Description: x86/entry/64: Don't use IST entry for #BP stack
References:
 http://www.openwall.com/lists/oss-security/2018/05/08/4
 https://marc.info/?l=linux-kernel&m=152580052406931
Notes:
Bugs:
upstream: released (4.16-rc7) [d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9]
4.9-upstream-stable: released (4.9.91) [3681c24a7d096b092cf05c8338adbb9019bb1536]
3.16-upstream-stable: released (3.16.57) [82dd4b92ebcb628723cf47156263503beaa573a6, 45dc1e88fb5a728c1f2186edafccf6581c9c99b8]
3.2-upstream-stable: released (3.2.102) [1a2ce896855bae80c079ce45d102633546a6a87f, 5a1f747c7f58e9820ebfb6b4811934a1f48bc4fe]
sid: released (4.15.17-1)
4.9-stretch-security: released (4.9.88-1+deb9u1) [bugfix/x86/x86-entry-64-Don-t-use-IST-entry-for-BP-stack.patch]
3.16-jessie-security: released (3.16.56-1+deb8u1) [bugfix/x86/x86-entry-64-Don-t-use-IST-entry-for-BP-stack.patch]
3.2-wheezy-security: released (3.2.102-1)