diff options
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 47 |
1 files changed, 44 insertions, 3 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 19146bd338b4..d9b51cb9cb8c 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -712,11 +712,52 @@ static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new, static void __init sort_ftr_regs(void) { - int i; + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(arm64_ftr_regs); i++) { + const struct arm64_ftr_reg *ftr_reg = arm64_ftr_regs[i].reg; + const struct arm64_ftr_bits *ftr_bits = ftr_reg->ftr_bits; + unsigned int j = 0; + + /* + * Features here must be sorted in descending order with respect + * to their shift values and should not overlap with each other. + */ + for (; ftr_bits->width != 0; ftr_bits++, j++) { + unsigned int width = ftr_reg->ftr_bits[j].width; + unsigned int shift = ftr_reg->ftr_bits[j].shift; + unsigned int prev_shift; + + WARN((shift + width) > 64, + "%s has invalid feature at shift %d\n", + ftr_reg->name, shift); + + /* + * Skip the first feature. There is nothing to + * compare against for now. + */ + if (j == 0) + continue; - /* Check that the array is sorted so that we can do the binary search */ - for (i = 1; i < ARRAY_SIZE(arm64_ftr_regs); i++) + prev_shift = ftr_reg->ftr_bits[j - 1].shift; + WARN((shift + width) > prev_shift, + "%s has feature overlap at shift %d\n", + ftr_reg->name, shift); + } + + /* + * Skip the first register. There is nothing to + * compare against for now. + */ + if (i == 0) + continue; + /* + * Registers here must be sorted in ascending order with respect + * to sys_id for subsequent binary search in get_arm64_ftr_reg() + * to work correctly. + */ BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id); + } } /* |