[PATCH bpf-next 0/2] Use overflow.h helpers to check for overflows

[Shung-Hsi Yu <shung-hsi.yu@suse.com>]

This patch set refactors kernel/bpf/verifier.c to use type-agnostic,
generic overflow-check helpers defined in include/linux/overflow.h to
check for addition and subtraction overflow, and drop the
signed_*_overflows() helpers we currently have in kernel/bpf/verifier.c.
There should be no functional change in how the verifier works.

The main motivation is to make future refactoring[1] easier.

While check_mul_overflow() also exists and could potentially replace what
we have in scalar*_min_max_mul(), it does not help with refactoring and
would either change how the verifier works (e.g. lifting restriction on
umax<=U32_MAX and u32_max<=U16_MAX) or make the code slightly harder to
read, so it is left for future endeavour.

1: https://github.com/kernel-patches/bpf/pull/7205/commits

Shung-Hsi Yu (2):
  bpf: use check_add_overflow() to check for addition overflows
  bpf: use check_sub_overflow() to check for subtraction overflows

 kernel/bpf/verifier.c | 120 ++++++++++++++++--------------------------
 1 file changed, 44 insertions(+), 76 deletions(-)

-- 
2.45.2