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powerpc/mm: implement *_user_accessible_page() for ptes

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Page table checking depends on architectures providing an implementation
of p{te,md,ud}_user_accessible_page.  With refactorisations made on
powerpc/mm, the pte_access_permitted() and similar methods verify whether
a userland page is accessible with the required permissions.

Since page table checking is the only user of
p{te,md,ud}_user_accessible_page(), implement these for all platforms,
using some of the same preliminary checks taken by pte_access_permitted()
on that platform.

Since commit 8e9bd41e4c ("powerpc/nohash: Replace pte_user() by
pte_read()") pte_user() is no longer required to be present on all
platforms as it may be equivalent to or implied by pte_read().  Hence
implementations of pte_user_accessible_page() are specialised.

[ajd@linux.ibm.com: rebase and clean up]
Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-10-755bc151a50b@linux.ibm.com
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Guo Weikang <guoweikang.kernel@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Cc: Thomas Huth <thuth@redhat.com>
Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Rohan McLure
2025-12-19 04:09:42 +11:00
committed by Andrew Morton
parent d79f9c9cf7
commit 2f5e576598
4 changed files with 35 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
arch/powerpc/include/asm/book3s/64/pgtable.h
View File

@@ -539,6 +539,11 @@ static inline bool pte_access_permitted(pte_t pte, bool write)
return arch_pte_access_permitted(pte_val(pte), write, 0);
}
static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
{
return pte_present(pte) && pte_user(pte);
}
/*
* Conversion functions: convert a page and protection to a page entry,
* and a page entry and page directory to the page they refer to.
@@ -909,6 +914,12 @@ static inline bool pud_access_permitted(pud_t pud, bool write)
return pte_access_permitted(pud_pte(pud), write);
}
#define pud_user_accessible_page pud_user_accessible_page
static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr)
{
return pud_leaf(pud) && pte_user_accessible_page(pud_pte(pud), addr);
}
#define __p4d_raw(x) ((p4d_t) { __pgd_raw(x) })
static inline __be64 p4d_raw(p4d_t x)
{
@@ -1074,6 +1085,12 @@ static inline bool pmd_access_permitted(pmd_t pmd, bool write)
return pte_access_permitted(pmd_pte(pmd), write);
}
#define pmd_user_accessible_page pmd_user_accessible_page
static inline bool pmd_user_accessible_page(pmd_t pmd, unsigned long addr)
{
return pmd_leaf(pmd) && pte_user_accessible_page(pmd_pte(pmd), addr);
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot);
extern pud_t pfn_pud(unsigned long pfn, pgprot_t pgprot);