Kallsyms

This function searches for the kallsyms_markers structure in the kernel memory starting at kallsyms_token_table and search backwards. The markers table contains offsets to the corresponding symbol name for each kernel symbol. The kallsyms_markers table is typically located immediately before the kallsyms_token_table in the kernel's read-only data section. Example structure: 0xffffffff827b2430: 0x00000000 0x00000b2a 0x00001762 0x000023f6 0xffffffff827b2440: 0x00002fe4 0x00003c9d 0x0000487c 0x000056fd 0xffffffff827b2450: 0x00006597 0x000073b9 0x000081be 0x00008f21 0xffffffff827b2460: 0x00009c94 0x0000a958 0x0000b632 0x0000c193 0xffffffff827b2470: 0x0000ce0b 0x0000db98 0x0000ea3e 0x0000f80a 0xffffffff827b2480: 0x000105be 0x000112d3 0x00011f8c 0x00012d75 0xffffffff827b2490: 0x0001384d 0x0001446e 0x00015138 0x00015d8c

This function searches for the kallsyms_num_syms variable in the kernel memory starting at kallsyms_markers. The kallsyms_num_syms holds the number of kernel symbols in the symbol table. The kallsyms_num_syms variable is typically located before the kallsyms_names table in the kernel's read-only data section. In newer kernel versions the kallsyms_num_syms is immediately behind the linux_banner and in older version its behind kallsyms_base_relative or kallsyms_addresses (it depends on CONFIG_KALLSYMS_BASE_RELATIVE y/n)

This function searches for the kallsyms_offsets/kallsyms_addresses table in the kernel memory starting at kallsyms_token_index. The offsets/addresses table containts offsets / addresses of each symbol in the kernel. The kallsyms_addresses is typically located before the kallsyms_num_syms variable in the kernel's read-only data section. Example structure: 0xffffffff827b3488: 0x00000000 0x00000000 0x00001000 0x00002000 0xffffffff827b3498: 0x00006000 0x0000b000 0x0000c000 0x0000d000 0xffffffff827b34a8: 0x00015000 0x00015008 0x00015010 0x00015018 0xffffffff827b34b8: 0x00015020 0x00015022 0x00015030 0x00015050 0xffffffff827b34c8: 0x00015450 0x00015460 0x00015860 0x00015888 0xffffffff827b34d8: 0x00015890 0x00015898 0x000158a0 0x000159c0

This function searches for the kallsyms_relative_base variable in the kernel memory. The relative base is used to calculate the actual virtual addresses of symbols from their offsets in the kallsyms_offsets table. The kallsyms_relative_base variable is typically located after the kallsyms_offsets table in the kernel's read-only data section.

This function searches for the kallsyms_token_index structure in the kernel memory starting at kallsyms_token_table. The token index table provides offsets into the kallsyms_token_table for each 256 byte-valued sub-table. The kallsyms_token_index is typically located immediately after the kallsyms_token_table in the kernel's read-only data section. Example structure: 0xffffffff827b3288: 0x0000 0x0003 0x0007 0x000a 0x000f 0x0018 0x001f 0x0023 0xffffffff827b3298: 0x0027 0x0031 0x0035 0x0038 0x003b 0x0043 0x0047 0x004a 0xffffffff827b32a8: 0x004f 0x0053 0x0056 0x0059 0x005d 0x0061 0x0067 0x006b 0xffffffff827b32b8: 0x006e 0x0071 0x0076 0x007c 0x0080 0x0088 0x008b 0x008f 0xffffffff827b32c8: 0x0094 0x0098 0x009b 0x009f 0x00a3 0x00a8 0x00ab 0x00b0

This function searches for the kallsyms_token_table structure in the kernel memory. The kallsyms_token_table contains 256 zero-terminated tokens from which symbol names are built. Example structure: 0xffffffff827b2f00: "mm" 0xffffffff827b2f03: "tim" 0xffffffff827b2f07: "bu" 0xffffffff827b2f0a: "ode_" 0xffffffff827b2f0f: "robestub" 0xffffffff827b2fdb: "0" 0xffffffff827b2fdd: "1" 0xffffffff827b2fdf: "2" 0xffffffff827b2fe1: "3" 0xffffffff827b2fe3: "4" 0xffffffff827b2fe5: "5" 0xffffffff827b2fe7: "6" 0xffffffff827b2fe9: "7" 0xffffffff827b2feb: "8" 0xffffffff827b2fed: "9"