forked from luck/tmp_suning_uos_patched
085fee1a72
The required protection is that the caller cannot be migrated to a different CPU as these places take either a hash bucket lock or might trigger a kprobe inside the memory allocator. Both scenarios can lead to deadlocks. The deadlock prevention is per CPU by incrementing a per CPU variable which temporarily blocks the invocation of BPF programs from perf and kprobes. Replace the open coded preempt_disable/enable() and this_cpu_inc/dec() pairs with the new recursion prevention helpers to prepare BPF to work on PREEMPT_RT enabled kernels. On a non-RT kernel the migrate disable/enable in the helpers map to preempt_disable/enable(), i.e. no functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200224145644.211208533@linutronix.de |
||
|---|---|---|
| .. | ||
| arraymap.c | ||
| bpf_lru_list.c | ||
| bpf_lru_list.h | ||
| bpf_struct_ops_types.h | ||
| bpf_struct_ops.c | ||
| btf.c | ||
| cgroup.c | ||
| core.c | ||
| cpumap.c | ||
| devmap.c | ||
| disasm.c | ||
| disasm.h | ||
| dispatcher.c | ||
| hashtab.c | ||
| helpers.c | ||
| inode.c | ||
| local_storage.c | ||
| lpm_trie.c | ||
| Makefile | ||
| map_in_map.c | ||
| map_in_map.h | ||
| offload.c | ||
| percpu_freelist.c | ||
| percpu_freelist.h | ||
| queue_stack_maps.c | ||
| reuseport_array.c | ||
| stackmap.c | ||
| syscall.c | ||
| sysfs_btf.c | ||
| tnum.c | ||
| trampoline.c | ||
| verifier.c | ||
| xskmap.c | ||