On 2025/12/19 20:27, Menglong Dong wrote: > On 2025/12/19 19:41, Andreas Schwab wrote: > > On Dez 19 2025, Menglong Dong wrote: > > > > > BPF_TRAMP_F_ORIG_STACK > > > > How can that ever be set? > > Oops, my bad! It should be BPF_TRAMP_F_CALL_ORIG here. I think > it is some kind of copy-paste mistake. I'll send a fix for it.
I sent the following patch twice, but I didn't see it in the mail list. I suspect there is something wrong with my gmail. Hi, Alexei. Can you see my patch? -->patch<-- >From 5dbae5dcba3aa7fa10e506e9fd1a28a6802d9b00 Mon Sep 17 00:00:00 2001 From: Menglong Dong <[email protected]> Date: Fri, 19 Dec 2025 20:33:10 +0800 Subject: [PATCH RESEND bpf] riscv, bpf: fix incorrect usage of BPF_TRAMP_F_ORIG_STACK The usage of BPF_TRAMP_F_ORIG_STACK in __arch_prepare_bpf_trampoline() is wrong, and it should be BPF_TRAMP_F_CALL_ORIG, which caused crash as Andreas reported: Insufficient stack space to handle exception! Task stack: [0xff20000000010000..0xff20000000014000] Overflow stack: [0xff600000ffdad070..0xff600000ffdae070] CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary) Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025 epc : copy_from_kernel_nofault+0xa/0x198 ra : bpf_probe_read_kernel+0x20/0x60 epc : ffffffff802b732a ra : ffffffff801e6070 sp : ff2000000000ffe0 gp : ffffffff82262ed0 tp : 0000000000000000 t0 : ffffffff80022320 t1 : ffffffff801e6056 t2 : 0000000000000000 s0 : ff20000000010040 s1 : 0000000000000008 a0 : ff20000000010050 a1 : ff60000083b3d320 a2 : 0000000000000008 a3 : 0000000000000097 a4 : 0000000000000000 a5 : 0000000000000000 a6 : 0000000000000021 a7 : 0000000000000003 s2 : ff20000000010050 s3 : ff6000008459fc18 s4 : ff60000083b3d340 s5 : ff20000000010060 s6 : 0000000000000000 s7 : ff20000000013aa8 s8 : 0000000000000000 s9 : 0000000000008000 s10: 000000000058dcb0 s11: 000000000058dca7 t3 : 000000006925116d t4 : ff6000008090f026 t5 : 00007fff9b0cbaa8 t6 : 0000000000000016 status: 0000000200000120 badaddr: 0000000000000000 cause: 8000000000000005 Kernel panic - not syncing: Kernel stack overflow CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary) Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025 Call Trace: [<ffffffff8001a1f8>] dump_backtrace+0x28/0x38 [<ffffffff80002502>] show_stack+0x3a/0x50 [<ffffffff800122be>] dump_stack_lvl+0x56/0x80 [<ffffffff80012300>] dump_stack+0x18/0x22 [<ffffffff80002abe>] vpanic+0xf6/0x328 [<ffffffff80002d2e>] panic+0x3e/0x40 [<ffffffff80019ef0>] handle_bad_stack+0x98/0xa0 [<ffffffff801e6070>] bpf_probe_read_kernel+0x20/0x60 Just fix it. Fixes: 47c9214dcbea ("bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME") Reported-by: Andreas Schwab <[email protected]> Closes: https://lore.kernel.org/bpf/[email protected]/ Signed-off-by: Menglong Dong <[email protected]> --- arch/riscv/net/bpf_jit_comp64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index 5f9457e910e8..09b70bf362d3 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -1134,7 +1134,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, store_args(nr_arg_slots, args_off, ctx); /* skip to actual body of traced function */ - if (flags & BPF_TRAMP_F_ORIG_STACK) + if (flags & BPF_TRAMP_F_CALL_ORIG) orig_call += RV_FENTRY_NINSNS * 4; if (flags & BPF_TRAMP_F_CALL_ORIG) { -- 2.52.0 --<patch>-- > > Thanks! > Menglong Dong > > > > > if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY)) > > return -ENOTSUPP; > > > > > > > > > >
