The old method for computing a member index for a CO-RE relocation
relied on a name comparison, which could SEGV if the member in question
is itself part of an anonymous inner struct or union.
This patch changes the index computation to not rely on a name, while
maintaining the ability to account for other sibling fields which may
not have a representation in BTF.
Tested in bpf-unknown-none, no known regressions.
OK?
Thanks.
gcc/ChangeLog:
PR target/106745
* config/bpf/coreout.cc (bpf_core_get_sou_member_index): Fix
computation of index for anonymous members.
gcc/testsuite/ChangeLog:
PR target/106745
* gcc.target/bpf/core-pr106745.c: New test.
---
gcc/config/bpf/coreout.cc | 19 +++++++++----
gcc/testsuite/gcc.target/bpf/core-pr106745.c | 30 ++++++++++++++++++++
2 files changed, 44 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/bpf/core-pr106745.c
diff --git a/gcc/config/bpf/coreout.cc b/gcc/config/bpf/coreout.cc
index cceaaa969cc..caad4380fa1 100644
--- a/gcc/config/bpf/coreout.cc
+++ b/gcc/config/bpf/coreout.cc
@@ -207,7 +207,6 @@ bpf_core_get_sou_member_index (ctf_container_ref ctfc,
const tree node)
if (TREE_CODE (node) == FIELD_DECL)
{
const tree container = DECL_CONTEXT (node);
- const char * name = IDENTIFIER_POINTER (DECL_NAME (node));
/* Lookup the CTF type info for the containing type. */
dw_die_ref die = lookup_type_die (container);
@@ -222,16 +221,26 @@ bpf_core_get_sou_member_index (ctf_container_ref ctfc,
const tree node)
if (kind != CTF_K_STRUCT && kind != CTF_K_UNION)
return -1;
+ tree field = TYPE_FIELDS (container);
int i = 0;
ctf_dmdef_t * dmd;
for (dmd = dtd->dtd_u.dtu_members;
dmd != NULL; dmd = (ctf_dmdef_t *) ctf_dmd_list_next (dmd))
{
if (get_btf_id (dmd->dmd_type) > BTF_MAX_TYPE)
- continue;
- if (strcmp (dmd->dmd_name, name) == 0)
- return i;
- i++;
+ {
+ /* This field does not have a BTF representation. */
+ if (field == node)
+ return -1;
+ }
+ else
+ {
+ if (field == node)
+ return i;
+ i++;
+ }
+
+ field = DECL_CHAIN (field);
}
}
return -1;
diff --git a/gcc/testsuite/gcc.target/bpf/core-pr106745.c
b/gcc/testsuite/gcc.target/bpf/core-pr106745.c
new file mode 100644
index 00000000000..9d347006a69
--- /dev/null
+++ b/gcc/testsuite/gcc.target/bpf/core-pr106745.c
@@ -0,0 +1,30 @@
+/* { dg-do compile } */
+/* { dg-options "-O0 -gbtf -dA -mco-re" } */
+
+struct weird
+{
+ struct
+ {
+ int b;
+ };
+
+ char x;
+
+ union
+ {
+ int a;
+ int c;
+ };
+};
+
+
+int test (struct weird *arg) {
+ int *x = __builtin_preserve_access_index (&arg->b);
+ int *y = __builtin_preserve_access_index (&arg->c);
+
+ return *x + *y;
+}
+
+
+/* { dg-final { scan-assembler-times "ascii \"0:0:0.0\"\[\t
\]+\[^\n\]*btf_aux_string" 1 } } */
+/* { dg-final { scan-assembler-times "ascii \"0:2:1.0\"\[\t
\]+\[^\n\]*btf_aux_string" 1 } } */
--
2.36.1
