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i386: Don't insert ENDBR after NOTE_INSN_DELETED_LABEL

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NOTE_INSN_DELETED_LABEL is used to mark what used to be a 'code_label',
but was not used for other purposes than taking its address which cannot
be used as target for indirect jumps.

Tested on Linux/x86-64 with -fcf-protection.

For x86-64 libc.so on glibc master branch (commit f43b8dd55588c3),

Before: 2961 endbr64
After:  2943 endbr64

gcc/

	PR target/89355
	* config/i386/i386-features.c (rest_of_insert_endbranch): Remove
	NOTE_INSN_DELETED_LABEL check.

gcc/testsuite/

	PR target/89355
	* gcc.target/i386/cet-label-3.c: New test.
	* gcc.target/i386/cet-label-4.c: Likewise.
	* gcc.target/i386/cet-label-5.c: Likewise.

Co-Authored-By: Hongtao Liu <hongtao.liu@intel.com>

From-SVN: r271828
This commit is contained in:
H.J. Lu 2019-05-31 23:59:16 +00:00 • committed by H.J. Lu
parent d030d4c5a4
commit 02ed904927
6 changed files with 63 additions and 4 deletions
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7
gcc/ChangeLog
View file

@ -1,3 +1,10 @@
2019-05-31 H.J. Lu <hongjiu.lu@intel.com>
Hongtao Liu <hongtao.liu@intel.com>
PR target/89355
* config/i386/i386-features.c (rest_of_insert_endbranch): Remove
NOTE_INSN_DELETED_LABEL check.
2019-05-31 Prachi Godbole <prachi.godbole@imgtec.com>
Robert Suchanek <robert.suchanek@mips.com>

5
gcc/config/i386/i386-features.c
View file

@ -1911,10 +1911,7 @@ rest_of_insert_endbranch (void)
continue;
}
if ((LABEL_P (insn) && LABEL_PRESERVE_P (insn))
|| (NOTE_P (insn)
&& NOTE_KIND (insn) == NOTE_INSN_DELETED_LABEL))
/* TODO. Check /s bit also. */
if (LABEL_P (insn) && LABEL_PRESERVE_P (insn))
{
cet_eb = gen_nop_endbr ();
emit_insn_after (cet_eb, insn);

7
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,10 @@
2019-05-31 H.J. Lu <hongjiu.lu@intel.com>
PR target/89355
* gcc.target/i386/cet-label-3.c: New test.
* gcc.target/i386/cet-label-4.c: Likewise.
* gcc.target/i386/cet-label-5.c: Likewise.
2019-05-31 Dragan Mladjenovic <dmladjenovic@wavecomp.com>
* gcc.target/mips/msa-fmadd.c: New.

23
gcc/testsuite/gcc.target/i386/cet-label-3.c Normal file
View file

@ -0,0 +1,23 @@
/* PR target/89355 */
/* { dg-do compile } */
/* { dg-options "-O2 -fcf-protection" } */
/* { dg-final { scan-assembler-times "endbr32" 1 { target ia32 } } } */
/* { dg-final { scan-assembler-times "endbr64" 1 { target { ! ia32 } } } } */
int
test (int* val)
{
int status = 99;
if (!val)
{
status = 22;
goto end;
}
extern int x;
*val = x;
status = 0;
end:
return status;
}

12
gcc/testsuite/gcc.target/i386/cet-label-4.c Normal file
View file

@ -0,0 +1,12 @@
/* PR target/89355 */
/* { dg-do compile { target { fpic && lp64 } } } */
/* { dg-options "-O2 -fcf-protection -fPIC -mcmodel=large" } */
/* { dg-final { scan-assembler-times "endbr64" 1 } } */
extern int val;
int
test (void)
{
return val;
}

13
gcc/testsuite/gcc.target/i386/cet-label-5.c Normal file
View file

@ -0,0 +1,13 @@
/* PR target/89355 */
/* { dg-do compile } */
/* { dg-options "-O2 -fcf-protection -Wno-return-local-addr" } */
/* { dg-final { scan-assembler-times "endbr32" 1 { target ia32 } } } */
/* { dg-final { scan-assembler-times "endbr64" 1 { target { ! ia32 } } } } */
void *
func (void)
{
return &&bar;
bar:
return 0;
}