[PATCH 5.7 050/163] powerpc/ptdump: Properly handle non standard page size

[Greg Kroah-Hartman]

From: Christophe Leroy <christophe.le...@csgroup.eu>

commit b00ff6d8c1c3898b0f768cbb38ef722d25bd2f39 upstream.

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: sta...@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Link: 
https://lore.kernel.org/r/a53b2a0ffd042a8d85464bf90d55bc5b970e00a1.1589866984.git.christophe.le...@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 arch/powerpc/mm/ptdump/ptdump.c |   21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

--- 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;
@@ -157,9 +158,9 @@ static void dump_addr(struct pg_state *s
 #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;
@@ -190,7 +191,7 @@ static void note_prot_wx(struct pg_state
 }
 
 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;
@@ -202,6 +203,7 @@ static void note_page(struct pg_state *s
                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:
@@ -213,7 +215,7 @@ static void note_page(struct pg_state *s
         */
        } 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 */
@@ -241,6 +243,7 @@ static void note_page(struct pg_state *s
                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 {
@@ -256,7 +259,7 @@ static void walk_pte(struct pg_state *st
 
        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);
 
        }
 }
@@ -273,7 +276,7 @@ static void walk_pmd(struct pg_state *st
                        /* 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);
        }
 }
 
@@ -289,7 +292,7 @@ static void walk_pud(struct pg_state *st
                        /* 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);
        }
 }
 
@@ -308,7 +311,7 @@ static void walk_pagetables(struct pg_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);
        }
 }
 
@@ -363,7 +366,7 @@ static int ptdump_show(struct seq_file *
 
        /* Traverse kernel page tables */
        walk_pagetables(&st);
-       note_page(&st, 0, 0, 0);
+       note_page(&st, 0, 0, 0, 0);
        return 0;
 }