diff --git a/libdl/libdl.c b/libdl/libdl.c index 548364cba..12ab39b4a 100644 --- a/libdl/libdl.c +++ b/libdl/libdl.c @@ -15,6 +15,8 @@ */ #include <dlfcn.h> +#include <stdlib.h> + /* These are stubs for functions that are actually defined * in the dynamic linker (dlfcn.c), and hijacked at runtime. */ @@ -24,6 +26,7 @@ void *dlsym(void *handle, const char *symbol) { return 0; } int dladdr(const void *addr, Dl_info *info) { return 0; } int dlclose(void *handle) { return 0; } +void android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) { } void android_update_LD_LIBRARY_PATH(const char* ld_library_path) { } #if defined(__arm__) diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp index 207e03c3d..8501ad638 100644 --- a/linker/dlfcn.cpp +++ b/linker/dlfcn.cpp @@ -54,6 +54,11 @@ const char* dlerror() { return old_value; } +void android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) { + ScopedPthreadMutexLocker locker(&gDlMutex); + do_android_get_LD_LIBRARY_PATH(buffer, buffer_size); +} + void android_update_LD_LIBRARY_PATH(const char* ld_library_path) { ScopedPthreadMutexLocker locker(&gDlMutex); do_android_update_LD_LIBRARY_PATH(ld_library_path); @@ -143,20 +148,6 @@ int dlclose(void* handle) { return do_dlclose(reinterpret_cast<soinfo*>(handle)); } -#if defined(__arm__) -// 0000000 00011111 111112 22222222 2333333 3333444444444455555555556666666 6667777777777888 8888888 -// 0123456 78901234 567890 12345678 9012345 6789012345678901234567890123456 7890123456789012 3456789 -#define ANDROID_LIBDL_STRTAB \ - "dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0dl_iterate_phdr\0dl_unwind_find_exidx\0" -#elif defined(__aarch64__) || defined(__i386__) || defined(__mips__) || defined(__x86_64__) -// 0000000 00011111 111112 22222222 2333333 3333444444444455555555556666666 6667 -// 0123456 78901234 567890 12345678 9012345 6789012345678901234567890123456 7890 -#define ANDROID_LIBDL_STRTAB \ - "dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0dl_iterate_phdr\0" -#else -#error Unsupported architecture. Only aarch64, arm, mips, x86, and x86_64 are presently supported. -#endif - // name_offset: starting index of the name in libdl_info.strtab #define ELF32_SYM_INITIALIZER(name_offset, value, shndx) \ { name_offset, \ @@ -182,47 +173,55 @@ int dlclose(void* handle) { # define ELF_SYM_INITIALIZER ELF32_SYM_INITIALIZER #endif +#if defined(__arm__) + // 0000000 00011111 111112 22222222 2333333 3333444444444455555555556666666 6667777777777888888888899999 9999900000000001 1 + // 0123456 78901234 567890 12345678 9012345 6789012345678901234567890123456 7890123456789012345678901234 5678901234567890 1 +# define ANDROID_LIBDL_STRTAB \ + "dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0android_get_LD_LIBRARY_PATH\0dl_iterate_phdr\0dl_unwind_find_exidx\0" +#elif defined(__aarch64__) || defined(__i386__) || defined(__mips__) || defined(__x86_64__) + // 0000000 00011111 111112 22222222 2333333 3333444444444455555555556666666 6667777777777888888888899999 9999900000000001 1 + // 0123456 78901234 567890 12345678 9012345 6789012345678901234567890123456 7890123456789012345678901234 5678901234567890 1 +# define ANDROID_LIBDL_STRTAB \ + "dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0android_get_LD_LIBRARY_PATH\0dl_iterate_phdr\0" +#else +# error Unsupported architecture. Only aarch64, arm, mips, x86, and x86_64 are presently supported. +#endif + static Elf_Sym gLibDlSymtab[] = { // Total length of libdl_info.strtab, including trailing 0. // This is actually the STH_UNDEF entry. Technically, it's // supposed to have st_name == 0, but instead, it points to an index // in the strtab with a \0 to make iterating through the symtab easier. ELF_SYM_INITIALIZER(sizeof(ANDROID_LIBDL_STRTAB) - 1, NULL, 0), - ELF_SYM_INITIALIZER( 0, &dlopen, 1), - ELF_SYM_INITIALIZER( 7, &dlclose, 1), - ELF_SYM_INITIALIZER(15, &dlsym, 1), - ELF_SYM_INITIALIZER(21, &dlerror, 1), - ELF_SYM_INITIALIZER(29, &dladdr, 1), - ELF_SYM_INITIALIZER(36, &android_update_LD_LIBRARY_PATH, 1), - ELF_SYM_INITIALIZER(67, &dl_iterate_phdr, 1), + ELF_SYM_INITIALIZER( 0, &dlopen, 1), + ELF_SYM_INITIALIZER( 7, &dlclose, 1), + ELF_SYM_INITIALIZER( 15, &dlsym, 1), + ELF_SYM_INITIALIZER( 21, &dlerror, 1), + ELF_SYM_INITIALIZER( 29, &dladdr, 1), + ELF_SYM_INITIALIZER( 36, &android_update_LD_LIBRARY_PATH, 1), + ELF_SYM_INITIALIZER( 67, &android_get_LD_LIBRARY_PATH, 1), + ELF_SYM_INITIALIZER( 95, &dl_iterate_phdr, 1), #if defined(__arm__) - ELF_SYM_INITIALIZER(83, &dl_unwind_find_exidx, 1), + ELF_SYM_INITIALIZER(111, &dl_unwind_find_exidx, 1), #endif }; // Fake out a hash table with a single bucket. -// A search of the hash table will look through -// gLibDlSymtab starting with index [1], then -// use gLibDlChains to find the next index to -// look at. gLibDlChains should be set up to -// walk through every element in gLibDlSymtab, -// and then end with 0 (sentinel value). // -// That is, gLibDlChains should look like -// { 0, 2, 3, ... N, 0 } where N is the number -// of actual symbols, or nelems(gLibDlSymtab)-1 -// (since the first element of gLibDlSymtab is not -// a real symbol). +// A search of the hash table will look through gLibDlSymtab starting with index 1, then +// use gLibDlChains to find the next index to look at. gLibDlChains should be set up to +// walk through every element in gLibDlSymtab, and then end with 0 (sentinel value). // -// (see soinfo_elf_lookup()) +// That is, gLibDlChains should look like { 0, 2, 3, ... N, 0 } where N is the number +// of actual symbols, or nelems(gLibDlSymtab)-1 (since the first element of gLibDlSymtab is not +// a real symbol). (See soinfo_elf_lookup().) // -// Note that adding any new symbols here requires -// stubbing them out in libdl. +// Note that adding any new symbols here requires stubbing them out in libdl. static unsigned gLibDlBuckets[1] = { 1 }; #if defined(__arm__) -static unsigned gLibDlChains[9] = { 0, 2, 3, 4, 5, 6, 7, 8, 0 }; +static unsigned gLibDlChains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 0 }; #else -static unsigned gLibDlChains[8] = { 0, 2, 3, 4, 5, 6, 7, 0 }; +static unsigned gLibDlChains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 0 }; #endif // This is used by the dynamic linker. Every process gets these symbols for free. diff --git a/linker/linker.cpp b/linker/linker.cpp index f4e426d2d..f58e22263 100755 --- a/linker/linker.cpp +++ b/linker/linker.cpp @@ -50,13 +50,6 @@ #include "linker_environ.h" #include "linker_phdr.h" -/* Assume average path length of 64 and max 8 paths */ -#define LDPATH_BUFSIZE 512 -#define LDPATH_MAX 8 - -#define LDPRELOAD_BUFSIZE 512 -#define LDPRELOAD_MAX 8 - /* >>> IMPORTANT NOTE - READ ME BEFORE MODIFYING <<< * * Do NOT use malloc() and friends or pthread_*() code here. @@ -91,7 +84,7 @@ static soinfo* solist = &libdl_info; static soinfo* sonext = &libdl_info; static soinfo* somain; /* main process, always the one after libdl_info */ -static const char* const gSoPaths[] = { +static const char* const gDefaultLdPaths[] = { #if defined(__LP64__) "/vendor/lib64", "/system/lib64", @@ -102,6 +95,12 @@ static const char* const gSoPaths[] = { NULL }; +#define LDPATH_BUFSIZE (LDPATH_MAX*64) +#define LDPATH_MAX 8 + +#define LDPRELOAD_BUFSIZE (LDPRELOAD_MAX*64) +#define LDPRELOAD_MAX 8 + static char gLdPathsBuffer[LDPATH_BUFSIZE]; static const char* gLdPaths[LDPATH_MAX + 1]; @@ -708,7 +707,7 @@ static int open_library(const char* name) { // Otherwise we try LD_LIBRARY_PATH first, and fall back to the built-in well known paths. int fd = open_library_on_path(name, gLdPaths); if (fd == -1) { - fd = open_library_on_path(name, gSoPaths); + fd = open_library_on_path(name, gDefaultLdPaths); } return fd; } @@ -828,6 +827,10 @@ static int soinfo_unload(soinfo* si) { return 0; } +void do_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) { + snprintf(buffer, buffer_size, "%s:%s", gDefaultLdPaths[0], gDefaultLdPaths[1]); +} + void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path) { if (!get_AT_SECURE()) { parse_LD_LIBRARY_PATH(ld_library_path); diff --git a/linker/linker.h b/linker/linker.h index 9afd9e137..67a86abd4 100644 --- a/linker/linker.h +++ b/linker/linker.h @@ -196,6 +196,7 @@ struct soinfo { extern soinfo libdl_info; +void do_android_get_LD_LIBRARY_PATH(char*, size_t); void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path); soinfo* do_dlopen(const char* name, int flags); int do_dlclose(soinfo* si);