函数逻辑报告

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\bpf\verifier.c Create Date:2022-07-27 14:18:40
Last Modify:2022-05-19 20:02:10 Copyright©Brick
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函数名称：look for pseudo eBPF instructions that access map FDs and* replace them with actual map pointers

函数原型：static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)

返回类型：int

参数：

类型参数名称
struct bpf_verifier_env *env
8166  insn等于insnsi
8167  insn_cnt等于 Number of filter blocks
8170  err等于bpf_prog_calc_tag(BPF program being verified )
8171  如果err则返回:err
8174  以i小于insn_cnt循环
8175  如果Instruction classes ( opcode )恒等于BPF_LDX且BPF BPF_DW 0x18 64-bit ( opcode )不等于BPF_MEM或 signed immediate constant 不等于0的值则
8177  verbose(env, "BPF_LDX uses reserved fields\n")
8178  返回:负EINVAL
8181  如果Instruction classes ( opcode )恒等于BPF_STX且BPF BPF_DW 0x18 64-bit ( opcode )不等于BPF_MEM且BPF BPF_DW 0x18 64-bit ( opcode )不等于xclusive add 或 signed immediate constant 不等于0的值则
8184  verbose(env, "BPF_STX uses reserved fields\n")
8185  返回:负EINVAL
8188  如果 opcode 恒等于BPF_LD按位或BPF_IMM按位或double word (64-bit) 的值则
8194  如果i恒等于insn_cnt减1或 opcode 不等于0或 dest register 不等于0或 source register 不等于0或 signed offset 不等于0则
8197  verbose(env, "invalid bpf_ld_imm64 insn\n")
8198  返回:负EINVAL
8201  如果 source register 恒等于0则转到:next_insn
8208  如果 source register 不等于When BPF ldimm64's insn[0]且 source register 不等于BPF_PSEUDO_MAP_VALUE或 source register 恒等于When BPF ldimm64's insn[0]且 signed immediate constant 不等于0则
8212  verbose(env, "unrecognized bpf_ld_imm64 insn\n")
8214  返回:负EINVAL
8217  f等于fdget( signed immediate constant )
8218  map等于 error is returned, fd is released.* On success caller should complete fd access with matching fdput()
8219  如果是错误则
8220  verbose(env, "fd %d is not pointing to valid bpf_map\n", signed immediate constant )
8222  返回:错误
8225  err等于check_map_prog_compatibility(env, map, BPF program being verified )
8226  如果err则
8227  fdput(f)
8228  返回:err
8231  aux等于array of per-insn state [i]
8232  如果 source register 恒等于When BPF ldimm64's insn[0]则
8233  addr等于map
8234  否则
8235  off等于 signed immediate constant
8237  如果off大于等于Maximum variable offset umax_value permitted when resolving memory accesses.* In practice this is far bigger than any realistic pointer offset; this limit* ensures that umax_value + (int)off + (int)size cannot overflow a u64.则
8238  verbose(env, "direct value offset of %u is not allowed\n", off)
8239  fdput(f)
8240  返回:负EINVAL
8243  如果非map_direct_value_addr则
8244  verbose(env, "no direct value access support for this map type\n")
8245  fdput(f)
8246  返回:负EINVAL
8249  err等于map_direct_value_addr(map, & addr, off)
8250  如果err则
8251  verbose(env, "invalid access to map value pointer, value_size=%u off=%u\n", value_size, off)
8253  fdput(f)
8254  返回:err
8257  offset from value base address 等于off
8258  addr加等于off
8261  signed immediate constant 等于addr
8262  signed immediate constant 等于addr右移32位
8265  以j小于umber of used maps 循环
8266  如果array of map's used by eBPF program [j]恒等于map则
8267  index into used_maps[] 等于j
8268  fdput(f)
8269  转到:next_insn
8273  如果umber of used maps 大于等于max number of maps accessed by one eBPF program 则
8274  fdput(f)
8275  返回:负E2BIG
8283  bpf_map_inc(map)
8285  index into used_maps[] 等于umber of used maps
8286  array of map's used by eBPF program [umber of used maps ++]等于map
8288  如果bpf_map_is_cgroup_storage(map)且bpf_cgroup_storage_assign( Auxiliary fields , map)则
8290  verbose(env, "only one cgroup storage of each type is allowed\n")
8291  fdput(f)
8292  返回:负EBUSY
8295  fdput(f)
8296  next_insn :
8297  insn自加
8298  i自加
8299  继续下一循环
8303  如果非bpf_opcode_in_insntable( opcode )则
8304  verbose(env, "unknown opcode %02x\n", opcode )
8305  返回:负EINVAL
8313  返回:0
调用者
名称描述
bpf_check