From dd654bf9ba1848bf9ed250f8ebaa5097c383dcf8 Mon Sep 17 00:00:00 2001
From: Allan McRae <allan@archlinux.org>
Date: Wed, 5 Feb 2014 21:19:51 +1000
Subject: Revert "Patch 2/4 of the effort to make TLS access
 async-signal-safe."

This reverts commit 1f33d36a8a9e78c81bed59b47f260723f56bb7e6.

Conflicts:
	elf/dl-misc.c

Also reverts the follow commits that were bug fixes to new code introduced
in the above commit:
063b2acbce83549df82ab30f5af573f1b9c4bd19
b627fdd58554bc36bd344dc40a8787c4b7a9cc46
e81c64bba13d2d8b2a4e53254a82cc80f27c8497
---
 elf/dl-misc.c | 142 ----------------------------------------------------------
 1 file changed, 142 deletions(-)

(limited to 'elf/dl-misc.c')

diff --git a/elf/dl-misc.c b/elf/dl-misc.c
index 043185a..8fd6710 100644
--- a/elf/dl-misc.c
+++ b/elf/dl-misc.c
@@ -19,7 +19,6 @@
 #include <assert.h>
 #include <fcntl.h>
 #include <ldsodefs.h>
-#include <libc-symbols.h>
 #include <limits.h>
 #include <link.h>
 #include <stdarg.h>
@@ -365,144 +364,3 @@ _dl_higher_prime_number (unsigned long int n)
 
   return *low;
 }
-
-/* To support accessing TLS variables from signal handlers, we need an
-   async signal safe memory allocator.  These routines are never
-   themselves invoked reentrantly (all calls to them are surrounded by
-   signal masks) but may be invoked concurrently from many threads.
-   The current implementation is not particularly performant nor space
-   efficient, but it will be used rarely (and only in binaries that use
-   dlopen.)  The API matches that of malloc() and friends.  */
-
-struct __signal_safe_allocator_header
-{
-  size_t size;
-  void *start;
-};
-
-static inline struct __signal_safe_allocator_header *
-ptr_to_signal_safe_allocator_header (void *ptr)
-{
-  return (struct __signal_safe_allocator_header *)
-    ((char *) (ptr) - sizeof (struct __signal_safe_allocator_header));
-}
-
-void *weak_function
-__signal_safe_memalign (size_t boundary, size_t size)
-{
-  struct __signal_safe_allocator_header *header;
-
-  if (boundary < sizeof (*header))
-    boundary = sizeof (*header);
-
-  /* Boundary must be a power of two.  */
-  if (!powerof2 (boundary))
-    return NULL;
-
-  size_t pg = GLRO (dl_pagesize);
-  size_t padded_size;
-  if (boundary <= pg)
-    {
-      /* We'll get a pointer certainly aligned to boundary, so just
-	 add one more boundary-sized chunk to hold the header.  */
-      padded_size = roundup (size, boundary) + boundary;
-    }
-  else
-    {
-      /* If we want K pages aligned to a J-page boundary, K+J+1 pages
-	 contains at least one such region that isn't directly at the start
-	 (so we can place the header.)	This is wasteful, but you're the one
-	 who wanted 64K-aligned TLS.  */
-      padded_size = roundup (size, pg) + boundary + pg;
-    }
-
-
-  size_t actual_size = roundup (padded_size, pg);
-  void *actual = mmap (NULL, actual_size, PROT_READ | PROT_WRITE,
-		       MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-  if (actual == MAP_FAILED)
-    return NULL;
-
-  if (boundary <= pg)
-    {
-      header = actual + boundary - sizeof (*header);
-    }
-  else
-    {
-      intptr_t actual_pg = ((intptr_t) actual) / pg;
-      intptr_t boundary_pg = boundary / pg;
-      intptr_t start_pg = actual_pg + boundary_pg;
-      start_pg -= start_pg % boundary_pg;
-      if (start_pg > (actual_pg + 1))
-	{
-	  int ret = munmap (actual, (start_pg - actual_pg - 1) * pg);
-	  assert (ret == 0);
-	  actual = (void *) ((start_pg - 1) * pg);
-	}
-      char *start = (void *) (start_pg * pg);
-      header = ptr_to_signal_safe_allocator_header (start);
-    }
-
-  header->size = actual_size;
-  header->start = actual;
-  void *ptr = header;
-  ptr += sizeof (*header);
-  if (((intptr_t) ptr) % boundary != 0)
-    _dl_fatal_printf ("__signal_safe_memalign produced incorrect alignment\n");
-  return ptr;
-}
-
-void * weak_function
-__signal_safe_malloc (size_t size)
-{
-  return __signal_safe_memalign (1, size);
-}
-
-void weak_function
-__signal_safe_free (void *ptr)
-{
-  if (ptr == NULL)
-    return;
-
-  struct __signal_safe_allocator_header *header
-    = ptr_to_signal_safe_allocator_header (ptr);
-  int ret = munmap (header->start, header->size);
-
-  assert (ret == 0);
-}
-
-void * weak_function
-__signal_safe_realloc (void *ptr, size_t size)
-{
-  if (size == 0)
-    {
-      __signal_safe_free (ptr);
-      return NULL;
-    }
-  if (ptr == NULL)
-    return __signal_safe_malloc (size);
-
-  struct __signal_safe_allocator_header *header
-    = ptr_to_signal_safe_allocator_header (ptr);
-  size_t old_size = header->size;
-  if (old_size - sizeof (*header) >= size)
-    return ptr;
-
-  void *new_ptr = __signal_safe_malloc (size);
-  if (new_ptr == NULL)
-    return NULL;
-
-  memcpy (new_ptr, ptr, old_size);
-  __signal_safe_free (ptr);
-
-  return new_ptr;
-}
-
-void * weak_function
-__signal_safe_calloc (size_t nmemb, size_t size)
-{
-  void *ptr = __signal_safe_malloc (nmemb * size);
-  if (ptr == NULL)
-    return NULL;
-  return memset (ptr, 0, nmemb * size);
-}
-- 
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