Mirrors/Magisk
1
0
Fork 0
mirror of https://github.com/topjohnwu/Magisk.git synced 2025-06-12 21:27:41 +02:00
Code Issues Packages Projects Releases Wiki Activity

Add preliminary zygote code injection support

Browse Source 
Prototyping the injection setup and a clean "self unloading" mechanism.
This commit is contained in:
topjohnwu
2021-01-06 22:21:17 -08:00
parent cd23d27048
commit 4060c2107c
13 changed files with 281 additions and 102 deletions
Download Patch File Download Diff File Expand all files Collapse all files

81
native/jni/inject/ptrace.cpp
View File

@ -24,6 +24,7 @@
#include <utils.hpp>
#include "inject.hpp"
#include "ptrace.hpp"
using namespace std;
@ -43,80 +44,6 @@ using namespace std;
#define ARM_r0 regs[0]
#endif
struct map_info {
uintptr_t start;
uintptr_t end;
int perms;
char *path;
map_info() : start(0), end(0), perms(0), path(nullptr) {}
enum {
EXEC = (1 << 0),
WRITE = (1 << 1),
READ = (1 << 2),
};
};
// Func signature: bool(map_info&)
template <typename Func>
static void parse_maps(int pid, Func fn) {
char file[32];
// format: start-end perms offset dev inode path
sprintf(file, "/proc/%d/maps", pid);
file_readline(true, file, [=](string_view l) -> bool {
char *pos = (char *) l.data();
map_info info;
// Parse address hex strings
info.start = strtoul(pos, &pos, 16);
info.end = strtoul(++pos, &pos, 16);
// Parse permissions
if (*(++pos) != '-')
info.perms |= map_info::READ;
if (*(++pos) != '-')
info.perms |= map_info::WRITE;
if (*(++pos) != '-')
info.perms |= map_info::EXEC;
pos += 3;
// Skip everything except path
int path_off;
sscanf(pos, "%*s %*s %*s %n%*s", &path_off);
pos += path_off;
info.path = pos;
return fn(info);
});
}
uintptr_t get_function_lib(uintptr_t addr, char *lib) {
uintptr_t base = 0;
parse_maps(getpid(), [=, &base](map_info &info) -> bool {
if (addr >= info.start && addr < info.end) {
strcpy(lib, info.path);
base = info.start;
return false;
}
return true;
});
return base;
}
uintptr_t get_remote_lib(int pid, const char *lib) {
uintptr_t base = 0;
parse_maps(pid, [=, &base](map_info &info) -> bool {
if (strcmp(info.path, lib) == 0 && (info.perms & map_info::EXEC)) {
base = info.start;
return false;
}
return true;
});
return base;
}
bool _remote_read(int pid, uintptr_t addr, void *buf, size_t len) {
for (size_t i = 0; i < len; i += sizeof(long)) {
long data = xptrace(PTRACE_PEEKTEXT, pid, reinterpret_cast<void*>(addr + i));
@ -165,7 +92,7 @@ static void _remote_setregs(int pid, pt_regs *regs) {
#endif
}
static uintptr_t remote_call_abi(int pid, uintptr_t func_addr, int nargs, va_list va) {
uintptr_t remote_call_abi(int pid, uintptr_t func_addr, int nargs, va_list va) {
pt_regs regs, regs_bak;
// Get registers and save a backup
@ -300,7 +227,11 @@ static uintptr_t remote_call_abi(int pid, uintptr_t func_addr, int nargs, va_lis
uintptr_t remote_call_vararg(int pid, uintptr_t addr, int nargs, ...) {
char lib_name[4096];
auto local = get_function_lib(addr, lib_name);
if (local == 0)
return 0;
auto remote = get_remote_lib(pid, lib_name);
if (remote == 0)
return 0;
addr = addr - local + remote;
va_list va;
va_start(va, nargs);