tequilaOS/platform_system_bpf
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

allow tagging a bpf .o as critical

Browse source 
This does not yet do anything with this information besides logging it.

Test: builds
  $ adb logcat -s -d LibBpfLoader:D | egrep Loading
  06-14 22:52:48.657   430   430 D LibBpfLoader: Loading critical for netd ELF object /system/etc/bpf/offload.o with license Apache 2.0
  06-14 22:52:48.682   430   430 D LibBpfLoader: Loading optional ELF object /system/etc/bpf/time_in_state.o with license GPL
  06-14 22:52:48.729   430   430 D LibBpfLoader: Loading critical for netd ELF object /system/etc/bpf/clatd.o with license Apache 2.0
  06-14 22:52:48.767   430   430 D LibBpfLoader: Loading critical for netd ELF object /system/etc/bpf/netd.o with license Apache 2.0
  06-14 22:53:26.052  2605  2605 D LibBpfLoader: Loading optional ELF object /data/local/tmp/32/kern.o with license Apache 2.0
  06-14 22:54:26.070  2605  2605 D LibBpfLoader: Loading optional ELF object /data/local/tmp/32/kern.o with license Apache 2.0
Bug: 150040815
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ie07549528800d6d7c5ff7f12b859702113d7194e
This commit is contained in:
Maciej Żenczykowski 2020-06-10 15:49:31 -07:00
parent 567dc56b57
commit 4ba8c1c1ac
2 changed files with 14 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
libbpf_android/Loader.cpp
View file

@ -608,19 +608,26 @@ static int loadCodeSections(const char* elfPath, vector<codeSection>& cs, const
int loadProg(const char* elfPath) {
vector<char> license;
vector<char> critical;
vector<codeSection> cs;
vector<unique_fd> mapFds;
bool is_critical;
int ret;
ifstream elfFile(elfPath, ios::in | ios::binary);
if (!elfFile.is_open()) return -1;
ret = readSectionByName("critical", elfFile, critical);
is_critical = !ret;
ret = readSectionByName("license", elfFile, license);
if (ret) {
ALOGE("Couldn't find license in %s\n", elfPath);
return ret;
} else {
ALOGD("Loading ELF object %s with license %s\n", elfPath, (char*)license.data());
ALOGD("Loading %s%s ELF object %s with license %s\n",
is_critical ? "critical for " : "optional", is_critical ? (char*)critical.data() : "",
elfPath, (char*)license.data());
}
ret = readCodeSections(elfFile, cs);

6
progs/include/bpf_helpers.h
View file

@ -12,6 +12,12 @@
/* Example use: LICENSE("GPL"); or LICENSE("Apache 2.0"); */
#define LICENSE(NAME) char _license[] SEC("license") = (NAME)
/* flag the resulting bpf .o file as critical to system functionality,
* loading all kernel version appropriate programs in it must succeed
* for bpfloader success
*/
#define CRITICAL(REASON) char _critical[] SEC("critical") = (REASON)
/*
* Helper functions called from eBPF programs written in C. These are
* implemented in the kernel sources.