| Message ID | 20221018074014.185687-1-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | mm: remove kern_addr_valid() completely | expand |
On Tue, Oct 18, 2022 at 9:25 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote: > Most architectures(except arm64/x86/sparc) simply return 1 for > kern_addr_valid(), which is only used in read_kcore(), and it > calls copy_from_kernel_nofault() which could check whether the > address is a valid kernel address, so no need kern_addr_valid(), > let's remove unneeded kern_addr_valid() completely. > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > arch/m68k/include/asm/pgtable_mm.h | 2 - > arch/m68k/include/asm/pgtable_no.h | 1 - Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Tue, Oct 18, 2022 at 03:40:14PM +0800, Kefeng Wang wrote: > Most architectures(except arm64/x86/sparc) simply return 1 for > kern_addr_valid(), which is only used in read_kcore(), and it > calls copy_from_kernel_nofault() which could check whether the > address is a valid kernel address, so no need kern_addr_valid(), > let's remove unneeded kern_addr_valid() completely. > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- ... > arch/s390/include/asm/pgtable.h | 2 - For s390: Acked-by: Heiko Carstens <hca@linux.ibm.com>
Thanks, this is long overdue!
Acked-by: Christoph Hellwig <hch@lst.de>
On 10/18/22 09:40, Kefeng Wang wrote: > Most architectures(except arm64/x86/sparc) simply return 1 for > kern_addr_valid(), which is only used in read_kcore(), and it > calls copy_from_kernel_nofault() which could check whether the > address is a valid kernel address, so no need kern_addr_valid(), > let's remove unneeded kern_addr_valid() completely. > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Helge Deller <deller@gmx.de> # parisc Thanks! Helge > --- > arch/alpha/include/asm/pgtable.h | 2 - > arch/arc/include/asm/pgtable-bits-arcv2.h | 2 - > arch/arm/include/asm/pgtable-nommu.h | 2 - > arch/arm/include/asm/pgtable.h | 4 -- > arch/arm64/include/asm/pgtable.h | 2 - > arch/arm64/mm/mmu.c | 47 ----------------------- > arch/arm64/mm/pageattr.c | 3 +- > arch/csky/include/asm/pgtable.h | 3 -- > arch/hexagon/include/asm/page.h | 7 ---- > arch/ia64/include/asm/pgtable.h | 16 -------- > arch/loongarch/include/asm/pgtable.h | 2 - > arch/m68k/include/asm/pgtable_mm.h | 2 - > arch/m68k/include/asm/pgtable_no.h | 1 - > arch/microblaze/include/asm/pgtable.h | 3 -- > arch/mips/include/asm/pgtable.h | 2 - > arch/nios2/include/asm/pgtable.h | 2 - > arch/openrisc/include/asm/pgtable.h | 2 - > arch/parisc/include/asm/pgtable.h | 15 -------- > arch/powerpc/include/asm/pgtable.h | 7 ---- > arch/riscv/include/asm/pgtable.h | 2 - > arch/s390/include/asm/pgtable.h | 2 - > arch/sh/include/asm/pgtable.h | 2 - > arch/sparc/include/asm/pgtable_32.h | 6 --- > arch/sparc/mm/init_32.c | 3 +- > arch/sparc/mm/init_64.c | 1 - > arch/um/include/asm/pgtable.h | 2 - > arch/x86/include/asm/pgtable_32.h | 9 ----- > arch/x86/include/asm/pgtable_64.h | 1 - > arch/x86/mm/init_64.c | 41 -------------------- > arch/xtensa/include/asm/pgtable.h | 2 - > fs/proc/kcore.c | 26 +++++-------- > 31 files changed, 11 insertions(+), 210 deletions(-) > > diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h > index 3ea9661c09ff..9e45f6735d5d 100644 > --- a/arch/alpha/include/asm/pgtable.h > +++ b/arch/alpha/include/asm/pgtable.h > @@ -313,8 +313,6 @@ extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > #define pte_ERROR(e) \ > printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) > #define pmd_ERROR(e) \ > diff --git a/arch/arc/include/asm/pgtable-bits-arcv2.h b/arch/arc/include/asm/pgtable-bits-arcv2.h > index b23be557403e..515e82db519f 100644 > --- a/arch/arc/include/asm/pgtable-bits-arcv2.h > +++ b/arch/arc/include/asm/pgtable-bits-arcv2.h > @@ -120,8 +120,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > #include <asm/hugepage.h> > #endif > diff --git a/arch/arm/include/asm/pgtable-nommu.h b/arch/arm/include/asm/pgtable-nommu.h > index d16aba48fa0a..25d8c7bb07e0 100644 > --- a/arch/arm/include/asm/pgtable-nommu.h > +++ b/arch/arm/include/asm/pgtable-nommu.h > @@ -21,8 +21,6 @@ > #define pgd_none(pgd) (0) > #define pgd_bad(pgd) (0) > #define pgd_clear(pgdp) > -#define kern_addr_valid(addr) (1) > -/* FIXME */ > /* > * PMD_SHIFT determines the size of the area a second-level page table can map > * PGDIR_SHIFT determines what a third-level page table entry can map > diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h > index 78a532068fec..00954ab1a039 100644 > --- a/arch/arm/include/asm/pgtable.h > +++ b/arch/arm/include/asm/pgtable.h > @@ -298,10 +298,6 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) > */ > #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) > > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -/* FIXME: this is not correct */ > -#define kern_addr_valid(addr) (1) > - > /* > * We provide our own arch_get_unmapped_area to cope with VIPT caches. > */ > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 71a1af42f0e8..4873c1d6e7d0 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -1021,8 +1021,6 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, > */ > #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) > > -extern int kern_addr_valid(unsigned long addr); > - > #ifdef CONFIG_ARM64_MTE > > #define __HAVE_ARCH_PREPARE_TO_SWAP > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 9a7c38965154..556154d821bf 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -814,53 +814,6 @@ void __init paging_init(void) > create_idmap(); > } > > -/* > - * Check whether a kernel address is valid (derived from arch/x86/). > - */ > -int kern_addr_valid(unsigned long addr) > -{ > - pgd_t *pgdp; > - p4d_t *p4dp; > - pud_t *pudp, pud; > - pmd_t *pmdp, pmd; > - pte_t *ptep, pte; > - > - addr = arch_kasan_reset_tag(addr); > - if ((((long)addr) >> VA_BITS) != -1UL) > - return 0; > - > - pgdp = pgd_offset_k(addr); > - if (pgd_none(READ_ONCE(*pgdp))) > - return 0; > - > - p4dp = p4d_offset(pgdp, addr); > - if (p4d_none(READ_ONCE(*p4dp))) > - return 0; > - > - pudp = pud_offset(p4dp, addr); > - pud = READ_ONCE(*pudp); > - if (pud_none(pud)) > - return 0; > - > - if (pud_sect(pud)) > - return pfn_valid(pud_pfn(pud)); > - > - pmdp = pmd_offset(pudp, addr); > - pmd = READ_ONCE(*pmdp); > - if (pmd_none(pmd)) > - return 0; > - > - if (pmd_sect(pmd)) > - return pfn_valid(pmd_pfn(pmd)); > - > - ptep = pte_offset_kernel(pmdp, addr); > - pte = READ_ONCE(*ptep); > - if (pte_none(pte)) > - return 0; > - > - return pfn_valid(pte_pfn(pte)); > -} > - > #ifdef CONFIG_MEMORY_HOTPLUG > static void free_hotplug_page_range(struct page *page, size_t size, > struct vmem_altmap *altmap) > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index d107c3d434e2..0a741a910a6a 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -201,8 +201,7 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) > > /* > * This function is used to determine if a linear map page has been marked as > - * not-valid. Walk the page table and check the PTE_VALID bit. This is based > - * on kern_addr_valid(), which almost does what we need. > + * not-valid. Walk the page table and check the PTE_VALID bit. > * > * Because this is only called on the kernel linear map, p?d_sect() implies > * p?d_present(). When debug_pagealloc is enabled, sections mappings are > diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h > index c3d9b92cbe61..77bc6caff2d2 100644 > --- a/arch/csky/include/asm/pgtable.h > +++ b/arch/csky/include/asm/pgtable.h > @@ -249,9 +249,6 @@ extern void paging_init(void); > void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, > pte_t *pte); > > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -#define kern_addr_valid(addr) (1) > - > #define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \ > remap_pfn_range(vma, vaddr, pfn, size, prot) > > diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h > index 7cbf719c578e..d7d4f9fca327 100644 > --- a/arch/hexagon/include/asm/page.h > +++ b/arch/hexagon/include/asm/page.h > @@ -131,13 +131,6 @@ static inline void clear_page(void *page) > > #define page_to_virt(page) __va(page_to_phys(page)) > > -/* > - * For port to Hexagon Virtual Machine, MAYBE we check for attempts > - * to reference reserved HVM space, but in any case, the VM will be > - * protected. > - */ > -#define kern_addr_valid(addr) (1) > - > #include <asm/mem-layout.h> > #include <asm-generic/memory_model.h> > /* XXX Todo: implement assembly-optimized version of getorder. */ > diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h > index 6925e28ae61d..01517a5e6778 100644 > --- a/arch/ia64/include/asm/pgtable.h > +++ b/arch/ia64/include/asm/pgtable.h > @@ -181,22 +181,6 @@ ia64_phys_addr_valid (unsigned long addr) > return (addr & (local_cpu_data->unimpl_pa_mask)) == 0; > } > > -/* > - * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel > - * memory. For the return value to be meaningful, ADDR must be >= > - * PAGE_OFFSET. This operation can be relatively expensive (e.g., > - * require a hash-, or multi-level tree-lookup or something of that > - * sort) but it guarantees to return TRUE only if accessing the page > - * at that address does not cause an error. Note that there may be > - * addresses for which kern_addr_valid() returns FALSE even though an > - * access would not cause an error (e.g., this is typically true for > - * memory mapped I/O regions. > - * > - * XXX Need to implement this for IA-64. > - */ > -#define kern_addr_valid(addr) (1) > - > - > /* > * Now come the defines and routines to manage and access the three-level > * page table. > diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h > index 946704bee599..fc70b7041b76 100644 > --- a/arch/loongarch/include/asm/pgtable.h > +++ b/arch/loongarch/include/asm/pgtable.h > @@ -421,8 +421,6 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, > __update_tlb(vma, address, (pte_t *)pmdp); > } > > -#define kern_addr_valid(addr) (1) > - > static inline unsigned long pmd_pfn(pmd_t pmd) > { > return (pmd_val(pmd) & _PFN_MASK) >> _PFN_SHIFT; > diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h > index 9b4e2fe2ac82..b93c41fe2067 100644 > --- a/arch/m68k/include/asm/pgtable_mm.h > +++ b/arch/m68k/include/asm/pgtable_mm.h > @@ -145,8 +145,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, > > #endif /* !__ASSEMBLY__ */ > > -#define kern_addr_valid(addr) (1) > - > /* MMU-specific headers */ > > #ifdef CONFIG_SUN3 > diff --git a/arch/m68k/include/asm/pgtable_no.h b/arch/m68k/include/asm/pgtable_no.h > index bce5ca56c388..fed58da3a6b6 100644 > --- a/arch/m68k/include/asm/pgtable_no.h > +++ b/arch/m68k/include/asm/pgtable_no.h > @@ -20,7 +20,6 @@ > #define pgd_none(pgd) (0) > #define pgd_bad(pgd) (0) > #define pgd_clear(pgdp) > -#define kern_addr_valid(addr) (1) > #define pmd_offset(a, b) ((void *)0) > > #define PAGE_NONE __pgprot(0) > diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h > index ba348e997dbb..42f5988e998b 100644 > --- a/arch/microblaze/include/asm/pgtable.h > +++ b/arch/microblaze/include/asm/pgtable.h > @@ -416,9 +416,6 @@ extern unsigned long iopa(unsigned long addr); > #define IOMAP_NOCACHE_NONSER 2 > #define IOMAP_NO_COPYBACK 3 > > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -#define kern_addr_valid(addr) (1) > - > void do_page_fault(struct pt_regs *regs, unsigned long address, > unsigned long error_code); > > diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h > index 6caec386ad2f..364a06033105 100644 > --- a/arch/mips/include/asm/pgtable.h > +++ b/arch/mips/include/asm/pgtable.h > @@ -550,8 +550,6 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, > __update_tlb(vma, address, pte); > } > > -#define kern_addr_valid(addr) (1) > - > /* > * Allow physical addresses to be fixed up to help 36-bit peripherals. > */ > diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h > index b3d45e815295..ab793bc517f5 100644 > --- a/arch/nios2/include/asm/pgtable.h > +++ b/arch/nios2/include/asm/pgtable.h > @@ -249,8 +249,6 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) > #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > > -#define kern_addr_valid(addr) (1) > - > extern void __init paging_init(void); > extern void __init mmu_init(void); > > diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h > index dcae8aea132f..6477c17b3062 100644 > --- a/arch/openrisc/include/asm/pgtable.h > +++ b/arch/openrisc/include/asm/pgtable.h > @@ -395,8 +395,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > typedef pte_t *pte_addr_t; > > #endif /* __ASSEMBLY__ */ > diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h > index ecd028854469..bd09a44cfb2d 100644 > --- a/arch/parisc/include/asm/pgtable.h > +++ b/arch/parisc/include/asm/pgtable.h > @@ -23,21 +23,6 @@ > #include <asm/processor.h> > #include <asm/cache.h> > > -/* > - * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel > - * memory. For the return value to be meaningful, ADDR must be >= > - * PAGE_OFFSET. This operation can be relatively expensive (e.g., > - * require a hash-, or multi-level tree-lookup or something of that > - * sort) but it guarantees to return TRUE only if accessing the page > - * at that address does not cause an error. Note that there may be > - * addresses for which kern_addr_valid() returns FALSE even though an > - * access would not cause an error (e.g., this is typically true for > - * memory mapped I/O regions. > - * > - * XXX Need to implement this for parisc. > - */ > -#define kern_addr_valid(addr) (1) > - > /* This is for the serialization of PxTLB broadcasts. At least on the N class > * systems, only one PxTLB inter processor broadcast can be active at any one > * time on the Merced bus. */ > diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h > index 283f40d05a4d..9972626ddaf6 100644 > --- a/arch/powerpc/include/asm/pgtable.h > +++ b/arch/powerpc/include/asm/pgtable.h > @@ -81,13 +81,6 @@ void poking_init(void); > extern unsigned long ioremap_bot; > extern const pgprot_t protection_map[16]; > > -/* > - * kern_addr_valid is intended to indicate whether an address is a valid > - * kernel address. Most 32-bit archs define it as always true (like this) > - * but most 64-bit archs actually perform a test. What should we do here? > - */ > -#define kern_addr_valid(addr) (1) > - > #ifndef CONFIG_TRANSPARENT_HUGEPAGE > #define pmd_large(pmd) 0 > #endif > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index 7ec936910a96..c7993bdf749f 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -801,8 +801,6 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, > > #endif /* !CONFIG_MMU */ > > -#define kern_addr_valid(addr) (1) /* FIXME */ > - > extern char _start[]; > extern void *_dtb_early_va; > extern uintptr_t _dtb_early_pa; > diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h > index f1cb9391190d..e1db07211818 100644 > --- a/arch/s390/include/asm/pgtable.h > +++ b/arch/s390/include/asm/pgtable.h > @@ -1773,8 +1773,6 @@ static inline swp_entry_t __swp_entry(unsigned long type, unsigned long offset) > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > extern int vmem_add_mapping(unsigned long start, unsigned long size); > extern void vmem_remove_mapping(unsigned long start, unsigned long size); > extern int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc); > diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h > index 6fb9ec54cf9b..3ce30becf6df 100644 > --- a/arch/sh/include/asm/pgtable.h > +++ b/arch/sh/include/asm/pgtable.h > @@ -92,8 +92,6 @@ static inline unsigned long phys_addr_mask(void) > > typedef pte_t *pte_addr_t; > > -#define kern_addr_valid(addr) (1) > - > #define pte_pfn(x) ((unsigned long)(((x).pte_low >> PAGE_SHIFT))) > > struct vm_area_struct; > diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h > index 8ff549004fac..5acc05b572e6 100644 > --- a/arch/sparc/include/asm/pgtable_32.h > +++ b/arch/sparc/include/asm/pgtable_32.h > @@ -368,12 +368,6 @@ __get_iospace (unsigned long addr) > } > } > > -extern unsigned long *sparc_valid_addr_bitmap; > - > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -#define kern_addr_valid(addr) \ > - (test_bit(__pa((unsigned long)(addr))>>20, sparc_valid_addr_bitmap)) > - > /* > * For sparc32&64, the pfn in io_remap_pfn_range() carries <iospace> in > * its high 4 bits. These macros/functions put it there or get it from there. > diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c > index d88e774c8eb4..9c0ea457bdf0 100644 > --- a/arch/sparc/mm/init_32.c > +++ b/arch/sparc/mm/init_32.c > @@ -37,8 +37,7 @@ > > #include "mm_32.h" > > -unsigned long *sparc_valid_addr_bitmap; > -EXPORT_SYMBOL(sparc_valid_addr_bitmap); > +static unsigned long *sparc_valid_addr_bitmap; > > unsigned long phys_base; > EXPORT_SYMBOL(phys_base); > diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c > index d6faee23c77d..04f9db0c3111 100644 > --- a/arch/sparc/mm/init_64.c > +++ b/arch/sparc/mm/init_64.c > @@ -1667,7 +1667,6 @@ bool kern_addr_valid(unsigned long addr) > > return pfn_valid(pte_pfn(*pte)); > } > -EXPORT_SYMBOL(kern_addr_valid); > > static unsigned long __ref kernel_map_hugepud(unsigned long vstart, > unsigned long vend, > diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h > index 66bc3f99d9be..4e3052f2671a 100644 > --- a/arch/um/include/asm/pgtable.h > +++ b/arch/um/include/asm/pgtable.h > @@ -298,8 +298,6 @@ extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr); > ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > /* Clear a kernel PTE and flush it from the TLB */ > #define kpte_clear_flush(ptep, vaddr) \ > do { \ > diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h > index 7c9c968a42ef..7d4ad8907297 100644 > --- a/arch/x86/include/asm/pgtable_32.h > +++ b/arch/x86/include/asm/pgtable_32.h > @@ -47,15 +47,6 @@ do { \ > > #endif /* !__ASSEMBLY__ */ > > -/* > - * kern_addr_valid() is (1) for FLATMEM and (0) for SPARSEMEM > - */ > -#ifdef CONFIG_FLATMEM > -#define kern_addr_valid(addr) (1) > -#else > -#define kern_addr_valid(kaddr) (0) > -#endif > - > /* > * This is used to calculate the .brk reservation for initial pagetables. > * Enough space is reserved to allocate pagetables sufficient to cover all > diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h > index e479491da8d5..7929327abe00 100644 > --- a/arch/x86/include/asm/pgtable_64.h > +++ b/arch/x86/include/asm/pgtable_64.h > @@ -240,7 +240,6 @@ static inline void native_pgd_clear(pgd_t *pgd) > #define __swp_entry_to_pte(x) ((pte_t) { .pte = (x).val }) > #define __swp_entry_to_pmd(x) ((pmd_t) { .pmd = (x).val }) > > -extern int kern_addr_valid(unsigned long addr); > extern void cleanup_highmap(void); > > #define HAVE_ARCH_UNMAPPED_AREA > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 3f040c6e5d13..e8db4edd7cc9 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -1416,47 +1416,6 @@ void mark_rodata_ro(void) > debug_checkwx(); > } > > -int kern_addr_valid(unsigned long addr) > -{ > - unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; > - pgd_t *pgd; > - p4d_t *p4d; > - pud_t *pud; > - pmd_t *pmd; > - pte_t *pte; > - > - if (above != 0 && above != -1UL) > - return 0; > - > - pgd = pgd_offset_k(addr); > - if (pgd_none(*pgd)) > - return 0; > - > - p4d = p4d_offset(pgd, addr); > - if (!p4d_present(*p4d)) > - return 0; > - > - pud = pud_offset(p4d, addr); > - if (!pud_present(*pud)) > - return 0; > - > - if (pud_large(*pud)) > - return pfn_valid(pud_pfn(*pud)); > - > - pmd = pmd_offset(pud, addr); > - if (!pmd_present(*pmd)) > - return 0; > - > - if (pmd_large(*pmd)) > - return pfn_valid(pmd_pfn(*pmd)); > - > - pte = pte_offset_kernel(pmd, addr); > - if (pte_none(*pte)) > - return 0; > - > - return pfn_valid(pte_pfn(*pte)); > -} > - > /* > * Block size is the minimum amount of memory which can be hotplugged or > * hotremoved. It must be power of two and must be equal or larger than > diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h > index 54f577c13afa..5b5484d707b2 100644 > --- a/arch/xtensa/include/asm/pgtable.h > +++ b/arch/xtensa/include/asm/pgtable.h > @@ -386,8 +386,6 @@ ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) > > #else > > -#define kern_addr_valid(addr) (1) > - > extern void update_mmu_cache(struct vm_area_struct * vma, > unsigned long address, pte_t *ptep); > > diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c > index dff921f7ca33..590ecb79ad8b 100644 > --- a/fs/proc/kcore.c > +++ b/fs/proc/kcore.c > @@ -541,25 +541,17 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) > fallthrough; > case KCORE_VMEMMAP: > case KCORE_TEXT: > - if (kern_addr_valid(start)) { > - /* > - * Using bounce buffer to bypass the > - * hardened user copy kernel text checks. > - */ > - if (copy_from_kernel_nofault(buf, (void *)start, > - tsz)) { > - if (clear_user(buffer, tsz)) { > - ret = -EFAULT; > - goto out; > - } > - } else { > - if (copy_to_user(buffer, buf, tsz)) { > - ret = -EFAULT; > - goto out; > - } > + /* > + * Using bounce buffer to bypass the > + * hardened user copy kernel text checks. > + */ > + if (copy_from_kernel_nofault(buf, (void *)start, tsz)) { > + if (clear_user(buffer, tsz)) { > + ret = -EFAULT; > + goto out; > } > } else { > - if (clear_user(buffer, tsz)) { > + if (copy_to_user(buffer, buf, tsz)) { > ret = -EFAULT; > goto out; > }
On 2022/10/18 15:40, Kefeng Wang wrote: > Most architectures(except arm64/x86/sparc) simply return 1 for one space before the opening parens > kern_addr_valid(), which is only used in read_kcore(), and it > calls copy_from_kernel_nofault() which could check whether the > address is a valid kernel address, so no need kern_addr_valid(), minor grammatical nit: "... which already checks whether the address is a valid kernel address. So kern_addr_valid is unnecessary, let's remove it." > let's remove unneeded kern_addr_valid() completely. > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > arch/alpha/include/asm/pgtable.h | 2 - > arch/arc/include/asm/pgtable-bits-arcv2.h | 2 - > arch/arm/include/asm/pgtable-nommu.h | 2 - > arch/arm/include/asm/pgtable.h | 4 -- > arch/arm64/include/asm/pgtable.h | 2 - > arch/arm64/mm/mmu.c | 47 ----------------------- > arch/arm64/mm/pageattr.c | 3 +- > arch/csky/include/asm/pgtable.h | 3 -- > arch/hexagon/include/asm/page.h | 7 ---- > arch/ia64/include/asm/pgtable.h | 16 -------- > arch/loongarch/include/asm/pgtable.h | 2 - > arch/m68k/include/asm/pgtable_mm.h | 2 - > arch/m68k/include/asm/pgtable_no.h | 1 - > arch/microblaze/include/asm/pgtable.h | 3 -- > arch/mips/include/asm/pgtable.h | 2 - > arch/nios2/include/asm/pgtable.h | 2 - > arch/openrisc/include/asm/pgtable.h | 2 - > arch/parisc/include/asm/pgtable.h | 15 -------- > arch/powerpc/include/asm/pgtable.h | 7 ---- > arch/riscv/include/asm/pgtable.h | 2 - > arch/s390/include/asm/pgtable.h | 2 - > arch/sh/include/asm/pgtable.h | 2 - > arch/sparc/include/asm/pgtable_32.h | 6 --- > arch/sparc/mm/init_32.c | 3 +- > arch/sparc/mm/init_64.c | 1 - > arch/um/include/asm/pgtable.h | 2 - > arch/x86/include/asm/pgtable_32.h | 9 ----- > arch/x86/include/asm/pgtable_64.h | 1 - > arch/x86/mm/init_64.c | 41 -------------------- > arch/xtensa/include/asm/pgtable.h | 2 - > fs/proc/kcore.c | 26 +++++-------- > 31 files changed, 11 insertions(+), 210 deletions(-) > > diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h > index 946704bee599..fc70b7041b76 100644 > --- a/arch/loongarch/include/asm/pgtable.h > +++ b/arch/loongarch/include/asm/pgtable.h > @@ -421,8 +421,6 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, > __update_tlb(vma, address, (pte_t *)pmdp); > } > > -#define kern_addr_valid(addr) (1) > - > static inline unsigned long pmd_pfn(pmd_t pmd) > { > return (pmd_val(pmd) & _PFN_MASK) >> _PFN_SHIFT; Acked-by: WANG Xuerui <git@xen0n.name> # loongarch Thanks!
On Tue, Oct 18, 2022 at 3:21 PM Kefeng Wang <wangkefeng.wang@huawei.com> wrote: > > Most architectures(except arm64/x86/sparc) simply return 1 for > kern_addr_valid(), which is only used in read_kcore(), and it > calls copy_from_kernel_nofault() which could check whether the > address is a valid kernel address, so no need kern_addr_valid(), > let's remove unneeded kern_addr_valid() completely. > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > arch/alpha/include/asm/pgtable.h | 2 - > arch/arc/include/asm/pgtable-bits-arcv2.h | 2 - > arch/arm/include/asm/pgtable-nommu.h | 2 - > arch/arm/include/asm/pgtable.h | 4 -- > arch/arm64/include/asm/pgtable.h | 2 - > arch/arm64/mm/mmu.c | 47 ----------------------- > arch/arm64/mm/pageattr.c | 3 +- > arch/csky/include/asm/pgtable.h | 3 -- > arch/hexagon/include/asm/page.h | 7 ---- > arch/ia64/include/asm/pgtable.h | 16 -------- > arch/loongarch/include/asm/pgtable.h | 2 - > arch/m68k/include/asm/pgtable_mm.h | 2 - > arch/m68k/include/asm/pgtable_no.h | 1 - > arch/microblaze/include/asm/pgtable.h | 3 -- > arch/mips/include/asm/pgtable.h | 2 - > arch/nios2/include/asm/pgtable.h | 2 - > arch/openrisc/include/asm/pgtable.h | 2 - > arch/parisc/include/asm/pgtable.h | 15 -------- > arch/powerpc/include/asm/pgtable.h | 7 ---- > arch/riscv/include/asm/pgtable.h | 2 - > arch/s390/include/asm/pgtable.h | 2 - > arch/sh/include/asm/pgtable.h | 2 - > arch/sparc/include/asm/pgtable_32.h | 6 --- > arch/sparc/mm/init_32.c | 3 +- > arch/sparc/mm/init_64.c | 1 - > arch/um/include/asm/pgtable.h | 2 - > arch/x86/include/asm/pgtable_32.h | 9 ----- > arch/x86/include/asm/pgtable_64.h | 1 - > arch/x86/mm/init_64.c | 41 -------------------- > arch/xtensa/include/asm/pgtable.h | 2 - > fs/proc/kcore.c | 26 +++++-------- > 31 files changed, 11 insertions(+), 210 deletions(-) > > diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h > index 3ea9661c09ff..9e45f6735d5d 100644 > --- a/arch/alpha/include/asm/pgtable.h > +++ b/arch/alpha/include/asm/pgtable.h > @@ -313,8 +313,6 @@ extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > #define pte_ERROR(e) \ > printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) > #define pmd_ERROR(e) \ > diff --git a/arch/arc/include/asm/pgtable-bits-arcv2.h b/arch/arc/include/asm/pgtable-bits-arcv2.h > index b23be557403e..515e82db519f 100644 > --- a/arch/arc/include/asm/pgtable-bits-arcv2.h > +++ b/arch/arc/include/asm/pgtable-bits-arcv2.h > @@ -120,8 +120,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > #include <asm/hugepage.h> > #endif > diff --git a/arch/arm/include/asm/pgtable-nommu.h b/arch/arm/include/asm/pgtable-nommu.h > index d16aba48fa0a..25d8c7bb07e0 100644 > --- a/arch/arm/include/asm/pgtable-nommu.h > +++ b/arch/arm/include/asm/pgtable-nommu.h > @@ -21,8 +21,6 @@ > #define pgd_none(pgd) (0) > #define pgd_bad(pgd) (0) > #define pgd_clear(pgdp) > -#define kern_addr_valid(addr) (1) > -/* FIXME */ > /* > * PMD_SHIFT determines the size of the area a second-level page table can map > * PGDIR_SHIFT determines what a third-level page table entry can map > diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h > index 78a532068fec..00954ab1a039 100644 > --- a/arch/arm/include/asm/pgtable.h > +++ b/arch/arm/include/asm/pgtable.h > @@ -298,10 +298,6 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) > */ > #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) > > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -/* FIXME: this is not correct */ > -#define kern_addr_valid(addr) (1) > - > /* > * We provide our own arch_get_unmapped_area to cope with VIPT caches. > */ > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 71a1af42f0e8..4873c1d6e7d0 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -1021,8 +1021,6 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, > */ > #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) > > -extern int kern_addr_valid(unsigned long addr); > - > #ifdef CONFIG_ARM64_MTE > > #define __HAVE_ARCH_PREPARE_TO_SWAP > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 9a7c38965154..556154d821bf 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -814,53 +814,6 @@ void __init paging_init(void) > create_idmap(); > } > > -/* > - * Check whether a kernel address is valid (derived from arch/x86/). > - */ > -int kern_addr_valid(unsigned long addr) > -{ > - pgd_t *pgdp; > - p4d_t *p4dp; > - pud_t *pudp, pud; > - pmd_t *pmdp, pmd; > - pte_t *ptep, pte; > - > - addr = arch_kasan_reset_tag(addr); > - if ((((long)addr) >> VA_BITS) != -1UL) > - return 0; > - > - pgdp = pgd_offset_k(addr); > - if (pgd_none(READ_ONCE(*pgdp))) > - return 0; > - > - p4dp = p4d_offset(pgdp, addr); > - if (p4d_none(READ_ONCE(*p4dp))) > - return 0; > - > - pudp = pud_offset(p4dp, addr); > - pud = READ_ONCE(*pudp); > - if (pud_none(pud)) > - return 0; > - > - if (pud_sect(pud)) > - return pfn_valid(pud_pfn(pud)); > - > - pmdp = pmd_offset(pudp, addr); > - pmd = READ_ONCE(*pmdp); > - if (pmd_none(pmd)) > - return 0; > - > - if (pmd_sect(pmd)) > - return pfn_valid(pmd_pfn(pmd)); > - > - ptep = pte_offset_kernel(pmdp, addr); > - pte = READ_ONCE(*ptep); > - if (pte_none(pte)) > - return 0; > - > - return pfn_valid(pte_pfn(pte)); > -} > - > #ifdef CONFIG_MEMORY_HOTPLUG > static void free_hotplug_page_range(struct page *page, size_t size, > struct vmem_altmap *altmap) > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index d107c3d434e2..0a741a910a6a 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -201,8 +201,7 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) > > /* > * This function is used to determine if a linear map page has been marked as > - * not-valid. Walk the page table and check the PTE_VALID bit. This is based > - * on kern_addr_valid(), which almost does what we need. > + * not-valid. Walk the page table and check the PTE_VALID bit. > * > * Because this is only called on the kernel linear map, p?d_sect() implies > * p?d_present(). When debug_pagealloc is enabled, sections mappings are > diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h > index c3d9b92cbe61..77bc6caff2d2 100644 > --- a/arch/csky/include/asm/pgtable.h > +++ b/arch/csky/include/asm/pgtable.h > @@ -249,9 +249,6 @@ extern void paging_init(void); > void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, > pte_t *pte); > > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -#define kern_addr_valid(addr) (1) > - Clean is good for me. Acked-by: Guo Ren <guoren@kernel.org> # csky part > #define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \ > remap_pfn_range(vma, vaddr, pfn, size, prot) > > diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h > index 7cbf719c578e..d7d4f9fca327 100644 > --- a/arch/hexagon/include/asm/page.h > +++ b/arch/hexagon/include/asm/page.h > @@ -131,13 +131,6 @@ static inline void clear_page(void *page) > > #define page_to_virt(page) __va(page_to_phys(page)) > > -/* > - * For port to Hexagon Virtual Machine, MAYBE we check for attempts > - * to reference reserved HVM space, but in any case, the VM will be > - * protected. > - */ > -#define kern_addr_valid(addr) (1) > - > #include <asm/mem-layout.h> > #include <asm-generic/memory_model.h> > /* XXX Todo: implement assembly-optimized version of getorder. */ > diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h > index 6925e28ae61d..01517a5e6778 100644 > --- a/arch/ia64/include/asm/pgtable.h > +++ b/arch/ia64/include/asm/pgtable.h > @@ -181,22 +181,6 @@ ia64_phys_addr_valid (unsigned long addr) > return (addr & (local_cpu_data->unimpl_pa_mask)) == 0; > } > > -/* > - * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel > - * memory. For the return value to be meaningful, ADDR must be >= > - * PAGE_OFFSET. This operation can be relatively expensive (e.g., > - * require a hash-, or multi-level tree-lookup or something of that > - * sort) but it guarantees to return TRUE only if accessing the page > - * at that address does not cause an error. Note that there may be > - * addresses for which kern_addr_valid() returns FALSE even though an > - * access would not cause an error (e.g., this is typically true for > - * memory mapped I/O regions. > - * > - * XXX Need to implement this for IA-64. > - */ > -#define kern_addr_valid(addr) (1) > - > - > /* > * Now come the defines and routines to manage and access the three-level > * page table. > diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h > index 946704bee599..fc70b7041b76 100644 > --- a/arch/loongarch/include/asm/pgtable.h > +++ b/arch/loongarch/include/asm/pgtable.h > @@ -421,8 +421,6 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, > __update_tlb(vma, address, (pte_t *)pmdp); > } > > -#define kern_addr_valid(addr) (1) > - > static inline unsigned long pmd_pfn(pmd_t pmd) > { > return (pmd_val(pmd) & _PFN_MASK) >> _PFN_SHIFT; > diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h > index 9b4e2fe2ac82..b93c41fe2067 100644 > --- a/arch/m68k/include/asm/pgtable_mm.h > +++ b/arch/m68k/include/asm/pgtable_mm.h > @@ -145,8 +145,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, > > #endif /* !__ASSEMBLY__ */ > > -#define kern_addr_valid(addr) (1) > - > /* MMU-specific headers */ > > #ifdef CONFIG_SUN3 > diff --git a/arch/m68k/include/asm/pgtable_no.h b/arch/m68k/include/asm/pgtable_no.h > index bce5ca56c388..fed58da3a6b6 100644 > --- a/arch/m68k/include/asm/pgtable_no.h > +++ b/arch/m68k/include/asm/pgtable_no.h > @@ -20,7 +20,6 @@ > #define pgd_none(pgd) (0) > #define pgd_bad(pgd) (0) > #define pgd_clear(pgdp) > -#define kern_addr_valid(addr) (1) > #define pmd_offset(a, b) ((void *)0) > > #define PAGE_NONE __pgprot(0) > diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h > index ba348e997dbb..42f5988e998b 100644 > --- a/arch/microblaze/include/asm/pgtable.h > +++ b/arch/microblaze/include/asm/pgtable.h > @@ -416,9 +416,6 @@ extern unsigned long iopa(unsigned long addr); > #define IOMAP_NOCACHE_NONSER 2 > #define IOMAP_NO_COPYBACK 3 > > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -#define kern_addr_valid(addr) (1) > - > void do_page_fault(struct pt_regs *regs, unsigned long address, > unsigned long error_code); > > diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h > index 6caec386ad2f..364a06033105 100644 > --- a/arch/mips/include/asm/pgtable.h > +++ b/arch/mips/include/asm/pgtable.h > @@ -550,8 +550,6 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, > __update_tlb(vma, address, pte); > } > > -#define kern_addr_valid(addr) (1) > - > /* > * Allow physical addresses to be fixed up to help 36-bit peripherals. > */ > diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h > index b3d45e815295..ab793bc517f5 100644 > --- a/arch/nios2/include/asm/pgtable.h > +++ b/arch/nios2/include/asm/pgtable.h > @@ -249,8 +249,6 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) > #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > > -#define kern_addr_valid(addr) (1) > - > extern void __init paging_init(void); > extern void __init mmu_init(void); > > diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h > index dcae8aea132f..6477c17b3062 100644 > --- a/arch/openrisc/include/asm/pgtable.h > +++ b/arch/openrisc/include/asm/pgtable.h > @@ -395,8 +395,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > typedef pte_t *pte_addr_t; > > #endif /* __ASSEMBLY__ */ > diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h > index ecd028854469..bd09a44cfb2d 100644 > --- a/arch/parisc/include/asm/pgtable.h > +++ b/arch/parisc/include/asm/pgtable.h > @@ -23,21 +23,6 @@ > #include <asm/processor.h> > #include <asm/cache.h> > > -/* > - * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel > - * memory. For the return value to be meaningful, ADDR must be >= > - * PAGE_OFFSET. This operation can be relatively expensive (e.g., > - * require a hash-, or multi-level tree-lookup or something of that > - * sort) but it guarantees to return TRUE only if accessing the page > - * at that address does not cause an error. Note that there may be > - * addresses for which kern_addr_valid() returns FALSE even though an > - * access would not cause an error (e.g., this is typically true for > - * memory mapped I/O regions. > - * > - * XXX Need to implement this for parisc. > - */ > -#define kern_addr_valid(addr) (1) > - > /* This is for the serialization of PxTLB broadcasts. At least on the N class > * systems, only one PxTLB inter processor broadcast can be active at any one > * time on the Merced bus. */ > diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h > index 283f40d05a4d..9972626ddaf6 100644 > --- a/arch/powerpc/include/asm/pgtable.h > +++ b/arch/powerpc/include/asm/pgtable.h > @@ -81,13 +81,6 @@ void poking_init(void); > extern unsigned long ioremap_bot; > extern const pgprot_t protection_map[16]; > > -/* > - * kern_addr_valid is intended to indicate whether an address is a valid > - * kernel address. Most 32-bit archs define it as always true (like this) > - * but most 64-bit archs actually perform a test. What should we do here? > - */ > -#define kern_addr_valid(addr) (1) > - > #ifndef CONFIG_TRANSPARENT_HUGEPAGE > #define pmd_large(pmd) 0 > #endif > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index 7ec936910a96..c7993bdf749f 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -801,8 +801,6 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, > > #endif /* !CONFIG_MMU */ > > -#define kern_addr_valid(addr) (1) /* FIXME */ > - > extern char _start[]; > extern void *_dtb_early_va; > extern uintptr_t _dtb_early_pa; > diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h > index f1cb9391190d..e1db07211818 100644 > --- a/arch/s390/include/asm/pgtable.h > +++ b/arch/s390/include/asm/pgtable.h > @@ -1773,8 +1773,6 @@ static inline swp_entry_t __swp_entry(unsigned long type, unsigned long offset) > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > extern int vmem_add_mapping(unsigned long start, unsigned long size); > extern void vmem_remove_mapping(unsigned long start, unsigned long size); > extern int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc); > diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h > index 6fb9ec54cf9b..3ce30becf6df 100644 > --- a/arch/sh/include/asm/pgtable.h > +++ b/arch/sh/include/asm/pgtable.h > @@ -92,8 +92,6 @@ static inline unsigned long phys_addr_mask(void) > > typedef pte_t *pte_addr_t; > > -#define kern_addr_valid(addr) (1) > - > #define pte_pfn(x) ((unsigned long)(((x).pte_low >> PAGE_SHIFT))) > > struct vm_area_struct; > diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h > index 8ff549004fac..5acc05b572e6 100644 > --- a/arch/sparc/include/asm/pgtable_32.h > +++ b/arch/sparc/include/asm/pgtable_32.h > @@ -368,12 +368,6 @@ __get_iospace (unsigned long addr) > } > } > > -extern unsigned long *sparc_valid_addr_bitmap; > - > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -#define kern_addr_valid(addr) \ > - (test_bit(__pa((unsigned long)(addr))>>20, sparc_valid_addr_bitmap)) > - > /* > * For sparc32&64, the pfn in io_remap_pfn_range() carries <iospace> in > * its high 4 bits. These macros/functions put it there or get it from there. > diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c > index d88e774c8eb4..9c0ea457bdf0 100644 > --- a/arch/sparc/mm/init_32.c > +++ b/arch/sparc/mm/init_32.c > @@ -37,8 +37,7 @@ > > #include "mm_32.h" > > -unsigned long *sparc_valid_addr_bitmap; > -EXPORT_SYMBOL(sparc_valid_addr_bitmap); > +static unsigned long *sparc_valid_addr_bitmap; > > unsigned long phys_base; > EXPORT_SYMBOL(phys_base); > diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c > index d6faee23c77d..04f9db0c3111 100644 > --- a/arch/sparc/mm/init_64.c > +++ b/arch/sparc/mm/init_64.c > @@ -1667,7 +1667,6 @@ bool kern_addr_valid(unsigned long addr) > > return pfn_valid(pte_pfn(*pte)); > } > -EXPORT_SYMBOL(kern_addr_valid); > > static unsigned long __ref kernel_map_hugepud(unsigned long vstart, > unsigned long vend, > diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h > index 66bc3f99d9be..4e3052f2671a 100644 > --- a/arch/um/include/asm/pgtable.h > +++ b/arch/um/include/asm/pgtable.h > @@ -298,8 +298,6 @@ extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr); > ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > /* Clear a kernel PTE and flush it from the TLB */ > #define kpte_clear_flush(ptep, vaddr) \ > do { \ > diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h > index 7c9c968a42ef..7d4ad8907297 100644 > --- a/arch/x86/include/asm/pgtable_32.h > +++ b/arch/x86/include/asm/pgtable_32.h > @@ -47,15 +47,6 @@ do { \ > > #endif /* !__ASSEMBLY__ */ > > -/* > - * kern_addr_valid() is (1) for FLATMEM and (0) for SPARSEMEM > - */ > -#ifdef CONFIG_FLATMEM > -#define kern_addr_valid(addr) (1) > -#else > -#define kern_addr_valid(kaddr) (0) > -#endif > - > /* > * This is used to calculate the .brk reservation for initial pagetables. > * Enough space is reserved to allocate pagetables sufficient to cover all > diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h > index e479491da8d5..7929327abe00 100644 > --- a/arch/x86/include/asm/pgtable_64.h > +++ b/arch/x86/include/asm/pgtable_64.h > @@ -240,7 +240,6 @@ static inline void native_pgd_clear(pgd_t *pgd) > #define __swp_entry_to_pte(x) ((pte_t) { .pte = (x).val }) > #define __swp_entry_to_pmd(x) ((pmd_t) { .pmd = (x).val }) > > -extern int kern_addr_valid(unsigned long addr); > extern void cleanup_highmap(void); > > #define HAVE_ARCH_UNMAPPED_AREA > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 3f040c6e5d13..e8db4edd7cc9 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -1416,47 +1416,6 @@ void mark_rodata_ro(void) > debug_checkwx(); > } > > -int kern_addr_valid(unsigned long addr) > -{ > - unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; > - pgd_t *pgd; > - p4d_t *p4d; > - pud_t *pud; > - pmd_t *pmd; > - pte_t *pte; > - > - if (above != 0 && above != -1UL) > - return 0; > - > - pgd = pgd_offset_k(addr); > - if (pgd_none(*pgd)) > - return 0; > - > - p4d = p4d_offset(pgd, addr); > - if (!p4d_present(*p4d)) > - return 0; > - > - pud = pud_offset(p4d, addr); > - if (!pud_present(*pud)) > - return 0; > - > - if (pud_large(*pud)) > - return pfn_valid(pud_pfn(*pud)); > - > - pmd = pmd_offset(pud, addr); > - if (!pmd_present(*pmd)) > - return 0; > - > - if (pmd_large(*pmd)) > - return pfn_valid(pmd_pfn(*pmd)); > - > - pte = pte_offset_kernel(pmd, addr); > - if (pte_none(*pte)) > - return 0; > - > - return pfn_valid(pte_pfn(*pte)); > -} > - > /* > * Block size is the minimum amount of memory which can be hotplugged or > * hotremoved. It must be power of two and must be equal or larger than > diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h > index 54f577c13afa..5b5484d707b2 100644 > --- a/arch/xtensa/include/asm/pgtable.h > +++ b/arch/xtensa/include/asm/pgtable.h > @@ -386,8 +386,6 @@ ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) > > #else > > -#define kern_addr_valid(addr) (1) > - > extern void update_mmu_cache(struct vm_area_struct * vma, > unsigned long address, pte_t *ptep); > > diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c > index dff921f7ca33..590ecb79ad8b 100644 > --- a/fs/proc/kcore.c > +++ b/fs/proc/kcore.c > @@ -541,25 +541,17 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) > fallthrough; > case KCORE_VMEMMAP: > case KCORE_TEXT: > - if (kern_addr_valid(start)) { > - /* > - * Using bounce buffer to bypass the > - * hardened user copy kernel text checks. > - */ > - if (copy_from_kernel_nofault(buf, (void *)start, > - tsz)) { > - if (clear_user(buffer, tsz)) { > - ret = -EFAULT; > - goto out; > - } > - } else { > - if (copy_to_user(buffer, buf, tsz)) { > - ret = -EFAULT; > - goto out; > - } > + /* > + * Using bounce buffer to bypass the > + * hardened user copy kernel text checks. > + */ > + if (copy_from_kernel_nofault(buf, (void *)start, tsz)) { > + if (clear_user(buffer, tsz)) { > + ret = -EFAULT; > + goto out; > } > } else { > - if (clear_user(buffer, tsz)) { > + if (copy_to_user(buffer, buf, tsz)) { > ret = -EFAULT; > goto out; > } > -- > 2.35.3 >
On Tue, Oct 18, 2022 at 03:40:14PM +0800, Kefeng Wang wrote: > Most architectures(except arm64/x86/sparc) simply return 1 for > kern_addr_valid(), which is only used in read_kcore(), and it > calls copy_from_kernel_nofault() which could check whether the > address is a valid kernel address, so no need kern_addr_valid(), > let's remove unneeded kern_addr_valid() completely. > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> For arm64: Acked-by: Catalin Marinas <catalin.marinas@arm.com>
On Tue, 18 Oct 2022 00:40:14 PDT (-0700), wangkefeng.wang@huawei.com wrote: > Most architectures(except arm64/x86/sparc) simply return 1 for > kern_addr_valid(), which is only used in read_kcore(), and it > calls copy_from_kernel_nofault() which could check whether the > address is a valid kernel address, so no need kern_addr_valid(), > let's remove unneeded kern_addr_valid() completely. > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > arch/alpha/include/asm/pgtable.h | 2 - > arch/arc/include/asm/pgtable-bits-arcv2.h | 2 - > arch/arm/include/asm/pgtable-nommu.h | 2 - > arch/arm/include/asm/pgtable.h | 4 -- > arch/arm64/include/asm/pgtable.h | 2 - > arch/arm64/mm/mmu.c | 47 ----------------------- > arch/arm64/mm/pageattr.c | 3 +- > arch/csky/include/asm/pgtable.h | 3 -- > arch/hexagon/include/asm/page.h | 7 ---- > arch/ia64/include/asm/pgtable.h | 16 -------- > arch/loongarch/include/asm/pgtable.h | 2 - > arch/m68k/include/asm/pgtable_mm.h | 2 - > arch/m68k/include/asm/pgtable_no.h | 1 - > arch/microblaze/include/asm/pgtable.h | 3 -- > arch/mips/include/asm/pgtable.h | 2 - > arch/nios2/include/asm/pgtable.h | 2 - > arch/openrisc/include/asm/pgtable.h | 2 - > arch/parisc/include/asm/pgtable.h | 15 -------- > arch/powerpc/include/asm/pgtable.h | 7 ---- > arch/riscv/include/asm/pgtable.h | 2 - > arch/s390/include/asm/pgtable.h | 2 - > arch/sh/include/asm/pgtable.h | 2 - > arch/sparc/include/asm/pgtable_32.h | 6 --- > arch/sparc/mm/init_32.c | 3 +- > arch/sparc/mm/init_64.c | 1 - > arch/um/include/asm/pgtable.h | 2 - > arch/x86/include/asm/pgtable_32.h | 9 ----- > arch/x86/include/asm/pgtable_64.h | 1 - > arch/x86/mm/init_64.c | 41 -------------------- > arch/xtensa/include/asm/pgtable.h | 2 - > fs/proc/kcore.c | 26 +++++-------- > 31 files changed, 11 insertions(+), 210 deletions(-) > > diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h > index 3ea9661c09ff..9e45f6735d5d 100644 > --- a/arch/alpha/include/asm/pgtable.h > +++ b/arch/alpha/include/asm/pgtable.h > @@ -313,8 +313,6 @@ extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > #define pte_ERROR(e) \ > printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) > #define pmd_ERROR(e) \ > diff --git a/arch/arc/include/asm/pgtable-bits-arcv2.h b/arch/arc/include/asm/pgtable-bits-arcv2.h > index b23be557403e..515e82db519f 100644 > --- a/arch/arc/include/asm/pgtable-bits-arcv2.h > +++ b/arch/arc/include/asm/pgtable-bits-arcv2.h > @@ -120,8 +120,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > #include <asm/hugepage.h> > #endif > diff --git a/arch/arm/include/asm/pgtable-nommu.h b/arch/arm/include/asm/pgtable-nommu.h > index d16aba48fa0a..25d8c7bb07e0 100644 > --- a/arch/arm/include/asm/pgtable-nommu.h > +++ b/arch/arm/include/asm/pgtable-nommu.h > @@ -21,8 +21,6 @@ > #define pgd_none(pgd) (0) > #define pgd_bad(pgd) (0) > #define pgd_clear(pgdp) > -#define kern_addr_valid(addr) (1) > -/* FIXME */ > /* > * PMD_SHIFT determines the size of the area a second-level page table can map > * PGDIR_SHIFT determines what a third-level page table entry can map > diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h > index 78a532068fec..00954ab1a039 100644 > --- a/arch/arm/include/asm/pgtable.h > +++ b/arch/arm/include/asm/pgtable.h > @@ -298,10 +298,6 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) > */ > #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) > > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -/* FIXME: this is not correct */ > -#define kern_addr_valid(addr) (1) > - > /* > * We provide our own arch_get_unmapped_area to cope with VIPT caches. > */ > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 71a1af42f0e8..4873c1d6e7d0 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -1021,8 +1021,6 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, > */ > #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) > > -extern int kern_addr_valid(unsigned long addr); > - > #ifdef CONFIG_ARM64_MTE > > #define __HAVE_ARCH_PREPARE_TO_SWAP > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 9a7c38965154..556154d821bf 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -814,53 +814,6 @@ void __init paging_init(void) > create_idmap(); > } > > -/* > - * Check whether a kernel address is valid (derived from arch/x86/). > - */ > -int kern_addr_valid(unsigned long addr) > -{ > - pgd_t *pgdp; > - p4d_t *p4dp; > - pud_t *pudp, pud; > - pmd_t *pmdp, pmd; > - pte_t *ptep, pte; > - > - addr = arch_kasan_reset_tag(addr); > - if ((((long)addr) >> VA_BITS) != -1UL) > - return 0; > - > - pgdp = pgd_offset_k(addr); > - if (pgd_none(READ_ONCE(*pgdp))) > - return 0; > - > - p4dp = p4d_offset(pgdp, addr); > - if (p4d_none(READ_ONCE(*p4dp))) > - return 0; > - > - pudp = pud_offset(p4dp, addr); > - pud = READ_ONCE(*pudp); > - if (pud_none(pud)) > - return 0; > - > - if (pud_sect(pud)) > - return pfn_valid(pud_pfn(pud)); > - > - pmdp = pmd_offset(pudp, addr); > - pmd = READ_ONCE(*pmdp); > - if (pmd_none(pmd)) > - return 0; > - > - if (pmd_sect(pmd)) > - return pfn_valid(pmd_pfn(pmd)); > - > - ptep = pte_offset_kernel(pmdp, addr); > - pte = READ_ONCE(*ptep); > - if (pte_none(pte)) > - return 0; > - > - return pfn_valid(pte_pfn(pte)); > -} > - > #ifdef CONFIG_MEMORY_HOTPLUG > static void free_hotplug_page_range(struct page *page, size_t size, > struct vmem_altmap *altmap) > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index d107c3d434e2..0a741a910a6a 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -201,8 +201,7 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) > > /* > * This function is used to determine if a linear map page has been marked as > - * not-valid. Walk the page table and check the PTE_VALID bit. This is based > - * on kern_addr_valid(), which almost does what we need. > + * not-valid. Walk the page table and check the PTE_VALID bit. > * > * Because this is only called on the kernel linear map, p?d_sect() implies > * p?d_present(). When debug_pagealloc is enabled, sections mappings are > diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h > index c3d9b92cbe61..77bc6caff2d2 100644 > --- a/arch/csky/include/asm/pgtable.h > +++ b/arch/csky/include/asm/pgtable.h > @@ -249,9 +249,6 @@ extern void paging_init(void); > void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, > pte_t *pte); > > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -#define kern_addr_valid(addr) (1) > - > #define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \ > remap_pfn_range(vma, vaddr, pfn, size, prot) > > diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h > index 7cbf719c578e..d7d4f9fca327 100644 > --- a/arch/hexagon/include/asm/page.h > +++ b/arch/hexagon/include/asm/page.h > @@ -131,13 +131,6 @@ static inline void clear_page(void *page) > > #define page_to_virt(page) __va(page_to_phys(page)) > > -/* > - * For port to Hexagon Virtual Machine, MAYBE we check for attempts > - * to reference reserved HVM space, but in any case, the VM will be > - * protected. > - */ > -#define kern_addr_valid(addr) (1) > - > #include <asm/mem-layout.h> > #include <asm-generic/memory_model.h> > /* XXX Todo: implement assembly-optimized version of getorder. */ > diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h > index 6925e28ae61d..01517a5e6778 100644 > --- a/arch/ia64/include/asm/pgtable.h > +++ b/arch/ia64/include/asm/pgtable.h > @@ -181,22 +181,6 @@ ia64_phys_addr_valid (unsigned long addr) > return (addr & (local_cpu_data->unimpl_pa_mask)) == 0; > } > > -/* > - * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel > - * memory. For the return value to be meaningful, ADDR must be >= > - * PAGE_OFFSET. This operation can be relatively expensive (e.g., > - * require a hash-, or multi-level tree-lookup or something of that > - * sort) but it guarantees to return TRUE only if accessing the page > - * at that address does not cause an error. Note that there may be > - * addresses for which kern_addr_valid() returns FALSE even though an > - * access would not cause an error (e.g., this is typically true for > - * memory mapped I/O regions. > - * > - * XXX Need to implement this for IA-64. > - */ > -#define kern_addr_valid(addr) (1) > - > - > /* > * Now come the defines and routines to manage and access the three-level > * page table. > diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h > index 946704bee599..fc70b7041b76 100644 > --- a/arch/loongarch/include/asm/pgtable.h > +++ b/arch/loongarch/include/asm/pgtable.h > @@ -421,8 +421,6 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, > __update_tlb(vma, address, (pte_t *)pmdp); > } > > -#define kern_addr_valid(addr) (1) > - > static inline unsigned long pmd_pfn(pmd_t pmd) > { > return (pmd_val(pmd) & _PFN_MASK) >> _PFN_SHIFT; > diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h > index 9b4e2fe2ac82..b93c41fe2067 100644 > --- a/arch/m68k/include/asm/pgtable_mm.h > +++ b/arch/m68k/include/asm/pgtable_mm.h > @@ -145,8 +145,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, > > #endif /* !__ASSEMBLY__ */ > > -#define kern_addr_valid(addr) (1) > - > /* MMU-specific headers */ > > #ifdef CONFIG_SUN3 > diff --git a/arch/m68k/include/asm/pgtable_no.h b/arch/m68k/include/asm/pgtable_no.h > index bce5ca56c388..fed58da3a6b6 100644 > --- a/arch/m68k/include/asm/pgtable_no.h > +++ b/arch/m68k/include/asm/pgtable_no.h > @@ -20,7 +20,6 @@ > #define pgd_none(pgd) (0) > #define pgd_bad(pgd) (0) > #define pgd_clear(pgdp) > -#define kern_addr_valid(addr) (1) > #define pmd_offset(a, b) ((void *)0) > > #define PAGE_NONE __pgprot(0) > diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h > index ba348e997dbb..42f5988e998b 100644 > --- a/arch/microblaze/include/asm/pgtable.h > +++ b/arch/microblaze/include/asm/pgtable.h > @@ -416,9 +416,6 @@ extern unsigned long iopa(unsigned long addr); > #define IOMAP_NOCACHE_NONSER 2 > #define IOMAP_NO_COPYBACK 3 > > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -#define kern_addr_valid(addr) (1) > - > void do_page_fault(struct pt_regs *regs, unsigned long address, > unsigned long error_code); > > diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h > index 6caec386ad2f..364a06033105 100644 > --- a/arch/mips/include/asm/pgtable.h > +++ b/arch/mips/include/asm/pgtable.h > @@ -550,8 +550,6 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, > __update_tlb(vma, address, pte); > } > > -#define kern_addr_valid(addr) (1) > - > /* > * Allow physical addresses to be fixed up to help 36-bit peripherals. > */ > diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h > index b3d45e815295..ab793bc517f5 100644 > --- a/arch/nios2/include/asm/pgtable.h > +++ b/arch/nios2/include/asm/pgtable.h > @@ -249,8 +249,6 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) > #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > > -#define kern_addr_valid(addr) (1) > - > extern void __init paging_init(void); > extern void __init mmu_init(void); > > diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h > index dcae8aea132f..6477c17b3062 100644 > --- a/arch/openrisc/include/asm/pgtable.h > +++ b/arch/openrisc/include/asm/pgtable.h > @@ -395,8 +395,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > typedef pte_t *pte_addr_t; > > #endif /* __ASSEMBLY__ */ > diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h > index ecd028854469..bd09a44cfb2d 100644 > --- a/arch/parisc/include/asm/pgtable.h > +++ b/arch/parisc/include/asm/pgtable.h > @@ -23,21 +23,6 @@ > #include <asm/processor.h> > #include <asm/cache.h> > > -/* > - * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel > - * memory. For the return value to be meaningful, ADDR must be >= > - * PAGE_OFFSET. This operation can be relatively expensive (e.g., > - * require a hash-, or multi-level tree-lookup or something of that > - * sort) but it guarantees to return TRUE only if accessing the page > - * at that address does not cause an error. Note that there may be > - * addresses for which kern_addr_valid() returns FALSE even though an > - * access would not cause an error (e.g., this is typically true for > - * memory mapped I/O regions. > - * > - * XXX Need to implement this for parisc. > - */ > -#define kern_addr_valid(addr) (1) > - > /* This is for the serialization of PxTLB broadcasts. At least on the N class > * systems, only one PxTLB inter processor broadcast can be active at any one > * time on the Merced bus. */ > diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h > index 283f40d05a4d..9972626ddaf6 100644 > --- a/arch/powerpc/include/asm/pgtable.h > +++ b/arch/powerpc/include/asm/pgtable.h > @@ -81,13 +81,6 @@ void poking_init(void); > extern unsigned long ioremap_bot; > extern const pgprot_t protection_map[16]; > > -/* > - * kern_addr_valid is intended to indicate whether an address is a valid > - * kernel address. Most 32-bit archs define it as always true (like this) > - * but most 64-bit archs actually perform a test. What should we do here? > - */ > -#define kern_addr_valid(addr) (1) > - > #ifndef CONFIG_TRANSPARENT_HUGEPAGE > #define pmd_large(pmd) 0 > #endif > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index 7ec936910a96..c7993bdf749f 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -801,8 +801,6 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, > > #endif /* !CONFIG_MMU */ > > -#define kern_addr_valid(addr) (1) /* FIXME */ > - > extern char _start[]; > extern void *_dtb_early_va; > extern uintptr_t _dtb_early_pa; > diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h > index f1cb9391190d..e1db07211818 100644 > --- a/arch/s390/include/asm/pgtable.h > +++ b/arch/s390/include/asm/pgtable.h > @@ -1773,8 +1773,6 @@ static inline swp_entry_t __swp_entry(unsigned long type, unsigned long offset) > #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > extern int vmem_add_mapping(unsigned long start, unsigned long size); > extern void vmem_remove_mapping(unsigned long start, unsigned long size); > extern int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc); > diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h > index 6fb9ec54cf9b..3ce30becf6df 100644 > --- a/arch/sh/include/asm/pgtable.h > +++ b/arch/sh/include/asm/pgtable.h > @@ -92,8 +92,6 @@ static inline unsigned long phys_addr_mask(void) > > typedef pte_t *pte_addr_t; > > -#define kern_addr_valid(addr) (1) > - > #define pte_pfn(x) ((unsigned long)(((x).pte_low >> PAGE_SHIFT))) > > struct vm_area_struct; > diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h > index 8ff549004fac..5acc05b572e6 100644 > --- a/arch/sparc/include/asm/pgtable_32.h > +++ b/arch/sparc/include/asm/pgtable_32.h > @@ -368,12 +368,6 @@ __get_iospace (unsigned long addr) > } > } > > -extern unsigned long *sparc_valid_addr_bitmap; > - > -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ > -#define kern_addr_valid(addr) \ > - (test_bit(__pa((unsigned long)(addr))>>20, sparc_valid_addr_bitmap)) > - > /* > * For sparc32&64, the pfn in io_remap_pfn_range() carries <iospace> in > * its high 4 bits. These macros/functions put it there or get it from there. > diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c > index d88e774c8eb4..9c0ea457bdf0 100644 > --- a/arch/sparc/mm/init_32.c > +++ b/arch/sparc/mm/init_32.c > @@ -37,8 +37,7 @@ > > #include "mm_32.h" > > -unsigned long *sparc_valid_addr_bitmap; > -EXPORT_SYMBOL(sparc_valid_addr_bitmap); > +static unsigned long *sparc_valid_addr_bitmap; > > unsigned long phys_base; > EXPORT_SYMBOL(phys_base); > diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c > index d6faee23c77d..04f9db0c3111 100644 > --- a/arch/sparc/mm/init_64.c > +++ b/arch/sparc/mm/init_64.c > @@ -1667,7 +1667,6 @@ bool kern_addr_valid(unsigned long addr) > > return pfn_valid(pte_pfn(*pte)); > } > -EXPORT_SYMBOL(kern_addr_valid); > > static unsigned long __ref kernel_map_hugepud(unsigned long vstart, > unsigned long vend, > diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h > index 66bc3f99d9be..4e3052f2671a 100644 > --- a/arch/um/include/asm/pgtable.h > +++ b/arch/um/include/asm/pgtable.h > @@ -298,8 +298,6 @@ extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr); > ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) }) > #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) > > -#define kern_addr_valid(addr) (1) > - > /* Clear a kernel PTE and flush it from the TLB */ > #define kpte_clear_flush(ptep, vaddr) \ > do { \ > diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h > index 7c9c968a42ef..7d4ad8907297 100644 > --- a/arch/x86/include/asm/pgtable_32.h > +++ b/arch/x86/include/asm/pgtable_32.h > @@ -47,15 +47,6 @@ do { \ > > #endif /* !__ASSEMBLY__ */ > > -/* > - * kern_addr_valid() is (1) for FLATMEM and (0) for SPARSEMEM > - */ > -#ifdef CONFIG_FLATMEM > -#define kern_addr_valid(addr) (1) > -#else > -#define kern_addr_valid(kaddr) (0) > -#endif > - > /* > * This is used to calculate the .brk reservation for initial pagetables. > * Enough space is reserved to allocate pagetables sufficient to cover all > diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h > index e479491da8d5..7929327abe00 100644 > --- a/arch/x86/include/asm/pgtable_64.h > +++ b/arch/x86/include/asm/pgtable_64.h > @@ -240,7 +240,6 @@ static inline void native_pgd_clear(pgd_t *pgd) > #define __swp_entry_to_pte(x) ((pte_t) { .pte = (x).val }) > #define __swp_entry_to_pmd(x) ((pmd_t) { .pmd = (x).val }) > > -extern int kern_addr_valid(unsigned long addr); > extern void cleanup_highmap(void); > > #define HAVE_ARCH_UNMAPPED_AREA > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 3f040c6e5d13..e8db4edd7cc9 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -1416,47 +1416,6 @@ void mark_rodata_ro(void) > debug_checkwx(); > } > > -int kern_addr_valid(unsigned long addr) > -{ > - unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; > - pgd_t *pgd; > - p4d_t *p4d; > - pud_t *pud; > - pmd_t *pmd; > - pte_t *pte; > - > - if (above != 0 && above != -1UL) > - return 0; > - > - pgd = pgd_offset_k(addr); > - if (pgd_none(*pgd)) > - return 0; > - > - p4d = p4d_offset(pgd, addr); > - if (!p4d_present(*p4d)) > - return 0; > - > - pud = pud_offset(p4d, addr); > - if (!pud_present(*pud)) > - return 0; > - > - if (pud_large(*pud)) > - return pfn_valid(pud_pfn(*pud)); > - > - pmd = pmd_offset(pud, addr); > - if (!pmd_present(*pmd)) > - return 0; > - > - if (pmd_large(*pmd)) > - return pfn_valid(pmd_pfn(*pmd)); > - > - pte = pte_offset_kernel(pmd, addr); > - if (pte_none(*pte)) > - return 0; > - > - return pfn_valid(pte_pfn(*pte)); > -} > - > /* > * Block size is the minimum amount of memory which can be hotplugged or > * hotremoved. It must be power of two and must be equal or larger than > diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h > index 54f577c13afa..5b5484d707b2 100644 > --- a/arch/xtensa/include/asm/pgtable.h > +++ b/arch/xtensa/include/asm/pgtable.h > @@ -386,8 +386,6 @@ ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) > > #else > > -#define kern_addr_valid(addr) (1) > - > extern void update_mmu_cache(struct vm_area_struct * vma, > unsigned long address, pte_t *ptep); > > diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c > index dff921f7ca33..590ecb79ad8b 100644 > --- a/fs/proc/kcore.c > +++ b/fs/proc/kcore.c > @@ -541,25 +541,17 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) > fallthrough; > case KCORE_VMEMMAP: > case KCORE_TEXT: > - if (kern_addr_valid(start)) { > - /* > - * Using bounce buffer to bypass the > - * hardened user copy kernel text checks. > - */ > - if (copy_from_kernel_nofault(buf, (void *)start, > - tsz)) { > - if (clear_user(buffer, tsz)) { > - ret = -EFAULT; > - goto out; > - } > - } else { > - if (copy_to_user(buffer, buf, tsz)) { > - ret = -EFAULT; > - goto out; > - } > + /* > + * Using bounce buffer to bypass the > + * hardened user copy kernel text checks. > + */ > + if (copy_from_kernel_nofault(buf, (void *)start, tsz)) { > + if (clear_user(buffer, tsz)) { > + ret = -EFAULT; > + goto out; > } > } else { > - if (clear_user(buffer, tsz)) { > + if (copy_to_user(buffer, buf, tsz)) { > ret = -EFAULT; > goto out; > } Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Thanks!
diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h index 3ea9661c09ff..9e45f6735d5d 100644 --- a/arch/alpha/include/asm/pgtable.h +++ b/arch/alpha/include/asm/pgtable.h @@ -313,8 +313,6 @@ extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) -#define kern_addr_valid(addr) (1) - #define pte_ERROR(e) \ printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) #define pmd_ERROR(e) \ diff --git a/arch/arc/include/asm/pgtable-bits-arcv2.h b/arch/arc/include/asm/pgtable-bits-arcv2.h index b23be557403e..515e82db519f 100644 --- a/arch/arc/include/asm/pgtable-bits-arcv2.h +++ b/arch/arc/include/asm/pgtable-bits-arcv2.h @@ -120,8 +120,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) -#define kern_addr_valid(addr) (1) - #ifdef CONFIG_TRANSPARENT_HUGEPAGE #include <asm/hugepage.h> #endif diff --git a/arch/arm/include/asm/pgtable-nommu.h b/arch/arm/include/asm/pgtable-nommu.h index d16aba48fa0a..25d8c7bb07e0 100644 --- a/arch/arm/include/asm/pgtable-nommu.h +++ b/arch/arm/include/asm/pgtable-nommu.h @@ -21,8 +21,6 @@ #define pgd_none(pgd) (0) #define pgd_bad(pgd) (0) #define pgd_clear(pgdp) -#define kern_addr_valid(addr) (1) -/* FIXME */ /* * PMD_SHIFT determines the size of the area a second-level page table can map * PGDIR_SHIFT determines what a third-level page table entry can map diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index 78a532068fec..00954ab1a039 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -298,10 +298,6 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) */ #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ -/* FIXME: this is not correct */ -#define kern_addr_valid(addr) (1) - /* * We provide our own arch_get_unmapped_area to cope with VIPT caches. */ diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 71a1af42f0e8..4873c1d6e7d0 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -1021,8 +1021,6 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, */ #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) -extern int kern_addr_valid(unsigned long addr); - #ifdef CONFIG_ARM64_MTE #define __HAVE_ARCH_PREPARE_TO_SWAP diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 9a7c38965154..556154d821bf 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -814,53 +814,6 @@ void __init paging_init(void) create_idmap(); } -/* - * Check whether a kernel address is valid (derived from arch/x86/). - */ -int kern_addr_valid(unsigned long addr) -{ - pgd_t *pgdp; - p4d_t *p4dp; - pud_t *pudp, pud; - pmd_t *pmdp, pmd; - pte_t *ptep, pte; - - addr = arch_kasan_reset_tag(addr); - if ((((long)addr) >> VA_BITS) != -1UL) - return 0; - - pgdp = pgd_offset_k(addr); - if (pgd_none(READ_ONCE(*pgdp))) - return 0; - - p4dp = p4d_offset(pgdp, addr); - if (p4d_none(READ_ONCE(*p4dp))) - return 0; - - pudp = pud_offset(p4dp, addr); - pud = READ_ONCE(*pudp); - if (pud_none(pud)) - return 0; - - if (pud_sect(pud)) - return pfn_valid(pud_pfn(pud)); - - pmdp = pmd_offset(pudp, addr); - pmd = READ_ONCE(*pmdp); - if (pmd_none(pmd)) - return 0; - - if (pmd_sect(pmd)) - return pfn_valid(pmd_pfn(pmd)); - - ptep = pte_offset_kernel(pmdp, addr); - pte = READ_ONCE(*ptep); - if (pte_none(pte)) - return 0; - - return pfn_valid(pte_pfn(pte)); -} - #ifdef CONFIG_MEMORY_HOTPLUG static void free_hotplug_page_range(struct page *page, size_t size, struct vmem_altmap *altmap) diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index d107c3d434e2..0a741a910a6a 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -201,8 +201,7 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) /* * This function is used to determine if a linear map page has been marked as - * not-valid. Walk the page table and check the PTE_VALID bit. This is based - * on kern_addr_valid(), which almost does what we need. + * not-valid. Walk the page table and check the PTE_VALID bit. * * Because this is only called on the kernel linear map, p?d_sect() implies * p?d_present(). When debug_pagealloc is enabled, sections mappings are diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h index c3d9b92cbe61..77bc6caff2d2 100644 --- a/arch/csky/include/asm/pgtable.h +++ b/arch/csky/include/asm/pgtable.h @@ -249,9 +249,6 @@ extern void paging_init(void); void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *pte); -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ -#define kern_addr_valid(addr) (1) - #define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \ remap_pfn_range(vma, vaddr, pfn, size, prot) diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h index 7cbf719c578e..d7d4f9fca327 100644 --- a/arch/hexagon/include/asm/page.h +++ b/arch/hexagon/include/asm/page.h @@ -131,13 +131,6 @@ static inline void clear_page(void *page) #define page_to_virt(page) __va(page_to_phys(page)) -/* - * For port to Hexagon Virtual Machine, MAYBE we check for attempts - * to reference reserved HVM space, but in any case, the VM will be - * protected. - */ -#define kern_addr_valid(addr) (1) - #include <asm/mem-layout.h> #include <asm-generic/memory_model.h> /* XXX Todo: implement assembly-optimized version of getorder. */ diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h index 6925e28ae61d..01517a5e6778 100644 --- a/arch/ia64/include/asm/pgtable.h +++ b/arch/ia64/include/asm/pgtable.h @@ -181,22 +181,6 @@ ia64_phys_addr_valid (unsigned long addr) return (addr & (local_cpu_data->unimpl_pa_mask)) == 0; } -/* - * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel - * memory. For the return value to be meaningful, ADDR must be >= - * PAGE_OFFSET. This operation can be relatively expensive (e.g., - * require a hash-, or multi-level tree-lookup or something of that - * sort) but it guarantees to return TRUE only if accessing the page - * at that address does not cause an error. Note that there may be - * addresses for which kern_addr_valid() returns FALSE even though an - * access would not cause an error (e.g., this is typically true for - * memory mapped I/O regions. - * - * XXX Need to implement this for IA-64. - */ -#define kern_addr_valid(addr) (1) - - /* * Now come the defines and routines to manage and access the three-level * page table. diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h index 946704bee599..fc70b7041b76 100644 --- a/arch/loongarch/include/asm/pgtable.h +++ b/arch/loongarch/include/asm/pgtable.h @@ -421,8 +421,6 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, __update_tlb(vma, address, (pte_t *)pmdp); } -#define kern_addr_valid(addr) (1) - static inline unsigned long pmd_pfn(pmd_t pmd) { return (pmd_val(pmd) & _PFN_MASK) >> _PFN_SHIFT; diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h index 9b4e2fe2ac82..b93c41fe2067 100644 --- a/arch/m68k/include/asm/pgtable_mm.h +++ b/arch/m68k/include/asm/pgtable_mm.h @@ -145,8 +145,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, #endif /* !__ASSEMBLY__ */ -#define kern_addr_valid(addr) (1) - /* MMU-specific headers */ #ifdef CONFIG_SUN3 diff --git a/arch/m68k/include/asm/pgtable_no.h b/arch/m68k/include/asm/pgtable_no.h index bce5ca56c388..fed58da3a6b6 100644 --- a/arch/m68k/include/asm/pgtable_no.h +++ b/arch/m68k/include/asm/pgtable_no.h @@ -20,7 +20,6 @@ #define pgd_none(pgd) (0) #define pgd_bad(pgd) (0) #define pgd_clear(pgdp) -#define kern_addr_valid(addr) (1) #define pmd_offset(a, b) ((void *)0) #define PAGE_NONE __pgprot(0) diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h index ba348e997dbb..42f5988e998b 100644 --- a/arch/microblaze/include/asm/pgtable.h +++ b/arch/microblaze/include/asm/pgtable.h @@ -416,9 +416,6 @@ extern unsigned long iopa(unsigned long addr); #define IOMAP_NOCACHE_NONSER 2 #define IOMAP_NO_COPYBACK 3 -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ -#define kern_addr_valid(addr) (1) - void do_page_fault(struct pt_regs *regs, unsigned long address, unsigned long error_code); diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h index 6caec386ad2f..364a06033105 100644 --- a/arch/mips/include/asm/pgtable.h +++ b/arch/mips/include/asm/pgtable.h @@ -550,8 +550,6 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, __update_tlb(vma, address, pte); } -#define kern_addr_valid(addr) (1) - /* * Allow physical addresses to be fixed up to help 36-bit peripherals. */ diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h index b3d45e815295..ab793bc517f5 100644 --- a/arch/nios2/include/asm/pgtable.h +++ b/arch/nios2/include/asm/pgtable.h @@ -249,8 +249,6 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) -#define kern_addr_valid(addr) (1) - extern void __init paging_init(void); extern void __init mmu_init(void); diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h index dcae8aea132f..6477c17b3062 100644 --- a/arch/openrisc/include/asm/pgtable.h +++ b/arch/openrisc/include/asm/pgtable.h @@ -395,8 +395,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) -#define kern_addr_valid(addr) (1) - typedef pte_t *pte_addr_t; #endif /* __ASSEMBLY__ */ diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h index ecd028854469..bd09a44cfb2d 100644 --- a/arch/parisc/include/asm/pgtable.h +++ b/arch/parisc/include/asm/pgtable.h @@ -23,21 +23,6 @@ #include <asm/processor.h> #include <asm/cache.h> -/* - * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel - * memory. For the return value to be meaningful, ADDR must be >= - * PAGE_OFFSET. This operation can be relatively expensive (e.g., - * require a hash-, or multi-level tree-lookup or something of that - * sort) but it guarantees to return TRUE only if accessing the page - * at that address does not cause an error. Note that there may be - * addresses for which kern_addr_valid() returns FALSE even though an - * access would not cause an error (e.g., this is typically true for - * memory mapped I/O regions. - * - * XXX Need to implement this for parisc. - */ -#define kern_addr_valid(addr) (1) - /* This is for the serialization of PxTLB broadcasts. At least on the N class * systems, only one PxTLB inter processor broadcast can be active at any one * time on the Merced bus. */ diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index 283f40d05a4d..9972626ddaf6 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -81,13 +81,6 @@ void poking_init(void); extern unsigned long ioremap_bot; extern const pgprot_t protection_map[16]; -/* - * kern_addr_valid is intended to indicate whether an address is a valid - * kernel address. Most 32-bit archs define it as always true (like this) - * but most 64-bit archs actually perform a test. What should we do here? - */ -#define kern_addr_valid(addr) (1) - #ifndef CONFIG_TRANSPARENT_HUGEPAGE #define pmd_large(pmd) 0 #endif diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 7ec936910a96..c7993bdf749f 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -801,8 +801,6 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, #endif /* !CONFIG_MMU */ -#define kern_addr_valid(addr) (1) /* FIXME */ - extern char _start[]; extern void *_dtb_early_va; extern uintptr_t _dtb_early_pa; diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index f1cb9391190d..e1db07211818 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1773,8 +1773,6 @@ static inline swp_entry_t __swp_entry(unsigned long type, unsigned long offset) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) -#define kern_addr_valid(addr) (1) - extern int vmem_add_mapping(unsigned long start, unsigned long size); extern void vmem_remove_mapping(unsigned long start, unsigned long size); extern int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc); diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h index 6fb9ec54cf9b..3ce30becf6df 100644 --- a/arch/sh/include/asm/pgtable.h +++ b/arch/sh/include/asm/pgtable.h @@ -92,8 +92,6 @@ static inline unsigned long phys_addr_mask(void) typedef pte_t *pte_addr_t; -#define kern_addr_valid(addr) (1) - #define pte_pfn(x) ((unsigned long)(((x).pte_low >> PAGE_SHIFT))) struct vm_area_struct; diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h index 8ff549004fac..5acc05b572e6 100644 --- a/arch/sparc/include/asm/pgtable_32.h +++ b/arch/sparc/include/asm/pgtable_32.h @@ -368,12 +368,6 @@ __get_iospace (unsigned long addr) } } -extern unsigned long *sparc_valid_addr_bitmap; - -/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ -#define kern_addr_valid(addr) \ - (test_bit(__pa((unsigned long)(addr))>>20, sparc_valid_addr_bitmap)) - /* * For sparc32&64, the pfn in io_remap_pfn_range() carries <iospace> in * its high 4 bits. These macros/functions put it there or get it from there. diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c index d88e774c8eb4..9c0ea457bdf0 100644 --- a/arch/sparc/mm/init_32.c +++ b/arch/sparc/mm/init_32.c @@ -37,8 +37,7 @@ #include "mm_32.h" -unsigned long *sparc_valid_addr_bitmap; -EXPORT_SYMBOL(sparc_valid_addr_bitmap); +static unsigned long *sparc_valid_addr_bitmap; unsigned long phys_base; EXPORT_SYMBOL(phys_base); diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index d6faee23c77d..04f9db0c3111 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -1667,7 +1667,6 @@ bool kern_addr_valid(unsigned long addr) return pfn_valid(pte_pfn(*pte)); } -EXPORT_SYMBOL(kern_addr_valid); static unsigned long __ref kernel_map_hugepud(unsigned long vstart, unsigned long vend, diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h index 66bc3f99d9be..4e3052f2671a 100644 --- a/arch/um/include/asm/pgtable.h +++ b/arch/um/include/asm/pgtable.h @@ -298,8 +298,6 @@ extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr); ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) -#define kern_addr_valid(addr) (1) - /* Clear a kernel PTE and flush it from the TLB */ #define kpte_clear_flush(ptep, vaddr) \ do { \ diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h index 7c9c968a42ef..7d4ad8907297 100644 --- a/arch/x86/include/asm/pgtable_32.h +++ b/arch/x86/include/asm/pgtable_32.h @@ -47,15 +47,6 @@ do { \ #endif /* !__ASSEMBLY__ */ -/* - * kern_addr_valid() is (1) for FLATMEM and (0) for SPARSEMEM - */ -#ifdef CONFIG_FLATMEM -#define kern_addr_valid(addr) (1) -#else -#define kern_addr_valid(kaddr) (0) -#endif - /* * This is used to calculate the .brk reservation for initial pagetables. * Enough space is reserved to allocate pagetables sufficient to cover all diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index e479491da8d5..7929327abe00 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -240,7 +240,6 @@ static inline void native_pgd_clear(pgd_t *pgd) #define __swp_entry_to_pte(x) ((pte_t) { .pte = (x).val }) #define __swp_entry_to_pmd(x) ((pmd_t) { .pmd = (x).val }) -extern int kern_addr_valid(unsigned long addr); extern void cleanup_highmap(void); #define HAVE_ARCH_UNMAPPED_AREA diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 3f040c6e5d13..e8db4edd7cc9 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1416,47 +1416,6 @@ void mark_rodata_ro(void) debug_checkwx(); } -int kern_addr_valid(unsigned long addr) -{ - unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; - pgd_t *pgd; - p4d_t *p4d; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - - if (above != 0 && above != -1UL) - return 0; - - pgd = pgd_offset_k(addr); - if (pgd_none(*pgd)) - return 0; - - p4d = p4d_offset(pgd, addr); - if (!p4d_present(*p4d)) - return 0; - - pud = pud_offset(p4d, addr); - if (!pud_present(*pud)) - return 0; - - if (pud_large(*pud)) - return pfn_valid(pud_pfn(*pud)); - - pmd = pmd_offset(pud, addr); - if (!pmd_present(*pmd)) - return 0; - - if (pmd_large(*pmd)) - return pfn_valid(pmd_pfn(*pmd)); - - pte = pte_offset_kernel(pmd, addr); - if (pte_none(*pte)) - return 0; - - return pfn_valid(pte_pfn(*pte)); -} - /* * Block size is the minimum amount of memory which can be hotplugged or * hotremoved. It must be power of two and must be equal or larger than diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h index 54f577c13afa..5b5484d707b2 100644 --- a/arch/xtensa/include/asm/pgtable.h +++ b/arch/xtensa/include/asm/pgtable.h @@ -386,8 +386,6 @@ ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) #else -#define kern_addr_valid(addr) (1) - extern void update_mmu_cache(struct vm_area_struct * vma, unsigned long address, pte_t *ptep); diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index dff921f7ca33..590ecb79ad8b 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -541,25 +541,17 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) fallthrough; case KCORE_VMEMMAP: case KCORE_TEXT: - if (kern_addr_valid(start)) { - /* - * Using bounce buffer to bypass the - * hardened user copy kernel text checks. - */ - if (copy_from_kernel_nofault(buf, (void *)start, - tsz)) { - if (clear_user(buffer, tsz)) { - ret = -EFAULT; - goto out; - } - } else { - if (copy_to_user(buffer, buf, tsz)) { - ret = -EFAULT; - goto out; - } + /* + * Using bounce buffer to bypass the + * hardened user copy kernel text checks. + */ + if (copy_from_kernel_nofault(buf, (void *)start, tsz)) { + if (clear_user(buffer, tsz)) { + ret = -EFAULT; + goto out; } } else { - if (clear_user(buffer, tsz)) { + if (copy_to_user(buffer, buf, tsz)) { ret = -EFAULT; goto out; }
Most architectures(except arm64/x86/sparc) simply return 1 for kern_addr_valid(), which is only used in read_kcore(), and it calls copy_from_kernel_nofault() which could check whether the address is a valid kernel address, so no need kern_addr_valid(), let's remove unneeded kern_addr_valid() completely. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- arch/alpha/include/asm/pgtable.h | 2 - arch/arc/include/asm/pgtable-bits-arcv2.h | 2 - arch/arm/include/asm/pgtable-nommu.h | 2 - arch/arm/include/asm/pgtable.h | 4 -- arch/arm64/include/asm/pgtable.h | 2 - arch/arm64/mm/mmu.c | 47 ----------------------- arch/arm64/mm/pageattr.c | 3 +- arch/csky/include/asm/pgtable.h | 3 -- arch/hexagon/include/asm/page.h | 7 ---- arch/ia64/include/asm/pgtable.h | 16 -------- arch/loongarch/include/asm/pgtable.h | 2 - arch/m68k/include/asm/pgtable_mm.h | 2 - arch/m68k/include/asm/pgtable_no.h | 1 - arch/microblaze/include/asm/pgtable.h | 3 -- arch/mips/include/asm/pgtable.h | 2 - arch/nios2/include/asm/pgtable.h | 2 - arch/openrisc/include/asm/pgtable.h | 2 - arch/parisc/include/asm/pgtable.h | 15 -------- arch/powerpc/include/asm/pgtable.h | 7 ---- arch/riscv/include/asm/pgtable.h | 2 - arch/s390/include/asm/pgtable.h | 2 - arch/sh/include/asm/pgtable.h | 2 - arch/sparc/include/asm/pgtable_32.h | 6 --- arch/sparc/mm/init_32.c | 3 +- arch/sparc/mm/init_64.c | 1 - arch/um/include/asm/pgtable.h | 2 - arch/x86/include/asm/pgtable_32.h | 9 ----- arch/x86/include/asm/pgtable_64.h | 1 - arch/x86/mm/init_64.c | 41 -------------------- arch/xtensa/include/asm/pgtable.h | 2 - fs/proc/kcore.c | 26 +++++-------- 31 files changed, 11 insertions(+), 210 deletions(-)