diff options
author | Douglas Raillard <douglas.raillard@arm.com> | 2022-05-24 12:44:47 +0300 |
---|---|---|
committer | Andrii Nakryiko <andrii@kernel.org> | 2022-06-03 02:26:51 +0300 |
commit | 610cd93b44ce1e7323878ef5f7b23dc10c7d45b7 (patch) | |
tree | 6c372b997f6df709c48ea99bfe1d40662aa43246 /tools/lib | |
parent | 4c46091ee985ae84c60c5e95055d779fcd291d87 (diff) | |
download | linux-610cd93b44ce1e7323878ef5f7b23dc10c7d45b7.tar.xz |
libbpf: Fix determine_ptr_size() guessing
One strategy employed by libbpf to guess the pointer size is by finding
the size of "unsigned long" type. This is achieved by looking for a type
of with the expected name and checking its size.
Unfortunately, the C syntax is friendlier to humans than to computers
as there is some variety in how such a type can be named. Specifically,
gcc and clang do not use the same names for integer types in debug info:
- clang uses "unsigned long"
- gcc uses "long unsigned int"
Lookup all the names for such a type so that libbpf can hope to find the
information it wants.
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220524094447.332186-1-douglas.raillard@arm.com
Diffstat (limited to 'tools/lib')
-rw-r--r-- | tools/lib/bpf/btf.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index bb1e06eb1eca..3d6c30d9a575 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -472,9 +472,22 @@ const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id) static int determine_ptr_size(const struct btf *btf) { + static const char * const long_aliases[] = { + "long", + "long int", + "int long", + "unsigned long", + "long unsigned", + "unsigned long int", + "unsigned int long", + "long unsigned int", + "long int unsigned", + "int unsigned long", + "int long unsigned", + }; const struct btf_type *t; const char *name; - int i, n; + int i, j, n; if (btf->base_btf && btf->base_btf->ptr_sz > 0) return btf->base_btf->ptr_sz; @@ -485,15 +498,16 @@ static int determine_ptr_size(const struct btf *btf) if (!btf_is_int(t)) continue; + if (t->size != 4 && t->size != 8) + continue; + name = btf__name_by_offset(btf, t->name_off); if (!name) continue; - if (strcmp(name, "long int") == 0 || - strcmp(name, "long unsigned int") == 0) { - if (t->size != 4 && t->size != 8) - continue; - return t->size; + for (j = 0; j < ARRAY_SIZE(long_aliases); j++) { + if (strcmp(name, long_aliases[j]) == 0) + return t->size; } } |