Re: [Crash-utility] [PATCH v4] Fix: move huge compressed obj from page to zspage

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.

Before: crash> mod -s zram zram.ko MODULE NAME BASE SIZE OBJECT FILE ffffffde224db800 zram ffffffde224d2000 57344 zram.ko crash> mod -s zsmalloc zsmalloc.ko MODULE NAME BASE SIZE OBJECT FILE ffffffde224c5180 zsmalloc ffffffde224bf000 40960 zsmalloc.ko crash> rd 0x13d89fb0 rd: zspage magic incorrect: b0 After: crash> rd 0x13d89fb0 13d89fb0: c2b54f7170883b20 ;.pqO.. Link: https://lkml.kernel.org/r/20211115185909.3949505-6-minchan@kernel.org

Signed-off-by: chenguanyou <chenguanyou(a)xiaomi.com&gt; --- defs.h | 13 +++++++++++ diskdump.c | 67 ++++++++++++++++++++++++++++++++++++++++++++---------- 2 files changed, 68 insertions(+), 12 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..02aaf1b 100644 --- a/diskdump.c +++ b/diskdump.c @@ -2754,6 +2754,9 @@ zram_init(void) if (INVALID_MEMBER(zram_table_flag)) MEMBER_OFFSET_INIT(zram_table_flag, "zram_table_entry", "value"); STRUCT_SIZE_INIT(zram_table_entry, "zram_table_entry"); + MEMBER_OFFSET_INIT(zspoll_size_class, "zs_pool", "size_class"); + MEMBER_OFFSET_INIT(size_class_size, "size_class", "size"); + MEMBER_OFFSET_INIT(zspage_huge, "zspage", "huge"); } static unsigned char * @@ -2761,9 +2764,11 @@ 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 +2777,19 @@ 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 +2807,13 @@ 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 +2830,15 @@ 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; @@ -2929,6 +2953,11 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong unsigned char *outbuf = NULL; ulong zram, zram_table_entry, sector, index, entry, flags, size, outsize, off; + unsigned long *same_buf = NULL; + bool is_same = false; + ulong ZRAM_SAME_PAGEFLAG; + ulong ZRAM_WB_PAGEFLAG; + long ZRAM_LOCK_VALUE = 24; if (INVALID_MEMBER(zram_compressor)) { zram_init(); @@ -2992,11 +3021,25 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong sizeof(void *), "entry of table", FAULT_ON_ERROR); readmem(zram_table_entry + OFFSET(zram_table_flag), KVADDR, &flags, sizeof(void *), "zram_table_flag", FAULT_ON_ERROR); - if (!entry || (flags & ZRAM_FLAG_SAME_BIT)) { - memset(buf, entry, len); + + if (!enumerator_value("ZRAM_LOCK", &ZRAM_LOCK_VALUE) + && THIS_KERNEL_VERSION >= LINUX(6,1,0)) + ZRAM_LOCK_VALUE = PAGESHIFT() + 1; + + ZRAM_SAME_PAGEFLAG = ZRAM_LOCK_VALUE + 1; + ZRAM_WB_PAGEFLAG = ZRAM_LOCK_VALUE + 2; + + if (!entry || flags & (1 << ZRAM_SAME_PAGEFLAG)) { + same_buf = (unsigned long *)GETBUF(PAGESIZE()); + for (int count = 0; count < PAGESIZE() / sizeof(unsigned long); count++) { + same_buf[count] = entry; + } + memcpy(buf, same_buf + off, PAGESIZE()); + FREEBUF(same_buf);