diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/bpf_verifier.h | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 6f47a3ccde86..b1e88016edb1 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -243,6 +243,14 @@ enum bpf_stack_slot_type { #define BPF_REG_SIZE 8 /* size of eBPF register in bytes */ +/* + * Largest number of BPF_REG_SIZE stack slots a single frame can have. A frame + * may use any part of the MAX_BPF_STACK budget; check_max_stack_depth() + * enforces the bound on the combined depth of frames sharing the kernel stack + * and on each frame using a private stack. + */ +#define MAX_BPF_STACK_SLOTS (MAX_BPF_STACK / BPF_REG_SIZE) + /* 4-byte stack slot granularity for liveness analysis */ #define BPF_HALF_REG_SIZE 4 #define STACK_SLOT_SZ 4 @@ -425,12 +433,11 @@ struct bpf_jmp_history_entry { /* insn idx can't be bigger than 1 million */ u32 idx : 20; u32 frame : 4; /* stack access frame number */ - u32 spi : 6; /* stack slot index (0..63) */ - u32 : 2; - u32 prev_idx : 20; /* special INSN_F_xxx flags */ u32 flags : 4; - u32 : 8; + u32 : 4; + u32 prev_idx : 20; + u32 spi : 12; /* stack slot index */ /* * additional registers that need precision tracking when this * jump is backtracked, vector of five 11-bit records @@ -439,12 +446,12 @@ struct bpf_jmp_history_entry { }; static_assert(MAX_CALL_FRAMES <= (1 << 4)); -static_assert(MAX_BPF_STACK / 8 <= (1 << 6)); +static_assert(MAX_BPF_STACK_SLOTS <= (1 << 12)); /* Maximum number of bpf_reg_state objects that can exist at once */ #define MAX_STACK_ARG_SLOTS (MAX_BPF_FUNC_ARGS - MAX_BPF_FUNC_REG_ARGS) -#define BPF_ID_MAP_SIZE ((MAX_BPF_REG + MAX_BPF_STACK / BPF_REG_SIZE + \ - MAX_STACK_ARG_SLOTS) * MAX_CALL_FRAMES) +#define BPF_ID_MAP_SIZE ((MAX_BPF_REG + MAX_BPF_STACK_SLOTS + MAX_STACK_ARG_SLOTS) * \ + MAX_CALL_FRAMES) struct bpf_verifier_state { /* call stack tracking */ struct bpf_func_state *frame[MAX_CALL_FRAMES]; |