[Crash-utility] Re: [PATCH v2] riscv64: support leaf PTEs in page table walks

From: yuandong <yuan.dong1(a)zte.com.cn&gt; The existing RISC-V virtual-to-physical address walkers descend to the last-level PTE unconditionally. This fails when an upper-level entry is a leaf mapping, as used for huge pages. Replace the separate Sv39, Sv48, and Sv57 page-table walkers with a common n-level implementation. Detect leaf entries at every level, calculate the physical address using the level-specific page offset, and reject misaligned leaf entries. This allows kvtop and uvtop to translate upper-level leaf mappings while retaining support for normal 4 KiB pages. Signed-off-by: yuandong <yuan.dong1(a)zte.com.cn&gt; --- defs.h | 2 + riscv64.c | 428 +++++++++++++++++++++++++----------------------------- 2 files changed, 201 insertions(+), 229 deletions(-) diff --git a/defs.h b/defs.h index e3027e2..ac0b128 100644 --- a/defs.h +++ b/defs.h @@ -3801,6 +3801,8 @@ typedef signed int s32; #define VM_L5_1G (0x200) #define IRQ_STACKS (0x400) #define OVERFLOW_STACKS (0x800) +#define RISCV64_PTE_LEAF(pte) \ + ((pte) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)) #define RISCV64_OVERFLOW_STACK_SIZE (1 << 12) diff --git a/riscv64.c b/riscv64.c index 4dcecc2..1b6396c 100644 --- a/riscv64.c +++ b/riscv64.c @@ -19,12 +19,8 @@ #include <math.h> static ulong riscv64_get_page_size(void); -static int riscv64_vtop_3level_4k(ulong *pgd, ulong vaddr, - physaddr_t *paddr, int verbose); -static int riscv64_vtop_4level_4k(ulong *pgd, ulong vaddr, - physaddr_t *paddr, int verbose); -static int riscv64_vtop_5level_4k(ulong *pgd, ulong vaddr, - physaddr_t *paddr, int verbose); +static int riscv64_vtop_nlevel_4k(ulong *pgd, ulong vaddr, + physaddr_t *paddr, int verbose, int levels); static void riscv64_page_type_init(void); static int riscv64_is_kvaddr(ulong vaddr); static int riscv64_is_uvaddr(ulong vaddr, struct task_context *tc); @@ -637,66 +633,208 @@ riscv64_page_type_init(void) } } +static ulong +riscv64_vtop_index(ulong vaddr, int levels, int level) +{ + switch (levels) { + case 3: + switch (level) { + case 2: + return pgd_index_l3_4k(vaddr); + case 1: + return pmd_index_l3_4k(vaddr); + case 0: + return pte_index_l3_4k(vaddr); + } + break; + + case 4: + switch (level) { + case 3: + return pgd_index_l4_4k(vaddr); + case 2: + return pud_index_l4_4k(vaddr); + case 1: + return pmd_index_l4_4k(vaddr); + case 0: + return pte_index_l4_4k(vaddr); + } + break; + + case 5: + switch (level) { + case 4: + return pgd_index_l5_4k(vaddr); + case 3: + return p4d_index_l5_4k(vaddr); + case 2: + return pud_index_l5_4k(vaddr); + case 1: + return pmd_index_l5_4k(vaddr); + case 0: + return pte_index_l5_4k(vaddr); + } + break; + } + + return 0; +} + +static const char * +riscv64_level_name(int levels, int level) +{ + if (level == levels - 1) + return "PGD"; + + if (level == 3) + return "P4D"; + + if (level == 2) + return "PUD"; + + if (level == 1) + return "PMD"; + + return "PTE"; +} + +static int +riscv64_pte_page_shift(int level) +{ + switch (level) { + case 0: + return PAGESHIFT(); + case 1: + return PMD_SHIFT; + case 2: + return PUD_SHIFT; + case 3: + return P4D_SHIFT; + case 4: + return PGD_SHIFT_L5; + default: + return PAGESHIFT(); + } +} + +static physaddr_t +riscv64_pte_page_mask(int level) +{ + return ((physaddr_t)1 << riscv64_pte_page_shift(level)) - 1; +} + +static physaddr_t +riscv64_pte_paddr_base(ulong pte) +{ + pte &= PTE_PFN_PROT_MASK; + return PTOB(pte >> _PAGE_PFN_SHIFT); +} + +static physaddr_t +riscv64_pte_to_paddr(ulong pte, ulong vaddr, int level) +{ + physaddr_t base, mask; + + base = riscv64_pte_paddr_base(pte); + mask = riscv64_pte_page_mask(level); + + return base + (vaddr & mask); +} + static int -riscv64_vtop_3level_4k(ulong *pgd, ulong vaddr, physaddr_t *paddr, int verbose) +riscv64_vtop_nlevel_4k(ulong *pgd, ulong vaddr, physaddr_t *paddr, + int verbose, int levels) { - ulong *pgd_ptr, pgd_val; - ulong pmd_base, pmd_addr, pmd_val; - ulong pte_base, pte_addr, pte_val, pte_pfn; + int level; + ulong index; + ulong entry_addr; + ulong pte; + ulong table_addr; + const char *name; + + if (levels < 3 || levels > 5) + return FALSE; + + *paddr = 0; if (verbose) fprintf(fp, "PAGE DIRECTORY: %lx\n", (ulong)pgd); - /* PGD */ - pgd_ptr = pgd + pgd_index_l3_4k(vaddr); - FILL_PGD(pgd, KVADDR, PAGESIZE()); - pgd_val = ULONG(machdep->pgd + PAGEOFFSET(pgd_ptr)); - if (verbose) - fprintf(fp, " PGD: %lx => %lx\n", (ulong)pgd_ptr, pgd_val); - if (!pgd_val) - goto no_page; - pgd_val &= PTE_PFN_PROT_MASK; - pmd_base = (pgd_val >> _PAGE_PFN_SHIFT) << PAGESHIFT(); - - /* PMD */ - FILL_PMD(PAGEBASE(pmd_base), PHYSADDR, PAGESIZE()); - pmd_addr = pmd_base + sizeof(pmd_t) * pmd_index_l3_4k(vaddr); - pmd_val = ULONG(machdep->pmd + PAGEOFFSET(pmd_addr)); - if (verbose) - fprintf(fp, " PMD: %016lx => %016lx\n", pmd_addr, pmd_val); - if (!pmd_val) - goto no_page; - pmd_val &= PTE_PFN_PROT_MASK; - pte_base = (pmd_val >> _PAGE_PFN_SHIFT) << PAGESHIFT(); - - /* PTE */ - FILL_PTBL(PAGEBASE(pte_base), PHYSADDR, PAGESIZE()); - pte_addr = pte_base + sizeof(pmd_t) * pte_index_l3_4k(vaddr); - pte_val = ULONG(machdep->ptbl + PAGEOFFSET(pte_addr)); - if (verbose) - fprintf(fp, " PTE: %lx => %lx\n", pte_addr, pte_val); - if (!pte_val) - goto no_page; - pte_val &= PTE_PFN_PROT_MASK; - pte_pfn = pte_val >> _PAGE_PFN_SHIFT; - - if (!(pte_val & _PAGE_PRESENT)) { - if (verbose) { - fprintf(fp, "\n"); - riscv64_translate_pte((ulong)pte_val, 0, 0); - fprintf(fp, " PAGE: %016lx not present\n\n", PAGEBASE(*paddr)); + table_addr = (ulong)pgd; + + for (level = levels - 1; level >= 0; level--) { + name = riscv64_level_name(levels, level); + index = riscv64_vtop_index(vaddr, levels, level); + + if (level == levels - 1) { + FILL_PGD((ulong *)PAGEBASE(table_addr), KVADDR, + PAGESIZE()); + + entry_addr = table_addr + sizeof(ulong) * index; + pte = ULONG(machdep->pgd + PAGEOFFSET(entry_addr)); + } else { + FILL_PTBL(PAGEBASE(table_addr), PHYSADDR, + PAGESIZE()); + + entry_addr = table_addr + sizeof(ulong) * index; + pte = ULONG(machdep->ptbl + PAGEOFFSET(entry_addr)); } - return FALSE; - } - *paddr = PTOB(pte_pfn) + PAGEOFFSET(vaddr); + if (verbose) + fprintf(fp, " %s: %016lx => %016lx\n", + name, entry_addr, pte); + + if (!pte) + goto no_page; + + pte &= PTE_PFN_PROT_MASK; + + if (!(pte & _PAGE_PRESENT)) { + if (verbose) { + fprintf(fp, "\n"); + riscv64_translate_pte(pte, 0, 0); + } + + fprintf(fp, " PAGE: %016lx not present\n\n", + PAGEBASE(vaddr)); + return FALSE; + } + + if (RISCV64_PTE_LEAF(pte)) { + physaddr_t base, mask; + + base = riscv64_pte_paddr_base(pte); + mask = riscv64_pte_page_mask(level); - if (verbose) { - fprintf(fp, " PAGE: %016lx\n\n", PAGEBASE(*paddr)); - riscv64_translate_pte(pte_val, 0, 0); + if (level && (base & mask)) { + if (verbose) { + fprintf(fp, "\n"); + riscv64_translate_pte(pte, 0, 0); + } + + fprintf(fp, + " PAGE: %016lx invalid misaligned leaf pte\n\n", + PAGEBASE(vaddr)); + return FALSE; + } + + *paddr = riscv64_pte_to_paddr(pte, vaddr, level); + + if (verbose) { + fprintf(fp, " PAGE: %016lx\n\n", + (ulong)(*paddr & ~mask)); + riscv64_translate_pte(pte, 0, 0); + } + + return TRUE; + } + + if (level == 0) + goto no_page; + + table_addr = (ulong)riscv64_pte_paddr_base(pte); } - return TRUE; no_page: if (verbose) fprintf(fp, "invalid for %lx address\n", vaddr); @@ -1218,174 +1356,6 @@ riscv64_get_frame(struct bt_info *bt, ulong *pcp, ulong *spp) return TRUE; } -static int -riscv64_vtop_4level_4k(ulong *pgd, ulong vaddr, physaddr_t *paddr, int verbose) -{ - ulong *pgd_ptr, pgd_val; - ulong pud_base, pud_addr, pud_val; - ulong pmd_base, pmd_addr, pmd_val; - ulong pte_base, pte_addr, pte_val, pte_pfn; - - if (verbose) - fprintf(fp, "PAGE DIRECTORY: %lx\n", (ulong)pgd); - - /* PGD */ - pgd_ptr = pgd + pgd_index_l4_4k(vaddr); - FILL_PGD(pgd, KVADDR, PAGESIZE()); - pgd_val = ULONG(machdep->pgd + PAGEOFFSET(pgd_ptr)); - if (verbose) - fprintf(fp, " PGD: %lx => %lx\n", (ulong)pgd_ptr, pgd_val); - if (!pgd_val) - goto no_page; - pgd_val &= PTE_PFN_PROT_MASK; - pud_base = (pgd_val >> _PAGE_PFN_SHIFT) << PAGESHIFT(); - - /* PUD */ - FILL_PUD(PAGEBASE(pud_base), PHYSADDR, PAGESIZE()); - pud_addr = pud_base + sizeof(pud_t) * pud_index_l4_4k(vaddr); - pud_val = ULONG(machdep->pud + PAGEOFFSET(pud_addr)); - if (verbose) - fprintf(fp, " PUD: %016lx => %016lx\n", pud_addr, pud_val); - if (!pud_val) - goto no_page; - pud_val &= PTE_PFN_PROT_MASK; - pmd_base = (pud_val >> _PAGE_PFN_SHIFT) << PAGESHIFT(); - - /* PMD */ - FILL_PMD(PAGEBASE(pmd_base), PHYSADDR, PAGESIZE()); - pmd_addr = pmd_base + sizeof(pmd_t) * pmd_index_l4_4k(vaddr); - pmd_val = ULONG(machdep->pmd + PAGEOFFSET(pmd_addr)); - if (verbose) - fprintf(fp, " PMD: %016lx => %016lx\n", pmd_addr, pmd_val); - if (!pmd_val) - goto no_page; - pmd_val &= PTE_PFN_PROT_MASK; - pte_base = (pmd_val >> _PAGE_PFN_SHIFT) << PAGESHIFT(); - - /* PTE */ - FILL_PTBL(PAGEBASE(pte_base), PHYSADDR, PAGESIZE()); - pte_addr = pte_base + sizeof(pte_t) * pte_index_l4_4k(vaddr); - pte_val = ULONG(machdep->ptbl + PAGEOFFSET(pte_addr)); - if (verbose) - fprintf(fp, " PTE: %lx => %lx\n", pte_addr, pte_val); - if (!pte_val) - goto no_page; - pte_val &= PTE_PFN_PROT_MASK; - pte_pfn = pte_val >> _PAGE_PFN_SHIFT; - - if (!(pte_val & _PAGE_PRESENT)) { - if (verbose) { - fprintf(fp, "\n"); - riscv64_translate_pte((ulong)pte_val, 0, 0); - fprintf(fp, " PAGE: %016lx not present\n\n", PAGEBASE(*paddr)); - } - return FALSE; - } - - *paddr = PTOB(pte_pfn) + PAGEOFFSET(vaddr); - - if (verbose) { - fprintf(fp, " PAGE: %016lx\n\n", PAGEBASE(*paddr)); - riscv64_translate_pte(pte_val, 0, 0); - } - - return TRUE; -no_page: - if (verbose) - fprintf(fp, "invalid for %lx address\n", vaddr); - return FALSE; -} - -static int -riscv64_vtop_5level_4k(ulong *pgd, ulong vaddr, physaddr_t *paddr, int verbose) -{ - ulong *pgd_ptr, pgd_val; - ulong p4d_base, p4d_addr, p4d_val; - ulong pud_base, pud_addr, pud_val; - ulong pmd_base, pmd_addr, pmd_val; - ulong pte_base, pte_addr, pte_val, pte_pfn; - - if (verbose) - fprintf(fp, "PAGE DIRECTORY: %lx\n", (ulong)pgd); - - /* PGD */ - pgd_ptr = pgd + pgd_index_l5_4k(vaddr); - FILL_PGD(pgd, KVADDR, PAGESIZE()); - pgd_val = ULONG(machdep->pgd + PAGEOFFSET(pgd_ptr)); - if (verbose) - fprintf(fp, " PGD: %lx => %lx\n", (ulong)pgd_ptr, pgd_val); - if (!pgd_val) - goto no_page; - pgd_val &= PTE_PFN_PROT_MASK; - p4d_base = (pgd_val >> _PAGE_PFN_SHIFT) << PAGESHIFT(); - - /* P4D */ - FILL_P4D(PAGEBASE(p4d_base), PHYSADDR, PAGESIZE()); - p4d_addr = p4d_base + sizeof(p4d_t) * p4d_index_l5_4k(vaddr); - p4d_val = ULONG(machdep->machspec->p4d + PAGEOFFSET(p4d_addr)); - if (verbose) - fprintf(fp, " P4D: %016lx => %016lx\n", p4d_addr, p4d_val); - if (!p4d_val) - goto no_page; - p4d_val &= PTE_PFN_PROT_MASK; - pud_base = (p4d_val >> _PAGE_PFN_SHIFT) << PAGESHIFT(); - - /* PUD */ - FILL_PUD(PAGEBASE(pud_base), PHYSADDR, PAGESIZE()); - pud_addr = pud_base + sizeof(pud_t) * pud_index_l5_4k(vaddr); - pud_val = ULONG(machdep->pud + PAGEOFFSET(pud_addr)); - if (verbose) - fprintf(fp, " PUD: %016lx => %016lx\n", pud_addr, pud_val); - if (!pud_val) - goto no_page; - pud_val &= PTE_PFN_PROT_MASK; - pmd_base = (pud_val >> _PAGE_PFN_SHIFT) << PAGESHIFT(); - - /* PMD */ - FILL_PMD(PAGEBASE(pmd_base), PHYSADDR, PAGESIZE()); - pmd_addr = pmd_base + sizeof(pmd_t) * pmd_index_l5_4k(vaddr); - pmd_val = ULONG(machdep->pmd + PAGEOFFSET(pmd_addr)); - if (verbose) - fprintf(fp, " PMD: %016lx => %016lx\n", pmd_addr, pmd_val); - if (!pmd_val) - goto no_page; - pmd_val &= PTE_PFN_PROT_MASK; - pte_base = (pmd_val >> _PAGE_PFN_SHIFT) << PAGESHIFT(); - - /* PTE */ - FILL_PTBL(PAGEBASE(pte_base), PHYSADDR, PAGESIZE()); - pte_addr = pte_base + sizeof(pte_t) * pte_index_l5_4k(vaddr); - pte_val = ULONG(machdep->ptbl + PAGEOFFSET(pte_addr)); - if (verbose) - fprintf(fp, " PTE: %lx => %lx\n", pte_base, pte_val); - if (!pte_val) - goto no_page; - pte_val &= PTE_PFN_PROT_MASK; - pte_pfn = pte_val >> _PAGE_PFN_SHIFT; - - if (!(pte_val & _PAGE_PRESENT)) { - if (verbose) { - fprintf(fp, "\n"); - riscv64_translate_pte((ulong)pte_val, 0, 0); - fprintf(fp, " PAGE: %016lx not present\n\n", PAGEBASE(*paddr)); - } - return FALSE; - } - - *paddr = PTOB(pte_pfn) + PAGEOFFSET(vaddr); - - if (verbose) { - fprintf(fp, " PAGE: %016lx\n\n", PAGEBASE(*paddr)); - riscv64_translate_pte(pte_val, 0, 0); - } - - return TRUE; -no_page: - if (verbose) - fprintf(fp, "invalid for %lx address\n", vaddr); - return FALSE; -} - static int riscv64_init_active_task_regs(void) { @@ -1610,11 +1580,11 @@ riscv64_uvtop(struct task_context *tc, ulong uvaddr, physaddr_t *paddr, int verb switch (machdep->flags & VM_FLAGS) { case VM_L3_4K: - return riscv64_vtop_3level_4k(pgd, uvaddr, paddr, verbose); + return riscv64_vtop_nlevel_4k(pgd, uvaddr, paddr, verbose, 3); case VM_L4_4K: - return riscv64_vtop_4level_4k(pgd, uvaddr, paddr, verbose); + return riscv64_vtop_nlevel_4k(pgd, uvaddr, paddr, verbose, 4); case VM_L5_4K: - return riscv64_vtop_5level_4k(pgd, uvaddr, paddr, verbose); + return riscv64_vtop_nlevel_4k(pgd, uvaddr, paddr, verbose, 5); default: return FALSE; } @@ -1669,11 +1639,11 @@ riscv64_kvtop(struct task_context *tc, ulong kvaddr, physaddr_t *paddr, int verb switch (machdep->flags & VM_FLAGS) { case VM_L3_4K: - return riscv64_vtop_3level_4k((ulong *)kernel_pgd, kvaddr, paddr, verbose); + return riscv64_vtop_nlevel_4k((ulong *)kernel_pgd, kvaddr, paddr, verbose, 3); case VM_L4_4K: - return riscv64_vtop_4level_4k((ulong *)kernel_pgd, kvaddr, paddr, verbose); + return riscv64_vtop_nlevel_4k((ulong *)kernel_pgd, kvaddr, paddr, verbose, 4); case VM_L5_4K: - return riscv64_vtop_5level_4k((ulong *)kernel_pgd, kvaddr, paddr, verbose); + return riscv64_vtop_nlevel_4k((ulong *)kernel_pgd, kvaddr, paddr, verbose, 5); default: return FALSE; } -- 2.27.0 -- Crash-utility mailing list -- devel(a)lists.crash-utility.osci.io To unsubscribe send an email to devel-leave(a)lists.crash-utility.osci.io https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki