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authorPaul Pluzhnikov <ppluzhnikov@google.com>2013-12-18 16:24:19 -0800
committerPaul Pluzhnikov <ppluzhnikov@google.com>2013-12-18 16:24:19 -0800
commit35e8f7ab94c910659de9d507aa0f3e1f8973d914 (patch)
treefca3c69ec2085dbeee15673472350c9067ddf4f7 /elf
parent69a17d9d245dc3551792e95e1823cc2d877592f3 (diff)
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Patch 3/4 of the effort to make TLS access async-signal-safe.
Factor out _dl_clear_dtv.

2013-12-18  Andrew Hunter  <ahh@google.com>

	* elf/Versions (ld): Add _dl_clear_dtv.
	* sysdeps/generic/ldsodefs.h (_dl_clear_dtv): New prototype.
	* elf/dl-tls.c (_dl_clear_dtv): New function.
	* nptl/allocatestack.c (get_cached_stack): Call _dl_clear_dtv.
Diffstat (limited to 'elf')
-rw-r--r--elf/Versions1
-rw-r--r--elf/dl-tls.c12
2 files changed, 13 insertions, 0 deletions
diff --git a/elf/Versions b/elf/Versions
index 238399232d..01b7a59d5e 100644
--- a/elf/Versions
+++ b/elf/Versions
@@ -53,6 +53,7 @@ ld {
     _dl_allocate_tls; _dl_allocate_tls_init;
     _dl_argv; _dl_find_dso_for_object; _dl_get_tls_static_info;
     _dl_deallocate_tls; _dl_make_stack_executable; _dl_out_of_memory;
+    _dl_clear_dtv;
     _dl_rtld_di_serinfo; _dl_starting_up; _dl_tls_setup;
     _rtld_global; _rtld_global_ro;
 
diff --git a/elf/dl-tls.c b/elf/dl-tls.c
index 576d9a1465..c60a6b7b80 100644
--- a/elf/dl-tls.c
+++ b/elf/dl-tls.c
@@ -463,6 +463,18 @@ _dl_allocate_tls (void *mem)
 }
 rtld_hidden_def (_dl_allocate_tls)
 
+void
+internal_function
+_dl_clear_dtv (dtv_t *dtv)
+{
+  for (size_t cnt = 0; cnt < dtv[-1].counter; ++cnt)
+    if (! dtv[1 + cnt].pointer.is_static
+	&& dtv[1 + cnt].pointer.val != TLS_DTV_UNALLOCATED)
+      free (dtv[1 + cnt].pointer.val);
+  memset (dtv, '\0', (dtv[-1].counter + 1) * sizeof (dtv_t));
+}
+
+rtld_hidden_def (_dl_clear_dtv)
 
 #ifndef SHARED
 extern dtv_t _dl_static_dtv[];