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bpf: convert 'c'/'b' to bpf_type at the very end

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This makes the code a bit longer, but easier to read I think, because
the cgroup v1 and v2 code paths are more similar. And whent he type is
a char, any backtrace is easier to interpret.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2019-11-09 12:32:44 +01:00
parent 7973f56468
commit 8ad08622d6
1 changed files with 18 additions and 10 deletions
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28
src/core/bpf-devices.c
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@ -38,7 +38,7 @@ static int bpf_access_type(const char *acc) {
return r;
}
static int bpf_prog_whitelist_device(BPFProgram *prog, int type, int major, int minor, const char *acc) {
static int bpf_prog_whitelist_device(BPFProgram *prog, char type, int major, int minor, const char *acc) {
int r, access;
assert(prog);
@ -50,8 +50,11 @@ static int bpf_prog_whitelist_device(BPFProgram *prog, int type, int major, int
if (access <= 0)
return -EINVAL;
assert(IN_SET(type, 'b', 'c'));
const int bpf_type = type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK;
const struct bpf_insn insn[] = {
BPF_JMP_IMM(BPF_JNE, BPF_REG_2, type, 6), /* compare device type */
BPF_JMP_IMM(BPF_JNE, BPF_REG_2, bpf_type, 6), /* compare device type */
BPF_MOV32_REG(BPF_REG_1, BPF_REG_3), /* calculate access type */
BPF_ALU32_IMM(BPF_AND, BPF_REG_1, access),
BPF_JMP_REG(BPF_JNE, BPF_REG_1, BPF_REG_3, 3), /* compare access type */
@ -67,7 +70,7 @@ static int bpf_prog_whitelist_device(BPFProgram *prog, int type, int major, int
return r;
}
static int bpf_prog_whitelist_major(BPFProgram *prog, int type, int major, const char *acc) {
static int bpf_prog_whitelist_major(BPFProgram *prog, char type, int major, const char *acc) {
int r, access;
assert(prog);
@ -79,8 +82,11 @@ static int bpf_prog_whitelist_major(BPFProgram *prog, int type, int major, const
if (access <= 0)
return -EINVAL;
assert(IN_SET(type, 'b', 'c'));
const int bpf_type = type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK;
const struct bpf_insn insn[] = {
BPF_JMP_IMM(BPF_JNE, BPF_REG_2, type, 5), /* compare device type */
BPF_JMP_IMM(BPF_JNE, BPF_REG_2, bpf_type, 5), /* compare device type */
BPF_MOV32_REG(BPF_REG_1, BPF_REG_3), /* calculate access type */
BPF_ALU32_IMM(BPF_AND, BPF_REG_1, access),
BPF_JMP_REG(BPF_JNE, BPF_REG_1, BPF_REG_3, 2), /* compare access type */
@ -95,7 +101,7 @@ static int bpf_prog_whitelist_major(BPFProgram *prog, int type, int major, const
return r;
}
static int bpf_prog_whitelist_class(BPFProgram *prog, int type, const char *acc) {
static int bpf_prog_whitelist_class(BPFProgram *prog, char type, const char *acc) {
int r, access;
assert(prog);
@ -107,8 +113,11 @@ static int bpf_prog_whitelist_class(BPFProgram *prog, int type, const char *acc)
if (access <= 0)
return -EINVAL;
assert(IN_SET(type, 'b', 'c'));
const int bpf_type = type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK;
const struct bpf_insn insn[] = {
BPF_JMP_IMM(BPF_JNE, BPF_REG_2, type, 4), /* compare device type */
BPF_JMP_IMM(BPF_JNE, BPF_REG_2, bpf_type, 4), /* compare device type */
BPF_MOV32_REG(BPF_REG_1, BPF_REG_3), /* calculate access type */
BPF_ALU32_IMM(BPF_AND, BPF_REG_1, access),
BPF_JMP_REG(BPF_JNE, BPF_REG_1, BPF_REG_3, 1), /* compare access type */
@ -292,13 +301,12 @@ static int whitelist_device_pattern(BPFProgram *prog, const char *path, char typ
if (!prog)
return 0;
const int bpf_type = type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK;
if (maj && min)
return bpf_prog_whitelist_device(prog, bpf_type, *maj, *min, acc);
return bpf_prog_whitelist_device(prog, type, *maj, *min, acc);
else if (maj)
return bpf_prog_whitelist_major(prog, bpf_type, *maj, acc);
return bpf_prog_whitelist_major(prog, type, *maj, acc);
else
return bpf_prog_whitelist_class(prog, bpf_type, acc);
return bpf_prog_whitelist_class(prog, type, acc);
} else {
char buf[2+DECIMAL_STR_MAX(unsigned)*2+2+4];