diff options
| author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-04-24 17:36:02 +0100 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-05-14 13:16:29 +0100 |
| commit | 9a1b74d49e2e25b29675fac4322bb7ba6cec5894 (patch) | |
| tree | 8e954596def3df9c1eba8d860aed105fee156d1a | |
| parent | f6e42cdee5de2b3441afc88c8888c1166bdffe57 (diff) | |
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:
Backport from mainline.
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.
gcc/testsuite/ChangeLog:
Backport from mainline.
2020-04-30 Szabolcs Nagy <szabolcs.nagy@arm.com>
PR target/94748
* gcc.target/aarch64/pr94748.c: New test.
| -rw-r--r-- | gcc/ChangeLog | 9 | ||||
| -rw-r--r-- | gcc/config/aarch64/aarch64-bti-insert.c | 8 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/aarch64/pr94748.c | 10 |
4 files changed, 29 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1b814c7308b..80a48f8341c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,6 +1,15 @@ 2020-05-14 Szabolcs Nagy <szabolcs.nagy@arm.com> Backport from mainline. + 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. + +2020-05-14 Szabolcs Nagy <szabolcs.nagy@arm.com> + + Backport from mainline. 2020-04-23 Szabolcs Nagy <szabolcs.nagy@arm.com> PR target/94697 diff --git a/gcc/config/aarch64/aarch64-bti-insert.c b/gcc/config/aarch64/aarch64-bti-insert.c index 9e0fc168435..7da89074ce0 100644 --- a/gcc/config/aarch64/aarch64-bti-insert.c +++ b/gcc/config/aarch64/aarch64-bti-insert.c @@ -137,14 +137,10 @@ 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 a642d0f9a19..b69958e23d0 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,6 +1,14 @@ 2020-05-14 Szabolcs Nagy <szabolcs.nagy@arm.com> Backport from mainline. + 2020-04-30 Szabolcs Nagy <szabolcs.nagy@arm.com> + + PR target/94748 + * gcc.target/aarch64/pr94748.c: New test. + +2020-05-14 Szabolcs Nagy <szabolcs.nagy@arm.com> + + Backport from mainline. 2020-04-27 Szabolcs Nagy <szabolcs.nagy@arm.com> PR target/94515 diff --git a/gcc/testsuite/gcc.target/aarch64/pr94748.c b/gcc/testsuite/gcc.target/aarch64/pr94748.c new file mode 100644 index 00000000000..2a2850d2fac --- /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)} } } */ |