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Peter Anvin" , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonas Bonn , Stefan Kristiansson , Stafford Horne Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-openrisc@vger.kernel.org, Yeoreum Yun X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4850; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=utmINuOW9x2oHy5QTeHH6EJ3UzwqSRAUlGRF/Q9Zr9w=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqsQ1S1hUmFwKYutGjknVs3EfJa02hkOz1+sVrz Nt7e2HHFbCJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCarENUgAKCRBt1cPRWsUx M4ztDACstHhQGkp2lzf026PXElKRVH5pN2UHEBDoHpCfhCT0PGU9NnuZhZ4adtSi0gmb5yJECZ+ GJwBPGy8ePxuxh87ECWLBX0FJ3HavCpZueK6xmBzdPeUtKfsJ+49BCX8+mZUijeksVmy9e4lDGX xYw9+oFa7r13sh5Ve1eySb5C1oLRmI0rxEWdGkluXK8YtAgV6KVVpodhZxZ4Y3LV10HExieovQA F1WyaWAf37wnCFSeOSYHSbdY5kQZdJbO7ODSG2U50AzNysgh7GBxfnFg+bEp5gzwDHxgQvvi49Q hNNx9zmXTq8lHsglrmKuYgeGrc27jkQ8iUowCFifM36aAC2VHLbJSa47WoQYELvVOGSpPuprEWM K+dyIkb+rkTaK7e38jUgeDVeyWxsz/Lj47nH49SY+no5kMkhgzP6Xg0V91KzOtE9E6SjkOBKrQR UJkaJf7EfpBVXQb//klJUcVH3CXodhSHG82mUtLSBs2nPuDnzGtHIUFOZDCkY2Al/QA/4= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 35B5114000E X-Stat-Signature: kqggfmuxqjt4inxancdwa4yzs4w1it6z X-Rspam-User: X-HE-Tag: 1789988303-312834 X-HE-Meta: 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 eoVzg71U unldOrZ0lmRdS7N/d99e5i3vI9uUIBEJJuJELT23/KH0sJzX64eR0CQTsnftg3HH77ZsnLDds2H/j1I/uZfaAP9jMbwDSHzWCP+MrdPTp5GVxdGAvodlTvyQE0ZgFtRUYHjaRt5/QGYuKwWg0lwzwEDEWQtDtTlsRGfDDMZZgohG4EzRDGiEbI5VPjVw/myLNRgyBslPQhlGkstcNGSDgfMpRYJXEYB4Q83ma3+Cch8hPTXZITBhSXrm6kG4rFP2mGzxGdlAGZI3fd6PtAti4yMPFfCjPF9o2haWyU5BC9pqS1bUuTlEUAQHfLjrIj11sZvnGSCYoz04fP+ldYnRA2crPRULhekUjLDWl Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: The behaviour of pXdp_get() will change with generic compile-time folded page tables. To prepare for that, rework effective_prot() to ignore any folded page tables entries, as it will unconditionally get called by ptdump core with pXd_val(pXdp_get()), and the value for folded entries really should be ignored. For this, introduce mm_first_pgtable_level() to identify the first real page-table level, move mm_pXd_folded() in !__ASSEMBLER__ and update effective_prot with higher_prot only when the current entry is not folded nor the first level. There should be no functional change. Reviewed-by: David Hildenbrand (Arm) Acked-by: Dave Hansen Signed-off-by: Yeoreum Yun --- arch/x86/mm/dump_pagetables.c | 6 +++-- include/linux/pgtable.h | 61 ++++++++++++++++++++++++++++++++----------- 2 files changed, 50 insertions(+), 17 deletions(-) diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index a18a61e732c3d..2acbe41eb58f2 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -38,6 +38,7 @@ struct pg_state { bool check_wx; unsigned long wx_pages; struct seq_file *seq; + struct mm_struct *mm; }; struct addr_marker { @@ -254,7 +255,7 @@ static void effective_prot(struct ptdump_state *pt_st, enum pgtable_level level, pgprotval_t prot = val & PTE_FLAGS_MASK; pgprotval_t effective; - if (level > PGTABLE_LEVEL_PGD) { + if (level > mm_first_pgtable_level(st->mm)) { pgprotval_t higher_prot = st->prot_levels[level - 1]; effective = (higher_prot & prot & (_PAGE_USER | _PAGE_RW)) | @@ -452,7 +453,8 @@ bool ptdump_walk_pgd_level_core(struct seq_file *m, .level = -1, .to_dmesg = dmesg, .check_wx = checkwx, - .seq = m + .seq = m, + .mm = mm, }; ptdump_walk_pgd(&st.ptdump, mm, pgd); diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 3186096a6e130..ed7101a13ce9c 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -392,6 +392,22 @@ static inline void lazy_mmu_mode_pause(void) {} static inline void lazy_mmu_mode_resume(void) {} #endif +/* + * On some architectures it depends on the mm if the p4d/pud or pmd + * layer of the page table hierarchy is folded or not. + */ +#ifndef mm_p4d_folded +#define mm_p4d_folded(mm) __is_defined(__PAGETABLE_P4D_FOLDED) +#endif + +#ifndef mm_pud_folded +#define mm_pud_folded(mm) __is_defined(__PAGETABLE_PUD_FOLDED) +#endif + +#ifndef mm_pmd_folded +#define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED) +#endif + #ifndef pte_batch_hint /** * pte_batch_hint - Number of pages that can be added to batch without scanning. @@ -2313,6 +2329,36 @@ static inline const char *pgtable_level_to_str(enum pgtable_level level) } } +#ifdef CONFIG_MMU +/** + * mm_first_pgtable_level - return the first non-folded page-table level + * @mm: The mm structure. + * + * With runtime- or compile-time folded page tables, page-table walkers + * effectively skip the folded top-level page tables, treating them as + * always-present entries pointing to the next lower-level page table. + * + * Return the first page-table level in @mm that is not folded. + * + * Return: the first non-folded page-table level. + */ +static inline enum pgtable_level mm_first_pgtable_level(struct mm_struct *mm) +{ + /* + * "PMD folded" actually means "PMD is folded into PUD", and + * pud_present() etc. are hard-coded to look like present page table + * levels, whereby pmd_present() etc. contain real logic. + */ + if (mm_pmd_folded(mm)) + return PGTABLE_LEVEL_PMD; + if (mm_pud_folded(mm)) + return PGTABLE_LEVEL_PUD; + if (mm_p4d_folded(mm)) + return PGTABLE_LEVEL_P4D; + return PGTABLE_LEVEL_PGD; +} +#endif /* CONFIG_MMU */ + void ptval_bytes_to_hex_str(char *buf, size_t buf_size, const void *entry, size_t entry_size); #define ptval_to_str(buf, val) \ @@ -2349,21 +2395,6 @@ void ptval_bytes_to_hex_str(char *buf, size_t buf_size, const void *entry, size_ #ifndef has_transparent_pud_hugepage #define has_transparent_pud_hugepage() IS_BUILTIN(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) #endif -/* - * On some architectures it depends on the mm if the p4d/pud or pmd - * layer of the page table hierarchy is folded or not. - */ -#ifndef mm_p4d_folded -#define mm_p4d_folded(mm) __is_defined(__PAGETABLE_P4D_FOLDED) -#endif - -#ifndef mm_pud_folded -#define mm_pud_folded(mm) __is_defined(__PAGETABLE_PUD_FOLDED) -#endif - -#ifndef mm_pmd_folded -#define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED) -#endif #ifndef p4d_offset_lockless #define p4d_offset_lockless(pgdp, pgd, address) p4d_offset(&(pgd), address) -- 2.43.0