Hi, Bibo, I applied this patch but drop the part of arch/loongarch/mm/kasan_init.c: https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson.git/commit/?h=loongarch-next&id=15832255e84494853f543b4c70ced50afc403067 Because kernel_pte_init() should operate on page-table pages, not on data pages. You have already handle page-table page in mm/kasan/init.c, and if we don't drop the modification on data pages in arch/loongarch/mm/kasan_init.c, the kernel fail to boot if KASAN is enabled. Huacai On Mon, Oct 14, 2024 at 11:59 AM Bibo Mao <maobibo@xxxxxxxxxxx> wrote: > > Unlike general architectures, there are two pages in one TLB entry > on LoongArch system. For kernel space, it requires both two pte > entries with PAGE_GLOBAL bit set, else HW treats it as non-global > tlb, there will be potential problems if tlb entry for kernel space > is not global. Such as fail to flush kernel tlb with function > local_flush_tlb_kernel_range() which only flush tlb with global bit. > > With function kernel_pte_init() added, it can be used to init pte > table when it is created for kernel address space, and the default > initial pte value is PAGE_GLOBAL rather than zero at beginning. > > Kernel address space areas includes fixmap, percpu, vmalloc, kasan > and vmemmap areas set default pte entry with PAGE_GLOBAL set. > > Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx> > --- > arch/loongarch/include/asm/pgalloc.h | 13 +++++++++++++ > arch/loongarch/include/asm/pgtable.h | 1 + > arch/loongarch/mm/init.c | 4 +++- > arch/loongarch/mm/kasan_init.c | 4 +++- > arch/loongarch/mm/pgtable.c | 22 ++++++++++++++++++++++ > include/linux/mm.h | 1 + > mm/kasan/init.c | 8 +++++++- > mm/sparse-vmemmap.c | 5 +++++ > 8 files changed, 55 insertions(+), 3 deletions(-) > > diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h > index 4e2d6b7ca2ee..b2698c03dc2c 100644 > --- a/arch/loongarch/include/asm/pgalloc.h > +++ b/arch/loongarch/include/asm/pgalloc.h > @@ -10,8 +10,21 @@ > > #define __HAVE_ARCH_PMD_ALLOC_ONE > #define __HAVE_ARCH_PUD_ALLOC_ONE > +#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL > #include <asm-generic/pgalloc.h> > > +static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm) > +{ > + pte_t *pte; > + > + pte = (pte_t *) __get_free_page(GFP_KERNEL); > + if (!pte) > + return NULL; > + > + kernel_pte_init(pte); > + return pte; > +} > + > static inline void pmd_populate_kernel(struct mm_struct *mm, > pmd_t *pmd, pte_t *pte) > { > diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h > index 9965f52ef65b..22e3a8f96213 100644 > --- a/arch/loongarch/include/asm/pgtable.h > +++ b/arch/loongarch/include/asm/pgtable.h > @@ -269,6 +269,7 @@ extern void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pm > extern void pgd_init(void *addr); > extern void pud_init(void *addr); > extern void pmd_init(void *addr); > +extern void kernel_pte_init(void *addr); > > /* > * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that > diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c > index 8a87a482c8f4..9f26e933a8a3 100644 > --- a/arch/loongarch/mm/init.c > +++ b/arch/loongarch/mm/init.c > @@ -198,9 +198,11 @@ pte_t * __init populate_kernel_pte(unsigned long addr) > if (!pmd_present(pmdp_get(pmd))) { > pte_t *pte; > > - pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE); > + pte = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE); > if (!pte) > panic("%s: Failed to allocate memory\n", __func__); > + > + kernel_pte_init(pte); > pmd_populate_kernel(&init_mm, pmd, pte); > } > > diff --git a/arch/loongarch/mm/kasan_init.c b/arch/loongarch/mm/kasan_init.c > index 427d6b1aec09..34988573b0d5 100644 > --- a/arch/loongarch/mm/kasan_init.c > +++ b/arch/loongarch/mm/kasan_init.c > @@ -152,6 +152,8 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, > phys_addr_t page_phys = early ? > __pa_symbol(kasan_early_shadow_page) > : kasan_alloc_zeroed_page(node); > + if (!early) > + kernel_pte_init(__va(page_phys)); > next = addr + PAGE_SIZE; > set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL)); > } while (ptep++, addr = next, addr != end && __pte_none(early, ptep_get(ptep))); > @@ -287,7 +289,7 @@ void __init kasan_init(void) > set_pte(&kasan_early_shadow_pte[i], > pfn_pte(__phys_to_pfn(__pa_symbol(kasan_early_shadow_page)), PAGE_KERNEL_RO)); > > - memset(kasan_early_shadow_page, 0, PAGE_SIZE); > + kernel_pte_init(kasan_early_shadow_page); > csr_write64(__pa_symbol(swapper_pg_dir), LOONGARCH_CSR_PGDH); > local_flush_tlb_all(); > > diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c > index eb6a29b491a7..228ffc1db0a3 100644 > --- a/arch/loongarch/mm/pgtable.c > +++ b/arch/loongarch/mm/pgtable.c > @@ -38,6 +38,28 @@ pgd_t *pgd_alloc(struct mm_struct *mm) > } > EXPORT_SYMBOL_GPL(pgd_alloc); > > +void kernel_pte_init(void *addr) > +{ > + unsigned long *p, *end; > + unsigned long entry; > + > + entry = (unsigned long)_PAGE_GLOBAL; > + p = (unsigned long *)addr; > + end = p + PTRS_PER_PTE; > + > + do { > + p[0] = entry; > + p[1] = entry; > + p[2] = entry; > + p[3] = entry; > + p[4] = entry; > + p += 8; > + p[-3] = entry; > + p[-2] = entry; > + p[-1] = entry; > + } while (p != end); > +} > + > void pgd_init(void *addr) > { > unsigned long *p, *end; > diff --git a/include/linux/mm.h b/include/linux/mm.h > index ecf63d2b0582..6909fe059a2c 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3818,6 +3818,7 @@ void *sparse_buffer_alloc(unsigned long size); > struct page * __populate_section_memmap(unsigned long pfn, > unsigned long nr_pages, int nid, struct vmem_altmap *altmap, > struct dev_pagemap *pgmap); > +void kernel_pte_init(void *addr); > void pmd_init(void *addr); > void pud_init(void *addr); > pgd_t *vmemmap_pgd_populate(unsigned long addr, int node); > diff --git a/mm/kasan/init.c b/mm/kasan/init.c > index 89895f38f722..ac607c306292 100644 > --- a/mm/kasan/init.c > +++ b/mm/kasan/init.c > @@ -106,6 +106,10 @@ static void __ref zero_pte_populate(pmd_t *pmd, unsigned long addr, > } > } > > +void __weak __meminit kernel_pte_init(void *addr) > +{ > +} > + > static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr, > unsigned long end) > { > @@ -126,8 +130,10 @@ static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr, > > if (slab_is_available()) > p = pte_alloc_one_kernel(&init_mm); > - else > + else { > p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); > + kernel_pte_init(p); > + } > if (!p) > return -ENOMEM; > > diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c > index edcc7a6b0f6f..c0388b2e959d 100644 > --- a/mm/sparse-vmemmap.c > +++ b/mm/sparse-vmemmap.c > @@ -184,6 +184,10 @@ static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node) > return p; > } > > +void __weak __meminit kernel_pte_init(void *addr) > +{ > +} > + > pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node) > { > pmd_t *pmd = pmd_offset(pud, addr); > @@ -191,6 +195,7 @@ pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node) > void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node); > if (!p) > return NULL; > + kernel_pte_init(p); > pmd_populate_kernel(&init_mm, pmd, p); > } > return pmd; > -- > 2.39.3 >
