From: Alexander Lobakin alobakin@dlink.ru
commit f596cf0d8062cb5d0a4513a8b3afca318c13be10 upstream.
It is completely wrong to check for compile-time MIPS ISA revision in the body of bpf_int_jit_compile() as it may lead to get MIPS JIT fully omitted by the CC while the rest system will think that the JIT is actually present and works [1]. We can check if the selected CPU really supports MIPS eBPF JIT at configure time and avoid such situations when kernel can be built without both JIT and interpreter, but with CONFIG_BPF_SYSCALL=y.
[1] https://lore.kernel.org/linux-mips/09d713a59665d745e21d021deeaebe0a@dlink.ru...
Fixes: 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture.") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Alexander Lobakin alobakin@dlink.ru Signed-off-by: Paul Burton paulburton@kernel.org Cc: Ralf Baechle ralf@linux-mips.org Cc: James Hogan jhogan@kernel.org Cc: Hassan Naveed hnaveed@wavecomp.com Cc: Alexei Starovoitov ast@kernel.org Cc: Daniel Borkmann daniel@iogearbox.net Cc: Martin KaFai Lau kafai@fb.com Cc: Song Liu songliubraving@fb.com Cc: Yonghong Song yhs@fb.com Cc: Andrii Nakryiko andriin@fb.com Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Cc: bpf@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/mips/Kconfig | 2 +- arch/mips/net/ebpf_jit.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
--- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -46,7 +46,7 @@ config MIPS select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE if CPU_SUPPORTS_HUGEPAGES select HAVE_ASM_MODVERSIONS - select HAVE_EBPF_JIT if (64BIT && !CPU_MICROMIPS) + select HAVE_EBPF_JIT if 64BIT && !CPU_MICROMIPS && TARGET_ISA_REV >= 2 select HAVE_CONTEXT_TRACKING select HAVE_COPY_THREAD_TLS select HAVE_C_RECORDMCOUNT --- a/arch/mips/net/ebpf_jit.c +++ b/arch/mips/net/ebpf_jit.c @@ -1803,7 +1803,7 @@ struct bpf_prog *bpf_int_jit_compile(str unsigned int image_size; u8 *image_ptr;
- if (!prog->jit_requested || MIPS_ISA_REV < 2) + if (!prog->jit_requested) return prog;
tmp = bpf_jit_blind_constants(prog);