Hi Chengen,
thank you for the patch.
On 2023/11/09 11:54, Chengen Du wrote:
> A kernel commit 7ac07a26dea7 (zram: preparation for multi-zcomp support)
> in Linux replaces "compressor" with "comp_algs" in the zram struct.
> If not fixed, the issue triggers the following error:
> rd: WARNING: Some pages are swapped out to zram. Please run mod -s zram.
> rd: invalid user virtual address: ffff7d23f010 type: "64-bit UVADDR"
>
> Signed-off-by: Chengen Du <chengen.du@xxxxxxxxxxxxx>
> ---
> defs.h | 1 +
> diskdump.c | 61 +++++++++++++++++++++++++++++++++++-------------------
> 2 files changed, 41 insertions(+), 21 deletions(-)
>
> diff --git a/defs.h b/defs.h
> index 788f63a..2cae5b6 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -2227,6 +2227,7 @@ struct offset_table { /* stash of commonly-used offsets */
> long module_memory_size;
> long irq_data_irq;
> long zspage_huge;
> + long zram_comp_algs;
> };
>
> struct size_table { /* stash of commonly-used sizes */
> diff --git a/diskdump.c b/diskdump.c
> index 0fe46f4..0103221 100644
> --- a/diskdump.c
> +++ b/diskdump.c
> @@ -2757,6 +2757,8 @@ diskdump_device_dump_info(FILE *ofp)
>
> static ulong ZRAM_FLAG_SHIFT;
> static ulong ZRAM_FLAG_SAME_BIT;
> +static ulong ZRAM_COMP_PRIORITY_BIT1;
> +static ulong ZRAM_COMP_PRIORITY_MASK;
>
> static void
> zram_init(void)
> @@ -2764,7 +2766,10 @@ zram_init(void)
> long zram_flag_shift;
>
> MEMBER_OFFSET_INIT(zram_mempoll, "zram", "mem_pool");
> - MEMBER_OFFSET_INIT(zram_compressor, "zram", "compressor");
> + if (THIS_KERNEL_VERSION >= LINUX(6, 2, 0))
> + MEMBER_OFFSET_INIT(zram_comp_algs, "zram", "comp_algs");
> + else
> + MEMBER_OFFSET_INIT(zram_compressor, "zram", "compressor");
Kernel patches can be backported to kernels older than 6.2.0, please
don't use the kernel version if possible. So, for example:
MEMBER_OFFSET_INIT(zram_compressor, "zram", "compressor");
if (INVALID_MEMBER(zram_compressor))
MEMBER_OFFSET_INIT(zram_comp_algs, "zram", "comp_algs");
> MEMBER_OFFSET_INIT(zram_table_flag, "zram_table_entry", "flags");
> if (INVALID_MEMBER(zram_table_flag))
> MEMBER_OFFSET_INIT(zram_table_flag, "zram_table_entry", "value");
> @@ -2782,6 +2787,8 @@ zram_init(void)
>
> ZRAM_FLAG_SHIFT = 1 << zram_flag_shift;
> ZRAM_FLAG_SAME_BIT = 1 << (zram_flag_shift+1);
> + ZRAM_COMP_PRIORITY_BIT1 = ZRAM_FLAG_SHIFT + 7;
> + ZRAM_COMP_PRIORITY_MASK = 0x3;
>
> if (CRASHDEBUG(1))
> fprintf(fp, "zram_flag_shift: %ld\n", zram_flag_shift);
> @@ -2980,13 +2987,17 @@ 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;
> + int comp_alg_unavail;
>
> - if (INVALID_MEMBER(zram_compressor)) {
> + comp_alg_unavail = (THIS_KERNEL_VERSION >= LINUX(6, 2, 0))
> + ? INVALID_MEMBER(zram_comp_algs) : INVALID_MEMBER(zram_compressor);
Same as above, for example, this works?
if (INVALID_MEMBER(zram_comp_algs) && INVALID_MEMBER(zram_compressor))
> + if (comp_alg_unavail) {
> zram_init();
> - if (INVALID_MEMBER(zram_compressor)) {
> - error(WARNING,
> - "Some pages are swapped out to zram. "
> - "Please run mod -s zram.\n");
> + comp_alg_unavail = (THIS_KERNEL_VERSION >= LINUX(6, 2, 0))
> + ? INVALID_MEMBER(zram_comp_algs) : INVALID_MEMBER(zram_compressor);
> + if (comp_alg_unavail) {
> + error(WARNING, "some pages are swapped out to zram. "
> + "please run mod -s zram.\n");
> return 0;
> }
> }
> @@ -2997,8 +3008,29 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong
> if (!get_disk_name_private_data(pte_val, vaddr, NULL, &zram))
> return 0;
>
> - readmem(zram + OFFSET(zram_compressor), KVADDR, name,
> - sizeof(name), "zram compressor", FAULT_ON_ERROR);
> + if (THIS_KERNEL_VERSION >= LINUX(2, 6, 0)) {
> + swp_offset = (ulonglong)__swp_offset(pte_val);
> + } else {
> + swp_offset = (ulonglong)SWP_OFFSET(pte_val);
> + }
> +
> + sector = swp_offset << (PAGESHIFT() - 9);
> + index = sector >> SECTORS_PER_PAGE_SHIFT;
> + readmem(zram, KVADDR, &zram_table_entry,
> + sizeof(void *), "zram_table_entry", FAULT_ON_ERROR);
> + zram_table_entry += (index * SIZE(zram_table_entry));
> + readmem(zram_table_entry + OFFSET(zram_table_flag), KVADDR, &flags,
> + sizeof(void *), "zram_table_flag", FAULT_ON_ERROR);
> + if (THIS_KERNEL_VERSION >= LINUX(6, 2, 0)) {
Same as above.
Thanks,
Kazu
> + ulong comp_alg_addr;
> + uint32_t prio = (flags >> ZRAM_COMP_PRIORITY_BIT1) & ZRAM_COMP_PRIORITY_MASK;
> + readmem(zram + OFFSET(zram_comp_algs) + sizeof(const char *) * prio, KVADDR,
> + &comp_alg_addr, sizeof(comp_alg_addr), "zram comp_algs", FAULT_ON_ERROR);
> + read_string(comp_alg_addr, name, sizeof(name));
> + } else {
> + readmem(zram + OFFSET(zram_compressor), KVADDR, name, sizeof(name),
> + "zram compressor", FAULT_ON_ERROR);
> + }
> if (STREQ(name, "lzo")) {
> #ifdef LZO
> if (!(dd->flags & LZO_SUPPORTED)) {
> @@ -3019,12 +3051,6 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong
> return 0;
> }
>
> - if (THIS_KERNEL_VERSION >= LINUX(2, 6, 0)) {
> - swp_offset = (ulonglong)__swp_offset(pte_val);
> - } else {
> - swp_offset = (ulonglong)SWP_OFFSET(pte_val);
> - }
> -
> zram_buf = (unsigned char *)GETBUF(PAGESIZE());
> /* lookup page from swap cache */
> off = PAGEOFFSET(vaddr);
> @@ -3034,15 +3060,8 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong
> goto out;
> }
>
> - sector = swp_offset << (PAGESHIFT() - 9);
> - index = sector >> SECTORS_PER_PAGE_SHIFT;
> - readmem(zram, KVADDR, &zram_table_entry,
> - sizeof(void *), "zram_table_entry", FAULT_ON_ERROR);
> - zram_table_entry += (index * SIZE(zram_table_entry));
> readmem(zram_table_entry, KVADDR, &entry,
> 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)) {
> int count;
> ulong *same_buf = (ulong *)GETBUF(PAGESIZE());
--
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