On Thu, Nov 5, 2020 at 8:45 AM Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > 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? > Nope, my bad, completely forgot to add it. Last time I touched sysfs was quite a while ago, I forgot about adding ABI description. Will add in the next version. > thanks, > > greg k-h
