diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mcheck/mce.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce.c | 18 |
1 files changed, 6 insertions, 12 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 3c1eec17312b..42cf2880d0ed 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -1095,19 +1095,7 @@ static void mce_unmap_kpfn(unsigned long pfn) * a legal address. */ -/* - * Build time check to see if we have a spare virtual bit. Don't want - * to leave this until run time because most developers don't have a - * system that can exercise this code path. This will only become a - * problem if/when we move beyond 5-level page tables. - * - * Hard code "9" here because cpp doesn't grok ilog2(PTRS_PER_PGD) - */ -#if PGDIR_SHIFT + 9 < 63 decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63)); -#else -#error "no unused virtual bit available" -#endif if (set_memory_np(decoy_addr, 1)) pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn); @@ -2357,6 +2345,12 @@ static __init int mcheck_init_device(void) { int err; + /* + * Check if we have a spare virtual bit. This will only become + * a problem if/when we move beyond 5-level page tables. + */ + MAYBE_BUILD_BUG_ON(__VIRTUAL_MASK_SHIFT >= 63); + if (!mce_available(&boot_cpu_data)) { err = -EIO; goto err_out; |