[PATCH v2 12/45] powerpc/ptdump: Properly handle non standard page size

From: Christophe Leroy
Date: Wed May 06 2020 - 12:50:07 EST


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

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Fixes: cabe8138b23c ("powerpc: dump as a single line areas mapping a single physical page.")
Cc: stable@xxxxxxxxxxxxxxx
---
arch/powerpc/mm/ptdump/ptdump.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 1f97668853e3..64434b66f240 100644
--- 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;
@@ -195,10 +196,11 @@ 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, int shift)
{
u64 flag = val & pg_level[level].mask;
u64 pa = val & PTE_RPN_MASK;
+ unsigned long page_size = 1 << shift;

/* At first no level is set */
if (!st->level) {
@@ -207,6 +209,7 @@ 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 +221,7 @@ 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 +249,7 @@ 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 +265,7 @@ 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_SHIFT);

}
}
@@ -278,7 +282,7 @@ 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), PTE_SHIFT);
}
}

@@ -294,7 +298,7 @@ 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), PMD_SHIFT);
}
}

@@ -313,7 +317,7 @@ 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), PUD_SHIFT);
}
}

@@ -368,7 +372,7 @@ 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;
}

--
2.25.0