diff options
| author | Jiaxun Yang <jiaxun.yang@flygoat.com> | 2023-02-28 11:33:04 +0000 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-02-28 14:52:40 +0100 |
| commit | bbefef2f07080cd502a93cb1c529e1c8a6c4ac8e (patch) | |
| tree | 559de75a3e3d3affdbe6991b5d5a867e6ff8dc2e | |
| parent | c8ee37bde4021a275d2e4f33bd48d54912bb00c4 (diff) | |
bpf, mips: Implement DADDI workarounds for JIT
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@flygoat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Link: https://lore.kernel.org/bpf/20230228113305.83751-2-jiaxun.yang@flygoat.com
| -rw-r--r-- | arch/mips/Kconfig | 1 | ||||
| -rw-r--r-- | arch/mips/net/bpf_jit_comp.c | 4 |
2 files changed, 4 insertions, 1 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 15cb692b0a09..b89c4bf2fa0a 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 b17130d510d4..a40d926b6513 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: |