On Thu, 2025-08-14 at 09:06 -0700, Eduard Zingerman wrote: > On Thu, 2025-08-14 at 13:23 +0200, Puranjay Mohan wrote: > > On Thu, Aug 14, 2025 at 2:35 AM Eduard Zingerman > > <eddy...@gmail.com> wrote: > > > > > > On Wed, 2025-08-13 at 23:29 +0800, KaFai Wan wrote: > > > > This test verifies socket filter attachment functionality on > > > > architectures > > > > supporting either BPF JIT compilation or the interpreter. > > > > > > > > It specifically validates the fallback to interpreter behavior > > > > when JIT fails, > > > > particularly targeting ARMv6 devices with the following > > > > configuration: > > > > # CONFIG_BPF_JIT_ALWAYS_ON is not set > > > > CONFIG_BPF_JIT_DEFAULT_ON=y > > > > > > > > Signed-off-by: KaFai Wan <kafai....@linux.dev> > > > > --- > > > > > > This test should not be landed as-is, first let's do an analysis > > > for > > > why the program fails to jit compile on arm. > > > > > > I modified kernel to dump BPF program before jit attempt, but > > > don't > > > see anything obviously wrong with it. The patch to get > > > disassembly > > > and disassembly itself with resolved kallsyms are attached. > > > > > > Can someone with access to ARM vm/machine take a looks at this? > > > Puranjay, Xu, would you have some time? > > > > Hi Eduard, > > Thanks for the email, I will look into it. > > > > Let me try to boot a kernel on ARMv6 qemu and reproduce this. > > Thank you, Puranjay, > > While looking at the code yesterday I found a legit case for failing > to jit on armv6: > > https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/arch/arm/net/bpf_jit_32.c#n445 > https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/arch/arm/net/bpf_jit_32.c#n2089 > > But attached program does not seem to be that big to hit 0xfff > boundary.
Hi Eduard, Puranjay OpenWRT users reported several tests that aren't working properly, which may be helpful. https://github.com/openwrt/openwrt/issues/19405#issuecomment-3121390534 https://github.com/openwrt/openwrt/issues/19405#issuecomment-3176820629 -- Thanks, KaFai
