diff options
Diffstat (limited to 'main/libc0.9.32/0001-libdl-rudimentary-locking-for-dlopen-dlsym-dlclose.patch')
| -rw-r--r-- | main/libc0.9.32/0001-libdl-rudimentary-locking-for-dlopen-dlsym-dlclose.patch | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/main/libc0.9.32/0001-libdl-rudimentary-locking-for-dlopen-dlsym-dlclose.patch b/main/libc0.9.32/0001-libdl-rudimentary-locking-for-dlopen-dlsym-dlclose.patch new file mode 100644 index 0000000000..d406f030d6 --- /dev/null +++ b/main/libc0.9.32/0001-libdl-rudimentary-locking-for-dlopen-dlsym-dlclose.patch @@ -0,0 +1,152 @@ +From 521807eb4d18c5e693f91ad53cb277c76aab8686 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi> +Date: Thu, 24 Mar 2011 13:24:32 +0200 +Subject: [PATCH] libdl: rudimentary locking for dlopen/dlsym/dlclose +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +This implements big-dlfcn lock to allow multithreaded usage of +dlopen/dlsym/dlclose. We should really clean up the dl code so +we can use more fine grained locking or even RCU where appropriate. +But at least we won't crash now. + +Signed-off-by: Timo Teräs <timo.teras@iki.fi> +--- + TODO | 1 + + ldso/libdl/libdl.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++---- + 2 files changed, 50 insertions(+), 5 deletions(-) + +diff --git a/TODO b/TODO +index ae305a5..95cabd5 100644 +--- a/TODO ++++ b/TODO +@@ -101,6 +101,7 @@ TODO list for AFTER the uClibc 1.0.0 release: + *) run 'nm -D --size-sort -t d libuClibc-0.9.26.so' and work on the + biggest things (i.e. stuff at the end of the list) to make + them smaller. ++ *) Fix dlopen/dlsym/dlclose locking to more fine grained or use RCU + <more wishlist items here> + + +diff --git a/ldso/libdl/libdl.c b/ldso/libdl/libdl.c +index 68cd579..e007f54 100644 +--- a/ldso/libdl/libdl.c ++++ b/ldso/libdl/libdl.c +@@ -34,6 +34,7 @@ + #include <stdio.h> + #include <string.h> /* Needed for 'strstr' prototype' */ + #include <stdbool.h> ++#include <bits/uClibc_mutex.h> + + #ifdef __UCLIBC_HAS_TLS__ + #include <tls.h> +@@ -44,6 +45,10 @@ + extern void _dl_add_to_slotinfo(struct link_map *l); + #endif + ++/* TODO: get rid of global lock and use more finegrained locking, or ++ * perhaps RCU for the global structures */ ++__UCLIBC_MUTEX_STATIC(_dl_mutex, PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP); ++ + #ifdef SHARED + # if defined(USE_TLS) && USE_TLS + # include <dl-tls.h> +@@ -271,7 +276,7 @@ void dl_cleanup(void) + } + } + +-void *dlopen(const char *libname, int flag) ++static void *do_dlopen(const char *libname, int flag) + { + struct elf_resolve *tpnt, *tfrom; + struct dyn_elf *dyn_chain, *rpnt = NULL, *dyn_ptr, *relro_ptr, *handle; +@@ -605,7 +610,18 @@ oops: + return NULL; + } + +-void *dlsym(void *vhandle, const char *name) ++void *dlopen(const char *libname, int flag) ++{ ++ void *ret; ++ ++ __UCLIBC_MUTEX_CONDITIONAL_LOCK(_dl_mutex, 1); ++ ret = do_dlopen(libname, flag); ++ __UCLIBC_MUTEX_CONDITIONAL_UNLOCK(_dl_mutex, 1); ++ ++ return ret; ++} ++ ++static void *do_dlsym(void *vhandle, const char *name, void *caller_address) + { + struct elf_resolve *tpnt, *tfrom; + struct dyn_elf *handle; +@@ -653,7 +669,7 @@ void *dlsym(void *vhandle, const char *name) + * dynamic loader itself, as it doesn't know + * how to properly treat it. + */ +- from = (ElfW(Addr)) __builtin_return_address(0); ++ from = (ElfW(Addr)) caller_address; + + tfrom = NULL; + for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next) { +@@ -690,6 +706,17 @@ out: + return ret; + } + ++void *dlsym(void *vhandle, const char *name) ++{ ++ void *ret; ++ ++ __UCLIBC_MUTEX_CONDITIONAL_LOCK(_dl_mutex, 1); ++ ret = do_dlsym(vhandle, name, __builtin_return_address(0)); ++ __UCLIBC_MUTEX_CONDITIONAL_UNLOCK(_dl_mutex, 1); ++ ++ return ret; ++} ++ + #if 0 + void *dlvsym(void *vhandle, const char *name, const char *version) + { +@@ -957,7 +984,13 @@ static int do_dlclose(void *vhandle, int need_fini) + + int dlclose(void *vhandle) + { +- return do_dlclose(vhandle, 1); ++ int ret; ++ ++ __UCLIBC_MUTEX_CONDITIONAL_LOCK(_dl_mutex, 1); ++ ret = do_dlclose(vhandle, 1); ++ __UCLIBC_MUTEX_CONDITIONAL_UNLOCK(_dl_mutex, 1); ++ ++ return ret; + } + + char *dlerror(void) +@@ -1004,7 +1037,7 @@ int dlinfo(void) + return 0; + } + +-int dladdr(const void *__address, Dl_info * __info) ++static int do_dladdr(const void *__address, Dl_info * __info) + { + struct elf_resolve *pelf; + struct elf_resolve *rpnt; +@@ -1108,3 +1141,14 @@ int dladdr(const void *__address, Dl_info * __info) + } + } + #endif ++ ++int dladdr(const void *__address, Dl_info * __info) ++{ ++ int ret; ++ ++ __UCLIBC_MUTEX_CONDITIONAL_LOCK(_dl_mutex, 1); ++ ret = do_dladdr(__address, __info); ++ __UCLIBC_MUTEX_CONDITIONAL_UNLOCK(_dl_mutex, 1); ++ ++ return ret; ++} +-- +1.7.1 + |