6.6-stable review patch. If anyone has any objections, please let me know.
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From: Aneesh Kumar K.V (IBM) aneesh.kumar@kernel.org
commit 720da1e593b85a550593b415bf1d79a053133451 upstream.
Architectures like powerpc add debug checks to ensure we find only devmap PUD pte entries. These debug checks are only done with CONFIG_DEBUG_VM. This patch marks the ptes used for PUD advanced test devmap pte entries so that we don't hit on debug checks on architecture like ppc64 as below.
WARNING: CPU: 2 PID: 1 at arch/powerpc/mm/book3s64/radix_pgtable.c:1382 radix__pud_hugepage_update+0x38/0x138 .... NIP [c0000000000a7004] radix__pud_hugepage_update+0x38/0x138 LR [c0000000000a77a8] radix__pudp_huge_get_and_clear+0x28/0x60 Call Trace: [c000000004a2f950] [c000000004a2f9a0] 0xc000000004a2f9a0 (unreliable) [c000000004a2f980] [000d34c100000000] 0xd34c100000000 [c000000004a2f9a0] [c00000000206ba98] pud_advanced_tests+0x118/0x334 [c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48 [c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388
Also
kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:202! ....
NIP [c000000000096510] pudp_huge_get_and_clear_full+0x98/0x174 LR [c00000000206bb34] pud_advanced_tests+0x1b4/0x334 Call Trace: [c000000004a2f950] [000d34c100000000] 0xd34c100000000 (unreliable) [c000000004a2f9a0] [c00000000206bb34] pud_advanced_tests+0x1b4/0x334 [c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48 [c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388
Link: https://lkml.kernel.org/r/20240129060022.68044-1-aneesh.kumar@kernel.org Fixes: 27af67f35631 ("powerpc/book3s64/mm: enable transparent pud hugepage") Signed-off-by: Aneesh Kumar K.V (IBM) aneesh.kumar@kernel.org Cc: Anshuman Khandual anshuman.khandual@arm.com Cc: Michael Ellerman mpe@ellerman.id.au Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/debug_vm_pgtable.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 5662e29fe253..65c19025da3d 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -362,6 +362,12 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args) vaddr &= HPAGE_PUD_MASK;
pud = pfn_pud(args->pud_pfn, args->page_prot); + /* + * Some architectures have debug checks to make sure + * huge pud mapping are only found with devmap entries + * For now test with only devmap entries. + */ + pud = pud_mkdevmap(pud); set_pud_at(args->mm, vaddr, args->pudp, pud); flush_dcache_page(page); pudp_set_wrprotect(args->mm, vaddr, args->pudp); @@ -374,6 +380,7 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args) WARN_ON(!pud_none(pud)); #endif /* __PAGETABLE_PMD_FOLDED */ pud = pfn_pud(args->pud_pfn, args->page_prot); + pud = pud_mkdevmap(pud); pud = pud_wrprotect(pud); pud = pud_mkclean(pud); set_pud_at(args->mm, vaddr, args->pudp, pud); @@ -391,6 +398,7 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args) #endif /* __PAGETABLE_PMD_FOLDED */
pud = pfn_pud(args->pud_pfn, args->page_prot); + pud = pud_mkdevmap(pud); pud = pud_mkyoung(pud); set_pud_at(args->mm, vaddr, args->pudp, pud); flush_dcache_page(page);