Platform BpfLoader: do not support mismatching bpf map/prog struct sizes
This is not needed, as all platform bpf .o's are built at the same time
(and thus from the same bpf map/prog structure definitions) as
the loader itself.
This effectively undoes much of aosp/1754794
'bpf loader improvements for better long term compatibility with mainline'
Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I8cd6865cfb49bb282b2dcff1957dd9826e501da1
diff --git a/libbpf_android/Loader.cpp b/libbpf_android/Loader.cpp
index 8686ccc..305c60e 100644
--- a/libbpf_android/Loader.cpp
+++ b/libbpf_android/Loader.cpp
@@ -371,33 +371,19 @@
return "UNKNOWN SECTION NAME " + std::to_string(type);
}
-static int readProgDefs(ifstream& elfFile, vector<struct bpf_prog_def>& pd,
- size_t sizeOfBpfProgDef) {
+static int readProgDefs(ifstream& elfFile, vector<struct bpf_prog_def>& pd) {
vector<char> pdData;
int ret = readSectionByName("progs", elfFile, pdData);
if (ret) return ret;
- if (pdData.size() % sizeOfBpfProgDef) {
+ if (pdData.size() % sizeof(struct bpf_prog_def)) {
ALOGE("readProgDefs failed due to improper sized progs section, %zu %% %zu != 0",
- pdData.size(), sizeOfBpfProgDef);
+ pdData.size(), sizeof(struct bpf_prog_def));
return -1;
};
- int progCount = pdData.size() / sizeOfBpfProgDef;
- pd.resize(progCount);
- size_t trimmedSize = std::min(sizeOfBpfProgDef, sizeof(struct bpf_prog_def));
-
- const char* dataPtr = pdData.data();
- for (auto& p : pd) {
- // First we zero initialize
- memset(&p, 0, sizeof(p));
- // Then we set non-zero defaults
- p.bpfloader_max_ver = DEFAULT_BPFLOADER_MAX_VER; // v1.0
- // Then we copy over the structure prefix from the ELF file.
- memcpy(&p, dataPtr, trimmedSize);
- // Move to next struct in the ELF file
- dataPtr += sizeOfBpfProgDef;
- }
+ pd.resize(pdData.size() / sizeof(struct bpf_prog_def));
+ memcpy(pd.data(), pdData.data(), pdData.size());
return 0;
}
@@ -460,7 +446,7 @@
}
/* Read a section by its index - for ex to get sec hdr strtab blob */
-static int readCodeSections(ifstream& elfFile, vector<codeSection>& cs, size_t sizeOfBpfProgDef,
+static int readCodeSections(ifstream& elfFile, vector<codeSection>& cs,
const bpf_prog_type* allowed, size_t numAllowed) {
vector<Elf64_Shdr> shTable;
int entries, ret = 0;
@@ -470,7 +456,7 @@
entries = shTable.size();
vector<struct bpf_prog_def> pd;
- ret = readProgDefs(elfFile, pd, sizeOfBpfProgDef);
+ ret = readProgDefs(elfFile, pd);
if (ret) return ret;
vector<string> progDefNames;
ret = getSectionSymNames(elfFile, "progs", progDefNames);
@@ -599,8 +585,7 @@
}
static int createMaps(const char* elfPath, ifstream& elfFile, vector<unique_fd>& mapFds,
- const char* prefix, const unsigned long long allowedDomainBitmask,
- const size_t sizeOfBpfMapDef) {
+ const char* prefix, const unsigned long long allowedDomainBitmask) {
int ret;
vector<char> mdData;
vector<struct bpf_map_def> md;
@@ -611,28 +596,13 @@
if (ret == -2) return 0; // no maps to read
if (ret) return ret;
- if (mdData.size() % sizeOfBpfMapDef) {
+ if (mdData.size() % sizeof(struct bpf_map_def)) {
ALOGE("createMaps failed due to improper sized maps section, %zu %% %zu != 0",
- mdData.size(), sizeOfBpfMapDef);
+ mdData.size(), sizeof(struct bpf_map_def));
return -1;
- };
-
- int mapCount = mdData.size() / sizeOfBpfMapDef;
- md.resize(mapCount);
- size_t trimmedSize = std::min(sizeOfBpfMapDef, sizeof(struct bpf_map_def));
-
- const char* dataPtr = mdData.data();
- for (auto& m : md) {
- // First we zero initialize
- memset(&m, 0, sizeof(m));
- // Then we set non-zero defaults
- m.bpfloader_max_ver = DEFAULT_BPFLOADER_MAX_VER; // v1.0
- m.max_kver = 0xFFFFFFFFu; // matches KVER_INF from bpf_helpers.h
- // Then we copy over the structure prefix from the ELF file.
- memcpy(&m, dataPtr, trimmedSize);
- // Move to next struct in the ELF file
- dataPtr += sizeOfBpfMapDef;
}
+ md.resize(mdData.size() / sizeof(struct bpf_map_def));
+ memcpy(md.data(), mdData.data(), mdData.size());
ret = getSectionSymNames(elfFile, "maps", mapNames);
if (ret) return ret;
@@ -1048,28 +1018,9 @@
elfPath, (char*)license.data());
}
- // the following default values are for bpfloader V0.0 format which does not include them
- size_t sizeOfBpfMapDef =
- readSectionUint("size_of_bpf_map_def", elfFile, DEFAULT_SIZEOF_BPF_MAP_DEF);
- size_t sizeOfBpfProgDef =
- readSectionUint("size_of_bpf_prog_def", elfFile, DEFAULT_SIZEOF_BPF_PROG_DEF);
-
ALOGI("Platform BpfLoader processing ELF object %s", elfPath);
- if (sizeOfBpfMapDef < DEFAULT_SIZEOF_BPF_MAP_DEF) {
- ALOGE("sizeof(bpf_map_def) of %zu is too small (< %d)", sizeOfBpfMapDef,
- DEFAULT_SIZEOF_BPF_MAP_DEF);
- return -1;
- }
-
- if (sizeOfBpfProgDef < DEFAULT_SIZEOF_BPF_PROG_DEF) {
- ALOGE("sizeof(bpf_prog_def) of %zu is too small (< %d)", sizeOfBpfProgDef,
- DEFAULT_SIZEOF_BPF_PROG_DEF);
- return -1;
- }
-
- ret = readCodeSections(elfFile, cs, sizeOfBpfProgDef, location.allowedProgTypes,
- location.allowedProgTypesLength);
+ ret = readCodeSections(elfFile, cs, location.allowedProgTypes, location.allowedProgTypesLength);
if (ret) {
ALOGE("Couldn't read all code sections in %s", elfPath);
return ret;
@@ -1078,8 +1029,7 @@
/* Just for future debugging */
if (0) dumpAllCs(cs);
- ret = createMaps(elfPath, elfFile, mapFds, location.prefix, location.allowedDomainBitmask,
- sizeOfBpfMapDef);
+ ret = createMaps(elfPath, elfFile, mapFds, location.prefix, location.allowedDomainBitmask);
if (ret) {
ALOGE("Failed to create maps: (ret=%d) in %s", ret, elfPath);
return ret;