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authorH.J. Lu <hjl.tools@gmail.com>2018-01-19 09:50:00 -0800
committerH.J. Lu <hjl.tools@gmail.com>2018-01-19 09:50:12 -0800
commitdcc03e70817985c2f16a1c4f419d5f53fd4f46e2 (patch)
treeba3e4ba5dd2056cab82cfd45ab26c7cdce43928e
parentedcf13e25c1559558a6f12ff5a71d4136a39235e (diff)
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x86-64: Properly align La_x86_64_retval to VEC_SIZE [BZ #22715]
_dl_runtime_profile calls _dl_call_pltexit, passing a pointer to
La_x86_64_retval which is allocated on stack.  The lrv_vector0
field in La_x86_64_retval must be aligned to size of vector register.
When allocating stack space for La_x86_64_retval, we need to make sure
that the address of La_x86_64_retval + RV_VECTOR0_OFFSET is aligned to
VEC_SIZE.  This patch checks the alignment of the lrv_vector0 field
and pads the stack space if needed.

Tested with x32 and x86-64 on SSE4, AVX and AVX512 machines.  It fixed

FAIL: elf/tst-audit10
FAIL: elf/tst-audit4
FAIL: elf/tst-audit5
FAIL: elf/tst-audit6
FAIL: elf/tst-audit7

on x32 AVX512 machine.

(cherry picked from commit 207a72e2988c6d6343f50fe0128eb4fc4edfdd15)

	[BZ #22715]
	* sysdeps/x86_64/dl-trampoline.h (_dl_runtime_profile): Properly
	align La_x86_64_retval to VEC_SIZE.
-rw-r--r--ChangeLog6
-rw-r--r--NEWS1
-rw-r--r--sysdeps/x86_64/dl-trampoline.h12
3 files changed, 17 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index 76850750d1..a875c01445 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2018-01-19  H.J. Lu  <hongjiu.lu@intel.com>
+
+	[BZ #22715]
+	* sysdeps/x86_64/dl-trampoline.h (_dl_runtime_profile): Properly
+	align La_x86_64_retval to VEC_SIZE.
+
 2018-01-16  Florian Weimer  <fweimer@redhat.com>
 
 	* nptl/Makefile [$(have-cxx-thread_local)] (tests-unsupported):
diff --git a/NEWS b/NEWS
index e7eba7610d..2f3f492edd 100644
--- a/NEWS
+++ b/NEWS
@@ -71,6 +71,7 @@ The following bugs are resolved with this release:
   [22637] nptl: Fix stack guard size accounting
   [22679] getcwd(3) can succeed without returning an absolute path
     (CVE-2018-1000001)
+  [22715] x86-64: Properly align La_x86_64_retval to VEC_SIZE
 
 Version 2.25
 
diff --git a/sysdeps/x86_64/dl-trampoline.h b/sysdeps/x86_64/dl-trampoline.h
index 9ddaafee17..5fdc391d08 100644
--- a/sysdeps/x86_64/dl-trampoline.h
+++ b/sysdeps/x86_64/dl-trampoline.h
@@ -440,8 +440,16 @@ _dl_runtime_profile:
 # ifdef RESTORE_AVX
 	/* sizeof(La_x86_64_retval).  Need extra space for 2 SSE
 	   registers to detect if xmm0/xmm1 registers are changed
-	   by audit module.  */
-	sub $(LRV_SIZE + XMM_SIZE*2), %RSP_LP
+	   by audit module.  Since rsp is aligned to VEC_SIZE, we
+	   need to make sure that the address of La_x86_64_retval +
+	   LRV_VECTOR0_OFFSET is aligned to VEC_SIZE.  */
+#  define LRV_SPACE (LRV_SIZE + XMM_SIZE*2)
+#  define LRV_MISALIGNED ((LRV_SIZE + LRV_VECTOR0_OFFSET) & (VEC_SIZE - 1))
+#  if LRV_MISALIGNED == 0
+	sub $LRV_SPACE, %RSP_LP
+#  else
+	sub $(LRV_SPACE + VEC_SIZE - LRV_MISALIGNED), %RSP_LP
+#  endif
 # else
 	sub $LRV_SIZE, %RSP_LP	# sizeof(La_x86_64_retval)
 # endif