[Crash-utility] [PATCH RFC] arm64: show zero pfn information when using vtop

Now vtop can not show us the page is zero pfn when PTE or PMD has attached ZERO PAGE. This patch supports show this information directly when using vtop, likes: crash> vtop -c 13674 ffff8917e000 VIRTUAL PHYSICAL ffff8917e000 836e71000 PAGE DIRECTORY: ffff000802f8d000 PGD: ffff000802f8dff8 => 884e29003 PUD: ffff000844e29ff0 => 884e93003 PMD: ffff000844e93240 => 840413003 PTE: ffff000800413bf0 => 160000836e71fc3 PAGE: 836e71000 (ZERO PAGE) PTE PHYSICAL FLAGS 160000836e71fc3 836e71000 (VALID|USER|RDONLY|SHARED|AF|NG|PXN|UXN|SPECIAL) VMA START END FLAGS FILE ffff000844f51860 ffff8917c000 ffff8957d000 100073 PAGE PHYSICAL MAPPING INDEX CNT FLAGS fffffe001fbb9c40 836e71000 0 0 1 2ffffc000001000 reserved If huge page found: crash> vtop -c 14538 ffff95800000 VIRTUAL PHYSICAL ffff95800000 910c00000 PAGE DIRECTORY: ffff000801fa0000 PGD: ffff000801fa0ff8 => 884f53003 PUD: ffff000844f53ff0 => 8426cb003 PMD: ffff0008026cb560 => 60000910c00fc1 PAGE: 910c00000 (2MB, ZERO PAGE) PTE PHYSICAL FLAGS 60000910c00fc1 910c00000 (VALID|USER|RDONLY|SHARED|AF|NG|PXN|UXN) VMA START END FLAGS FILE ffff0000caa711e0 ffff956a9000 ffff95aaa000 100073 PAGE PHYSICAL MAPPING INDEX CNT FLAGS fffffe0023230000 910c00000 0 0 1 6ffffc000010000 head That seems be sensible with this patch. Signed-off-by: Rongwei Wang <rongwei.wang(a)linux.alibaba.com&gt; --- arm64.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++------ defs.h | 5 ++++ 2 files changed, 88 insertions(+), 9 deletions(-) diff --git a/arm64.c b/arm64.c index 56fb841..264572d 100644 --- a/arm64.c +++ b/arm64.c @@ -419,7 +419,25 @@ arm64_init(int when) /* use machdep parameters */ arm64_calc_phys_offset(); arm64_calc_physvirt_offset(); - + + if (kernel_symbol_exists("zero_pfn")) { + ulong zero_pfn = 0; + + if (readmem(symbol_value("zero_pfn"), KVADDR, + &zero_pfn, sizeof(zero_pfn), + "read zero_pfn", QUIET|RETURN_ON_ERROR)) + machdep->zero_pfn = zero_pfn; + } + + if (kernel_symbol_exists("huge_zero_pfn")) { + ulong huge_zero_pfn = 0; + + if (readmem(symbol_value("huge_zero_pfn"), KVADDR, + &huge_zero_pfn, sizeof(huge_zero_pfn), + "read huge_zero_pfn", QUIET|RETURN_ON_ERROR)) + machdep->huge_zero_pfn = huge_zero_pfn; + } + if (CRASHDEBUG(1)) { if (machdep->flags & NEW_VMEMMAP) fprintf(fp, "kimage_voffset: %lx\n", @@ -1787,7 +1805,14 @@ arm64_vtop_2level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if ((pgd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) { ulong sectionbase = (pgd_val & SECTION_PAGE_MASK_512MB) & PHYS_MASK; if (verbose) { - fprintf(fp, " PAGE: %lx (512MB)\n\n", sectionbase); + if (kernel_symbol_exists("huge_zero_pfn")) { + if (sectionbase == (HUGE_ZEROPFN() << PAGESHIFT())) + fprintf(fp, " PAGE: %lx (512MB, ZERO PAGE)\n\n", + HUGE_ZEROPFN() << PAGESHIFT()); + else + fprintf(fp, " PAGE: %lx (512MB)\n\n", sectionbase); + } else + fprintf(fp, " PAGE: %lx (512MB)\n\n", sectionbase); arm64_translate_pte(pgd_val, 0, 0); } *paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_512MB); @@ -1806,7 +1831,14 @@ arm64_vtop_2level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if (pte_val & PTE_VALID) { *paddr = (PAGEBASE(pte_val) & PHYS_MASK) + PAGEOFFSET(vaddr); if (verbose) { - fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + if (kernel_symbol_exists("zero_pfn")) { + if (PAGEBASE(*paddr) == (ZEROPFN() << PAGESHIFT())) + fprintf(fp, " PAGE: %lx (ZERO PAGE)\n\n", + ZEROPFN() << PAGESHIFT()); + else + fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + } else + fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); arm64_translate_pte(pte_val, 0, 0); } } else { @@ -1859,7 +1891,14 @@ arm64_vtop_3level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if ((pmd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) { ulong sectionbase = PTE_TO_PHYS(pmd_val) & SECTION_PAGE_MASK_512MB; if (verbose) { - fprintf(fp, " PAGE: %lx (512MB)\n\n", sectionbase); + if (kernel_symbol_exists("huge_zero_pfn")) { + if (sectionbase == (HUGE_ZEROPFN() << PAGESHIFT())) + fprintf(fp, " PAGE: %lx (512MB, ZERO PAGE)\n\n", + HUGE_ZEROPFN() << PAGESHIFT()); + else + fprintf(fp, " PAGE: %lx (512MB)\n\n", sectionbase); + } else + fprintf(fp, " PAGE: %lx (512MB)\n\n", sectionbase); arm64_translate_pte(pmd_val, 0, 0); } *paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_512MB); @@ -1878,7 +1917,14 @@ arm64_vtop_3level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if (pte_val & PTE_VALID) { *paddr = PTE_TO_PHYS(pte_val) + PAGEOFFSET(vaddr); if (verbose) { - fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + if (kernel_symbol_exists("zero_pfn")) { + if (PAGEBASE(*paddr) == (ZEROPFN() << PAGESHIFT())) + fprintf(fp, " PAGE: %lx (ZERO PAGE)\n\n", + ZEROPFN() << PAGESHIFT()); + else + fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + } else + fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); arm64_translate_pte(pte_val, 0, 0); } } else { @@ -1940,7 +1986,14 @@ arm64_vtop_3level_4k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if ((pmd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) { ulong sectionbase = (pmd_val & SECTION_PAGE_MASK_2MB) & PHYS_MASK; if (verbose) { - fprintf(fp, " PAGE: %lx (2MB)\n\n", sectionbase); + if (kernel_symbol_exists("huge_zero_pfn")) { + if (sectionbase == (HUGE_ZEROPFN() << PAGESHIFT())) + fprintf(fp, " PAGE: %lx (2MB, ZERO PAGE)\n\n", + HUGE_ZEROPFN() << PAGESHIFT()); + else + fprintf(fp, " PAGE: %lx (2MB)\n\n", sectionbase); + } else + fprintf(fp, " PAGE: %lx (2MB)\n\n", sectionbase); arm64_translate_pte(pmd_val, 0, 0); } *paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_2MB); @@ -1959,7 +2012,14 @@ arm64_vtop_3level_4k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if (pte_val & PTE_VALID) { *paddr = (PAGEBASE(pte_val) & PHYS_MASK) + PAGEOFFSET(vaddr); if (verbose) { - fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + if (kernel_symbol_exists("zero_pfn")) { + if (PAGEBASE(*paddr) == (ZEROPFN() << PAGESHIFT())) + fprintf(fp, " PAGE: %lx (ZERO PAGE)\n\n", + ZEROPFN() << PAGESHIFT()); + else + fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + } else + fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); arm64_translate_pte(pte_val, 0, 0); } } else { @@ -2029,7 +2089,14 @@ arm64_vtop_4level_4k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if ((pmd_val & PMD_TYPE_MASK) == PMD_TYPE_SECT) { ulong sectionbase = (pmd_val & SECTION_PAGE_MASK_2MB) & PHYS_MASK; if (verbose) { - fprintf(fp, " PAGE: %lx (2MB)\n\n", sectionbase); + if (kernel_symbol_exists("huge_zero_pfn")) { + if (sectionbase == (HUGE_ZEROPFN() << PAGESHIFT())) + fprintf(fp, " PAGE: %lx (2MB, ZERO PAGE)\n\n", + HUGE_ZEROPFN() << PAGESHIFT()); + else + fprintf(fp, " PAGE: %lx (2MB)\n\n", sectionbase); + } else + fprintf(fp, " PAGE: %lx (2MB)\n\n", sectionbase); arm64_translate_pte(pmd_val, 0, 0); } *paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_2MB); @@ -2048,7 +2115,14 @@ arm64_vtop_4level_4k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose) if (pte_val & PTE_VALID) { *paddr = (PAGEBASE(pte_val) & PHYS_MASK) + PAGEOFFSET(vaddr); if (verbose) { - fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + if (kernel_symbol_exists("zero_pfn")) { + if (PAGEBASE(*paddr) == (ZEROPFN() << PAGESHIFT())) + fprintf(fp, " PAGE: %lx (ZERO PAGE)\n\n", + ZEROPFN() << PAGESHIFT()); + else + fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); + } else + fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr)); arm64_translate_pte(pte_val, 0, 0); } } else { diff --git a/defs.h b/defs.h index 12ad6aa..4ed2d0a 100644 --- a/defs.h +++ b/defs.h @@ -1071,6 +1071,8 @@ struct machdep_table { void (*show_interrupts)(int, ulong *); int (*is_page_ptr)(ulong, physaddr_t *); int (*get_cpu_reg)(int, int, const char *, int, void *); + ulong zero_pfn; + ulong huge_zero_pfn; }; /* @@ -2999,6 +3001,9 @@ struct load_module { #define VIRTPAGEBASE(X) (((ulong)(X)) & (ulong)machdep->pagemask) #define PHYSPAGEBASE(X) (((physaddr_t)(X)) & (physaddr_t)machdep->pagemask) +#define ZEROPFN() (machdep->zero_pfn) +#define HUGE_ZEROPFN() (machdep->huge_zero_pfn) + /* * Sparse memory stuff * These must follow the definitions in the kernel mmzone.h -- 2.27.0