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)
...
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)
...
That seems be sensible with this patch.
Signed-off-by: Rongwei Wang <rongwei.wang@xxxxxxxxxxxxxxxxx>
---
arm64.c | 24 ++++++++++++++++--------
defs.h | 5 +++++
memory.c | 23 +++++++++++++++++++++++
x86_64.c | 9 +++++----
4 files changed, 49 insertions(+), 12 deletions(-)
diff --git a/arm64.c b/arm64.c
index 56fb841..efbdccb 100644
--- a/arm64.c
+++ b/arm64.c
@@ -1787,7 +1787,8 @@ 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);
+ fprintf(fp, " PAGE: %lx (512MB%s)\n\n", sectionbase,
+ IS_ZEROPAGE(sectionbase) ? ", ZERO PAGE" : "");
arm64_translate_pte(pgd_val, 0, 0);
}
*paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_512MB);
@@ -1806,7 +1807,8 @@ 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));
+ fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr),
+ IS_ZEROPAGE(PAGEBASE(*paddr)) ? "(ZERO PAGE)" : "");
arm64_translate_pte(pte_val, 0, 0);
}
} else {
@@ -1859,7 +1861,8 @@ 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);
+ fprintf(fp, " PAGE: %lx (512MB%s)\n\n", sectionbase,
+ IS_ZEROPAGE(sectionbase) ? ", ZERO PAGE" : "");
arm64_translate_pte(pmd_val, 0, 0);
}
*paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_512MB);
@@ -1878,7 +1881,8 @@ 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));
+ fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr),
+ IS_ZEROPAGE(PAGEBASE(*paddr)) ? "(ZERO PAGE)" : "");
arm64_translate_pte(pte_val, 0, 0);
}
} else {
@@ -1940,7 +1944,8 @@ 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);
+ fprintf(fp, " PAGE: %lx (2MB%s)\n\n", sectionbase,
+ IS_ZEROPAGE(sectionbase) ? ", ZERO PAGE" : "");
arm64_translate_pte(pmd_val, 0, 0);
}
*paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_2MB);
@@ -1959,7 +1964,8 @@ 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));
+ fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr),
+ IS_ZEROPAGE(PAGEBASE(*paddr)) ? "(ZERO PAGE)" : "");
arm64_translate_pte(pte_val, 0, 0);
}
} else {
@@ -2029,7 +2035,8 @@ 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);
+ fprintf(fp, " PAGE: %lx (2MB%s)\n\n", sectionbase,
+ IS_ZEROPAGE(sectionbase) ? ", ZERO PAGE" : "");
arm64_translate_pte(pmd_val, 0, 0);
}
*paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_2MB);
@@ -2048,7 +2055,8 @@ 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));
+ fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr),
+ IS_ZEROPAGE(PAGEBASE(*paddr)) ? "(ZERO PAGE)" : "");
arm64_translate_pte(pte_val, 0, 0);
}
} else {
diff --git a/defs.h b/defs.h
index 12ad6aa..a6e4ef3 100644
--- a/defs.h
+++ b/defs.h
@@ -2618,6 +2618,8 @@ struct vm_table { /* kernel VM-related data */
char *name;
} *pageflags_data;
ulong max_mem_section_nr;
+ ulong zero_paddr;
+ ulong huge_zero_paddr;
};
#define NODES (0x1)
@@ -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 IS_ZEROPAGE(paddr) ((paddr) == vt->zero_paddr || \
+ (paddr) == vt->huge_zero_paddr)
+
/*
* Sparse memory stuff
* These must follow the definitions in the kernel mmzone.h
diff --git a/memory.c b/memory.c
index 0568f18..d791283 100644
--- a/memory.c
+++ b/memory.c
@@ -1208,6 +1208,27 @@ vm_init(void)
machdep->memory_size()));
vt->paddr_prlen = strlen(buf);
+ vt->zero_paddr = ~0UL;
+ if (kernel_symbol_exists("zero_pfn")) {
+ ulong zero_pfn;
+
+ if (readmem(symbol_value("zero_pfn"), KVADDR,
+ &zero_pfn, sizeof(zero_pfn),
+ "read zero_pfn", QUIET|RETURN_ON_ERROR))
+ vt->zero_paddr = zero_pfn << PAGESHIFT();
+ }
+
+ vt->huge_zero_paddr = ~0UL;
+ if (kernel_symbol_exists("huge_zero_pfn")) {
+ ulong huge_zero_pfn;
+
+ if (readmem(symbol_value("huge_zero_pfn"), KVADDR,
+ &huge_zero_pfn, sizeof(huge_zero_pfn),
+ "read huge_zero_pfn", QUIET|RETURN_ON_ERROR) &&
+ huge_zero_pfn != ~0UL)
+ vt->huge_zero_paddr = huge_zero_pfn << PAGESHIFT();
+ }
+
if (vt->flags & PERCPU_KMALLOC_V1)
vt->dump_kmem_cache = dump_kmem_cache_percpu_v1;
else if (vt->flags & PERCPU_KMALLOC_V2)
@@ -14063,6 +14084,8 @@ dump_vm_table(int verbose)
} else {
fprintf(fp, " node_online_map: (unused)\n");
}
+ fprintf(fp, " zero_paddr: %lx\n", vt->zero_paddr);
+ fprintf(fp, " huge_zero_paddr: %lx\n", vt->huge_zero_paddr);
fprintf(fp, " nr_vm_stat_items: %d\n", vt->nr_vm_stat_items);
fprintf(fp, " vm_stat_items: %s", (vt->flags & VM_STAT) ?
"\n" : "(not used)\n");
diff --git a/x86_64.c b/x86_64.c
index 5019c69..693a08b 100644
--- a/x86_64.c
+++ b/x86_64.c
@@ -2114,8 +2114,9 @@ x86_64_uvtop_level4(struct task_context *tc, ulong uvaddr, physaddr_t *paddr, in
goto no_upage;
if (pmd_pte & _PAGE_PSE) {
if (verbose) {
- fprintf(fp, " PAGE: %lx (2MB)\n\n",
- PAGEBASE(pmd_pte) & PHYSICAL_PAGE_MASK);
+ fprintf(fp, " PAGE: %lx (2MB%s)\n\n",
+ PAGEBASE(pmd_pte) & PHYSICAL_PAGE_MASK,
+ IS_ZEROPAGE(PAGEBASE(pmd_pte) & PHYSICAL_PAGE_MASK) ? ", ZERO PAGE" : "");
x86_64_translate_pte(pmd_pte, 0, 0);
}
@@ -2143,8 +2144,8 @@ x86_64_uvtop_level4(struct task_context *tc, ulong uvaddr, physaddr_t *paddr, in
*paddr = (PAGEBASE(pte) & PHYSICAL_PAGE_MASK) + PAGEOFFSET(uvaddr);
if (verbose) {
- fprintf(fp, " PAGE: %lx\n\n",
- PAGEBASE(*paddr) & PHYSICAL_PAGE_MASK);
+ fprintf(fp, " PAGE: %lx %s\n\n", PAGEBASE(*paddr) & PHYSICAL_PAGE_MASK,
+ IS_ZEROPAGE(PAGEBASE(*paddr) & PHYSICAL_PAGE_MASK) ? "(ZERO PAGE)" : "");
x86_64_translate_pte(pte, 0, 0);
}
--
2.27.0
--
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