attach_probe selftest fails on Debian-based distros with `failed to
resolve full path for 'libc.so.6'`. The reason is that these distros
embraced multiarch to the point where even for the "main" architecture
they store libc in /lib/<triple>.
This is configured in /etc/ld.so.conf and in theory it's possible to
replicate the loader's parsing and processing logic in libbpf, however
a much simpler solution is to just enumerate the known library paths.
Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
---
tools/lib/bpf/libbpf.c | 54 ++++++++++++++++++++++++++++++++++++------
1 file changed, 47 insertions(+), 7 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 6d2be53e4ba9..4f616b11564f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -10707,21 +10707,61 @@ static long elf_find_func_offset(const char *binary_path, const char *name)
return ret;
}
+static void add_debian_library_paths(const char **search_paths, int *n)
+{
+ /*
+ * Based on https://packages.debian.org/sid/libc6.
+ *
+ * Assume that the traced program is built for the same architecture
+ * as libbpf, which should cover the vast majority of cases.
+ */
+#if defined(__x86_64__)
+ search_paths[(*n)++] = "/lib/x86_64-linux-gnu";
+#elif defined(__i386__)
+ search_paths[(*n)++] = "/lib/i386-linux-gnu";
+#elif defined(__s390x__)
+ search_paths[(*n)++] = "/lib/s390x-linux-gnu";
+#elif defined(__s390__)
+ search_paths[(*n)++] = "/lib/s390-linux-gnu";
+#elif defined(__arm__)
+#if defined(__SOFTFP__)
+ search_paths[(*n)++] = "/lib/arm-linux-gnueabi";
+#else
+ search_paths[(*n)++] = "/lib/arm-linux-gnueabihf";
+#endif /* defined(__SOFTFP__) */
+#elif defined(__aarch64__)
+ search_paths[(*n)++] = "/lib/aarch64-linux-gnu";
+#elif defined(__mips__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+#if _MIPS_SZLONG == 64
+ search_paths[(*n)++] = "/lib/mips64el-linux-gnuabi64";
+#elif _MIPS_SZLONG == 32
+ search_paths[(*n)++] = "/lib/mipsel-linux-gnu";
+#endif
+#elif defined(__powerpc__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+ search_paths[(*n)++] = "/lib/powerpc64le-linux-gnu";
+#elif defined(__sparc__)
+ search_paths[(*n)++] = "/lib/sparc64-linux-gnu";
+#elif defined(__riscv) && __riscv_xlen == 64
+ search_paths[(*n)++] = "/lib/riscv64-linux-gnu";
+#endif
+}
+
/* Get full path to program/shared library. */
static int resolve_full_path(const char *file, char *result, size_t result_sz)
{
- const char *search_paths[2];
- int i;
+ const char *search_paths[3];
+ int i, n = 0;
if (strstr(file, ".so")) {
- search_paths[0] = getenv("LD_LIBRARY_PATH");
- search_paths[1] = "/usr/lib64:/usr/lib";
+ search_paths[n++] = getenv("LD_LIBRARY_PATH");
+ search_paths[n++] = "/usr/lib64:/usr/lib";
+ add_debian_library_paths(search_paths, &n);
} else {
- search_paths[0] = getenv("PATH");
- search_paths[1] = "/usr/bin:/usr/sbin";
+ search_paths[n++] = getenv("PATH");
+ search_paths[n++] = "/usr/bin:/usr/sbin";
}
- for (i = 0; i < ARRAY_SIZE(search_paths); i++) {
+ for (i = 0; i < n; i++) {
const char *s;
if (!search_paths[i])
--
2.35.1
