[Kernel] Re: [PATCH OpenHarmony-4.19 05/17] bpf: extend is_branch_taken to registers

在 2021/7/31 11:14, Yu Changchun 写道:

From: Alexei Starovoitov

stable inclusion from linux-4.19.193 commit e0b86677fb3e4622b444dcdd8546caa0dba8a689 category: bugfix issue: #I42H19 CVE: NA

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commit fb8d251ee2a6bf4d7f4af5548e9c8f4fb5f90402 upstream

This patch extends is_branch_taken() logic from JMP+K instructions to JMP+X instructions. Conditional branches are often done when src and dst registers contain known scalars. In such case the verifier can follow the branch that is going to be taken when program executes. That speeds up the verification and is essential feature to support bounded loops.

Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann [OP: drop is_jmp32 parameter from is_branch_taken() calls and adjust context] Signed-off-by: Ovidiu Panait Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang Signed-off-by: Yu Changchun --- kernel/bpf/verifier.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-)

Looks good to me