Re: [Crash-utility] 答复: [External Mail]Re: zram decompress support for gcore/crash-utility

Hi,Dave The latest patch have been attached,please check Thanks. ________________________________________ From: Dave Anderson <anderson(a)redhat.com&gt; Sent: Monday, April 6, 2020 22:38 To: 赵乾利 Cc: d hatayama; Discussion list for crash utility usage, maintenance and development Subject: Re: 答复: [External Mail]Re: [Crash-utility] zram decompress support for gcore/crash-utility ----- Original Message ----- The changes to defs.h and memory.c look good. My comments for diskdump.c are interspersed below, where many of them are redundant: +#ifdef LZO +static unsigned char *zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf) +{ + ulong obj, off, class, page, zspage; + struct zspage zspage_s; + physaddr_t paddr; + unsigned int obj_idx, class_idx, size; + ulong pages[2], sizes[2]; + + readmem(handle, KVADDR, &obj, sizeof(void *), "readmem address", RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + obj >>= OBJ_TAG_BITS; + phys_to_page(PTOB(obj >> OBJ_INDEX_BITS), &page); + obj_idx = (obj & OBJ_INDEX_MASK); + + readmem(page + OFFSET(page_private), KVADDR, &zspage, + sizeof(void *), "readmem address", RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + readmem(zspage, KVADDR, &zspage_s, sizeof(struct zspage), "readmem address",RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + + class_idx = zspage_s.class; + if (zspage_s.magic != ZSPAGE_MAGIC) + error(FATAL, "zspage magic incorrect:0x%x\n", zspage_s.magic); + + class = pool + OFFSET(zspoll_size_class); + class += (class_idx * sizeof(void *)); + readmem(class, KVADDR, &class, sizeof(void *), "readmem address",RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + readmem(class + OFFSET(size_class_size), KVADDR, + &size, sizeof(unsigned int), "readmem address", RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + off = (size * obj_idx) & (~machdep->pagemask); + if (off + size <= PAGESIZE()) { + if (!is_page_ptr(page, &paddr)) { + error(WARNING, "zspage not a page pointer:%lx\n", page); + return NULL; + } + readmem(paddr + off, PHYSADDR, zram_buf, size, "readmem zram buffer", RETURN_ON_ERROR); + goto out; + } + + pages[0] = page; + readmem(page + OFFSET(page_freelist), KVADDR, &pages[1], + sizeof(void *), "readmem address",RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + sizes[0] = PAGESIZE() - off; + sizes[1] = size - sizes[0]; + if (!is_page_ptr(pages[0], &paddr)) { + error(WARNING, "pages[0] not a page pointer\n"); Maybe display the bogus value in pages[0] in the message? + return NULL; + } + + readmem(paddr + off, PHYSADDR, zram_buf, sizes[0], "readmem zram buffer", RETURN_ON_ERROR); + if (!is_page_ptr(pages[1], &paddr)) { + error(WARNING, "pages[1] not a page pointer\n"); Maybe display the bogus value in pages[1] in the message? + return NULL; + } + + readmem(paddr, PHYSADDR, zram_buf + sizes[0], sizes[1], "readmem zram buffer", RETURN_ON_ERROR); + +out: + readmem(page, KVADDR, &obj, sizeof(void *), "readmem address",RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + if (!(obj & (1<<10))) { //PG_OwnerPriv1 flag + return (zram_buf + ZS_HANDLE_SIZE); + } + + return zram_buf; +} + +static unsigned char *lookup_swap_cache(ulong pte_val, unsigned char *zram_buf) +{ + ulong swp_type, swp_offset, swp_space; + struct list_pair lp; + physaddr_t paddr; + swp_type = __swp_type(pte_val); + if (THIS_KERNEL_VERSION >= LINUX(2,6,0)) { + swp_offset = (ulonglong)__swp_offset(pte_val); + } else { + swp_offset = (ulonglong)SWP_OFFSET(pte_val); + } + + if (!symbol_exists("swapper_spaces")) + return NULL; + swp_space = symbol_value("swapper_spaces"); + swp_space += swp_type * sizeof(void *); + + readmem(swp_space, KVADDR, &swp_space, sizeof(void *), + "readmem address",RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + swp_space += (swp_offset >> SWAP_ADDRESS_SPACE_SHIFT) * SIZE(address_space); + + lp.index = swp_offset; + if (do_radix_tree(swp_space, RADIX_TREE_SEARCH, &lp)){ + fprintf(fp, "Find page in swap cache\n"); I don't think you meant to leave this message, right? + if (!is_page_ptr((ulong)lp.value, &paddr)) { + error(WARNING, "radix page not a page pointer\n"); + return NULL; + } + readmem(paddr, PHYSADDR, zram_buf, PAGESIZE(), "readmem zram buffer", RETURN_ON_ERROR); + return zram_buf; + } + return NULL; +} + +ulong (*decompressor)(unsigned char *in_addr, ulong in_size, unsigned char *out_addr, ulong *out_size, void *other/* NOT USED */); +/* +try_zram_decompress returns decompressed page data and data length +If userspace address was swaped out to zram,call this function to decompress this object. +*/ +ulong try_zram_decompress(ulong pte_val, unsigned char *buf, ulong len, uint32_t off) +{ + char name[32] = {0}; + ulonglong swp_offset; + ulong swap_info, bdev, bd_disk, zram, zram_table_entry, sector, index, entry, flags, size, outsize; + unsigned char *obj_addr = NULL; + unsigned char *zram_buf = NULL; + unsigned char *outbuf = NULL; + + + if (!symbol_exists("swap_info")) + return 0; + + swap_info = symbol_value("swap_info"); + + swap_info_init(); + if (vt->flags & SWAPINFO_V2) { + swap_info += (__swp_type(pte_val) * sizeof(void *)); + readmem(swap_info, KVADDR, &swap_info, + sizeof(void *), "readmem address", RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + } else { + swap_info += (SIZE(swap_info_struct) * __swp_type(pte_val)); + } + + readmem(swap_info + OFFSET(swap_info_struct_bdev), KVADDR, &bdev, + sizeof(void *), "read swap_info_struct_bdev", RETURN_ON_ERROR); + readmem(bdev + OFFSET(block_device_bd_disk), KVADDR, &bd_disk, + sizeof(void *), "read block_device_bd_disk", RETURN_ON_ERROR); + readmem(bd_disk + OFFSET(gendisk_disk_name), KVADDR, name, + strlen("zram"), "read gendisk_disk_name", RETURN_ON_ERROR); + if (!strncmp(name, "zram", strlen("zram"))) { + if (CRASHDEBUG(2)) + error(WARNING, "This page has swaped to zram\n"); + + readmem(bd_disk + OFFSET(gendisk_private_data), KVADDR, &zram, + sizeof(void *), "gendisk_private_data", RETURN_ON_ERROR); + + readmem(zram + OFFSET(zram_compressor), KVADDR, name, + sizeof(name), "zram compressor", RETURN_ON_ERROR); + if (!strncmp(name, "lzo", strlen("lzo"))) { + if (!(dd->flags & LZO_SUPPORTED)) { + if (lzo_init() == LZO_E_OK) + dd->flags |= LZO_SUPPORTED; + else + return 0; + } + decompressor = (void *)lzo1x_decompress_safe; + } else {//todo,support more compressor + error(WARNING, "Only support lzo compressor\n"); + 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); + } + + if ((zram_buf = (unsigned char*)malloc(PAGESIZE())) == NULL) + error(FATAL, "cannot malloc zram_buf space."); Never use malloc/free for temporary buffers during runtime. Either use GETBUF()/FREEBUF() or just put it on the stack. + + /*lookup page from swap cache*/ + obj_addr = lookup_swap_cache(pte_val, zram_buf); + if (obj_addr != NULL) { + memcpy(buf, obj_addr + off, len); + goto out; + } + + sector = swp_offset << (PAGESHIFT() - 9); + index = sector >> SECTORS_PER_PAGE_SHIFT; + readmem(zram, KVADDR, &zram_table_entry, + sizeof(void *), "readmem address", RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + zram_table_entry += (index * SIZE(zram_table_entry)); + readmem(zram_table_entry, KVADDR, &entry, + sizeof(void *), "readmem address", RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + readmem(zram_table_entry + OFFSET(zram_table_flag), KVADDR, &flags, + sizeof(void *), "readmem address", RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + if (!entry || (flags & ZRAM_FLAG_SAME_BIT)) { + memset(buf, entry, len); + goto out; + } + size = flags & (ZRAM_FLAG_SHIFT -1); + if (size == 0) { + len = 0; + goto out; + } + + readmem(zram + OFFSET(zram_mempoll), KVADDR, &zram, + sizeof(void *), "readmem address", RETURN_ON_ERROR); Can you make the error message type string something more helpful than "readmem address"? + + obj_addr = zram_object_addr(zram, entry, zram_buf); + if (obj_addr == NULL) { + len = 0; + goto out; + } + + if (size == PAGESIZE()) { + memcpy(buf, obj_addr + off, len); + } else { + if ((outbuf = (unsigned char*)malloc(PAGESIZE())) == NULL) + error(FATAL, "cannot malloc outbuf space."); Never use malloc/free for temporary buffers during runtime. Either use GETBUF()/FREEBUF() or just put it on the stack. + + if (!decompressor(obj_addr, size, outbuf, &outsize, NULL)) + memcpy(buf, outbuf + off, len); + else { + error(WARNING, "zram decompress error\n"); + len = 0; + } + free(outbuf); + } + } + +out: + free(zram_buf); + return len; +} +#else +ulong try_zram_decompress(ulong pte_val, unsigned char *buf, ulong len, uint32_t off) +{ + return 0; +} +#endif #/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. 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