src/patches/glibc/glibc-rh1291270.patch

   1 Description: Allow loading more libraries with static TLS.
   2 Author: Carlos O'Donell <codonell@redhat.com>
   3 Origin: PATCH
   4 Bug-RHEL: #1291270 (rhel-6.7.z), #1198802 (rhel-6.8), #1202952 (rhel-7.2)
   5 Bug-Fedora: #1124987 (F21)
   6 Bug-Upstream: #17090, #17620, #17621, #17628 (2.22)
   7 Upstream status: not-needed
   8 #
   9 # The correct fix for this is already upstream and involves
  10 # changing the heuristics for DTV slot increases. In RHEL6
  11 # we take the conservative approach and provide a larger
  12 # slot surplus. This matches what was done in Fedora 21 before
  13 # we had the upstream fix: f8aeae347377f3dfa8cbadde057adf1827fb1d44.
  14 # In RHEL7 we have the upstream fix. This is fixed upstream as of
  15 # glibc 2.22.
  16 #
  17 Index: glibc-2.12-2-gc4ccff1/sysdeps/generic/ldsodefs.h
  18 ===================================================================
  19 --- glibc-2.12-2-gc4ccff1.orig/sysdeps/generic/ldsodefs.h
  20 +++ glibc-2.12-2-gc4ccff1/sysdeps/generic/ldsodefs.h
  21 @@ -496,8 +496,18 @@ struct rtld_global
  22     have to iterate beyond the first element in the slotinfo list.  */
  23  #define TLS_SLOTINFO_SURPLUS (62)
  24
  25 -/* Number of additional slots in the dtv allocated.  */
  26 -#define DTV_SURPLUS    (14)
  27 +/* Number of additional allocated dtv slots.  This was initially
  28 +   14, but problems with python, MESA, and X11's uses of static TLS meant
  29 +   that most distributions were very close to this limit when they loaded
  30 +   dynamically interpreted languages that used graphics. The simplest
  31 +   solution was to roughly double the number of slots. The actual static
  32 +   image space usage was relatively small, for example in MESA you
  33 +   had only two dispatch pointers for a total of 16 bytes.  If we hit up
  34 +   against this limit again we should start a campaign with the
  35 +   distributions to coordinate the usage of static TLS.  Any user of this
  36 +   resource is effectively coordinating a global resource since this
  37 +   surplus is allocated for each thread at startup.  */
  38 +#define DTV_SURPLUS    (32)
  39
  40    /* Initial dtv of the main thread, not allocated with normal malloc.  */
  41    EXTERN void *_dl_initial_dtv;