add arch-generic support for tlsdesc relocations to dynamic linker

this code is non-functional without further changes to link up the
arch-specific reloc types for tlsdesc and add asm implementations of
__tlsdesc_static and __tlsdesc_dynamic.

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 1e78a27531e06d7ca9bdc00d4645a53ac6639168..66bca5069bf103f432c689f8e0ae81e0043ea165 100644 (file)
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -2,6 +2,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
+#include <stddef.h>
 #include <string.h>
 #include <unistd.h>
 #include <stdint.h>
@@ -49,6 +50,11 @@ struct debug {
        void *base;
 };
 
+struct td_index {
+       size_t args[2];
+       struct td_index *next;
+};
+
 struct dso {
        unsigned char *base;
        char *name;
@@ -80,6 +86,7 @@ struct dso {
        void **new_dtv;
        unsigned char *new_tls;
        int new_dtv_idx, new_tls_idx;
+       struct td_index *td_index;
        struct dso *fini_next;
        char *shortname;
        char buf[];
@@ -105,6 +112,7 @@ enum {
        REL_DTPOFF,
        REL_TPOFF,
        REL_TPOFF_NEG,
+       REL_TLSDESC,
 };
 
 #include "reloc.h"
@@ -125,6 +133,7 @@ static jmp_buf *rtld_fail;
 static pthread_rwlock_t lock;
 static struct debug debug;
 static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
+static size_t static_tls_cnt;
 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 static long long builtin_tls[(sizeof(struct pthread) + 64)/sizeof(long long)];
 
@@ -258,6 +267,8 @@ static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 
 #define NO_INLINE_ADDEND (1<<REL_COPY | 1<<REL_GOT | 1<<REL_PLT)
 
+ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
+
 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 {
        unsigned char *base = dso->base;
@@ -351,6 +362,30 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
                        *reloc_addr = def.dso->tls_offset - tls_val + addend;
                        break;
 #endif
+               case REL_TLSDESC:
+                       if (stride<3) addend = reloc_addr[1];
+                       if (runtime && def.dso->tls_id >= static_tls_cnt) {
+                               struct td_index *new = malloc(sizeof *new);
+                               if (!new) error(errbuf, sizeof errbuf,
+                                       "Error relocating %s: cannot allocate TLSDESC for %s",
+                                       dso->name, sym ? name : "(local)" );
+                               new->next = dso->td_index;
+                               dso->td_index = new;
+                               new->args[0] = def.dso->tls_id;
+                               new->args[1] = tls_val + addend;
+                               reloc_addr[0] = (size_t)__tlsdesc_dynamic;
+                               reloc_addr[1] = (size_t)new;
+                       } else {
+                               reloc_addr[0] = (size_t)__tlsdesc_static;
+#ifdef TLS_ABOVE_TP
+                               reloc_addr[1] = tls_val + def.dso->tls_offset
+                                       + TPOFF_K + addend;
+#else
+                               reloc_addr[1] = tls_val - def.dso->tls_offset
+                                       + addend;
+#endif
+                       }
+                       break;
                }
        }
 }
@@ -1277,6 +1312,7 @@ void *__dynlink(int argc, char **argv)
                dprintf(2, "%s: Thread-local storage not supported by kernel.\n", argv[0]);
                _exit(127);
        }
+       static_tls_cnt = tls_cnt;
 
        if (ldso_fail) _exit(127);
        if (ldd_mode) _exit(0);
@@ -1332,6 +1368,11 @@ void *dlopen(const char *file, int mode)
                for (p=orig_tail->next; p; p=next) {
                        next = p->next;
                        munmap(p->map, p->map_len);
+                       while (p->td_index) {
+                               void *tmp = p->td_index->next;
+                               free(p->td_index);
+                               p->td_index = tmp;
+                       }
                        free(p->deps);
                        free(p);
                }

diff --git a/src/ldso/tlsdesc.c b/src/ldso/tlsdesc.c
new file mode 100644 (file)
index 0000000..031b5b8
--- /dev/null
+++ b/src/ldso/tlsdesc.c
@@ -0,0 +1,13 @@
+#ifdef SHARED
+
+#include <stddef.h>
+#include "libc.h"
+
+ptrdiff_t __tlsdesc_static()
+{
+       return 0;
+}
+
+weak_alias(__tlsdesc_static, __tlsdesc_dynamic);
+
+#endif