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mm: remove kern_addr_valid() completely

Browse source 
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 as there is no need for kern_addr_valid(), let's
remove it.

Link: https://lkml.kernel.org/r/20221018074014.185687-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Heiko Carstens <hca@linux.ibm.com>		[s390]
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Helge Deller <deller@gmx.de>			[parisc]
Acked-by: Michael Ellerman <mpe@ellerman.id.au>		[powerpc]
Acked-by: Guo Ren <guoren@kernel.org>			[csky]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: <aou@eecs.berkeley.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Xuerui Wang <kernel@xen0n.name>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Kefeng Wang 2022-10-18 15:40:14 +08:00 committed by Andrew Morton
parent 65f199b2b4
commit e025ab842e
31 changed files with 11 additions and 210 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
arch/alpha/include/asm/pgtable.h
View file

@ -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) \

2
arch/arc/include/asm/pgtable-bits-arcv2.h
View file

@ -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

2
arch/arm/include/asm/pgtable-nommu.h
View file

@ -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

4
arch/arm/include/asm/pgtable.h
View file

@ -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.
*/

2
arch/arm64/include/asm/pgtable.h
View file

@ -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

47
arch/arm64/mm/mmu.c
View file

@ -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)

3
arch/arm64/mm/pageattr.c
View file

@ -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

3
arch/csky/include/asm/pgtable.h
View file

@ -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)

7
arch/hexagon/include/asm/page.h
View file

@ -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. */

16
arch/ia64/include/asm/pgtable.h
View file

@ -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.

2
arch/loongarch/include/asm/pgtable.h
View file

@ -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;

2
arch/m68k/include/asm/pgtable_mm.h
View file

@ -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

1
arch/m68k/include/asm/pgtable_no.h
View file

@ -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)

3
arch/microblaze/include/asm/pgtable.h
View file

@ -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);

2
arch/mips/include/asm/pgtable.h
View file

@ -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.
*/

2
arch/nios2/include/asm/pgtable.h
View file

@ -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);

2
arch/openrisc/include/asm/pgtable.h
View file

@ -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__ */

15
arch/parisc/include/asm/pgtable.h
View file

@ -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. */

7
arch/powerpc/include/asm/pgtable.h
View file

@ -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

2
arch/riscv/include/asm/pgtable.h
View file

@ -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;

2
arch/s390/include/asm/pgtable.h
View file

@ -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);

2
arch/sh/include/asm/pgtable.h
View file

@ -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;

6
arch/sparc/include/asm/pgtable_32.h
View file

@ -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.

3
arch/sparc/mm/init_32.c
View file

@ -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);

1
arch/sparc/mm/init_64.c
View file

@ -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,

2
arch/um/include/asm/pgtable.h
View file

@ -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 { \

9
arch/x86/include/asm/pgtable_32.h
View file

@ -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

1
arch/x86/include/asm/pgtable_64.h
View file

@ -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

41
arch/x86/mm/init_64.c
View file

@ -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

2
arch/xtensa/include/asm/pgtable.h
View file

@ -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);

26
fs/proc/kcore.c
View file

@ -540,25 +540,17 @@ 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;
}