From 1ef22b6865a73a8aed36d43375fe8c7b30869326 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 4 May 2023 21:33:12 -0700 Subject: bpf: maintain bitmasks across all active frames in __mark_chain_precision Teach __mark_chain_precision logic to maintain register/stack masks across all active frames when going from child state to parent state. Currently this should be mostly no-op, as precision backtracking usually bails out when encountering subprog entry/exit. It's not very apparent from the diff due to increased indentation, but the logic remains the same, except everything is done on specific `fr` frame index. Calls to bt_clear_reg() and bt_clear_slot() are replaced with frame-specific bt_clear_frame_reg() and bt_clear_frame_slot(), where frame index is passed explicitly, instead of using current frame number. We also adjust logging to emit affected frame number. And we also add better logging of human-readable register and stack slot masks, similar to previous patch. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230505043317.3629845-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/verifier/precise.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/verifier/precise.c b/tools/testing/selftests/bpf/verifier/precise.c index a22fabd404ed..77ea018582c5 100644 --- a/tools/testing/selftests/bpf/verifier/precise.c +++ b/tools/testing/selftests/bpf/verifier/precise.c @@ -44,7 +44,7 @@ mark_precise: frame0: regs=r2 stack= before 23\ mark_precise: frame0: regs=r2 stack= before 22\ mark_precise: frame0: regs=r2 stack= before 20\ - parent didn't have regs=4 stack=0 marks:\ + mark_precise: frame0: parent state regs=r2 stack=:\ mark_precise: frame0: last_idx 19 first_idx 10\ mark_precise: frame0: regs=r2 stack= before 19\ mark_precise: frame0: regs=r9 stack= before 18\ @@ -55,7 +55,7 @@ mark_precise: frame0: regs=r9 stack= before 12\ mark_precise: frame0: regs=r9 stack= before 11\ mark_precise: frame0: regs=r9 stack= before 10\ - parent already had regs=0 stack=0 marks:", + mark_precise: frame0: parent state regs= stack=:", }, { "precise: test 2", @@ -104,15 +104,15 @@ mark_precise: frame0: regs=r2 stack= before 24\ mark_precise: frame0: regs=r2 stack= before 23\ mark_precise: frame0: regs=r2 stack= before 22\ - parent didn't have regs=4 stack=0 marks:\ + mark_precise: frame0: parent state regs=r2 stack=:\ mark_precise: frame0: last_idx 20 first_idx 20\ mark_precise: frame0: regs=r2 stack= before 20\ - parent didn't have regs=4 stack=0 marks:\ + mark_precise: frame0: parent state regs=r2 stack=:\ mark_precise: frame0: last_idx 19 first_idx 17\ mark_precise: frame0: regs=r2 stack= before 19\ mark_precise: frame0: regs=r9 stack= before 18\ mark_precise: frame0: regs=r8,r9 stack= before 17\ - parent already had regs=0 stack=0 marks:", + mark_precise: frame0: parent state regs= stack=:", }, { "precise: cross frame pruning", @@ -153,14 +153,14 @@ .prog_type = BPF_PROG_TYPE_XDP, .flags = BPF_F_TEST_STATE_FREQ, .errstr = "mark_precise: frame0: last_idx 5 first_idx 5\ - parent didn't have regs=10 stack=0 marks:\ + mark_precise: frame0: parent state regs=r4 stack=:\ mark_precise: frame0: last_idx 4 first_idx 2\ mark_precise: frame0: regs=r4 stack= before 4\ mark_precise: frame0: regs=r4 stack= before 3\ mark_precise: frame0: regs= stack=-8 before 2\ mark_precise: frame0: falling back to forcing all scalars precise\ mark_precise: frame0: last_idx 5 first_idx 5\ - parent didn't have regs=1 stack=0 marks:", + mark_precise: frame0: parent state regs=r0 stack=:", .result = VERBOSE_ACCEPT, .retval = -1, }, @@ -179,7 +179,7 @@ .prog_type = BPF_PROG_TYPE_XDP, .flags = BPF_F_TEST_STATE_FREQ, .errstr = "mark_precise: frame0: last_idx 6 first_idx 6\ - parent didn't have regs=10 stack=0 marks:\ + mark_precise: frame0: parent state regs=r4 stack=:\ mark_precise: frame0: last_idx 5 first_idx 3\ mark_precise: frame0: regs=r4 stack= before 5\ mark_precise: frame0: regs=r4 stack= before 4\ @@ -188,7 +188,7 @@ force_precise: frame0: forcing r0 to be precise\ force_precise: frame0: forcing r0 to be precise\ mark_precise: frame0: last_idx 6 first_idx 6\ - parent didn't have regs=1 stack=0 marks:\ + mark_precise: frame0: parent state regs=r0 stack=:\ mark_precise: frame0: last_idx 5 first_idx 3\ mark_precise: frame0: regs=r0 stack= before 5", .result = VERBOSE_ACCEPT, -- cgit v1.2.3