Move seccomp policy logic to bionic
Test: Make sure builds, runs, seccomp policy still applied
Bug: 35720753
Change-Id: I2d3a4ac9284a733010d74cb509237e35df17588f
diff --git a/core/jni/android_os_seccomp.cpp b/core/jni/android_os_seccomp.cpp
index f1bc76e..dd5622d 100644
--- a/core/jni/android_os_seccomp.cpp
+++ b/core/jni/android_os_seccomp.cpp
@@ -14,128 +14,11 @@
* limitations under the License.
*/
-#include "JNIHelp.h"
#include "core_jni_helpers.h"
#include "JniConstants.h"
#include "utils/Log.h"
-#include "utils/misc.h"
-
-#if defined __arm__ || defined __aarch64__
-
-#include <vector>
-
-#include <sys/prctl.h>
-
-#include <linux/unistd.h>
-#include <linux/audit.h>
-#include <linux/filter.h>
-#include <linux/seccomp.h>
-
#include "seccomp_policy.h"
-#define syscall_nr (offsetof(struct seccomp_data, nr))
-#define arch_nr (offsetof(struct seccomp_data, arch))
-
-typedef std::vector<sock_filter> filter;
-
-// We want to keep the below inline functions for debugging and future
-// development even though they are not all sed currently.
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunused-function"
-
-static inline void Kill(filter& f) {
- f.push_back(BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL));
-}
-
-static inline void Trap(filter& f) {
- f.push_back(BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP));
-}
-
-static inline void Error(filter& f, __u16 retcode) {
- f.push_back(BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO + retcode));
-}
-
-inline static void Trace(filter& f) {
- f.push_back(BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE));
-}
-
-inline static void Allow(filter& f) {
- f.push_back(BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW));
-}
-
-#pragma clang diagnostic pop
-
-inline static void ExamineSyscall(filter& f) {
- f.push_back(BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_nr));
-}
-
-inline static int SetValidateArchitectureJumpTarget(size_t offset, filter& f) {
- size_t jump_length = f.size() - offset - 1;
- auto u8_jump_length = (__u8) jump_length;
- if (u8_jump_length != jump_length) {
- ALOGE("Can't set jump greater than 255 - actual jump is %zu",
- jump_length);
- return -1;
- }
- f[offset] = BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, AUDIT_ARCH_ARM, u8_jump_length, 0);
- return 0;
-}
-
-inline static size_t ValidateArchitectureAndJumpIfNeeded(filter& f) {
- f.push_back(BPF_STMT(BPF_LD|BPF_W|BPF_ABS, arch_nr));
-
- f.push_back(BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, AUDIT_ARCH_AARCH64, 2, 0));
- f.push_back(BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, AUDIT_ARCH_ARM, 1, 0));
- Trap(f);
- return f.size() - 2;
-}
-
-static bool install_filter(filter const& f) {
- struct sock_fprog prog = {
- (unsigned short) f.size(),
- (struct sock_filter*) &f[0],
- };
-
- if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog) < 0) {
- ALOGE("SECCOMP: Could not set seccomp filter of size %zu: %s", f.size(), strerror(errno));
- return false;
- }
-
- ALOGI("SECCOMP: Global filter of size %zu installed", f.size());
- return true;
-}
-
-bool set_seccomp_filter() {
- filter f;
-
- // Note that for mixed 64/32 bit architectures, ValidateArchitecture inserts a
- // jump that must be changed to point to the start of the 32-bit policy
- // 32 bit syscalls will not hit the policy between here and the call to SetJump
- auto offset_to_32bit_filter =
- ValidateArchitectureAndJumpIfNeeded(f);
-
- // 64-bit filter
- ExamineSyscall(f);
-
- // arm64-only filter - autogenerated from bionic syscall usage
- for (size_t i = 0; i < arm64_filter_size; ++i)
- f.push_back(arm64_filter[i]);
- Trap(f);
-
- if (SetValidateArchitectureJumpTarget(offset_to_32bit_filter, f) != 0)
- return -1;
-
- // 32-bit filter
- ExamineSyscall(f);
-
- // arm32 filter - autogenerated from bionic syscall usage
- for (size_t i = 0; i < arm_filter_size; ++i)
- f.push_back(arm_filter[i]);
- Trap(f);
-
- return install_filter(f);
-}
-
static void Seccomp_setPolicy(JNIEnv* /*env*/) {
if (!set_seccomp_filter()) {
ALOGE("Failed to set seccomp policy - killing");
@@ -143,13 +26,6 @@
}
}
-#else // #if defined __arm__ || defined __aarch64__
-
-static void Seccomp_setPolicy(JNIEnv* /*env*/) {
-}
-
-#endif
-
static const JNINativeMethod method_table[] = {
NATIVE_METHOD(Seccomp, setPolicy, "()V"),
};