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xash3d-fwgs
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platform/android: implement dumb dladdr fallback (only searches in server library)

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mittorn 2023-10-28 23:26:11 +03:00 committed by Alibek Omarov
parent 06c6371e69
commit 44b1a8e863
1 changed files with 77 additions and 0 deletions
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77
engine/platform/android/dlsym-weak.cpp
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@ -29,6 +29,7 @@
#if defined __ANDROID__ && !defined XASH_64BIT
#include <string.h>
#include <android/log.h>
#include <dlfcn.h>
#include "linker.h"
static Elf_Sym* soinfo_elf_lookup(soinfo* si, unsigned hash, const char* name) {
@ -56,6 +57,33 @@ static Elf_Sym* soinfo_elf_lookup(soinfo* si, unsigned hash, const char* name) {
return NULL;
}
static Elf_Sym* soinfo_elf_lookup_reverse(soinfo* si, size_t addr) {
Elf_Sym* symtab = si->symtab;
if( si->nbucket == 0 )
return NULL;
for(int j = 0; j < si->nbucket; j++)
for (unsigned n = si->bucket[j]; n != 0; n = si->chain[n]) {
Elf_Sym* s = symtab + n;
if (s->st_value != addr) continue;
/* only concern ourselves with global and weak symbol definitions */
switch (ELF_ST_BIND(s->st_info)) {
case STB_GLOBAL:
case STB_LOCAL:
case STB_WEAK:
if (s->st_shndx == SHN_UNDEF) {
continue;
}
return s;
}
}
return NULL;
}
static unsigned elfhash(const char* _name) {
const unsigned char* name = (const unsigned char*) _name;
unsigned h = 0, g;
@ -82,6 +110,55 @@ static Elf_Sym* dlsym_handle_lookup(soinfo* si, const char* name) {
return soinfo_elf_lookup(si, elfhash(name), name);
}
extern "C" void *ANDROID_LoadLibrary( const char *dllname );
static int dladdr_fallback( const void *addr, Dl_info *info )
{
static soinfo *server_info;
Elf_Sym *sym;
if( !server_info )
server_info = (soinfo*)ANDROID_LoadLibrary( "server" );
if( !server_info )
return 0;
//__android_log_print( ANDROID_LOG_ERROR, "dladdr_fb", "%p %p\n", addr, server_info );
sym = soinfo_elf_lookup_reverse( server_info, ((char*)addr) - ((char*)server_info->base ));
//__android_log_print( ANDROID_LOG_ERROR, "dladdr_fb", "sym %p %p\n", addr, sym );
if( sym )
{
info->dli_sname = server_info->strtab + sym->st_name;
info->dli_fname = "server";
info->dli_fbase = (void*)server_info->base;
info->dli_saddr = (void*)addr;
//__android_log_print( ANDROID_LOG_ERROR, "dladdr_fb", "name %p %s\n", addr, info->dli_sname );
return 1;
}
return 0;
}
extern "C" int __attribute__((visibility("hidden"))) dladdr( const void *addr, Dl_info *info )
{
static int (*pDladdr)( const void *addr, Dl_info *info );
// __android_log_print( ANDROID_LOG_ERROR, "dladdr", "dladdr %p %p %p\n", addr, pDladdr, &dladdr );
if(!pDladdr)
{
void *lib = dlopen( "libdl.so", RTLD_NOW );
if( lib )
*(void**)&pDladdr = dlsym( lib, "dladdr" );
if( (void*)pDladdr == (void*)&dladdr )
pDladdr = 0;
if( !pDladdr )
pDladdr = dladdr_fallback;
}
// __android_log_print( ANDROID_LOG_ERROR, "dladdr", "dladdr %p\n", addr );
return pDladdr( addr, info );
}
extern "C" void* dlsym_weak(void* handle, const char* symbol) {
soinfo* found = NULL;