powerpc/ptdump: Properly handle non standard page size

In order to properly display information regardless of the page size,
it is necessary to take into account real page size.

Fixes: cabe8138b23c ("powerpc: dump as a single line areas mapping a single physical page.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a53b2a0ffd042a8d85464bf90d55bc5b970e00a1.1589866984.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 1f97668853e3dfa9e0e5b0a5f106c7b70f41aa3e..98d82dcf6f0b9f57533e0c234981de461152dbf2 100644 (file)
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -60,6 +60,7 @@ struct pg_state {
        unsigned long start_address;
        unsigned long start_pa;
        unsigned long last_pa;
+       unsigned long page_size;
        unsigned int level;
        u64 current_flags;
        bool check_wx;
@@ -168,9 +169,9 @@ static void dump_addr(struct pg_state *st, unsigned long addr)
 #endif
 
        pt_dump_seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);
-       if (st->start_pa == st->last_pa && st->start_address + PAGE_SIZE != addr) {
+       if (st->start_pa == st->last_pa && st->start_address + st->page_size != addr) {
                pt_dump_seq_printf(st->seq, "[" REG "]", st->start_pa);
-               delta = PAGE_SIZE >> 10;
+               delta = st->page_size >> 10;
        } else {
                pt_dump_seq_printf(st->seq, " " REG " ", st->start_pa);
                delta = (addr - st->start_address) >> 10;
@@ -195,7 +196,7 @@ static void note_prot_wx(struct pg_state *st, unsigned long addr)
 }
 
 static void note_page(struct pg_state *st, unsigned long addr,
-              unsigned int level, u64 val)
+              unsigned int level, u64 val, unsigned long page_size)
 {
        u64 flag = val & pg_level[level].mask;
        u64 pa = val & PTE_RPN_MASK;
@@ -207,6 +208,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
                st->start_address = addr;
                st->start_pa = pa;
                st->last_pa = pa;
+               st->page_size = page_size;
                pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
        /*
         * Dump the section of virtual memory when:
@@ -218,7 +220,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
         */
        } else if (flag != st->current_flags || level != st->level ||
                   addr >= st->marker[1].start_address ||
-                  (pa != st->last_pa + PAGE_SIZE &&
+                  (pa != st->last_pa + st->page_size &&
                    (pa != st->start_pa || st->start_pa != st->last_pa))) {
 
                /* Check the PTE flags */
@@ -246,6 +248,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
                st->start_address = addr;
                st->start_pa = pa;
                st->last_pa = pa;
+               st->page_size = page_size;
                st->current_flags = flag;
                st->level = level;
        } else {
@@ -261,7 +264,7 @@ static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start)
 
        for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
                addr = start + i * PAGE_SIZE;
-               note_page(st, addr, 4, pte_val(*pte));
+               note_page(st, addr, 4, pte_val(*pte), PAGE_SIZE);
 
        }
 }
@@ -278,7 +281,7 @@ static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start)
                        /* pmd exists */
                        walk_pte(st, pmd, addr);
                else
-                       note_page(st, addr, 3, pmd_val(*pmd));
+                       note_page(st, addr, 3, pmd_val(*pmd), PMD_SIZE);
        }
 }
 
@@ -294,7 +297,7 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
                        /* pud exists */
                        walk_pmd(st, pud, addr);
                else
-                       note_page(st, addr, 2, pud_val(*pud));
+                       note_page(st, addr, 2, pud_val(*pud), PUD_SIZE);
        }
 }
 
@@ -313,7 +316,7 @@ static void walk_pagetables(struct pg_state *st)
                        /* pgd exists */
                        walk_pud(st, pgd, addr);
                else
-                       note_page(st, addr, 1, pgd_val(*pgd));
+                       note_page(st, addr, 1, pgd_val(*pgd), PGDIR_SIZE);
        }
 }
 
@@ -368,7 +371,7 @@ static int ptdump_show(struct seq_file *m, void *v)
 
        /* Traverse kernel page tables */
        walk_pagetables(&st);
-       note_page(&st, 0, 0, 0);
+       note_page(&st, 0, 0, 0, 0);
        return 0;
 }