Pu Lehui 1732ebc4a2 riscv, bpf: Fix unpredictable kernel crash about RV64 struct_ops ... We encountered a kernel crash triggered by the bpf_tcp_ca testcase as show below: Unable to handle kernel paging request at virtual address ff60000088554500 Oops [#1] ... CPU: 3 PID: 458 Comm: test_progs Tainted: G OE 6.8.0-rc1-kselftest_plain #1 Hardware name: riscv-virtio,qemu (DT) epc : 0xff60000088554500 ra : tcp_ack+0x288/0x1232 epc : ff60000088554500 ra : ffffffff80cc7166 sp : ff2000000117ba50 gp : ffffffff82587b60 tp : ff60000087be0040 t0 : ff60000088554500 t1 : ffffffff801ed24e t2 : 0000000000000000 s0 : ff2000000117bbc0 s1 : 0000000000000500 a0 : ff20000000691000 a1 : 0000000000000018 a2 : 0000000000000001 a3 : ff60000087be03a0 a4 : 0000000000000000 a5 : 0000000000000000 a6 : 0000000000000021 a7 : ffffffff8263f880 s2 : 000000004ac3c13b s3 : 000000004ac3c13a s4 : 0000000000008200 s5 : 0000000000000001 s6 : 0000000000000104 s7 : ff2000000117bb00 s8 : ff600000885544c0 s9 : 0000000000000000 s10: ff60000086ff0b80 s11: 000055557983a9c0 t3 : 0000000000000000 t4 : 000000000000ffc4 t5 : ffffffff8154f170 t6 : 0000000000000030 status: 0000000200000120 badaddr: ff60000088554500 cause: 000000000000000c Code: c796 67d7 0000 0000 0052 0002 c13b 4ac3 0000 0000 (0001) 0000 ---[ end trace 0000000000000000 ]--- The reason is that commit 2cd3e3772e ("x86/cfi,bpf: Fix bpf_struct_ops CFI") changes the func_addr of arch_prepare_bpf_trampoline in struct_ops from NULL to non-NULL, while we use func_addr on RV64 to differentiate between struct_ops and regular trampoline. When the struct_ops testcase is triggered, it emits wrong prologue and epilogue, and lead to unpredictable issues. After commit 2cd3e3772e, we can use BPF_TRAMP_F_INDIRECT to distinguish them as it always be set in struct_ops. Fixes: 2cd3e3772e ("x86/cfi,bpf: Fix bpf_struct_ops CFI") Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20240123023207.1917284-1-pulehui@huaweicloud.com		2024-01-23 23:21:38 +01:00
..
bpf_jit_comp32.c	bpf: Change value of MAX_TAIL_CALL_CNT from 32 to 33	2021-11-16 14:03:15 +01:00
bpf_jit_comp64.c	riscv, bpf: Fix unpredictable kernel crash about RV64 struct_ops	2024-01-23 23:21:38 +01:00
bpf_jit_core.c	bpf, riscv: use prog pack allocator in the BPF JIT	2023-09-06 06:26:07 -07:00
bpf_jit.h	bpf, riscv: use prog pack allocator in the BPF JIT	2023-09-06 06:26:07 -07:00
Makefile	riscv, bpf: Add RV32G eBPF JIT	2020-03-05 16:13:47 +01:00