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| author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-04-24 17:36:02 +0100 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-04-30 13:08:13 +0100 |
| commit | 6ac83d350604c3e934d5e8a455ba7ec1c1c0240b (patch) | |
| tree | 8b9427647583160e8ccb026c6a5e718a070aa25a /gcc | |
| parent | 852c4b04520d19d5a75e7f9ec5a5d980d5d1acc8 (diff) | |
| download | gcc-6ac83d350604c3e934d5e8a455ba7ec1c1c0240b.zip gcc-6ac83d350604c3e934d5e8a455ba7ec1c1c0240b.tar.gz gcc-6ac83d350604c3e934d5e8a455ba7ec1c1c0240b.tar.bz2 | |
aarch64: don't emit bti j after NOTE_INSN_DELETED_LABEL [PR94748]
It was previously discussed that indirect branches cannot go to
NOTE_INSN_DELETED_LABEL so inserting a landing pad is unnecessary.
See https://gcc.gnu.org/pipermail/gcc-patches/2019-May/522625.html
Before the patch a bti j was inserted after the label in
__attribute__((target("branch-protection=bti")))
int foo (void)
{
label:
return 0;
}
This is not necessary and weakens the security protection.
gcc/ChangeLog:
PR target/94748
* config/aarch64/aarch64-bti-insert.c (rest_of_insert_bti): Remove
the check for NOTE_INSN_DELETED_LABEL.
gcc/testsuite/ChangeLog:
PR target/94748
* gcc.target/aarch64/pr94748.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/config/aarch64/aarch64-bti-insert.c | 8 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/aarch64/pr94748.c | 10 |
4 files changed, 23 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 5b69334..c81801f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2020-04-30 Szabolcs Nagy <szabolcs.nagy@arm.com> + + PR target/94748 + * config/aarch64/aarch64-bti-insert.c (rest_of_insert_bti): Remove + the check for NOTE_INSN_DELETED_LABEL. + 2020-04-30 Jakub Jelinek <jakub@redhat.com> * configure.ac (--with-documentation-root-url, diff --git a/gcc/config/aarch64/aarch64-bti-insert.c b/gcc/config/aarch64/aarch64-bti-insert.c index aa091c3..57663ee 100644 --- a/gcc/config/aarch64/aarch64-bti-insert.c +++ b/gcc/config/aarch64/aarch64-bti-insert.c @@ -139,14 +139,10 @@ rest_of_insert_bti (void) insn = NEXT_INSN (insn)) { /* If a label is marked to be preserved or can be a non-local goto - target, it must be protected with a BTI J. The same applies to - NOTE_INSN_DELETED_LABEL since they are basically labels that might - be referenced via variables or constant pool. */ - if ((LABEL_P (insn) + target, it must be protected with a BTI J. */ + if (LABEL_P (insn) && (LABEL_PRESERVE_P (insn) || bb->flags & BB_NON_LOCAL_GOTO_TARGET)) - || (NOTE_P (insn) - && NOTE_KIND (insn) == NOTE_INSN_DELETED_LABEL)) { bti_insn = gen_bti_j (); emit_insn_after (bti_insn, insn); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 9d5944b..66ac670 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-04-30 Szabolcs Nagy <szabolcs.nagy@arm.com> + + PR target/94748 + * gcc.target/aarch64/pr94748.c: New test. + 2020-04-30 Andreas Krebbel <krebbel@linux.ibm.com> * gcc.target/s390/zvector/vec_load_len_r.c: New test. diff --git a/gcc/testsuite/gcc.target/aarch64/pr94748.c b/gcc/testsuite/gcc.target/aarch64/pr94748.c new file mode 100644 index 0000000..2a2850d --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/pr94748.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ + +__attribute__ ((target("branch-protection=bti"))) +int foo () +{ +label: + return 0; +} + +/* { dg-final { scan-assembler-not {hint (36|38) // bti (j|jc)} } } */ |