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Preserve bound registers for pointer pass/return
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We need to save/restore bound registers and add a BND prefix before
branches in _dl_runtime_profile so that bound registers for pointer
pass and return are preserved when LD_AUDIT is used.

	[BZ #18134]
	* sysdeps/i386/configure.ac: Set HAVE_MPX_SUPPORT.
	* sysdeps/i386/configure: Regenerated.
	* sysdeps/i386/dl-trampoline.S (PRESERVE_BND_REGS_PREFIX): New.
	(_dl_runtime_profile): Save and restore Intel MPX return bound
	registers when calling _dl_call_pltexit.  Add
	PRESERVE_BND_REGS_PREFIX before return.
	* sysdeps/i386/link-defines.sym (LRV_BND0_OFFSET): New.
	(LRV_BND1_OFFSET): Likewise.
	* sysdeps/x86/bits/link.h (La_i86_retval): Add lrv_bnd0 and
	lrv_bnd1.
	* sysdeps/x86_64/dl-trampoline.S (_dl_runtime_profile): Fix
	typo in bndmov encoding.
	* sysdeps/x86_64/dl-trampoline.h: Properly save and restore
	Intel MPX bound registers.  Add PRESERVE_BND_REGS_PREFIX before
	branch instructions to preserve bounds.
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Igor Zamyatin authored and H.J. Lu committed Jul 9, 2015
1 parent 632b3db commit 14c5cba
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20 changes: 20 additions & 0 deletions ChangeLog
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@@ -1,3 +1,23 @@
2015-07-09 Igor Zamyatin <igor.zamyatin@intel.com>
H.J. Lu <hongjiu.lu@intel.com>

[BZ #18134]
* sysdeps/i386/configure.ac: Set HAVE_MPX_SUPPORT.
* sysdeps/i386/configure: Regenerated.
* sysdeps/i386/dl-trampoline.S (PRESERVE_BND_REGS_PREFIX): New.
(_dl_runtime_profile): Save and restore Intel MPX return bound
registers when calling _dl_call_pltexit. Add
PRESERVE_BND_REGS_PREFIX before return.
* sysdeps/i386/link-defines.sym (LRV_BND0_OFFSET): New.
(LRV_BND1_OFFSET): Likewise.
* sysdeps/x86/bits/link.h (La_i86_retval): Add lrv_bnd0 and
lrv_bnd1.
* sysdeps/x86_64/dl-trampoline.S (_dl_runtime_profile): Fix
typo in bndmov encoding.
* sysdeps/x86_64/dl-trampoline.h: Properly save and restore
Intel MPX bound registers. Add PRESERVE_BND_REGS_PREFIX before
branch instructions to preserve bounds.

2015-07-09 Adhemerval Zanella <adhemerval.zanella@linaro.org>

* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
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14 changes: 7 additions & 7 deletions NEWS
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Expand Up @@ -21,13 +21,13 @@ Version 2.22
18049, 18068, 18080, 18093, 18100, 18104, 18110, 18111, 18116, 18125,
18128, 18138, 18185, 18196, 18197, 18206, 18210, 18211, 18217, 18219,
18220, 18221, 18234, 18244, 18245, 18247, 18287, 18319, 18324, 18333,
18346, 18371, 18383, 18397, 18400, 18409, 18410, 18412, 18418, 18422,
18434, 18435, 18444, 18468, 18469, 18470, 18479, 18483, 18495, 18496,
18497, 18498, 18502, 18507, 18508, 18512, 18513, 18519, 18520, 18522,
18527, 18528, 18529, 18530, 18532, 18533, 18534, 18536, 18539, 18540,
18542, 18544, 18545, 18546, 18547, 18549, 18553, 18557, 18558, 18569,
18583, 18585, 18586, 18592, 18593, 18594, 18602, 18612, 18613, 18619,
18633, 18641, 18643, 18648.
18346, 18371, 18383, 18397, 18400, 18409, 18410, 18412, 18134, 18418,
18422, 18434, 18435, 18444, 18468, 18469, 18470, 18479, 18483, 18495,
18496, 18497, 18498, 18502, 18507, 18508, 18512, 18513, 18519, 18520,
18522, 18527, 18528, 18529, 18530, 18532, 18533, 18534, 18536, 18539,
18540, 18542, 18544, 18545, 18546, 18547, 18549, 18553, 18557, 18558,
18569, 18583, 18585, 18586, 18592, 18593, 18594, 18602, 18612, 18613,
18619, 18633, 18641, 18643, 18648.

* Cache information can be queried via sysconf() function on s390 e.g. with
_SC_LEVEL1_ICACHE_SIZE as argument.
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27 changes: 27 additions & 0 deletions sysdeps/i386/configure
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Expand Up @@ -240,6 +240,33 @@ $as_echo "$libc_cv_cc_novzeroupper" >&6; }
config_vars="$config_vars
config-cflags-novzeroupper = $libc_cv_cc_novzeroupper"

{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for Intel MPX support" >&5
$as_echo_n "checking for Intel MPX support... " >&6; }
if ${libc_cv_asm_mpx+:} false; then :
$as_echo_n "(cached) " >&6
else
cat > conftest.s <<\EOF
bndmov %bnd0,(%esp)
EOF
if { ac_try='${CC-cc} -c $ASFLAGS conftest.s 1>&5'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }; }; then
libc_cv_asm_mpx=yes
else
libc_cv_asm_mpx=no
fi
rm -f conftest*
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_asm_mpx" >&5
$as_echo "$libc_cv_asm_mpx" >&6; }
if test $libc_cv_asm_mpx == yes; then
$as_echo "#define HAVE_MPX_SUPPORT 1" >>confdefs.h

fi

{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for AVX2 support" >&5
$as_echo_n "checking for AVX2 support... " >&6; }
if ${libc_cv_cc_avx2+:} false; then :
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15 changes: 15 additions & 0 deletions sysdeps/i386/configure.ac
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Expand Up @@ -88,6 +88,21 @@ LIBC_TRY_CC_OPTION([-mno-vzeroupper],
])
LIBC_CONFIG_VAR([config-cflags-novzeroupper], [$libc_cv_cc_novzeroupper])

dnl Check whether asm supports Intel MPX
AC_CACHE_CHECK(for Intel MPX support, libc_cv_asm_mpx, [dnl
cat > conftest.s <<\EOF
bndmov %bnd0,(%esp)
EOF
if AC_TRY_COMMAND(${CC-cc} -c $ASFLAGS conftest.s 1>&AS_MESSAGE_LOG_FD); then
libc_cv_asm_mpx=yes
else
libc_cv_asm_mpx=no
fi
rm -f conftest*])
if test $libc_cv_asm_mpx == yes; then
AC_DEFINE(HAVE_MPX_SUPPORT)
fi

dnl Check if -mavx2 works.
AC_CACHE_CHECK(for AVX2 support, libc_cv_cc_avx2, [dnl
LIBC_TRY_CC_OPTION([-mavx2], [libc_cv_cc_avx2=yes], [libc_cv_cc_avx2=no])
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21 changes: 21 additions & 0 deletions sysdeps/i386/dl-trampoline.S
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Expand Up @@ -19,6 +19,12 @@
#include <sysdep.h>
#include <link-defines.h>

#ifdef HAVE_MPX_SUPPORT
# define PRESERVE_BND_REGS_PREFIX bnd
#else
# define PRESERVE_BND_REGS_PREFIX .byte 0xf2
#endif

.text
.globl _dl_runtime_resolve
.type _dl_runtime_resolve, @function
Expand Down Expand Up @@ -172,6 +178,13 @@ _dl_runtime_profile:
movl %edx, LRV_EDX_OFFSET(%esp)
fstpt LRV_ST0_OFFSET(%esp)
fstpt LRV_ST1_OFFSET(%esp)
#ifdef HAVE_MPX_SUPPORT
bndmov %bnd0, LRV_BND0_OFFSET(%esp)
bndmov %bnd1, LRV_BND1_OFFSET(%esp)
#else
.byte 0x66,0x0f,0x1b,0x44,0x24,LRV_BND0_OFFSET
.byte 0x66,0x0f,0x1b,0x4c,0x24,LRV_BND1_OFFSET
#endif
pushl %esp
cfi_adjust_cfa_offset (4)
# Address of La_i86_regs area.
Expand All @@ -185,9 +198,17 @@ _dl_runtime_profile:
movl LRV_EDX_OFFSET(%esp), %edx
fldt LRV_ST1_OFFSET(%esp)
fldt LRV_ST0_OFFSET(%esp)
#ifdef HAVE_MPX_SUPPORT
bndmov LRV_BND0_OFFSET(%esp), %bnd0
bndmov LRV_BND1_OFFSET(%esp), %bnd1
#else
.byte 0x66,0x0f,0x1a,0x44,0x24,LRV_BND0_OFFSET
.byte 0x66,0x0f,0x1a,0x4c,0x24,LRV_BND1_OFFSET
#endif
# Restore stack before return.
addl $(LRV_SIZE + 4 + LR_SIZE + 4), %esp
cfi_adjust_cfa_offset (-(LRV_SIZE + 4 + LR_SIZE + 4))
PRESERVE_BND_REGS_PREFIX
ret
cfi_endproc
.size _dl_runtime_profile, .-_dl_runtime_profile
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2 changes: 2 additions & 0 deletions sysdeps/i386/link-defines.sym
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Expand Up @@ -16,3 +16,5 @@ LRV_EAX_OFFSET offsetof (struct La_i86_retval, lrv_eax)
LRV_EDX_OFFSET offsetof (struct La_i86_retval, lrv_edx)
LRV_ST0_OFFSET offsetof (struct La_i86_retval, lrv_st0)
LRV_ST1_OFFSET offsetof (struct La_i86_retval, lrv_st1)
LRV_BND0_OFFSET offsetof (struct La_i86_retval, lrv_bnd0)
LRV_BND1_OFFSET offsetof (struct La_i86_retval, lrv_bnd1)
2 changes: 2 additions & 0 deletions sysdeps/x86/bits/link.h
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Expand Up @@ -38,6 +38,8 @@ typedef struct La_i86_retval
uint32_t lrv_edx;
long double lrv_st0;
long double lrv_st1;
uint64_t lrv_bnd0;
uint64_t lrv_bnd1;
} La_i86_retval;


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4 changes: 2 additions & 2 deletions sysdeps/x86_64/dl-trampoline.S
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Expand Up @@ -206,8 +206,8 @@ _dl_runtime_profile:
# else
.byte 0x66,0x0f,0x1b,0x84,0x24;.long (LR_BND_OFFSET)
.byte 0x66,0x0f,0x1b,0x8c,0x24;.long (LR_BND_OFFSET + BND_SIZE)
.byte 0x66,0x0f,0x1b,0x84,0x24;.long (LR_BND_OFFSET + BND_SIZE*2)
.byte 0x66,0x0f,0x1b,0x8c,0x24;.long (LR_BND_OFFSET + BND_SIZE*3)
.byte 0x66,0x0f,0x1b,0x94,0x24;.long (LR_BND_OFFSET + BND_SIZE*2)
.byte 0x66,0x0f,0x1b,0x9c,0x24;.long (LR_BND_OFFSET + BND_SIZE*3)
# endif
# endif

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41 changes: 23 additions & 18 deletions sysdeps/x86_64/dl-trampoline.h
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Original file line number Diff line number Diff line change
Expand Up @@ -63,20 +63,6 @@
movaps (LR_XMM_OFFSET + XMM_SIZE*6)(%rsp), %xmm6
movaps (LR_XMM_OFFSET + XMM_SIZE*7)(%rsp), %xmm7

#ifndef __ILP32__
# ifdef HAVE_MPX_SUPPORT
bndmov (LR_BND_OFFSET)(%rsp), %bnd0 # Restore bound
bndmov (LR_BND_OFFSET + BND_SIZE)(%rsp), %bnd1 # registers.
bndmov (LR_BND_OFFSET + BND_SIZE*2)(%rsp), %bnd2
bndmov (LR_BND_OFFSET + BND_SIZE*3)(%rsp), %bnd3
# else
.byte 0x66,0x0f,0x1a,0x84,0x24;.long (LR_BND_OFFSET)
.byte 0x66,0x0f,0x1a,0x8c,0x24;.long (LR_BND_OFFSET + BND_SIZE)
.byte 0x66,0x0f,0x1a,0x94,0x24;.long (LR_BND_OFFSET + BND_SIZE*2)
.byte 0x66,0x0f,0x1a,0x9c,0x24;.long (LR_BND_OFFSET + BND_SIZE*3)
# endif
#endif

#ifdef RESTORE_AVX
/* Check if any xmm0-xmm7 registers are changed by audit
module. */
Expand Down Expand Up @@ -154,8 +140,24 @@

1:
#endif

#ifndef __ILP32__
# ifdef HAVE_MPX_SUPPORT
bndmov (LR_BND_OFFSET)(%rsp), %bnd0 # Restore bound
bndmov (LR_BND_OFFSET + BND_SIZE)(%rsp), %bnd1 # registers.
bndmov (LR_BND_OFFSET + BND_SIZE*2)(%rsp), %bnd2
bndmov (LR_BND_OFFSET + BND_SIZE*3)(%rsp), %bnd3
# else
.byte 0x66,0x0f,0x1a,0x84,0x24;.long (LR_BND_OFFSET)
.byte 0x66,0x0f,0x1a,0x8c,0x24;.long (LR_BND_OFFSET + BND_SIZE)
.byte 0x66,0x0f,0x1a,0x94,0x24;.long (LR_BND_OFFSET + BND_SIZE*2)
.byte 0x66,0x0f,0x1a,0x9c,0x24;.long (LR_BND_OFFSET + BND_SIZE*3)
# endif
#endif

mov 16(%rbx), %R10_LP # Anything in framesize?
test %R10_LP, %R10_LP
PRESERVE_BND_REGS_PREFIX
jns 3f

/* There's nothing in the frame size, so there
Expand All @@ -174,6 +176,7 @@
addq $48, %rsp # Adjust the stack to the return value
# (eats the reloc index and link_map)
cfi_adjust_cfa_offset(-48)
PRESERVE_BND_REGS_PREFIX
jmp *%r11 # Jump to function address.

3:
Expand All @@ -200,6 +203,7 @@
movq 32(%rdi), %rsi
movq 40(%rdi), %rdi

PRESERVE_BND_REGS_PREFIX
call *%r11

mov 24(%rbx), %rsp # Drop the copied stack content
Expand Down Expand Up @@ -280,11 +284,11 @@

#ifndef __ILP32__
# ifdef HAVE_MPX_SUPPORT
bndmov LRV_BND0_OFFSET(%rcx), %bnd0 # Restore bound registers.
bndmov LRV_BND1_OFFSET(%rcx), %bnd1
bndmov LRV_BND0_OFFSET(%rsp), %bnd0 # Restore bound registers.
bndmov LRV_BND1_OFFSET(%rsp), %bnd1
# else
.byte 0x66,0x0f,0x1a,0x81;.long (LRV_BND0_OFFSET)
.byte 0x66,0x0f,0x1a,0x89;.long (LRV_BND1_OFFSET)
.byte 0x66,0x0f,0x1a,0x84,0x24;.long (LRV_BND0_OFFSET)
.byte 0x66,0x0f,0x1a,0x8c,0x24;.long (LRV_BND1_OFFSET)
# endif
#endif

Expand All @@ -299,6 +303,7 @@
addq $48, %rsp # Adjust the stack to the return value
# (eats the reloc index and link_map)
cfi_adjust_cfa_offset(-48)
PRESERVE_BND_REGS_PREFIX
retq

#ifdef MORE_CODE
Expand Down

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