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-rw-r--r--elf/dl-open.c6
-rw-r--r--elf/dl-reloc.c39
-rw-r--r--sysdeps/generic/dl-tls.c12
-rw-r--r--sysdeps/generic/ldsodefs.h3
-rw-r--r--sysdeps/generic/libc-tls.c13
5 files changed, 63 insertions, 10 deletions
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 0e74996473..7dd18b7d97 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -34,6 +34,12 @@
#include <dl-dst.h>
+#ifdef SHARED
+/* 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 = 576;
+#endif
+
extern ElfW(Addr) _dl_sysdep_start (void **start_argptr,
void (*dl_main) (const ElfW(Phdr) *phdr,
ElfW(Word) phnum,
diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c
index 16017b3933..37c4be2049 100644
--- a/elf/dl-reloc.c
+++ b/elf/dl-reloc.c
@@ -35,6 +35,33 @@
#endif
+#ifdef USE_TLS
+/* We are trying to perform a static TLS relocation in MAP, but it was
+ dynamically loaded. This can only work if there is enough surplus in
+ the static TLS area already allocated for each running thread. If this
+ object's TLS segment is too big to fit, we return false. If it fits,
+ we set MAP->l_tls_offset and return true. */
+static bool
+allocate_static_tls (struct link_map *map)
+{
+ size_t offset = roundup (GL(dl_tls_static_used), map->l_tls_align);
+ if (offset + map->l_tls_blocksize > (GL(dl_tls_static_size)
+# if TLS_TCB_AT_TP
+ - TLS_TCB_SIZE
+# elif TLS_DTV_AT_TP
+ /* dl_tls_static_used includes the TCB at the beginning. */
+# else
+# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+ ))
+ return false;
+ map->l_tls_offset = offset;
+ GL(dl_tls_static_used) = offset + map->l_tls_blocksize;
+ return true;
+}
+#endif
+
+
void
_dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[],
int lazy, int consider_profiling)
@@ -159,9 +186,19 @@ _dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[],
l->l_lookup_cache.value = _lr; })) \
: l->l_addr)
+ /* This macro is used as a callback from elf_machine_rel{a,} when a
+ static TLS reloc is about to be performed. Since (in dl-load.c) we
+ permit dynamic loading of objects that might use such relocs, we
+ have to check whether each use is actually doable. If the object
+ whose TLS segment the reference resolves to was allocated space in
+ the static TLS block at startup, then it's ok. Otherwise, we make
+ an attempt to allocate it in surplus space on the fly. If that
+ can't be done, we fall back to the error that DF_STATIC_TLS is
+ intended to produce. */
#define CHECK_STATIC_TLS(map, sym_map) \
do { \
- if (__builtin_expect ((sym_map)->l_tls_offset == 0, 0)) \
+ if (__builtin_expect ((sym_map)->l_tls_offset == 0, 0) \
+ && !allocate_static_tls (sym_map)) \
{ \
errstring = N_("shared object cannot be dlopen()ed"); \
INTUSE(_dl_signal_error) (0, (map)->l_name, NULL, errstring); \
diff --git a/sysdeps/generic/dl-tls.c b/sysdeps/generic/dl-tls.c
index b92fecbe27..2c68a251b6 100644
--- a/sysdeps/generic/dl-tls.c
+++ b/sysdeps/generic/dl-tls.c
@@ -31,6 +31,10 @@
# include <dl-tls.h>
# include <ldsodefs.h>
+/* Amount of excess space to allocate in the static TLS area
+ to allow dynamic loading of modules defining IE-model TLS data. */
+# define TLS_STATIC_SURPLUS 64
+
/* Value used for dtv entries for which the allocation is delayed. */
# define TLS_DTV_UNALLOCATED ((void *) -1l)
@@ -150,7 +154,9 @@ _dl_determine_tlsoffset (void)
// XXX would invalidate the offsets the linker creates for the LE
// XXX model.
- GL(dl_tls_static_size) = offset + TLS_TCB_SIZE;
+ GL(dl_tls_static_used) = offset;
+ GL(dl_tls_static_size) = roundup (offset + TLS_STATIC_SURPLUS + TLS_TCB_SIZE,
+ TLS_TCB_ALIGN);
# elif TLS_DTV_AT_TP
/* The TLS blocks start right after the TCB. */
offset = TLS_TCB_SIZE;
@@ -186,7 +192,9 @@ _dl_determine_tlsoffset (void)
offset += prev_size;
}
- GL(dl_tls_static_size) = offset;
+ GL(dl_tls_static_used) = offset;
+ GL(dl_tls_static_size) = roundup (offset + TLS_STATIC_SURPLUS,
+ TLS_TCB_ALIGN);
# else
# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
# endif
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 92fe6191b9..8321b96b5f 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -326,9 +326,6 @@ struct rtld_global
/* Number of additional slots in the dtv allocated. */
# define DTV_SURPLUS (14)
-/* The value of _dl_tls_static_size is kept a multiple of this. */
-# define TLS_STATIC_MIN (1024)
-
/* Initial dtv of the main thread, not allocated with normal malloc. */
EXTERN void *_dl_initial_dtv;
/* Generation counter for the dtv. */
diff --git a/sysdeps/generic/libc-tls.c b/sysdeps/generic/libc-tls.c
index 64fe7c3ad7..26fd6e09c9 100644
--- a/sysdeps/generic/libc-tls.c
+++ b/sysdeps/generic/libc-tls.c
@@ -182,12 +182,17 @@ __libc_setup_tls (size_t tcbsize, size_t tcbalign)
GL(dl_tls_max_dtv_idx) = 1;
GL(dl_tls_dtv_slotinfo_list) = &static_slotinfo.si;
- /* That is the size of the TLS memory for this object. */
- GL(dl_tls_static_size) = (roundup (memsz, align ?: 1)
+ memsz = roundup (memsz, align ?: 1);
# if TLS_TCB_AT_TP
- + tcbsize
+ memsz += tcbsize;
# endif
- );
+
+ /* That is the size of the TLS memory for this object. The initialized
+ value of _dl_tls_static_size is provided by dl-open.c to request some
+ surplus that permits dynamic loading of modules with IE-model TLS. */
+ GL(dl_tls_static_size) = roundup (memsz + GL(dl_tls_static_size),
+ TLS_TCB_ALIGN);
+ GL(dl_tls_static_used) = memsz;
/* The alignment requirement for the static TLS block. */
GL(dl_tls_static_align) = MAX (TLS_TCB_ALIGN, max_align);
/* Number of elements in the static TLS block. */