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| author | Michael Ellerman <mpe@ellerman.id.au> | 2024-05-09 22:12:48 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2024-07-11 17:31:55 +1000 |
| commit | db25a9625dbc3aa6613c0347f574689c248a3d0b (patch) | |
| tree | 56b670922f624c27addf0eddce2f681d6759b05b /arch/powerpc/include | |
| parent | 14196e47c5ffe32af7ed5a51c9e421c5ea5bccce (diff) | |
powerpc: Check only single values are passed to CPU/MMU feature checks
cpu_has_feature()/mmu_has_feature() are only able to check a single
feature at a time, but there is no enforcement of that.
In fact, as fixed in the previous commit, there was code that was
passing multiple values to cpu_has_feature().
So add a check that only a single feature is passed using popcount.
Note that the test allows 0 or 1 bits to be set, because some code
relies on cpu_has_feature(0) being false, the check with
CPU_FTRS_POSSIBLE ensures that. See for example CPU_FTR_PPC_LE.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240509121248.270878-3-mpe@ellerman.id.au
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/cpu_has_feature.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/mmu.h | 1 |
2 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/cpu_has_feature.h b/arch/powerpc/include/asm/cpu_has_feature.h index 92e24e979954..bf8a228229fa 100644 --- a/arch/powerpc/include/asm/cpu_has_feature.h +++ b/arch/powerpc/include/asm/cpu_has_feature.h @@ -25,6 +25,7 @@ static __always_inline bool cpu_has_feature(unsigned long feature) int i; BUILD_BUG_ON(!__builtin_constant_p(feature)); + BUILD_BUG_ON(__builtin_popcountl(feature) > 1); #ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG if (!static_key_feature_checks_initialized) { diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h index 1d1395b769a8..4182d68d9cd1 100644 --- a/arch/powerpc/include/asm/mmu.h +++ b/arch/powerpc/include/asm/mmu.h @@ -240,6 +240,7 @@ static __always_inline bool mmu_has_feature(unsigned long feature) int i; BUILD_BUG_ON(!__builtin_constant_p(feature)); + BUILD_BUG_ON(__builtin_popcountl(feature) > 1); #ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG if (!static_key_feature_checks_initialized) { |