git/linux-cryptodev-2.6
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git synced 2026-05-01 15:15:19 -04:00
Code Issues Packages Projects Releases Wiki Activity

bpf: Use scalar ids in mark_chain_precision()

Browse Source 
Change mark_chain_precision() to track precision in situations
like below:

    r2 = unknown value
    ...
  --- state #0 ---
    ...
    r1 = r2                 // r1 and r2 now share the same ID
    ...
  --- state #1 {r1.id = A, r2.id = A} ---
    ...
    if (r2 > 10) goto exit; // find_equal_scalars() assigns range to r1
    ...
  --- state #2 {r1.id = A, r2.id = A} ---
    r3 = r10
    r3 += r1                // need to mark both r1 and r2

At the beginning of the processing of each state, ensure that if a
register with a scalar ID is marked as precise, all registers sharing
this ID are also marked as precise.

This property would be used by a follow-up change in regsafe().

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230613153824.3324830-2-eddyz87@gmail.com
This commit is contained in:
Eduard Zingerman
2023-06-13 18:38:21 +03:00
committed by Andrii Nakryiko
parent 25085b4e92
commit 904e6ddf41
3 changed files with 128 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
include/linux/bpf_verifier.h
View File

@@ -557,6 +557,11 @@ struct backtrack_state {
u64 stack_masks[MAX_CALL_FRAMES];
};
struct bpf_idset {
u32 count;
u32 ids[BPF_ID_MAP_SIZE];
};
/* single container for all structs
* one verifier_env per bpf_check() call
*/
@@ -588,7 +593,10 @@ struct bpf_verifier_env {
const struct bpf_line_info *prev_linfo;
struct bpf_verifier_log log;
struct bpf_subprog_info subprog_info[BPF_MAX_SUBPROGS + 1];
struct bpf_id_pair idmap_scratch[BPF_ID_MAP_SIZE];
union {
struct bpf_id_pair idmap_scratch[BPF_ID_MAP_SIZE];
struct bpf_idset idset_scratch;
};
struct {
int *insn_state;
int *insn_stack;