On Thu, Nov 05, 2020 at 08:39:25AM -0800, Jakub Kicinski wrote: > On Wed, 4 Nov 2020 20:51:39 -0800 Andrii Nakryiko wrote: > > Add kernel module listener that will load/validate and unload module BTF. > > Module BTFs gets ID generated for them, which makes it possible to iterate > > them with existing BTF iteration API. They are given their respective module's > > names, which will get reported through GET_OBJ_INFO API. They are also marked > > as in-kernel BTFs for tooling to distinguish them from user-provided BTFs. > > > > Also, similarly to vmlinux BTF, kernel module BTFs are exposed through > > sysfs as /sys/kernel/btf/<module-name>. This is convenient for user-space > > tools to inspect module BTF contents and dump their types with existing tools: > > Is there any precedent for creating per-module files under a new > sysfs directory structure? My intuition would be that these files > belong under /sys/module/ Ick, why? What's wrong with them under btf? The module core code "owns" the /sys/modules/ tree. If you want others to mess with that, it will get tricky. > Also the CC list on these patches is quite narrow. You should have > at least CCed the module maintainer. Adding some folks now. > > > [vmuser@archvm bpf]$ ls -la /sys/kernel/btf > > total 0 > > drwxr-xr-x 2 root root 0 Nov 4 19:46 . > > drwxr-xr-x 13 root root 0 Nov 4 19:46 .. > > > > ... > > > > -r--r--r-- 1 root root 888 Nov 4 19:46 irqbypass > > -r--r--r-- 1 root root 100225 Nov 4 19:46 kvm > > -r--r--r-- 1 root root 35401 Nov 4 19:46 kvm_intel > > -r--r--r-- 1 root root 120 Nov 4 19:46 pcspkr > > -r--r--r-- 1 root root 399 Nov 4 19:46 serio_raw > > -r--r--r-- 1 root root 4094095 Nov 4 19:46 vmlinux > > > > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > > --- > > include/linux/bpf.h | 2 + > > include/linux/module.h | 4 + > > kernel/bpf/btf.c | 193 +++++++++++++++++++++++++++++++++++++++++ > > kernel/bpf/sysfs_btf.c | 2 +- > > kernel/module.c | 32 +++++++ > > 5 files changed, 232 insertions(+), 1 deletion(-) > > > > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > > index 2fffd30e13ac..3cb89cd7177b 100644 > > --- a/include/linux/bpf.h > > +++ b/include/linux/bpf.h > > @@ -36,9 +36,11 @@ struct seq_operations; > > struct bpf_iter_aux_info; > > struct bpf_local_storage; > > struct bpf_local_storage_map; > > +struct kobject; > > > > extern struct idr btf_idr; > > extern spinlock_t btf_idr_lock; > > +extern struct kobject *btf_kobj; I don't see any Documentation/ABI/ updates for the sysfs changes here, did I miss it? thanks, greg k-h
