about summary refs log tree commit diff
path: root/sysdeps/x86_64
diff options
context:
space:
mode:
authorH.J. Lu <hjl.tools@gmail.com>2018-01-15 19:39:56 -0800
committerH.J. Lu <hjl.tools@gmail.com>2018-01-17 05:10:59 -0800
commita802568bde90a5c1e97c2b4ff56221620476066a (patch)
tree6ec2e271b72d1841cabe8f908405745032bd229e /sysdeps/x86_64
parentedcf13e25c1559558a6f12ff5a71d4136a39235e (diff)
downloadglibc-hjl/pr22715/2.25.tar.gz
glibc-hjl/pr22715/2.25.tar.xz
glibc-hjl/pr22715/2.25.zip
x86-64: Properly align La_x86_64_retval to VEC_SIZE [BZ #22715] hjl/pr22715/2.25
_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.
Diffstat (limited to 'sysdeps/x86_64')
-rw-r--r--sysdeps/x86_64/dl-trampoline.h12
1 files changed, 10 insertions, 2 deletions
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