ioremap_page_range doesn't honour break-before-make and attempts to put
down huge mappings (using p*d_set_huge) over the top of pre-existing
table entries. This leads to us leaking page table memory and also gives
rise to TLB conflicts and spurious aborts, which have been seen in
practice on Cortex-A75.
Until this has been resolved, refuse to put block mappings when the
existing entry is found to be present.
Fixes:
324420bf91f60 ("arm64: add support for ioremap() block mappings")
Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
Reported-by: Lei Li <lious.lilei@hisilicon.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
{
pgprot_t sect_prot = __pgprot(PUD_TYPE_SECT |
pgprot_val(mk_sect_prot(prot)));
+
+ /* ioremap_page_range doesn't honour BBM */
+ if (pud_present(READ_ONCE(*pudp)))
+ return 0;
+
BUG_ON(phys & ~PUD_MASK);
set_pud(pudp, pfn_pud(__phys_to_pfn(phys), sect_prot));
return 1;
{
pgprot_t sect_prot = __pgprot(PMD_TYPE_SECT |
pgprot_val(mk_sect_prot(prot)));
+
+ /* ioremap_page_range doesn't honour BBM */
+ if (pmd_present(READ_ONCE(*pmdp)))
+ return 0;
+
BUG_ON(phys & ~PMD_MASK);
set_pmd(pmdp, pfn_pmd(__phys_to_pfn(phys), sect_prot));
return 1;