On Thu, 6 Jul 2023, Aneesh Kumar K.V wrote: > With commit 0d940a9b270b ("mm/pgtable: allow pte_offset_map[_lock]() to > fail") the kernel is now using pmd_same to compare pmd values that are > pointing to a level 4 page table page. Move the functions out of #ifdef > CONFIG_TRANSPARENT_HUGEPAGE and add a variant that can work with both 4K > and 64K page size. > > kernel BUG at arch/powerpc/include/asm/book3s/64/hash-4k.h:141! > Oops: Exception in kernel mode, sig: 5 [#1] > LE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries > ..... > NIP [c00000000048aee0] __pte_offset_map_lock+0xf0/0x164 > LR [c00000000048ae78] __pte_offset_map_lock+0x88/0x164 > Call Trace: > 0xc0003f000009a340 (unreliable) > __handle_mm_fault+0x1340/0x1980 > handle_mm_fault+0xbc/0x380 > __get_user_pages+0x320/0x550 > get_user_pages_remote+0x13c/0x520 > get_arg_page+0x80/0x1d0 > copy_string_kernel+0xc8/0x250 > kernel_execve+0x11c/0x270 > run_init_process+0xe4/0x10c > kernel_init+0xbc/0x1a0 > ret_from_kernel_user_thread+0x14/0x1c > > Cc: Hugh Dickins <hu...@google.com> > Reported-by: Michael Ellerman <m...@ellerman.id.au> > Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
Acked-by: Hugh Dickins <hu...@google.com> Thanks for rescuing us so quickly! > --- > arch/powerpc/include/asm/book3s/64/hash-4k.h | 6 ------ > arch/powerpc/include/asm/book3s/64/hash-64k.h | 5 ----- > arch/powerpc/include/asm/book3s/64/hash.h | 5 +++++ > 3 files changed, 5 insertions(+), 11 deletions(-) > > diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h > b/arch/powerpc/include/asm/book3s/64/hash-4k.h > index b6ac4f86c87b..6472b08fa1b0 100644 > --- a/arch/powerpc/include/asm/book3s/64/hash-4k.h > +++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h > @@ -136,12 +136,6 @@ static inline int hash__pmd_trans_huge(pmd_t pmd) > return 0; > } > > -static inline int hash__pmd_same(pmd_t pmd_a, pmd_t pmd_b) > -{ > - BUG(); > - return 0; > -} > - > static inline pmd_t hash__pmd_mkhuge(pmd_t pmd) > { > BUG(); > diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h > b/arch/powerpc/include/asm/book3s/64/hash-64k.h > index 338e62fbea0b..0bf6fd0bf42a 100644 > --- a/arch/powerpc/include/asm/book3s/64/hash-64k.h > +++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h > @@ -263,11 +263,6 @@ static inline int hash__pmd_trans_huge(pmd_t pmd) > (_PAGE_PTE | H_PAGE_THP_HUGE)); > } > > -static inline int hash__pmd_same(pmd_t pmd_a, pmd_t pmd_b) > -{ > - return (((pmd_raw(pmd_a) ^ pmd_raw(pmd_b)) & > ~cpu_to_be64(_PAGE_HPTEFLAGS)) == 0); > -} > - > static inline pmd_t hash__pmd_mkhuge(pmd_t pmd) > { > return __pmd(pmd_val(pmd) | (_PAGE_PTE | H_PAGE_THP_HUGE)); > diff --git a/arch/powerpc/include/asm/book3s/64/hash.h > b/arch/powerpc/include/asm/book3s/64/hash.h > index 17e7a778c856..d4a19e6547ac 100644 > --- a/arch/powerpc/include/asm/book3s/64/hash.h > +++ b/arch/powerpc/include/asm/book3s/64/hash.h > @@ -132,6 +132,11 @@ static inline int get_region_id(unsigned long ea) > return region_id; > } > > +static inline int hash__pmd_same(pmd_t pmd_a, pmd_t pmd_b) > +{ > + return (((pmd_raw(pmd_a) ^ pmd_raw(pmd_b)) & > ~cpu_to_be64(_PAGE_HPTEFLAGS)) == 0); > +} > + > #define hash__pmd_bad(pmd) (pmd_val(pmd) & H_PMD_BAD_BITS) > #define hash__pud_bad(pud) (pud_val(pud) & H_PUD_BAD_BITS) > static inline int hash__p4d_bad(p4d_t p4d) > -- > 2.41.0 > >