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

From: Alexei Starovoitov <ast(a)kernel.org> stable inclusion from linux-4.19.193 commit e0b86677fb3e4622b444dcdd8546caa0dba8a689 category: bugfix issue: #I42H19 CVE: NA -------------------------------- 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 <ast(a)kernel.org> Acked-by: Andrii Nakryiko <andriin(a)fb.com> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> [OP: drop is_jmp32 parameter from is_branch_taken() calls and adjust context] Signed-off-by: Ovidiu Panait <ovidiu.panait(a)windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Signed-off-by: Yu Changchun <yuchangchun1(a)huawei.com> --- kernel/bpf/verifier.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-)