On 8/31/20 9:15 AM, Paul E. McKenney wrote:
On Mon, Aug 31, 2020 at 08:51:55AM -0700, Alexei Starovoitov wrote:From: Alexei Starovoitov <ast@xxxxxxxxxx> When CONFIG_BPF_SYSCALL is not set, but CONFIG_BPF_JIT=y the kernel build fails: In file included from ../kernel/bpf/trampoline.c:11: ../kernel/bpf/trampoline.c: In function ‘bpf_trampoline_update’: ../kernel/bpf/trampoline.c:220:39: error: ‘call_rcu_tasks_trace’ undeclared ../kernel/bpf/trampoline.c: In function ‘__bpf_prog_enter_sleepable’: ../kernel/bpf/trampoline.c:411:2: error: implicit declaration of function ‘rcu_read_lock_trace’ ../kernel/bpf/trampoline.c: In function ‘__bpf_prog_exit_sleepable’: ../kernel/bpf/trampoline.c:416:2: error: implicit declaration of function ‘rcu_read_unlock_trace’ This is due to: obj-$(CONFIG_BPF_JIT) += trampoline.o obj-$(CONFIG_BPF_JIT) += dispatcher.o There is a number of functions that arch/x86/net/bpf_jit_comp.c is using from these two files, but none of them will be used when only cBPF is on (which is the case for BPF_SYSCALL=n BPF_JIT=y). Add rcu_trace functions to rcupdate_trace.h. The JITed code won't execute them and BPF trampoline logic won't be used without BPF_SYSCALL. Reported-by: kernel test robot <lkp@xxxxxxxxx> Fixes: 1e6c62a88215 ("bpf: Introduce sleepable BPF programs") Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxx> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>Looks good, and unless someone tells me otherwise, I am assuming that this one goes up the normal BPF patch route.
Yes. It fixes the issue in bpf-next tree.
