Re: [RFC V1 01/16] mm: Abstract printing of pxd_val()
From: Usama Arif <hidden>
Date: 2026-02-26 12:34:58
Also in:
linux-mm, lkml
On Tue, 24 Feb 2026 10:41:38 +0530 Anshuman Khandual [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Ahead of adding support for D128 pgtables, refactor places that print PTE values to use the new __PRIpte format specifier and __PRIpte_args() macro to prepare the argument(s). When using D128 pgtables in future, we can simply redefine __PRIpte and __PTIpte_args(). Besides there is also an assumption about pxd_val() being always capped at 'unsigned long long' size but that will not work for D128 pgtables. Just increase its size to u128 if the compiler supports via a separate data type pxdval_t which also defaults to existing 'unsigned long long'. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Hildenbrand <david@kernel.org> Cc: Lorenzo Stoakes <redacted> Cc: Mike Rapoport <rppt@kernel.org> Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <redacted> --- include/linux/pgtable.h | 5 +++++ mm/memory.c | 29 +++++++++++++++++++---------- 2 files changed, 24 insertions(+), 10 deletions(-)diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index a50df42a893f..da17139a1279 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h@@ -17,6 +17,11 @@ #include <asm-generic/pgtable_uffd.h> #include <linux/page_table_check.h> +#ifndef __PRIpte +#define __PRIpte "016llx" +#define __PRIpte_args(val) ((u64)val) +#endif + #if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \ defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS #error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDEDdiff --git a/mm/memory.c b/mm/memory.c index 07778814b4a8..cfc3077fc52f 100644 --- a/mm/memory.c +++ b/mm/memory.c@@ -532,9 +532,15 @@ static bool is_bad_page_map_ratelimited(void) return false; } +#ifdef __SIZEOF_INT128__ + typedef u128 pxdval_t; +#else + typedef unsigned long long pxdval_t; +#endif + static void __print_bad_page_map_pgtable(struct mm_struct *mm, unsigned long addr) { - unsigned long long pgdv, p4dv, pudv, pmdv; + pxdval_t pgdv, p4dv, pudv, pmdv; p4d_t p4d, *p4dp; pud_t pud, *pudp; pmd_t pmd, *pmdp;@@ -548,7 +554,7 @@ static void __print_bad_page_map_pgtable(struct mm_struct *mm, unsigned long add pgdv = pgd_val(*pgdp); if (!pgd_present(*pgdp) || pgd_leaf(*pgdp)) { - pr_alert("pgd:%08llx\n", pgdv); + pr_alert("pgd:%" __PRIpte "\n", __PRIpte_args(pgdv)); return; }@@ -557,7 +563,8 @@ static void __print_bad_page_map_pgtable(struct mm_struct *mm, unsigned long add p4dv = p4d_val(p4d); if (!p4d_present(p4d) || p4d_leaf(p4d)) { - pr_alert("pgd:%08llx p4d:%08llx\n", pgdv, p4dv); + pr_alert("pgd:%" __PRIpte "p4d:%" __PRIpte "\n",
Hi Anshuman,
The original format had a space between values ("pgd:%08llx p4d:%08llx").
The replacement loses the space separator producing output like
"pgd:123p4d:456" instead of "pgd:123 p4d:456". The same issue exists
in other places in this commit.
quoted hunk ↗ jump to hunk
+ __PRIpte_args(pgdv), __PRIpte_args(p4dv)); return; }@@ -566,7 +573,8 @@ static void __print_bad_page_map_pgtable(struct mm_struct *mm, unsigned long add pudv = pud_val(pud); if (!pud_present(pud) || pud_leaf(pud)) { - pr_alert("pgd:%08llx p4d:%08llx pud:%08llx\n", pgdv, p4dv, pudv); + pr_alert("pgd:%" __PRIpte "p4d:%" __PRIpte "pud:%" __PRIpte "\n", + __PRIpte_args(pgdv), __PRIpte_args(p4dv), __PRIpte_args(pudv)); return; }@@ -580,8 +588,9 @@ static void __print_bad_page_map_pgtable(struct mm_struct *mm, unsigned long add * doing another map would be bad. print_bad_page_map() should * already take care of printing the PTE. */ - pr_alert("pgd:%08llx p4d:%08llx pud:%08llx pmd:%08llx\n", pgdv, - p4dv, pudv, pmdv); + pr_alert("pgd:%" __PRIpte "p4d:%" __PRIpte "pud:%" __PRIpte "pmd:%" __PRIpte "\n", + __PRIpte_args(pgdv), __PRIpte_args(p4dv), + __PRIpte_args(pudv), __PRIpte_args(pmdv)); } /*@@ -597,7 +606,7 @@ static void __print_bad_page_map_pgtable(struct mm_struct *mm, unsigned long add * page table lock. */ static void print_bad_page_map(struct vm_area_struct *vma, - unsigned long addr, unsigned long long entry, struct page *page, + unsigned long addr, pxdval_t entry, struct page *page, enum pgtable_level level) { struct address_space *mapping;@@ -609,8 +618,8 @@ static void print_bad_page_map(struct vm_area_struct *vma, mapping = vma->vm_file ? vma->vm_file->f_mapping : NULL; index = linear_page_index(vma, addr); - pr_alert("BUG: Bad page map in process %s %s:%08llx", current->comm, - pgtable_level_to_str(level), entry); + pr_alert("BUG: Bad page map in process %s %s:%" __PRIpte, current->comm, + pgtable_level_to_str(level), __PRIpte_args(entry)); __print_bad_page_map_pgtable(vma->vm_mm, addr); if (page) dump_page(page, "bad page map");@@ -695,7 +704,7 @@ static void print_bad_page_map(struct vm_area_struct *vma, */ static inline struct page *__vm_normal_page(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn, bool special, - unsigned long long entry, enum pgtable_level level) + pxdval_t entry, enum pgtable_level level) { if (IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL)) { if (unlikely(special)) {-- 2.43.0