[PATCH] mm: remove kern_addr_valid() completely

From: Kefeng Wang
Date: Tue Oct 18 2022 - 03:21:20 EST

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@xxxxxxxxxx>
---
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;
}
--
2.35.3