[PATCH 2/2] mm: ptdump: Expand type of 'val' in note_page()

From: Steven Price
Date: Thu May 21 2020 - 11:23:27 EST


The page table entry is passed in the 'val' argument to note_page(),
however this was previously an "unsigned long" which is fine on 64-bit
platforms. But for 32 bit x86 it is not always big enough to contain a
page table entry which may be 64 bits.

Change the type to u64 to ensure that it is always big enough.

Reported-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
arch/arm64/mm/dump.c | 2 +-
arch/x86/mm/dump_pagetables.c | 2 +-
include/linux/ptdump.h | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index 860c00ec8bd3..d4313bc0c4c1 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -247,7 +247,7 @@ static void note_prot_wx(struct pg_state *st, unsigned long addr)
}

static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
- unsigned long val)
+ u64 val)
{
struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
static const char units[] = "KMGTPE";
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 199bbb7fbd79..17aa7ac94a34 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -273,7 +273,7 @@ static void effective_prot(struct ptdump_state *pt_st, int level, u64 val)
* print what we collected so far.
*/
static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
- unsigned long val)
+ u64 val)
{
struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
pgprotval_t new_prot, new_eff;
diff --git a/include/linux/ptdump.h b/include/linux/ptdump.h
index ac01502763bf..2a3a95586425 100644
--- a/include/linux/ptdump.h
+++ b/include/linux/ptdump.h
@@ -13,7 +13,7 @@ struct ptdump_range {
struct ptdump_state {
/* level is 0:PGD to 4:PTE, or -1 if unknown */
void (*note_page)(struct ptdump_state *st, unsigned long addr,
- int level, unsigned long val);
+ int level, u64 val);
void (*effective_prot)(struct ptdump_state *st, int level, u64 val);
const struct ptdump_range *range;
};
--
2.20.1