BTF support was added to bpfloader during Android T dev cycle.
As it causes bpfloader boot time process to shell out to a new
btfloader subprocess for every bpf.o file with BTF debugging
information compiled in, I'm worried this might have unforeseen
consequences - things like crashes or boot time bpfloader cpu
regressions.
However, BTF is exceedingly useful for debugging,
and it would be a huge pity if we were forced to disable it
and keep it disabled in mainline tethering module just to support
Android T devices for the next 5+ years.
It would also be a pity if the bpf.o files in prebuilt mainline
tethering apex in dev branches (like tm-dev) did not include
BTF debug information simply due to compatibility with older
kernels or OSes, since this would require rebuilding the module
everytime BTF information could be of use.
One of the things functioning BTF enables is 'cat /sys/fs/bpf/map_*'
as root on a userdebug build. Among other things this can be
used to verify that in kernel bpf map state matches that dumped
by the mainline module's pretty dump code.
Even if there's issues wrt. BTF in Android T (or on older kernels),
we can always fix them in Android U or later (for example build
btfloader into bpfloader to avoid exec overhead, etc...).
Bug: 218408035
Bug: 230585250
Bug: 235559605
Test: TreeHugger, cuttlefish devices boots, and:
adb root && adb shell cat /sys/fs/bpf/map_time_in_state_cpu_last_pid_map
continues to show information which is available due to BTF debug provided
in /system/etc/bpf/time_in_state.o file (due to "btf: true" in Android.bp)
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I553e90e0414453f8f3aaca8cf05d5decc8b911a2
(cherry picked from commit 37b3d06333)
Merged-In: I553e90e0414453f8f3aaca8cf05d5decc8b911a2
This reverts commit 8e5e239dd0a7856e486a9e2d772ef3a9e38021eb.
No longer required now that selinux change has landed.
(while we're at it bump the bpfloader version to v0.19 just
to make sure we can tell these apart in the future)
This is a cherrypick to tm-dev of reviewed/approved but unsubmitted:
https://android-review.googlesource.com/c/platform/system/bpf/+/2132534
Ignore-AOSP-First: will be cherrypicked to aosp master
Bug: 218408035
Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I0b3349ef908bbfd225b8b7f83b2a4a8870c1e409
This is needed to make it safe to share maps across different .o's.
Bug: 218408035
Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I9e8a5893ed4f91354f6544be587b10a97d179de6
(cherry picked from commit 12bb520707)
Merged-In: I9e8a5893ed4f91354f6544be587b10a97d179de6
For use by:
- maps netd should have read but not write access to
(needed due to netd being root with DAC_OVERRIDE,
and thus not obeying standard unix permissions)
- programs that netd should have access to but
not netutils_wrappers (which due to being able to
run iptables, needs access to xt_bpf programs)
Bug: 218408035
Test: booted on cuttlefish
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I72b106692a25077ff54252fd93db81f46b52125d
(cherry picked from commit 32c0b8f46e)
Merged-In: I72b106692a25077ff54252fd93db81f46b52125d
combined with content of /proc/${pid}/fd/${fd}
and /proc/${pid}/fdinfo/${fd} this allows figuring
out which programs/maps a process continues to
have open
See:
adbz logcat -d | egrep '(map|prog) .* id'
adbz root
adbz_bpf_progs_and_maps
Bug: 230880517
Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I66c7fa12d079257486569105368bf1eea2d3ab0c
(cherry picked from commit 57412c2a27)
Merged-In: I66c7fa12d079257486569105368bf1eea2d3ab0c
This is needed due to the other half of this topic getting into tm-dev via automerger via sc-mainline-prod
Also this topic was always meant for T.
Original change: https://android-review.googlesource.com/c/platform/system/bpf/+/2071267
Test: manual
Bug: 218408035
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Merged-In: Id5ef7f3b119743ef26b062068756c4e0f754e694
Change-Id: I6ffab207294946357f3a97685d3eacc75b724e89
This also fixes a permissions issue if a non-root user is set. The read
permissions should be set before the file is set as non-root to ensure
that the permissions can be set without error.
Bump the BPF loader version.
Bug: 203462310
Test: Ensure that vendor skfilter bpf programs can load
Change-Id: Ib6b9a64d8652ff464c9d4d734bb8ae351673b6ce
With the addition of special handling for SDK sandbox uids, the UID
definitions provided by this header are needed in order to compile the
mock time_in_state program for testing.
Bug: 219080829
Test: m bpf-time-in-state-tests
Signed-off-by: Connor O'Brien <connoro@google.com>
Change-Id: I92464cf76fb49bcf7490794ed5b7c07d865a7e14
Allow vendors to use bpf programs, but limit to tracepoints
for now (other types of programs, for instance skfilter, aren't
safe to expose, because the kernel gives us limited ways to
control which resources can have BPF programs attached, and
some shared resources only support a single BPF program at an
attach point).
Bug: 140330870
Bug: 162057235
Test: install bpf program to /vendor/etc/bpf/ and use it.
Test: atest libbpf_load_test
Change-Id: I6c876fe52739c38db73689ffd784167e7d35d58a
