Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\bpf\verifier.c Create Date:2022-07-28 12:58:27
Last Modify:2022-05-19 20:02:10 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:check_ptr_to_btf_access

Proto:static int check_ptr_to_btf_access(struct bpf_verifier_env *env, struct bpf_reg_state *regs, int regno, int off, int size, enum bpf_access_type atype, int value_regno)

Type:int

Parameter:

TypeParameterName
struct bpf_verifier_env *env
struct bpf_reg_state *regs
intregno
intoff
intsize
enum bpf_access_typeatype
intvalue_regno
2855  reg = regs + regno
2856  t = btf_type_by_id(btf_vmlinux, for PTR_TO_BTF_ID )
2857  tname = btf_name_by_offset(btf_vmlinux, name_off)
2861  If atype != BPF_READ Then
2862  verbose(env, "only read is supported\n")
2863  Return -EACCES
2866  If off < 0 Then
2867  verbose(env, "R%d is ptr_%s invalid negative access: off=%d\n", regno, tname, off)
2870  Return -EACCES
2872  If Not Returns true if @a is a known constant || value Then
2875  Format a tnum as a pair of hex numbers (value; mask)
2876  verbose(env, "R%d is ptr_%s invalid variable offset: off=%d, var_off=%s\n", regno, tname, off, tn_buf)
2879  Return -EACCES
2882  ret = btf_struct_access( & log, t, off, size, atype, & btf_id)
2883  If ret < 0 Then Return ret
2886  If ret == g doesn't contain a valid pointer Then
2887  mark_reg_unknown(env, regs, value_regno)
2888  Return 0
2890  mark_reg_known_zero(env, regs, value_regno)
2891  Ordering of fields matters. See states_equal() = g points to kernel struct
2892  for PTR_TO_BTF_ID = btf_id
2893  Return 0
Caller
NameDescribe
check_mem_accessheck whether memory at (regno + off) is accessible for t = (read | write)* if t==write, value_regno is a register which value is stored into memory* if t==read, value_regno is a register which will receive the value from memory* if t==write &&