> 2023年5月4日 20:40，Sasha Levin <sashal@xxxxxxxxxx> 写道： > > From: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> > > [ Upstream commit bbefef2f07080cd502a93cb1c529e1c8a6c4ac8e ] > > For DADDI errata we just workaround by disable immediate operation > for BPF_ADD / BPF_SUB to avoid generation of DADDIU. > > All other use cases in JIT won't cause overflow thus they are all safe. > > Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> > Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> > Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx> > Acked-by: Johan Almbladh <johan.almbladh@xxxxxxxxxxxxxxxxx> > Link: https://lore.kernel.org/bpf/20230228113305.83751-2-jiaxun.yang@xxxxxxxxxxx > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> Hi Sasha, I think this patch should count as a functional improvement instead of regression fix. Please drop it from stable queue. Thanks Jiaxun > --- > arch/mips/Kconfig | 1 - > arch/mips/net/bpf_jit_comp.c | 4 ++++ > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig > index e2f3ca73f40d6..edc7d8790f1e8 100644 > --- a/arch/mips/Kconfig > +++ b/arch/mips/Kconfig > @@ -64,7 +64,6 @@ config MIPS > select HAVE_DMA_CONTIGUOUS > select HAVE_DYNAMIC_FTRACE > select HAVE_EBPF_JIT if !CPU_MICROMIPS && \ > - !CPU_DADDI_WORKAROUNDS && \ > !CPU_R4000_WORKAROUNDS && \ > !CPU_R4400_WORKAROUNDS > select HAVE_EXIT_THREAD > diff --git a/arch/mips/net/bpf_jit_comp.c b/arch/mips/net/bpf_jit_comp.c > index b17130d510d49..a40d926b65139 100644 > --- a/arch/mips/net/bpf_jit_comp.c > +++ b/arch/mips/net/bpf_jit_comp.c > @@ -218,9 +218,13 @@ bool valid_alu_i(u8 op, s32 imm) > /* All legal eBPF values are valid */ > return true; > case BPF_ADD: > + if (IS_ENABLED(CONFIG_CPU_DADDI_WORKAROUNDS)) > + return false; > /* imm must be 16 bits */ > return imm >= -0x8000 && imm <= 0x7fff; > case BPF_SUB: > + if (IS_ENABLED(CONFIG_CPU_DADDI_WORKAROUNDS)) > + return false; > /* -imm must be 16 bits */ > return imm >= -0x7fff && imm <= 0x8000; > case BPF_AND: > -- > 2.39.2 >
