior to jump labels being initialised.
mpe: Use printk() and dump_stack() rather than WARN_ON(), because
WARN_ON() may not work this early in boot. Rename the Kconfig.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/Kconfig.debug | 10 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/cpu_has_feature.h | 8 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/mmu.h | 8 |
3 files changed, 26 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index 36d7e345f599..63292f64b25a 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -69,6 +69,16 @@ config JUMP_LABEL_FEATURE_CHECKS feature checks. This should generate more optimal code for those checks. +config JUMP_LABEL_FEATURE_CHECK_DEBUG + bool "Do extra check on feature fixup calls" + depends on DEBUG_KERNEL && JUMP_LABEL_FEATURE_CHECKS + default n + help + This tries to catch incorrect usage of cpu_has_feature() and + mmu_has_feature() in the code. + + If you don't know what this means, say N. + config FTR_FIXUP_SELFTEST bool "Run self-tests of the feature-fixup code" depends on DEBUG_KERNEL diff --git a/arch/powerpc/include/asm/cpu_has_feature.h b/arch/powerpc/include/asm/cpu_has_feature.h index 039c011b4252..2ef55f8968a2 100644 --- a/arch/powerpc/include/asm/cpu_has_feature.h +++ b/arch/powerpc/include/asm/cpu_has_feature.h @@ -25,6 +25,14 @@ static __always_inline bool cpu_has_feature(unsigned long feature) BUILD_BUG_ON(!__builtin_constant_p(feature)); +#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG + if (!static_key_initialized) { + printk("Warning! cpu_has_feature() used prior to jump label init!\n"); + dump_stack(); + return early_cpu_has_feature(feature); + } +#endif + if (CPU_FTRS_ALWAYS & feature) return true; diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h index 1bf919aafd50..e2fb408f8398 100644 --- a/arch/powerpc/include/asm/mmu.h +++ b/arch/powerpc/include/asm/mmu.h @@ -156,6 +156,14 @@ static __always_inline bool mmu_has_feature(unsigned long feature) BUILD_BUG_ON(!__builtin_constant_p(feature)); +#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG + if (!static_key_initialized) { + printk("Warning! mmu_has_feature() used prior to jump label init!\n"); + dump_stack(); + return early_mmu_has_feature(feature); + } +#endif + if (!(MMU_FTRS_POSSIBLE & feature)) return false; |