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authorH.J. Lu <hjl.tools@gmail.com>2018-01-19 09:51:58 -0800
committerH.J. Lu <hjl.tools@gmail.com>2018-01-19 09:52:15 -0800
commit17d5d67f4f0350bdcfb5bf1a31cef2e14dabf7de (patch)
tree676390977e1ef9d86b7bad7ada28461244d9ca00
parentf24c345bf5486cc8d659f7a17463adcae402ec8e (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 723b363df8..33f5758073 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.
+
 2017-12-30  Aurelien Jarno  <aurelien@aurel32.net>
 	    Dmitry V. Levin  <ldv@altlinux.org>
 
diff --git a/NEWS b/NEWS
index c2de2df4b5..d11dfe1429 100644
--- a/NEWS
+++ b/NEWS
@@ -60,6 +60,7 @@ The following bugs are resolved with this release:
   [21609] x86-64: Align the stack in __tls_get_addr
   [21624] Unsafe alloca allows local attackers to alias stack and heap (CVE-2017-1000366)
   [21654] nss: Fix invalid cast in group merging
+  [22715] x86-64: Properly align La_x86_64_retval to VEC_SIZE
 
 Version 2.24
 
diff --git a/sysdeps/x86_64/dl-trampoline.h b/sysdeps/x86_64/dl-trampoline.h
index b9c2f1796f..60c8a595c8 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