diff options
| author | Ben Hutchings <ben.hutchings@codethink.co.uk> | 2018-12-05 22:45:15 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-17 21:55:15 +0100 |
| commit | 168cb9b7b2839e861278f9fde03820aba32c4ee0 (patch) | |
| tree | 461055ac2587afbe04b04e7ef25265cb239ccfae /kernel | |
| parent | 3c4bb079e16e222324c68d7594b1ab6f699edfca (diff) | |
bpf/verifier: Add spi variable to check_stack_write()
Extracted from commit dc503a8ad984 "bpf/verifier: track liveness for
pruning".
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a937611c2570..4756b88c828e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -572,7 +572,7 @@ static bool is_spillable_regtype(enum bpf_reg_type type) static int check_stack_write(struct verifier_state *state, int off, int size, int value_regno) { - int i; + int i, spi = (MAX_BPF_STACK + off) / BPF_REG_SIZE; /* caller checked that off % size == 0 and -MAX_BPF_STACK <= off < 0, * so it's aligned access and [off, off + size) are within stack limits */ @@ -587,15 +587,13 @@ static int check_stack_write(struct verifier_state *state, int off, int size, } /* save register state */ - state->spilled_regs[(MAX_BPF_STACK + off) / BPF_REG_SIZE] = - state->regs[value_regno]; + state->spilled_regs[spi] = state->regs[value_regno]; for (i = 0; i < BPF_REG_SIZE; i++) state->stack_slot_type[MAX_BPF_STACK + off + i] = STACK_SPILL; } else { /* regular write of data into stack */ - state->spilled_regs[(MAX_BPF_STACK + off) / BPF_REG_SIZE] = - (struct reg_state) {}; + state->spilled_regs[spi] = (struct reg_state) {}; for (i = 0; i < size; i++) state->stack_slot_type[MAX_BPF_STACK + off + i] = STACK_MISC; |