diff options
| -rw-r--r-- | elf/dl-open.c | 6 | ||||
| -rw-r--r-- | elf/dl-reloc.c | 39 | ||||
| -rw-r--r-- | sysdeps/generic/dl-tls.c | 12 | ||||
| -rw-r--r-- | sysdeps/generic/ldsodefs.h | 3 | ||||
| -rw-r--r-- | sysdeps/generic/libc-tls.c | 13 |
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. */ |