From b66a1357266a43174bd1ed42a902875f86cebb49 Mon Sep 17 00:00:00 2001
From: Kyle McMartin <kyle@mcmartin.ca>
Date: Fri, 20 Jun 2014 11:49:56 -0400
Subject: [PATCH] AArch64: Save & restore NZCV (flags) upon entry to
 _dl_tlsdesc_dynamic

  in order to work around GCC reordering compares across the TLS
  descriptor sequence (GCC PR61545.) Committing a (temporary) fix here
  allows us to avoid rebuilding the world with gcc 4.9.0-11.fc21.
---
 ...4-workaround-nzcv-clobber-in-tlsdesc.patch | 33 +++++++++++++++++++
 glibc.spec                                    | 12 +++++--
 2 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 glibc-aarch64-workaround-nzcv-clobber-in-tlsdesc.patch

diff --git a/glibc-aarch64-workaround-nzcv-clobber-in-tlsdesc.patch b/glibc-aarch64-workaround-nzcv-clobber-in-tlsdesc.patch
new file mode 100644
index 0000000..ed628ac
--- /dev/null
+++ b/glibc-aarch64-workaround-nzcv-clobber-in-tlsdesc.patch
@@ -0,0 +1,33 @@
+diff --git a/sysdeps/aarch64/dl-tlsdesc.S b/sysdeps/aarch64/dl-tlsdesc.S
+index ded5471..7d28496 100644
+--- a/sysdeps/aarch64/dl-tlsdesc.S
++++ b/sysdeps/aarch64/dl-tlsdesc.S
+@@ -140,7 +140,7 @@ _dl_tlsdesc_undefweak:
+ 	cfi_startproc
+ 	.align 2
+ _dl_tlsdesc_dynamic:
+-# define NSAVEXREGPAIRS 2
++# define NSAVEXREGPAIRS 3
+ 	stp	x29, x30, [sp,#-(32+16*NSAVEXREGPAIRS)]!
+ 	cfi_adjust_cfa_offset (32+16*NSAVEXREGPAIRS)
+ 	mov	x29, sp
+@@ -151,6 +151,10 @@ _dl_tlsdesc_dynamic:
+ 	stp	x1,  x2, [sp, #32+16*0]
+ 	stp	x3,  x4, [sp, #32+16*1]
+ 
++	/* Work around GCC rescheduling compares across tlsdesc calls.  */
++	mrs	x30, nzcv
++	stp	xzr, x30, [sp, #32+16*2]
++
+ 	mrs	x4, tpidr_el0
+ 	ldr	x1, [x0,#8]
+ 	ldr	x0, [x4]
+@@ -169,6 +173,8 @@ _dl_tlsdesc_dynamic:
+ 1:
+ 	ldp	 x1,  x2, [sp, #32+16*0]
+ 	ldp	 x3,  x4, [sp, #32+16*1]
++	ldp	 xzr, x30, [sp, #32+16*2]
++	msr	 nzcv, x30
+ 
+ 	ldp	x29, x30, [sp], #(32+16*NSAVEXREGPAIRS)
+ 	cfi_adjust_cfa_offset (32+16*NSAVEXREGPAIRS)
diff --git a/glibc.spec b/glibc.spec
index 0d89c72..b4d39eb 100644
--- a/glibc.spec
+++ b/glibc.spec
@@ -1,6 +1,6 @@
 %define glibcsrcdir  glibc-2.19-591-ga729111
 %define glibcversion 2.19.90
-%define glibcrelease 21%{?dist}
+%define glibcrelease 22%{?dist}
 # Pre-release tarballs are pulled in from git using a command that is
 # effectively:
 #
@@ -219,7 +219,8 @@ Patch2027: %{name}-rh819430.patch
 
 Patch2031: %{name}-rh1070416.patch
 
-Patch2033: glibc-aarch64-tls-fixes.patch
+Patch2033: %{name}-aarch64-tls-fixes.patch
+Patch2034: %{name}-aarch64-workaround-nzcv-clobber-in-tlsdesc.patch
 
 ##############################################################################
 # End of glibc patches.
@@ -550,6 +551,7 @@ package or when debugging this package.
 %patch2031 -p1
 %patch0047 -p1
 %patch2033 -p1
+%patch2034 -p1
 
 ##############################################################################
 # %%prep - Additional prep required...
@@ -1639,6 +1641,12 @@ rm -f *.filelist*
 %endif
 
 %changelog
+* Fri Jun 20 2014 Kyle McMartin <kmcmarti@redhat.com> - 2.19.90-22
+- AArch64: Save & restore NZCV (flags) upon entry to _dl_tlsdesc_dynamic
+  in order to work around GCC reordering compares across the TLS
+  descriptor sequence (GCC PR61545.) Committing a (temporary) fix here
+  allows us to avoid rebuilding the world with gcc 4.9.0-11.fc21.
+
 * Mon Jun 16 2014 Kyle McMartin <kmcmarti@redhat.com> - 2.19.90-21
 - Auto-sync with upstream master.