svn commit: r285038 - head/libexec/rtld-elf/aarch64

[Andrew Turner]

Author: andrew
Date: Thu Jul  2 14:00:07 2015
New Revision: 285038
URL: https://svnweb.freebsd.org/changeset/base/285038

Log:
  Save & restore the floating-pont argument registers before calling
  _rtld_bind. The compiler may generate code using these registers and not
  save them. Unfortunately, as we make use of libc, we are unable to disallow
  rtld from using floating-point register without also doing the same for the
  parts of libc we use, or by limiting what _rtld_bind is able to call.
  
  Obtained from:	ABT Systems Ltd
  Sponsored by:	The FReeBSD Foundation

Modified:
  head/libexec/rtld-elf/aarch64/rtld_start.S

Modified: head/libexec/rtld-elf/aarch64/rtld_start.S
==============================================================================
--- head/libexec/rtld-elf/aarch64/rtld_start.S	Thu Jul  2 13:57:26 2015	(r285037)
+++ head/libexec/rtld-elf/aarch64/rtld_start.S	Thu Jul  2 14:00:07 2015	(r285038)
@@ -70,6 +70,12 @@ ENTRY(_rtld_bind_start)
 	stp	x6, x7, [sp, #-16]!
 	stp	x8, xzr, [sp, #-16]!
 
+	/* Save any floating-point arguments */
+	stp	q0, q1, [sp, #-32]!
+	stp	q2, q3, [sp, #-32]!
+	stp	q4, q5, [sp, #-32]!
+	stp	q6, q7, [sp, #-32]!
+
 	/* Calculate reloff */
 	ldr	x2, [x17, #0]	/* Get the address of the entry */
 	sub	x1, x2, x16	/* Find its offset */
@@ -85,12 +91,16 @@ ENTRY(_rtld_bind_start)
 	bl	_rtld_bind
 
 	/* Restore the registers saved by the plt code */
-	ldp	xzr, x30, [sp, #(5 * 16)]
+	ldp	xzr, x30, [sp, #(5 * 16 + 4 * 32)]
 
 	/* Backup the address to branch to */
 	mov	x16, x0
 
 	/* restore the arguments */
+	ldp	q6, q7, [sp], #32
+	ldp	q4, q5, [sp], #32
+	ldp	q2, q3, [sp], #32
+	ldp	q0, q1, [sp], #32
 	ldp	x8, xzr, [sp], #16
 	ldp	x6, x7, [sp], #16
 	ldp	x4, x5, [sp], #16