when zspage define 'huge', crash-utility zram decompress fail.

we need to be compatible with the previous kernel,

so we can't define 'huge' directly in zspage, just move to the right when calculating.

Link: https://lkml.kernel.org/r/20211115185909.3949505-6-minchan@kernel.org

Signed-off-by: chenguanyou <chenguanyou@xiaomi.com>

---

defs.h | 13 +++++++++++++

diskdump.c | 39 ++++++++++++++++++++++++++++++---------

2 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/defs.h b/defs.h

index 96a7a2a..0af69cc 100644

--- a/defs.h

+++ b/defs.h

@@ -2225,6 +2225,7 @@ struct offset_table { /* stash of commonly-used offsets */

long module_memory_base;

long module_memory_size;

long irq_data_irq;

+ long zspage_huge;

};

struct size_table { /* stash of commonly-used sizes */

@@ -7221,6 +7222,18 @@ struct zspage {

unsigned int freeobj;

};

+struct zspage6 {

+ struct {

+ unsigned int huge : 1;

+ unsigned int fullness : 2;

+ unsigned int class : 9;

+ unsigned int isolated : 3;

+ unsigned int magic : 8;

+ };

+ unsigned int inuse;

+ unsigned int freeobj;

+};

* makedumpfile.c

diff --git a/diskdump.c b/diskdump.c

index 2c284ff..99a8112 100644

--- a/diskdump.c

+++ b/diskdump.c

@@ -2761,9 +2761,11 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)

{

ulong obj, off, class, page, zspage;

struct zspage zspage_s;

+ struct zspage6 zspage6_s;

physaddr_t paddr;

unsigned int obj_idx, class_idx, size;

ulong pages[2], sizes[2];

+ ulong zs_magic;

readmem(handle, KVADDR, &obj, sizeof(void *), "zram entry", FAULT_ON_ERROR);

obj >>= OBJ_TAG_BITS;

@@ -2772,11 +2774,19 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)

readmem(page + OFFSET(page_private), KVADDR, &zspage,

sizeof(void *), "page_private", FAULT_ON_ERROR);

- readmem(zspage, KVADDR, &zspage_s, sizeof(struct zspage), "zspage", FAULT_ON_ERROR);

- class_idx = zspage_s.class;

- if (zspage_s.magic != ZSPAGE_MAGIC)

- error(FATAL, "zspage magic incorrect: %x\n", zspage_s.magic);

+ if (VALID_MEMBER(zspage_huge)) {

+ readmem(zspage, KVADDR, &zspage6_s, sizeof(struct zspage6), "zspage6", FAULT_ON_ERROR);

+ class_idx = zspage6_s.class;

+ zs_magic = zspage6_s.magic;

+ } else {

+ readmem(zspage, KVADDR, &zspage_s, sizeof(struct zspage), "zspage", FAULT_ON_ERROR);

+ class_idx = zspage_s.class;

+ zs_magic = zspage_s.magic;

+ }

+ if (zs_magic != ZSPAGE_MAGIC)

+ error(FATAL, "zspage magic incorrect: %x\n", zs_magic);

class = pool + OFFSET(zspoll_size_class);

class += (class_idx * sizeof(void *));

@@ -2794,8 +2804,13 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)

}

pages[0] = page;

- readmem(page + OFFSET(page_freelist), KVADDR, &pages[1],

- sizeof(void *), "page_freelist", FAULT_ON_ERROR);

+ if (VALID_MEMBER(page_freelist)) {

+ readmem(page + OFFSET(page_freelist), KVADDR, &pages[1],

+ sizeof(void *), "page_freelist", FAULT_ON_ERROR);

+ } else {

+ readmem(page + OFFSET(page_index), KVADDR, &pages[1],

+ sizeof(void *), "page_index", FAULT_ON_ERROR);

+ }

sizes[0] = PAGESIZE() - off;

sizes[1] = size - sizes[0];

if (!is_page_ptr(pages[0], &paddr)) {

@@ -2812,9 +2827,15 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)

readmem(paddr, PHYSADDR, zram_buf + sizes[0], sizes[1], "zram buffer[1]", FAULT_ON_ERROR);

out:

- readmem(page, KVADDR, &obj, sizeof(void *), "page flags", FAULT_ON_ERROR);

- if (!(obj & (1<<10))) { //PG_OwnerPriv1 flag

- return (zram_buf + ZS_HANDLE_SIZE);

+ if (!VALID_MEMBER(zspage_huge)) {

+ readmem(page, KVADDR, &obj, sizeof(void *), "page flags", FAULT_ON_ERROR);

+ if (!(obj & (1<<10))) { //PG_OwnerPriv1 flag

+ return (zram_buf + ZS_HANDLE_SIZE);

+ }

+ } else {

+ if (!zspage6_s.huge) {

+ return (zram_buf + ZS_HANDLE_SIZE);

+ }

}

return zram_buf;

2.39.0