答复: 答复: [External Mail]Re: [PATCH v4] Fix: move huge compressed obj from page to zspage

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Subject: [PATCH] Fix: "rd" command to read zram buf on Linux 5.17 and later


Kernel commit a41ec880aa7b ("zsmalloc: move huge compressed obj from page to zspage"),
which is contained in Linux 5.17 and later kernels.
Kernel commit ffedd09fa9b06 ("zsmalloc: Stop using slab fields in struct page")
Kernel commit f635725c3905e ("zram: do not waste zram_table_entry flags bits"),
which is contained in Linux 6.1 and later kernels.

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@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20220912152744.527438-1-senozhatsky@xxxxxxxxxxxx

Signed-off-by: chenguanyou <chenguanyou@xxxxxxxxxx>
---
 defs.h     | 13 +++++++++++
 diskdump.c | 67 ++++++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 68 insertions(+), 12 deletions(-)

diff --git a/defs.h b/defs.h
index 96a7a2a..95ccbb4 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 zspage_5_17 {
+    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..625b3a0 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 zspage_5_17 zspage_5_17_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, &zspage_5_17_s, sizeof(struct zspage_5_17), "zspage_5_17", FAULT_ON_ERROR);
+       class_idx = zspage_5_17_s.class;
+       zs_magic = zspage_5_17_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 (!zspage_5_17_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);
        goto out;
    }
-   size = flags & (ZRAM_FLAG_SHIFT -1);
+
+   size = flags & ((1 << ZRAM_LOCK_VALUE) - 1);
    if (size == 0) {
        len = 0;
        goto out;
-- 
2.39.0

Thanks.
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发件人: HAGIO KAZUHITO(?尾 一仁) <k-hagio-ab@xxxxxxx>
发送时间: 2023年10月12日 16:17:43
收件人: 陈冠有; crash-utility@xxxxxxxxxx
抄送: lijiang@xxxxxxxxxx
主题: Re: 答复: [External Mail]Re: [PATCH v4] Fix: move huge compressed obj from page to zspage
 
[外部邮件] 此邮件来源于小米公司外部,请谨慎处理。若对邮件安全性存疑,请将邮件转发给misec@xxxxxxxxxx进行反馈

On 2023/10/09 15:09, 陈冠有 wrote:
> Hi Kazu
>

Thank you for the information.

I'm reviewing this, but could you please resend a patch as an attached
plain text file?  Your email cannot be applied with "git am" due to
base64 encoding and broken indents.

>
> a41ec880aa7b ("zsmalloc: move huge compressed obj from page to zspage")
>
> zspage6 meam linux 6 and later, because I don't have a better way at the moment.

ok, the commit a41ec880aa7b exists since Linux 5.17, so "zspage_5_17"
would be better.

Thanks,
Kazu

>
>
> ffedd09fa9b06 ("zsmalloc: Stop using slab fields in struct page")
>
> using page->index to store 'page' (page->index and page->freelist are at the same offset in struct page).
>
>
> f635725c3905e ("zram: do not waste zram_table_entry flags bits")
>
> -#define ZRAM_FLAG_SHIFT 24
> +#define ZRAM_FLAG_SHIFT (PAGE_SHIFT + 1)
>
>
> enum zram_pageflags {
>      /* zram slot is locked */
>      ZRAM_LOCK = ZRAM_FLAG_SHIFT,
>      ZRAM_SAME,  /* Page consists the same element */
>      ZRAM_WB,    /* page is stored on backing_device */
>      ZRAM_UNDER_WB,  /* page is under writeback */
>      ZRAM_HUGE,  /* Incompressible page */
>      ZRAM_IDLE,  /* not accessed page since last idle marking */
>      ZRAM_INCOMPRESSIBLE, /* none of the algorithms could compress it */
>
>      ZRAM_COMP_PRIORITY_BIT1, /* First bit of comp priority index */
>      ZRAM_COMP_PRIORITY_BIT2, /* Second bit of comp priority index */
>
>      __NR_ZRAM_PAGEFLAGS,
> };
>
> Thanks
>
>
> ________________________________
> 发件人: HAGIO KAZUHITO(?尾 一仁) <k-hagio-ab@xxxxxxx>
> 发送时间: 2023年10月4日 9:33:57
> 收件人: 陈冠有; crash-utility@xxxxxxxxxx
> 抄送: lijiang@xxxxxxxxxx
> 主题: [External Mail]Re: [PATCH v4] Fix: move huge compressed obj from page to zspage
>
> [外部邮件] 此邮件来源于小米公司外部,请谨慎处理。若对邮件安全性存疑,请将邮件转发给misec@xxxxxxxxxx进行反馈
>
> On 2023/09/20 12:28, 陈冠有 wrote:
>> 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.
>
> Thank you for the patch, is this v4 patch the latest one?
>
>>
>> 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@xxxxxxxxxx
>
> Please use the commit information if it's already in the kernel.
> a41ec880aa7b ("zsmalloc: move huge compressed obj from page to zspage")
>
>>
>> Signed-off-by: chenguanyou <chenguanyou@xxxxxxxxxx>
>> ---
>>    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 {
>
> Why is this name "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);
>> +   }
>
> What is the kernel commit related to this hunk?
>
>>       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);
>
> What is the kernel commit related to this hunk?
>
> And I could not apply this, could you resend it as a plain text email or
> an attached plain text file?
>
> Thanks,
> Kazu
>
>>           goto out;
>>       }
>> -   size = flags & (ZRAM_FLAG_SHIFT -1);
>> +
>> +   size = flags & ((1 << ZRAM_LOCK_VALUE) - 1);
>>       if (size == 0) {
>>           len = 0;
>>           goto out;
>> --
>> 2.39.0
>>
>>
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>
>
> Hi Kazu
>
>
> a41ec880aa7b ("zsmalloc: move huge compressed obj from page to zspage")
>
> zspage6 meam linux 6 and later, because I don't have a better way at the
> moment.
>
>
> ffedd09fa9b06 ("zsmalloc: Stop using slab fields in struct page")
>
> using page->index to store 'page' (page->index and page->freelist are at
> the same offset in struct page).
>
>
> f635725c3905e ("zram: do not waste zram_table_entry flags bits")
>
> -#define ZRAM_FLAG_SHIFT 24
> +#define ZRAM_FLAG_SHIFT (PAGE_SHIFT + 1)
>
> enum zram_pageflags {
>      /* zram slot is locked */
>      ZRAM_LOCK = ZRAM_FLAG_SHIFT,
>      ZRAM_SAME,  /* Page consists the same element */
>      ZRAM_WB,    /* page is stored on backing_device */
>      ZRAM_UNDER_WB,  /* page is under writeback */
>      ZRAM_HUGE,  /* Incompressible page */
>      ZRAM_IDLE,  /* not accessed page since last idle marking */
>      ZRAM_INCOMPRESSIBLE, /* none of the algorithms could compress it */
>
>      ZRAM_COMP_PRIORITY_BIT1, /* First bit of comp priority index */
>      ZRAM_COMP_PRIORITY_BIT2, /* Second bit of comp priority index */
>
>      __NR_ZRAM_PAGEFLAGS,
> };
>
> Thanks
>
> ------------------------------------------------------------------------
> *发件人:* HAGIO KAZUHITO(?尾 一仁) <k-hagio-ab@xxxxxxx>
> *发送时间:* 2023年10月4日 9:33:57
> *收件人:* 陈冠有; crash-utility@xxxxxxxxxx
> *抄送:* lijiang@xxxxxxxxxx
> *主题:* [External Mail]Re: [PATCH v4] Fix: move huge compressed obj from
> page to zspage
> [外部邮件] 此邮件来源于小米公司外部,请谨慎处理。若对邮件安全性存疑,请
> 将邮件转发给misec@xxxxxxxxxx进行反馈
>
> On 2023/09/20 12:28, 陈冠有 wrote:
>> 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.
>
> Thank you for the patch, is this v4 patch the latest one?
>
>>
>> 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@xxxxxxxxxx
> <https://lkml.kernel.org/r/20211115185909.3949505-6-minchan@xxxxxxxxxx>
>
> Please use the commit information if it's already in the kernel.
> a41ec880aa7b ("zsmalloc: move huge compressed obj from page to zspage")
>
>>
>> Signed-off-by: chenguanyou <chenguanyou@xxxxxxxxxx>
>> ---
>>   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 {
>
> Why is this name "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);
>> +   }
>
> What is the kernel commit related to this hunk?
>
>>      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);
>
> What is the kernel commit related to this hunk?
>
> And I could not apply this, could you resend it as a plain text email or
> an attached plain text file?
>
> Thanks,
> Kazu
>
>>          goto out;
>>      }
>> -   size = flags & (ZRAM_FLAG_SHIFT -1);
>> +
>> +   size = flags & ((1 << ZRAM_LOCK_VALUE) - 1);
>>      if (size == 0) {
>>          len = 0;
>>          goto out;
>> --
>> 2.39.0
>>
>>
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From 0eda13bc2fe666904971ea9803b82faf9fa4c0ba Mon Sep 17 00:00:00 2001
From: chenguanyou <chenguanyou@xxxxxxxxxx>
Date: Mon, 11 Sep 2023 20:59:39 +0800
Subject: [PATCH] Fix: "rd" command to read zram buf on Linux 5.17 and later

Kernel commit a41ec880aa7b ("zsmalloc: move huge compressed obj from page to zspage"),
which is contained in Linux 5.17 and later kernels.
Kernel commit ffedd09fa9b06 ("zsmalloc: Stop using slab fields in struct page")
Kernel commit f635725c3905e ("zram: do not waste zram_table_entry flags bits"),
which is contained in Linux 6.1 and later kernels.

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@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20220912152744.527438-1-senozhatsky@xxxxxxxxxxxx

Signed-off-by: chenguanyou <chenguanyou@xxxxxxxxxx>
---
 defs.h     | 13 +++++++++++
 diskdump.c | 67 ++++++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 68 insertions(+), 12 deletions(-)

diff --git a/defs.h b/defs.h
index 96a7a2a..95ccbb4 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 zspage_5_17 {
+    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..625b3a0 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 zspage_5_17 zspage_5_17_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, &zspage_5_17_s, sizeof(struct zspage_5_17), "zspage_5_17", FAULT_ON_ERROR);
+		class_idx = zspage_5_17_s.class;
+		zs_magic = zspage_5_17_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 (!zspage_5_17_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);
 		goto out;
 	}
-	size = flags & (ZRAM_FLAG_SHIFT -1);
+
+	size = flags & ((1 << ZRAM_LOCK_VALUE) - 1);
 	if (size == 0) {
 		len = 0;
 		goto out;
-- 
2.39.0

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