| Message ID | 20230228113305.83751-2-jiaxun.yang@flygoat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | bbefef2f07080cd502a93cb1c529e1c8a6c4ac8e |
| Delegated to: | BPF |
| Headers | show |
| Series | MIPS: Implement two workarounds for BPF JIT | expand |
On 28/2/23 12:33, Jiaxun Yang wrote: > 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> > --- > v2: Drop 64BIT ifdef > --- > arch/mips/Kconfig | 1 - > arch/mips/net/bpf_jit_comp.c | 4 ++++ > 2 files changed, 4 insertions(+), 1 deletion(-) Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> On Tue, Feb 28, 2023 at 12:33 PM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote: > > 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> > --- > v2: Drop 64BIT ifdef > --- > 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 37072e15b263..df0910e3895c 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: > -- > 2.37.1 (Apple Git-137.1) >
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 37072e15b263..df0910e3895c 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:
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> --- v2: Drop 64BIT ifdef --- arch/mips/Kconfig | 1 - arch/mips/net/bpf_jit_comp.c | 4 ++++ 2 files changed, 4 insertions(+), 1 deletion(-)