From: Jean-Philippe Brucker <jean-phili...@linaro.org>
[ Upstream commit 702eddc77a905782083b14ccd05b23840675fd18 ]
When building Arm NEON (SIMD) code from lib/raid6/neon.uc, GCC emits
DWARF information using a base type "__Poly8_t", which is internal to
GCC and not recognized by Clang. This causes build failures when
building with Clang a vmlinux.h generated from an arm64 kernel that was
built with GCC.
vmlinux.h:47284:9: error: unknown type name '__Poly8_t'
typedef __Poly8_t poly8x16_t[16];
^~~~~~~~~
The polyX_t types are defined as unsigned integers in the "Arm C
Language Extension" document (101028_Q220_00_en). Emit typedefs based on
standard integer types for the GCC internal types, similar to those
emitted by Clang.
Including linux/kernel.h to use ARRAY_SIZE() incidentally redefined
max(), causing a build bug due to different types, hence the seemingly
unrelated change.
Reported-by: Jakov Petrina <jakov.petr...@sartura.hr>
Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org>
Signed-off-by: Alexei Starovoitov <a...@kernel.org>
Acked-by: Andrii Nakryiko <andr...@fb.com>
Link:
https://lore.kernel.org/bpf/20200812143909.3293280-1-jean-phili...@linaro.org
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
tools/lib/bpf/btf_dump.c | 35 ++++++++++++++++++++++++++++++++++-
1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index bbb4303172606..4edf76c5a7101 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -13,6 +13,7 @@
#include <errno.h>
#include <linux/err.h>
#include <linux/btf.h>
+#include <linux/kernel.h>
#include "btf.h"
#include "hashmap.h"
#include "libbpf.h"
@@ -548,6 +549,9 @@ static int btf_dump_order_type(struct btf_dump *d, __u32
id, bool through_ptr)
}
}
+static void btf_dump_emit_missing_aliases(struct btf_dump *d, __u32 id,
+ const struct btf_type *t);
+
static void btf_dump_emit_struct_fwd(struct btf_dump *d, __u32 id,
const struct btf_type *t);
static void btf_dump_emit_struct_def(struct btf_dump *d, __u32 id,
@@ -670,6 +674,9 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32
id, __u32 cont_id)
switch (kind) {
case BTF_KIND_INT:
+ /* Emit type alias definitions if necessary */
+ btf_dump_emit_missing_aliases(d, id, t);
+
tstate->emit_state = EMITTED;
break;
case BTF_KIND_ENUM:
@@ -869,7 +876,7 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
btf_dump_printf(d, ": %d", m_sz);
off = m_off + m_sz;
} else {
- m_sz = max(0, btf__resolve_size(d->btf, m->type));
+ m_sz = max(0LL, btf__resolve_size(d->btf, m->type));
off = m_off + m_sz * 8;
}
btf_dump_printf(d, ";");
@@ -889,6 +896,32 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
btf_dump_printf(d, " __attribute__((packed))");
}
+static const char *missing_base_types[][2] = {
+ /*
+ * GCC emits typedefs to its internal __PolyX_t types when compiling Arm
+ * SIMD intrinsics. Alias them to standard base types.
+ */
+ { "__Poly8_t", "unsigned char" },
+ { "__Poly16_t", "unsigned short" },
+ { "__Poly64_t", "unsigned long long" },
+ { "__Poly128_t", "unsigned __int128" },
+};
+
+static void btf_dump_emit_missing_aliases(struct btf_dump *d, __u32 id,
+ const struct btf_type *t)
+{
+ const char *name = btf_dump_type_name(d, id);
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(missing_base_types); i++) {
+ if (strcmp(name, missing_base_types[i][0]) == 0) {
+ btf_dump_printf(d, "typedef %s %s;\n\n",
+ missing_base_types[i][1], name);
+ break;
+ }
+ }
+}
+
static void btf_dump_emit_enum_fwd(struct btf_dump *d, __u32 id,
const struct btf_type *t)
{
--
2.25.1
