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Re: [PATCH] x86: Allow -fcf-protection with multi-byte NOPs
On Fri, Apr 20, 2018 at 09:39:58AM +0200, Jakub Jelinek wrote:
> On Fri, Apr 20, 2018 at 06:25:10AM +0000, Tsimbalist, Igor V wrote:
> > > Something like this?
> >
> > Shouldn't this
> >
> > -# ifdef __IBT__
> > +# if (__CET__ & 1) != 0
> >
> > Be as
> >
> > -# ifdef __IBT__
> > +#ifdef __CET__
> > +# if (__CET__ & 1) != 0
> >
> > OK otherwise.
>
> Only if you use -Wundef warning (not part of -Wall or -W) and, if this
> is a system header, only with -Wundef -Wsystem-headers.
> But perhaps it doesn't hurt to wrap it.
>
> Jakub
Here is the patch. OK for trunk?
Thanks.
H.J.
---
With revision 259496:
commit b1384095a7c1d06a44b70853372ebe037b2f7867
Author: hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu Apr 19 15:15:04 2018 +0000
x86: Enable -fcf-protection with multi-byte NOPs
-mibt does nothing and can be removed. Define __CET__ to indicate level
protection with -fcf-protection:
(__CET__ & 1) != 0: -fcf-protection=branch or -fcf-protection=full
(__CET__ & 2) != 0: -fcf-protection=return or -fcf-protection=full
gcc/
PR target/85469
* common/config/i386/i386-common.c (OPTION_MASK_ISA_IBT_SET):
Removed.
(OPTION_MASK_ISA_IBT_UNSET): Likewise.
(ix86_handle_option): Don't handle OPT_mibt.
* config/i386/cet.h: Check __CET__ instead of __IBT__ and
__SHSTK__.
* config/i386/driver-i386.c (host_detect_local_cpu): Remove
has_ibt and ibt.
* config/i386/i386-c.c (ix86_target_macros_internal): Don't
check OPTION_MASK_ISA_IBT nor flag_cf_protection.
(ix86_target_macros): Define __CET__ with flag_cf_protection
for -fcf-protection.
* config/i386/i386.c (isa2_opts): Remove -mibt.
* config/i386/i386.h (TARGET_IBT): Removed.
(TARGET_IBT_P): Likewise.
(ix86_valid_target_attribute_inner_p): Don't check OPT_mibt.
* config/i386/i386.md (nop_endbr): Don't check TARGET_IBT.
* config/i386/i386.opt (mcet): Update help message.
(mshstk): Likewise.
(mibt): Removed.
* doc/invoke.texi: Remove -mibt. Document __CET__. Document
-mcet as an alias for -mshstk.
gcc/testsuite/
PR target/85469
* gcc.target/i386/pr85044.c (dg-options): Remove -mibt.
* gcc.target/i386/sse-26.c (dg-options): Remove -mno-ibt.
---
gcc/common/config/i386/i386-common.c | 17 -----------------
gcc/config/i386/cet.h | 6 +++---
gcc/config/i386/driver-i386.c | 6 ++----
gcc/config/i386/i386-c.c | 20 ++++++--------------
gcc/config/i386/i386.c | 2 --
gcc/config/i386/i386.h | 2 --
gcc/config/i386/i386.md | 2 +-
gcc/config/i386/i386.opt | 12 ++++--------
gcc/doc/invoke.texi | 28 +++++++++++-----------------
gcc/testsuite/gcc.target/i386/pr85044.c | 2 +-
gcc/testsuite/gcc.target/i386/sse-26.c | 2 +-
11 files changed, 29 insertions(+), 70 deletions(-)
diff --git a/gcc/common/config/i386/i386-common.c b/gcc/common/config/i386/i386-common.c
index 0bb2783cfab..74a3490f7a3 100644
--- a/gcc/common/config/i386/i386-common.c
+++ b/gcc/common/config/i386/i386-common.c
@@ -147,7 +147,6 @@ along with GCC; see the file COPYING3. If not see
#define OPTION_MASK_ISA_PKU_SET OPTION_MASK_ISA_PKU
#define OPTION_MASK_ISA_RDPID_SET OPTION_MASK_ISA_RDPID
#define OPTION_MASK_ISA_GFNI_SET OPTION_MASK_ISA_GFNI
-#define OPTION_MASK_ISA_IBT_SET OPTION_MASK_ISA_IBT
#define OPTION_MASK_ISA_SHSTK_SET OPTION_MASK_ISA_SHSTK
#define OPTION_MASK_ISA_VAES_SET OPTION_MASK_ISA_VAES
#define OPTION_MASK_ISA_VPCLMULQDQ_SET OPTION_MASK_ISA_VPCLMULQDQ
@@ -224,7 +223,6 @@ along with GCC; see the file COPYING3. If not see
#define OPTION_MASK_ISA_PKU_UNSET OPTION_MASK_ISA_PKU
#define OPTION_MASK_ISA_RDPID_UNSET OPTION_MASK_ISA_RDPID
#define OPTION_MASK_ISA_GFNI_UNSET OPTION_MASK_ISA_GFNI
-#define OPTION_MASK_ISA_IBT_UNSET OPTION_MASK_ISA_IBT
#define OPTION_MASK_ISA_SHSTK_UNSET OPTION_MASK_ISA_SHSTK
#define OPTION_MASK_ISA_VAES_UNSET OPTION_MASK_ISA_VAES
#define OPTION_MASK_ISA_VPCLMULQDQ_UNSET OPTION_MASK_ISA_VPCLMULQDQ
@@ -546,21 +544,6 @@ ix86_handle_option (struct gcc_options *opts,
return true;
case OPT_mcet:
- case OPT_mibt:
- if (value)
- {
- opts->x_ix86_isa_flags2 |= OPTION_MASK_ISA_IBT_SET;
- opts->x_ix86_isa_flags2_explicit |= OPTION_MASK_ISA_IBT_SET;
- }
- else
- {
- opts->x_ix86_isa_flags2 &= ~OPTION_MASK_ISA_IBT_UNSET;
- opts->x_ix86_isa_flags2_explicit |= OPTION_MASK_ISA_IBT_UNSET;
- }
- if (code != OPT_mcet)
- return true;
- /* fall through. */
-
case OPT_mshstk:
if (value)
{
diff --git a/gcc/config/i386/cet.h b/gcc/config/i386/cet.h
index 9dca41bad2d..309f6428735 100644
--- a/gcc/config/i386/cet.h
+++ b/gcc/config/i386/cet.h
@@ -32,7 +32,7 @@
#ifdef __ASSEMBLER__
-# ifdef __IBT__
+# if defined __CET__ && (__CET__ & 1) != 0
# ifdef __x86_64__
# define _CET_ENDBR endbr64
# else
@@ -44,14 +44,14 @@
# ifdef __ELF__
# ifdef __CET__
-# ifdef __IBT__
+# if (__CET__ & 1) != 0
/* GNU_PROPERTY_X86_FEATURE_1_IBT. */
# define __PROPERTY_IBT 0x1
# else
# define __PROPERTY_IBT 0x0
# endif
-# ifdef __SHSTK__
+# if (__CET__ & 2) != 0
/* GNU_PROPERTY_X86_FEATURE_1_SHSTK. */
# define __PROPERTY_SHSTK 0x2
# else
diff --git a/gcc/config/i386/driver-i386.c b/gcc/config/i386/driver-i386.c
index 19db252dfc0..704cadd8fcf 100644
--- a/gcc/config/i386/driver-i386.c
+++ b/gcc/config/i386/driver-i386.c
@@ -420,7 +420,7 @@ const char *host_detect_local_cpu (int argc, const char **argv)
unsigned int has_avx5124fmaps = 0, has_avx5124vnniw = 0;
unsigned int has_gfni = 0, has_avx512vbmi2 = 0;
unsigned int has_avx512bitalg = 0;
- unsigned int has_ibt = 0, has_shstk = 0;
+ unsigned int has_shstk = 0;
unsigned int has_avx512vnni = 0, has_vaes = 0;
unsigned int has_vpclmulqdq = 0;
unsigned int has_movdiri = 0, has_movdir64b = 0;
@@ -526,7 +526,6 @@ const char *host_detect_local_cpu (int argc, const char **argv)
has_avx5124fmaps = edx & bit_AVX5124FMAPS;
has_shstk = ecx & bit_SHSTK;
- has_ibt = edx & bit_IBT;
has_pconfig = edx & bit_PCONFIG;
}
@@ -1095,7 +1094,6 @@ const char *host_detect_local_cpu (int argc, const char **argv)
const char *pku = has_pku ? " -mpku" : " -mno-pku";
const char *rdpid = has_rdpid ? " -mrdpid" : " -mno-rdpid";
const char *gfni = has_gfni ? " -mgfni" : " -mno-gfni";
- const char *ibt = has_ibt ? " -mibt" : " -mno-ibt";
const char *shstk = has_shstk ? " -mshstk" : " -mno-shstk";
const char *vaes = has_vaes ? " -mvaes" : " -mno-vaes";
const char *vpclmulqdq = has_vpclmulqdq ? " -mvpclmulqdq" : " -mno-vpclmulqdq";
@@ -1112,7 +1110,7 @@ const char *host_detect_local_cpu (int argc, const char **argv)
avx512cd, avx512pf, prefetchwt1, clflushopt,
xsavec, xsaves, avx512dq, avx512bw, avx512vl,
avx512ifma, avx512vbmi, avx5124fmaps, avx5124vnniw,
- clwb, mwaitx, clzero, pku, rdpid, gfni, ibt, shstk,
+ clwb, mwaitx, clzero, pku, rdpid, gfni, shstk,
avx512vbmi2, avx512vnni, vaes, vpclmulqdq,
avx512bitalg, movdiri, movdir64b, NULL);
}
diff --git a/gcc/config/i386/i386-c.c b/gcc/config/i386/i386-c.c
index fa8b3682b0c..ae7d678e77e 100644
--- a/gcc/config/i386/i386-c.c
+++ b/gcc/config/i386/i386-c.c
@@ -499,20 +499,8 @@ ix86_target_macros_internal (HOST_WIDE_INT isa_flag,
def_or_undef (parse_in, "__RDPID__");
if (isa_flag & OPTION_MASK_ISA_GFNI)
def_or_undef (parse_in, "__GFNI__");
- if ((isa_flag2 & OPTION_MASK_ISA_IBT)
- || (flag_cf_protection & CF_BRANCH))
- {
- def_or_undef (parse_in, "__IBT__");
- if (flag_cf_protection != CF_NONE)
- def_or_undef (parse_in, "__CET__");
- }
- if ((isa_flag & OPTION_MASK_ISA_SHSTK)
- || (flag_cf_protection & CF_RETURN))
- {
- def_or_undef (parse_in, "__SHSTK__");
- if (flag_cf_protection != CF_NONE)
- def_or_undef (parse_in, "__CET__");
- }
+ if ((isa_flag & OPTION_MASK_ISA_SHSTK))
+ def_or_undef (parse_in, "__SHSTK__");
if (isa_flag2 & OPTION_MASK_ISA_VAES)
def_or_undef (parse_in, "__VAES__");
if (isa_flag & OPTION_MASK_ISA_VPCLMULQDQ)
@@ -680,6 +668,10 @@ ix86_target_macros (void)
cpp_define (parse_in, "__SEG_FS");
cpp_define (parse_in, "__SEG_GS");
+
+ if (flag_cf_protection != CF_NONE)
+ cpp_define_formatted (parse_in, "__CET__=%d",
+ flag_cf_protection & ~CF_SET);
}
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index a0435377872..dc80b34f302 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -2766,7 +2766,6 @@ ix86_target_string (HOST_WIDE_INT isa, HOST_WIDE_INT isa2,
{ "-msgx", OPTION_MASK_ISA_SGX },
{ "-mavx5124vnniw", OPTION_MASK_ISA_AVX5124VNNIW },
{ "-mavx5124fmaps", OPTION_MASK_ISA_AVX5124FMAPS },
- { "-mibt", OPTION_MASK_ISA_IBT },
{ "-mhle", OPTION_MASK_ISA_HLE },
{ "-mmovbe", OPTION_MASK_ISA_MOVBE },
{ "-mclzero", OPTION_MASK_ISA_CLZERO },
@@ -5377,7 +5376,6 @@ ix86_valid_target_attribute_inner_p (tree args, char *p_strings[],
IX86_ATTR_ISA ("clwb", OPT_mclwb),
IX86_ATTR_ISA ("rdpid", OPT_mrdpid),
IX86_ATTR_ISA ("gfni", OPT_mgfni),
- IX86_ATTR_ISA ("ibt", OPT_mibt),
IX86_ATTR_ISA ("shstk", OPT_mshstk),
IX86_ATTR_ISA ("vaes", OPT_mvaes),
IX86_ATTR_ISA ("vpclmulqdq", OPT_mvpclmulqdq),
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 3734ba1bc12..795ad2a322b 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -183,8 +183,6 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
#define TARGET_MWAITX_P(x) TARGET_ISA_MWAITX_P(x)
#define TARGET_PKU TARGET_ISA_PKU
#define TARGET_PKU_P(x) TARGET_ISA_PKU_P(x)
-#define TARGET_IBT TARGET_ISA_IBT
-#define TARGET_IBT_P(x) TARGET_ISA_IBT_P(x)
#define TARGET_SHSTK TARGET_ISA_SHSTK
#define TARGET_SHSTK_P(x) TARGET_ISA_SHSTK_P(x)
#define TARGET_MOVDIRI TARGET_ISA_MOVDIRI
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 33e8060fa56..a134ca88014 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -20332,7 +20332,7 @@
(define_insn "nop_endbr"
[(unspec_volatile [(const_int 0)] UNSPECV_NOP_ENDBR)]
- "TARGET_IBT || (flag_cf_protection & CF_BRANCH)"
+ "(flag_cf_protection & CF_BRANCH)"
"*
{ return (TARGET_64BIT)? \"endbr64\" : \"endbr32\"; }"
[(set_attr "length" "4")
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index 646cfcbbd3b..815eceb713d 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -1008,17 +1008,13 @@ Generate code which uses only the general registers.
mcet
Target Report Var(flag_cet) Init(0)
-Support Control-flow Enforcement Technology (CET) built-in functions.
-
-mibt
-Target Report Mask(ISA_IBT) Var(ix86_isa_flags2) Save
-Specifically enable indirect branch tracking built-in functions from
-Control-flow Enforcement Technology (CET).
+Enable shadow stack built-in functions from Control-flow Enforcement
+Technology (CET).
mshstk
Target Report Mask(ISA_SHSTK) Var(ix86_isa_flags) Save
-Specifically enable shadow stack built-in functions from Control-flow
-Enforcement Technology (CET).
+Enable shadow stack built-in functions from Control-flow Enforcement
+Technology (CET).
mcet-switch
Target Report Undocumented Var(flag_cet_switch) Init(0)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 0f2c83964f4..b6784b75fa2 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -1261,7 +1261,7 @@ See RS/6000 and PowerPC Options.
-msse4a -m3dnow -m3dnowa -mpopcnt -mabm -mbmi -mtbm -mfma4 -mxop @gol
-mlzcnt -mbmi2 -mfxsr -mxsave -mxsaveopt -mrtm -mlwp -mmpx @gol
-mmwaitx -mclzero -mpku -mthreads -mgfni -mvaes @gol
--mcet -mibt -mshstk -mforce-indirect-call -mavx512vbmi2 @gol
+-mcet -mshstk -mforce-indirect-call -mavx512vbmi2 @gol
-mvpclmulqdq -mavx512bitalg -mmovdiri -mmovdir64b -mavx512vpopcntdq @gol
-mms-bitfields -mno-align-stringops -minline-all-stringops @gol
-minline-stringops-dynamically -mstringop-strategy=@var{alg} @gol
@@ -11829,6 +11829,11 @@ function. The value @code{full} is an alias for specifying both
@code{branch} and @code{return}. The value @code{none} turns off
instrumentation.
+The macro @code{__CET__} is defined when @option{-fcf-protection} is
+used. The first bit of @code{__CET__} is set to 1 for the value
+@code{branch} and the second bit of @code{__CET__} is set to 1 for
+the @code{return}.
+
You can also use the @code{nocf_check} attribute to identify
which functions and calls should be skipped from instrumentation
(@pxref{Function Attributes}).
@@ -27349,11 +27354,6 @@ supported architecture, using the appropriate flags. In particular,
the file containing the CPU detection code should be compiled without
these options.
-The @option{-mcet} option turns on the @option{-mibt} and @option{-mshstk}
-options. The compiler provides a number of built-in functions for
-fine-grained control in a CET-based application. See
-@xref{x86 Built-in Functions}, for more information.
-
@item -mdump-tune-features
@opindex mdump-tune-features
This option instructs GCC to dump the names of the x86 performance
@@ -27446,19 +27446,13 @@ see @ref{Other Builtins} for details.
This option enables use of the @code{movbe} instruction to implement
@code{__builtin_bswap32} and @code{__builtin_bswap64}.
-@item -mibt
-@opindex mibt
-This option enables indirect branch tracking built-in functions from
-x86 Control-flow Enforcement Technology (CET). The option
-@option{-mibt} is on by default when the @code{-mcet} option is
-specified.
-
@item -mshstk
+@itemx -mcet
@opindex mshstk
-This option enables shadow stack built-in functions from x86
-Control-flow Enforcement Technology (CET). The option
-@option{-mshstk} is on by default when the @option{-mcet} option is
-specified.
+@opindex mcet
+The @option{-mshstk} option enables shadow stack built-in functions
+from x86 Control-flow Enforcement Technology (CET). The @option{-mcet}
+option is an alias for the @option{-mshstk} option.
@item -mcrc32
@opindex mcrc32
diff --git a/gcc/testsuite/gcc.target/i386/pr85044.c b/gcc/testsuite/gcc.target/i386/pr85044.c
index 332f582d79b..a25cc7fe325 100644
--- a/gcc/testsuite/gcc.target/i386/pr85044.c
+++ b/gcc/testsuite/gcc.target/i386/pr85044.c
@@ -1,5 +1,5 @@
/* { dg-do run { target cet } } */
-/* { dg-options "-O2 -fcf-protection=branch -mibt" } */
+/* { dg-options "-O2 -fcf-protection=branch" } */
void callme (void (*callback) (void));
diff --git a/gcc/testsuite/gcc.target/i386/sse-26.c b/gcc/testsuite/gcc.target/i386/sse-26.c
index f2607e64b59..04ffe10f42a 100644
--- a/gcc/testsuite/gcc.target/i386/sse-26.c
+++ b/gcc/testsuite/gcc.target/i386/sse-26.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -Werror-implicit-function-declaration -march=k8 -msse2 -mmmx -mno-sse3 -mno-3dnow -mno-fma -mno-fxsr -mno-xsave -mno-rtm -mno-prfchw -mno-rdseed -mno-adx -mno-prefetchwt1 -mno-clflushopt -mno-xsavec -mno-xsaves -mno-clwb -mno-mwaitx -mno-clzero -mno-pku -mno-rdpid -mno-gfni -mno-ibt -mno-shstk -mno-vaes -mno-vpclmulqdq" } */
+/* { dg-options "-O2 -Werror-implicit-function-declaration -march=k8 -msse2 -mmmx -mno-sse3 -mno-3dnow -mno-fma -mno-fxsr -mno-xsave -mno-rtm -mno-prfchw -mno-rdseed -mno-adx -mno-prefetchwt1 -mno-clflushopt -mno-xsavec -mno-xsaves -mno-clwb -mno-mwaitx -mno-clzero -mno-pku -mno-rdpid -mno-gfni -mno-shstk -mno-vaes -mno-vpclmulqdq" } */
/* { dg-add-options bind_pic_locally } */
#include "sse-13.c"
--
2.14.3