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> --- 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
