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Diffstat (limited to 'ldso/libdl/libdl.c')
-rw-r--r--ldso/libdl/libdl.c325
1 files changed, 322 insertions, 3 deletions
diff --git a/ldso/libdl/libdl.c b/ldso/libdl/libdl.c
index 8646a74d8..7f7f70bd9 100644
--- a/ldso/libdl/libdl.c
+++ b/ldso/libdl/libdl.c
@@ -35,13 +35,25 @@
#include <string.h> /* Needed for 'strstr' prototype' */
#include <stdbool.h>
+#ifdef __UCLIBC_HAS_TLS__
+#include <tls.h>
+#endif
+
+#if USE_TLS
+#include <ldsodefs.h>
+extern void (*_dl_init_static_tls) (struct link_map *);
+extern void _dl_add_to_slotinfo(struct link_map *l);
+#endif
#ifdef SHARED
+# if USE_TLS
+# include <dl-tls.h>
+extern struct link_map *_dl_update_slotinfo(unsigned long int req_modid);
+# endif
/* When libdl is loaded as a shared library, we need to load in
* and use a pile of symbols from ldso... */
-extern char *_dl_find_hash(const char *, struct dyn_elf *, struct elf_resolve *, int);
extern struct elf_resolve * _dl_load_shared_library(int, struct dyn_elf **,
struct elf_resolve *, char *, int);
extern int _dl_fixup(struct dyn_elf *rpnt, int lazy);
@@ -50,6 +62,7 @@ extern int _dl_errno;
extern struct dyn_elf *_dl_symbol_tables;
extern struct dyn_elf *_dl_handles;
extern struct elf_resolve *_dl_loaded_modules;
+extern void _dl_free (void *__ptr);
extern struct r_debug *_dl_debug_addr;
extern unsigned long _dl_error_number;
extern void *(*_dl_malloc_function)(size_t);
@@ -83,7 +96,7 @@ char *_dl_debug_reloc = NULL;
char *_dl_debug_detail = NULL;
char *_dl_debug_nofixups = NULL;
char *_dl_debug_bindings = NULL;
-int _dl_debug_file = NULL;
+int _dl_debug_file = 2;
#endif
const char *_dl_progname = ""; /* Program name */
void *(*_dl_malloc_function)(size_t);
@@ -97,6 +110,15 @@ struct r_debug *_dl_debug_addr = NULL;
#include "../ldso/dl-array.c"
#include "../ldso/dl-debug.c"
+
+
+# if USE_TLS
+/*
+ * Giving this initialized value preallocates some surplus bytes in the
+ * static TLS area, see __libc_setup_tls (libc-tls.c).
+ */
+size_t _dl_tls_static_size = 2048;
+# endif
#include LDSO_ELFINTERP
#include "../ldso/dl-hash.c"
#define _dl_trace_loaded_objects 0
@@ -133,6 +155,7 @@ static const char *const dl_error_names[] = {
"Not an ELF shared library",
"Unable to mmap file",
"No dynamic section",
+ "Library contains unsupported TLS",
#ifdef ELF_USES_RELOCA
"Unable to process REL relocs",
#else
@@ -142,6 +165,111 @@ static const char *const dl_error_names[] = {
"Unable to resolve symbol"
};
+
+#if USE_TLS
+#ifdef SHARED
+/*
+ * Systems which do not have tls_index also probably have to define
+ * DONT_USE_TLS_INDEX.
+ */
+
+# ifndef __TLS_GET_ADDR
+# define __TLS_GET_ADDR __tls_get_addr
+# endif
+
+/*
+ * Return the symbol address given the map of the module it is in and
+ * the symbol record. This is used in dl-sym.c.
+ */
+static void *
+internal_function
+_dl_tls_symaddr(struct link_map *map, const Elf32_Addr st_value)
+{
+# ifndef DONT_USE_TLS_INDEX
+ tls_index tmp =
+ {
+ .ti_module = map->l_tls_modid,
+ .ti_offset = st_value
+ };
+
+ return __TLS_GET_ADDR (&tmp);
+# else
+ return __TLS_GET_ADDR (map->l_tls_modid, st_value);
+# endif
+}
+#endif
+
+/* Returns true we an non-empty was found. */
+static bool
+remove_slotinfo(size_t idx, struct dtv_slotinfo_list *listp, size_t disp,
+ bool should_be_there)
+{
+ if(idx - disp >= listp->len)
+ {
+ if(listp->next == NULL)
+ {
+ /*
+ * The index is not actually valid in the slotinfo list,
+ * because this object was closed before it was fully set
+ * up due to some error.
+ */
+ _dl_assert(!should_be_there);
+ }
+ else
+ {
+ if(remove_slotinfo(idx, listp->next, disp + listp->len,
+ should_be_there))
+ return true;
+
+ /*
+ * No non-empty entry. Search from the end of this element's
+ * slotinfo array.
+ */
+ idx = disp + listp->len;
+ }
+ }
+ else
+ {
+ struct link_map *old_map = listp->slotinfo[idx - disp].map;
+
+ /*
+ * The entry might still be in its unused state if we are
+ * closing an object that wasn't fully set up.
+ */
+ if(__builtin_expect(old_map != NULL, 1))
+ {
+ _dl_assert(old_map->l_tls_modid == idx);
+
+ /* Mark the entry as unused. */
+ listp->slotinfo[idx - disp].gen = _dl_tls_generation + 1;
+ listp->slotinfo[idx - disp].map = NULL;
+ }
+
+ /*
+ * If this is not the last currently used entry no need to
+ * look further.
+ */
+ if (idx != _dl_tls_max_dtv_idx)
+ return true;
+ }
+
+ while(idx - disp > (disp == 0 ? 1 + _dl_tls_static_nelem : 0))
+ {
+ --idx;
+
+ if(listp->slotinfo[idx - disp].map != NULL)
+ {
+ /* Found a new last used index. */
+ _dl_tls_max_dtv_idx = idx;
+ return true;
+ }
+ }
+
+ /* No non-entry in this list element. */
+ return false;
+}
+#endif
+
void dl_cleanup(void) __attribute__ ((destructor));
void dl_cleanup(void)
{
@@ -165,6 +293,9 @@ void *dlopen(const char *libname, int flag)
unsigned int nlist, i;
struct elf_resolve **init_fini_list;
static bool _dl_init;
+#if USE_TLS
+ bool any_tls = false;
+#endif
/* A bit of sanity checking... */
if (!(flag & (RTLD_LAZY|RTLD_NOW))) {
@@ -396,6 +527,52 @@ void *dlopen(const char *libname, int flag)
}
/* TODO: Should we set the protections of all pages back to R/O now ? */
+
+#if USE_TLS
+
+ for (i=0; i < nlist; i++) {
+ struct elf_resolve *tmp_tpnt = init_fini_list[i];
+ /* Only add TLS memory if this object is loaded now and
+ therefore is not yet initialized. */
+
+ if (!(tmp_tpnt->init_flag & INIT_FUNCS_CALLED)
+ /* Only if the module defines thread local data. */
+ && __builtin_expect (tmp_tpnt->l_tls_blocksize > 0, 0)) {
+
+ /* Now that we know the object is loaded successfully add
+ modules containing TLS data to the slot info table. We
+ might have to increase its size. */
+ _dl_add_to_slotinfo ((struct link_map*)tmp_tpnt);
+
+ /* It is the case in which we couldn't perform TLS static
+ initialization at relocation time, and we delayed it until
+ the relocation has been completed. */
+
+ if (tmp_tpnt->l_need_tls_init) {
+ tmp_tpnt->l_need_tls_init = 0;
+# ifdef SHARED
+ /* Update the slot information data for at least the
+ generation of the DSO we are allocating data for. */
+ _dl_update_slotinfo (tmp_tpnt->l_tls_modid);
+# endif
+
+ _dl_init_static_tls((struct link_map*)tmp_tpnt);
+ _dl_assert (tmp_tpnt->l_need_tls_init == 0);
+ }
+
+ /* We have to bump the generation counter. */
+ any_tls = true;
+ }
+ }
+
+ /* Bump the generation number if necessary. */
+ if (any_tls && __builtin_expect (++_dl_tls_generation == 0, 0)) {
+ _dl_debug_early("TLS generation counter wrapped! Please report this.");
+ _dl_exit(30);
+ }
+
+#endif
+
/* Notify the debugger we have added some objects. */
if (_dl_debug_addr) {
dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
@@ -445,6 +622,7 @@ void *dlsym(void *vhandle, const char *name)
ElfW(Addr) from;
struct dyn_elf *rpnt;
void *ret;
+ struct elf_resolve *tls_tpnt = NULL;
/* Nastiness to support underscore prefixes. */
#ifdef __UCLIBC_UNDERSCORES__
char tmp_buf[80];
@@ -499,7 +677,15 @@ void *dlsym(void *vhandle, const char *name)
tpnt = NULL;
if (handle == _dl_symbol_tables)
tpnt = handle->dyn; /* Only search RTLD_GLOBAL objs if global object */
- ret = _dl_find_hash(name2, handle, tpnt, ELF_RTYPE_CLASS_DLSYM);
+ ret = _dl_find_hash(name2, handle, NULL, 0, &tls_tpnt);
+
+#if defined USE_TLS && defined SHARED
+ if(tls_tpnt) {
+ /* The found symbol is a thread-local storage variable.
+ Return the address for to the current thread. */
+ ret = _dl_tls_symaddr ((struct link_map *)tls_tpnt, (Elf32_Addr)ret);
+ }
+#endif
/*
* Nothing found.
@@ -532,6 +718,12 @@ static int do_dlclose(void *vhandle, int need_fini)
struct dyn_elf *handle;
unsigned int end;
unsigned int i, j;
+#if USE_TLS
+ bool any_tls = false;
+ size_t tls_free_start = NO_TLS_OFFSET;
+ size_t tls_free_end = NO_TLS_OFFSET;
+ struct link_map *tls_lmap;
+#endif
handle = (struct dyn_elf *) vhandle;
if (handle == _dl_symbol_tables)
@@ -587,6 +779,118 @@ static int do_dlclose(void *vhandle, int need_fini)
if (end < ppnt->p_vaddr + ppnt->p_memsz)
end = ppnt->p_vaddr + ppnt->p_memsz;
}
+
+#if USE_TLS
+ /* Do the cast to make things easy. */
+ tls_lmap = (struct link_map *) tpnt;
+
+ /* Remove the object from the dtv slotinfo array if it uses TLS. */
+ if (__builtin_expect (tls_lmap->l_tls_blocksize > 0, 0))
+ {
+ any_tls = true;
+
+ if (_dl_tls_dtv_slotinfo_list != NULL
+ && ! remove_slotinfo (tls_lmap->l_tls_modid,
+ _dl_tls_dtv_slotinfo_list, 0,
+ (tpnt->init_flag & INIT_FUNCS_CALLED)))
+ /* All dynamically loaded modules with TLS are unloaded. */
+ _dl_tls_max_dtv_idx = _dl_tls_static_nelem;
+
+ if (tls_lmap->l_tls_offset != NO_TLS_OFFSET)
+ {
+ /*
+ * Collect a contiguous chunk built from the objects in
+ * this search list, going in either direction. When the
+ * whole chunk is at the end of the used area then we can
+ * reclaim it.
+ */
+# if defined(TLS_TCB_AT_TP)
+ if (tls_free_start == NO_TLS_OFFSET
+ || (size_t) tls_lmap->l_tls_offset == tls_free_start)
+ {
+ /* Extend the contiguous chunk being reclaimed. */
+ tls_free_start
+ = tls_lmap->l_tls_offset -
+ tls_lmap->l_tls_blocksize;
+
+ if (tls_free_end == NO_TLS_OFFSET)
+ tls_free_end = tls_lmap->l_tls_offset;
+ }
+ else if (tls_lmap->l_tls_offset - tls_lmap->l_tls_blocksize
+ == tls_free_end)
+ /* Extend the chunk backwards. */
+ tls_free_end = tls_lmap->l_tls_offset;
+ else
+ {
+ /*
+ * This isn't contiguous with the last chunk freed.
+ * One of them will be leaked unless we can free
+ * one block right away.
+ */
+ if (tls_free_end == _dl_tls_static_used)
+ {
+ _dl_tls_static_used = tls_free_start;
+ tls_free_end = tls_lmap->l_tls_offset;
+ tls_free_start
+ = tls_free_end - tls_lmap->l_tls_blocksize;
+ }
+ else if ((size_t) tls_lmap->l_tls_offset
+ == _dl_tls_static_used)
+ _dl_tls_static_used = tls_lmap->l_tls_offset -
+ tls_lmap->l_tls_blocksize;
+ else if (tls_free_end < (size_t) tls_lmap->l_tls_offset)
+ {
+ /*
+ * We pick the later block. It has a chance
+ * to be freed.
+ */
+ tls_free_end = tls_lmap->l_tls_offset;
+ tls_free_start = tls_free_end -
+ tls_lmap->l_tls_blocksize;
+ }
+ }
+# elif defined(TLS_DTV_AT_TP)
+ if ((size_t) tls_lmap->l_tls_offset == tls_free_end)
+ /* Extend the contiguous chunk being reclaimed. */
+ tls_free_end -= tls_lmap->l_tls_blocksize;
+ else if (tls_lmap->l_tls_offset + tls_lmap->l_tls_blocksize
+ == tls_free_start)
+ /* Extend the chunk backwards. */
+ tls_free_start = tls_lmap->l_tls_offset;
+ else
+ {
+ /*
+ * This isn't contiguous with the last chunk
+ * freed. One of them will be leaked.
+ */
+ if (tls_free_end == _dl_tls_static_used)
+ _dl_tls_static_used = tls_free_start;
+ tls_free_start = tls_lmap->l_tls_offset;
+ tls_free_end = tls_free_start +
+ tls_lmap->l_tls_blocksize;
+ }
+# else
+# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+ } else {
+
+#define TLS_DTV_UNALLOCATED ((void *) -1l)
+
+ dtv_t *dtv = THREAD_DTV ();
+
+ _dl_assert(!(dtv[tls_lmap->l_tls_modid].pointer.is_static));
+ if(dtv[tls_lmap->l_tls_modid].pointer.val != TLS_DTV_UNALLOCATED) {
+ /* Note that free is called for NULL is well. We
+ deallocate even if it is this dtv entry we are
+ supposed to load. The reason is that we call
+ memalign and not malloc. */
+ _dl_free (dtv[tls_lmap->l_tls_modid].pointer.val);
+ dtv[tls_lmap->l_tls_modid].pointer.val = TLS_DTV_UNALLOCATED;
+ }
+ }
+ }
+#endif
+
DL_LIB_UNMAP (tpnt, end);
/* Free elements in RTLD_LOCAL scope list */
for (runp = tpnt->rtld_local; runp; runp = tmp) {
@@ -638,6 +942,21 @@ static int do_dlclose(void *vhandle, int need_fini)
free(handle->init_fini.init_fini);
free(handle);
+#if USE_TLS
+ /* If we removed any object which uses TLS bump the generation counter. */
+ if (any_tls)
+ {
+ if (__builtin_expect (++_dl_tls_generation == 0, 0))
+ {
+ _dl_debug_early ("TLS generation counter wrapped! Please report to the uClibc mailing list.\n");
+ _dl_exit(30);
+ }
+
+ if (tls_free_end == _dl_tls_static_used)
+ _dl_tls_static_used = tls_free_start;
+ }
+#endif
+
if (_dl_debug_addr) {
dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
if (dl_brk != NULL) {
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-26 04:36:28 +0000