diff options
author | Alexei Starovoitov <ast@kernel.org> | 2020-08-31 18:51:55 +0300 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-08-31 21:54:57 +0300 |
commit | 9667305c6374df8672be46bc496f52f040999531 (patch) | |
tree | 98e3e2e1e28369f82efd1d3eb267e3b12c28ff98 /include/linux/rcupdate_trace.h | |
parent | 10496f261ed30592c6a7f8315f6b5ec055db624a (diff) | |
download | linux-9667305c6374df8672be46bc496f52f040999531.tar.xz |
bpf: Fix build without BPF_SYSCALL, but with BPF_JIT.
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.
Fixes: 1e6c62a88215 ("bpf: Introduce sleepable BPF programs")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/bpf/20200831155155.62754-1-alexei.starovoitov@gmail.com
Diffstat (limited to 'include/linux/rcupdate_trace.h')
-rw-r--r-- | include/linux/rcupdate_trace.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/include/linux/rcupdate_trace.h b/include/linux/rcupdate_trace.h index d9015aac78c6..aaaac8ac927c 100644 --- a/include/linux/rcupdate_trace.h +++ b/include/linux/rcupdate_trace.h @@ -82,7 +82,14 @@ static inline void rcu_read_unlock_trace(void) void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func); void synchronize_rcu_tasks_trace(void); void rcu_barrier_tasks_trace(void); - +#else +/* + * The BPF JIT forms these addresses even when it doesn't call these + * functions, so provide definitions that result in runtime errors. + */ +static inline void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func) { BUG(); } +static inline void rcu_read_lock_trace(void) { BUG(); } +static inline void rcu_read_unlock_trace(void) { BUG(); } #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ #endif /* __LINUX_RCUPDATE_TRACE_H */ |