Commit a1c9d61b authored by Alan Maguire's avatar Alan Maguire Committed by Andrii Nakryiko
Browse files

libbpf: Improve library identification for uprobe binary path resolution 



In the process of doing path resolution for uprobe attach, libraries are
identified by matching a ".so" substring in the binary_path.
This matches a lot of patterns that do not conform to library.so[.version]
format, so instead match a ".so" _suffix_, and if that fails match a
".so." substring for the versioned library case.

Suggested-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlan Maguire <alan.maguire@oracle.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1649245431-29956-2-git-send-email-alan.maguire@oracle.com
parent 9fc4476a

tools/lib/bpf/libbpf.c

+1 −1
Original line number Diff line number Diff line
@@ -10766,7 +10766,7 @@ static int resolve_full_path(const char *file, char *result, size_t result_sz) 
	const char *search_paths[3] = {};

	int i;



	if (strstr(file, ".so")) {

	if (str_has_sfx(file, ".so") || strstr(file, ".so.")) {

		search_paths[0] = getenv("LD_LIBRARY_PATH");

		search_paths[1] = "/usr/lib64:/usr/lib";

		search_paths[2] = arch_specific_lib_paths();

tools/lib/bpf/libbpf_internal.h

+11 −0
Original line number Diff line number Diff line
@@ -103,6 +103,17 @@ 
#define str_has_pfx(str, pfx) \

	(strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0)



/* suffix check */

static inline bool str_has_sfx(const char *str, const char *sfx)

{

	size_t str_len = strlen(str);

	size_t sfx_len = strlen(sfx);



	if (sfx_len <= str_len)

		return strcmp(str + str_len - sfx_len, sfx);

	return false;

}



/* Symbol versioning is different between static and shared library.

 * Properly versioned symbols are needed for shared library, but

 * only the symbol of the new version is needed for static library.