* Re: [PATCH] mm: remove kern_addr_valid() completely
2022-10-18 7:40 [PATCH] mm: remove kern_addr_valid() completely Kefeng Wang
@ 2022-10-18 7:30 ` Geert Uytterhoeven
2022-10-18 8:03 ` Heiko Carstens
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Geert Uytterhoeven @ 2022-10-18 7:30 UTC (permalink / raw)
To: Kefeng Wang
Cc: Andrew Morton, linux-alpha, linux-kernel, linux-snps-arc,
linux-arm-kernel, linux-csky, linux-hexagon, linux-ia64,
loongarch, linux-m68k, linux-mips, openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-xtensa, linux-fsdevel, Richard Henderson,
Ivan Kokshaysky, Matt Turner, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Guo Ren, Huacai Chen, WANG Xuerui,
Greg Ungerer, Michal Simek, Thomas Bogendoerfer, Dinh Nguyen,
Jonas Bonn, Stefan Kristiansson, Stafford Horne,
James E . J . Bottomley, Helge Deller, Michael Ellerman,
Nicholas Piggin, Christophe Leroy, Paul Walmsley, Palmer Dabbelt,
Albert Ou, Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Yoshinori Sato,
Rich Felker, David S . Miller, Richard Weinberger, Anton Ivanov,
Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H . Peter Anvin, Andy Lutomirski,
Peter Zijlstra, Chris Zankel, Max Filippov
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
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] mm: remove kern_addr_valid() completely
@ 2022-10-18 7:40 Kefeng Wang
2022-10-18 7:30 ` Geert Uytterhoeven
` (7 more replies)
0 siblings, 8 replies; 9+ messages in thread
From: Kefeng Wang @ 2022-10-18 7:40 UTC (permalink / raw)
To: Andrew Morton, linux-alpha, linux-kernel, linux-snps-arc,
linux-arm-kernel, linux-csky, linux-hexagon, linux-ia64,
loongarch, linux-m68k, linux-mips, openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-xtensa, linux-fsdevel
Cc: Richard Henderson, Ivan Kokshaysky, Matt Turner, Vineet Gupta,
Russell King, Catalin Marinas, Will Deacon, Guo Ren, Huacai Chen,
WANG Xuerui, Geert Uytterhoeven, Greg Ungerer, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn,
Stefan Kristiansson, Stafford Horne, James E . J . Bottomley,
Helge Deller, Michael Ellerman, Nicholas Piggin,
Christophe Leroy, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Yoshinori Sato,
Rich Felker, David S . Miller, Richard Weinberger, Anton Ivanov,
Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H . Peter Anvin, Andy Lutomirski,
Peter Zijlstra, Chris Zankel, Max Filippov, Kefeng Wang
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;
}
--
2.35.3
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] mm: remove kern_addr_valid() completely
2022-10-18 7:40 [PATCH] mm: remove kern_addr_valid() completely Kefeng Wang
2022-10-18 7:30 ` Geert Uytterhoeven
@ 2022-10-18 8:03 ` Heiko Carstens
2022-10-18 8:09 ` Christoph Hellwig
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Heiko Carstens @ 2022-10-18 8:03 UTC (permalink / raw)
To: Kefeng Wang
Cc: Andrew Morton, linux-alpha, linux-kernel, linux-snps-arc,
linux-arm-kernel, linux-csky, linux-hexagon, linux-ia64,
loongarch, linux-m68k, linux-mips, openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-xtensa, linux-fsdevel, Richard Henderson,
Ivan Kokshaysky, Matt Turner, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Guo Ren, Huacai Chen, WANG Xuerui,
Geert Uytterhoeven, Greg Ungerer, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn,
Stefan Kristiansson, Stafford Horne, James E . J . Bottomley,
Helge Deller, Michael Ellerman, Nicholas Piggin,
Christophe Leroy, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Vasily Gorbik, Alexander Gordeev, Christian Borntraeger,
Sven Schnelle, Yoshinori Sato, Rich Felker, David S . Miller,
Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, x86, H . Peter Anvin,
Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov
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>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] mm: remove kern_addr_valid() completely
2022-10-18 7:40 [PATCH] mm: remove kern_addr_valid() completely Kefeng Wang
2022-10-18 7:30 ` Geert Uytterhoeven
2022-10-18 8:03 ` Heiko Carstens
@ 2022-10-18 8:09 ` Christoph Hellwig
2022-10-18 8:32 ` Helge Deller
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Christoph Hellwig @ 2022-10-18 8:09 UTC (permalink / raw)
To: Kefeng Wang
Cc: Andrew Morton, linux-alpha, linux-kernel, linux-snps-arc,
linux-arm-kernel, linux-csky, linux-hexagon, linux-ia64,
loongarch, linux-m68k, linux-mips, openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-xtensa, linux-fsdevel, Richard Henderson,
Ivan Kokshaysky, Matt Turner, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Guo Ren, Huacai Chen, WANG Xuerui,
Geert Uytterhoeven, Greg Ungerer, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn,
Stefan Kristiansson, Stafford Horne, James E . J . Bottomley,
Helge Deller, Michael Ellerman, Nicholas Piggin,
Christophe Leroy, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Yoshinori Sato,
Rich Felker, David S . Miller, Richard Weinberger, Anton Ivanov,
Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H . Peter Anvin, Andy Lutomirski,
Peter Zijlstra, Chris Zankel, Max Filippov
Thanks, this is long overdue!
Acked-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] mm: remove kern_addr_valid() completely
2022-10-18 7:40 [PATCH] mm: remove kern_addr_valid() completely Kefeng Wang
` (2 preceding siblings ...)
2022-10-18 8:09 ` Christoph Hellwig
@ 2022-10-18 8:32 ` Helge Deller
2022-10-18 9:20 ` WANG Xuerui
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Helge Deller @ 2022-10-18 8:32 UTC (permalink / raw)
To: Kefeng Wang, Andrew Morton, linux-alpha, linux-kernel,
linux-snps-arc, linux-arm-kernel, linux-csky, linux-hexagon,
linux-ia64, loongarch, linux-m68k, linux-mips, openrisc,
linux-parisc, linuxppc-dev, linux-riscv, linux-s390, linux-sh,
sparclinux, linux-um, linux-xtensa, linux-fsdevel
Cc: Richard Henderson, Ivan Kokshaysky, Matt Turner, Vineet Gupta,
Russell King, Catalin Marinas, Will Deacon, Guo Ren, Huacai Chen,
WANG Xuerui, Geert Uytterhoeven, Greg Ungerer, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn,
Stefan Kristiansson, Stafford Horne, James E . J . Bottomley,
Michael Ellerman, Nicholas Piggin, Christophe Leroy,
Paul Walmsley, Palmer Dabbelt, Albert Ou, Heiko Carstens,
Vasily Gorbik, Alexander Gordeev, Christian Borntraeger,
Sven Schnelle, Yoshinori Sato, Rich Felker, David S . Miller,
Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, x86, H . Peter Anvin,
Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov
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;
> }
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] mm: remove kern_addr_valid() completely
2022-10-18 7:40 [PATCH] mm: remove kern_addr_valid() completely Kefeng Wang
` (3 preceding siblings ...)
2022-10-18 8:32 ` Helge Deller
@ 2022-10-18 9:20 ` WANG Xuerui
2022-10-19 1:31 ` Guo Ren
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: WANG Xuerui @ 2022-10-18 9:20 UTC (permalink / raw)
To: Kefeng Wang, Andrew Morton, linux-alpha, linux-kernel,
linux-snps-arc, linux-arm-kernel, linux-csky, linux-hexagon,
linux-ia64, loongarch, linux-m68k, linux-mips, openrisc,
linux-parisc, linuxppc-dev, linux-riscv, linux-s390, linux-sh,
sparclinux, linux-um, linux-xtensa, linux-fsdevel
Cc: Richard Henderson, Ivan Kokshaysky, Matt Turner, Vineet Gupta,
Russell King, Catalin Marinas, Will Deacon, Guo Ren, Huacai Chen,
Geert Uytterhoeven, Greg Ungerer, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn,
Stefan Kristiansson, Stafford Horne, James E . J . Bottomley,
Helge Deller, Michael Ellerman, Nicholas Piggin,
Christophe Leroy, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Yoshinori Sato,
Rich Felker, David S . Miller, Richard Weinberger, Anton Ivanov,
Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H . Peter Anvin, Andy Lutomirski,
Peter Zijlstra, Chris Zankel, Max Filippov
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!
--
WANG "xen0n" Xuerui
Linux/LoongArch mailing list: https://lore.kernel.org/loongarch/
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] mm: remove kern_addr_valid() completely
2022-10-18 7:40 [PATCH] mm: remove kern_addr_valid() completely Kefeng Wang
` (4 preceding siblings ...)
2022-10-18 9:20 ` WANG Xuerui
@ 2022-10-19 1:31 ` Guo Ren
2022-11-01 17:47 ` Catalin Marinas
2022-11-11 2:50 ` Palmer Dabbelt
7 siblings, 0 replies; 9+ messages in thread
From: Guo Ren @ 2022-10-19 1:31 UTC (permalink / raw)
To: Kefeng Wang
Cc: Andrew Morton, linux-alpha, linux-kernel, linux-snps-arc,
linux-arm-kernel, linux-csky, linux-hexagon, linux-ia64,
loongarch, linux-m68k, linux-mips, openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-xtensa, linux-fsdevel, Richard Henderson,
Ivan Kokshaysky, Matt Turner, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Huacai Chen, WANG Xuerui,
Geert Uytterhoeven, Greg Ungerer, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn,
Stefan Kristiansson, Stafford Horne, James E . J . Bottomley,
Helge Deller, Michael Ellerman, Nicholas Piggin,
Christophe Leroy, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Yoshinori Sato,
Rich Felker, David S . Miller, Richard Weinberger, Anton Ivanov,
Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H . Peter Anvin, Andy Lutomirski,
Peter Zijlstra, Chris Zankel, Max Filippov
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
>
--
Best Regards
Guo Ren
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] mm: remove kern_addr_valid() completely
2022-10-18 7:40 [PATCH] mm: remove kern_addr_valid() completely Kefeng Wang
` (5 preceding siblings ...)
2022-10-19 1:31 ` Guo Ren
@ 2022-11-01 17:47 ` Catalin Marinas
2022-11-11 2:50 ` Palmer Dabbelt
7 siblings, 0 replies; 9+ messages in thread
From: Catalin Marinas @ 2022-11-01 17:47 UTC (permalink / raw)
To: Kefeng Wang
Cc: Andrew Morton, linux-alpha, linux-kernel, linux-snps-arc,
linux-arm-kernel, linux-csky, linux-hexagon, linux-ia64,
loongarch, linux-m68k, linux-mips, openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-xtensa, linux-fsdevel, Richard Henderson,
Ivan Kokshaysky, Matt Turner, Vineet Gupta, Russell King,
Will Deacon, Guo Ren, Huacai Chen, WANG Xuerui,
Geert Uytterhoeven, Greg Ungerer, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn,
Stefan Kristiansson, Stafford Horne, James E . J . Bottomley,
Helge Deller, Michael Ellerman, Nicholas Piggin,
Christophe Leroy, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Yoshinori Sato,
Rich Felker, David S . Miller, Richard Weinberger, Anton Ivanov,
Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H . Peter Anvin, Andy Lutomirski,
Peter Zijlstra, Chris Zankel, Max Filippov
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>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] mm: remove kern_addr_valid() completely
2022-10-18 7:40 [PATCH] mm: remove kern_addr_valid() completely Kefeng Wang
` (6 preceding siblings ...)
2022-11-01 17:47 ` Catalin Marinas
@ 2022-11-11 2:50 ` Palmer Dabbelt
7 siblings, 0 replies; 9+ messages in thread
From: Palmer Dabbelt @ 2022-11-11 2:50 UTC (permalink / raw)
To: wangkefeng.wang
Cc: akpm, linux-alpha, linux-kernel, linux-snps-arc,
linux-arm-kernel, linux-csky, linux-hexagon, linux-ia64,
loongarch, linux-m68k, linux-mips, openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-xtensa, linux-fsdevel, Richard Henderson, ink,
mattst88, vgupta, linux, catalin.marinas, Will Deacon, guoren,
chenhuacai, kernel, geert, gerg, monstr, tsbogend, dinguyen,
jonas, stefan.kristiansson, shorne, James.Bottomley, deller, mpe,
npiggin, christophe.leroy, Paul Walmsley, aou, hca, gor,
agordeev, borntraeger, svens, ysato, dalias, davem, richard,
anton.ivanov, johannes, tglx, mingo, bp, dave.hansen, x86, hpa,
luto, peterz, chris, jcmvbkbc, wangkefeng.wang
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!
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2022-11-11 2:51 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-10-18 7:40 [PATCH] mm: remove kern_addr_valid() completely Kefeng Wang
2022-10-18 7:30 ` Geert Uytterhoeven
2022-10-18 8:03 ` Heiko Carstens
2022-10-18 8:09 ` Christoph Hellwig
2022-10-18 8:32 ` Helge Deller
2022-10-18 9:20 ` WANG Xuerui
2022-10-19 1:31 ` Guo Ren
2022-11-01 17:47 ` Catalin Marinas
2022-11-11 2:50 ` Palmer Dabbelt
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