tests: expand link test, add link-P test

* tests/.gitignore: Add link-P.
* tests/Makefile.am (check_PROGRAMS): Likewise.
* tests/gen_tests.in (link): Add -a17 option.
(link-P): New test.
* tests/link-P.c: New file.
* tests/link.c: Add checks, print the output based on the presence
of the PATH_TRACING macro.

5 files changed, 48 insertions, 5 deletions

diff --git a/tests/.gitignore b/tests/.gitignore
index 83f1e96f6..eff845cdd 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -467,6 +467,7 @@ lchown
 lchown32
 libtests.a
 link
+link-P
 linkat
 list_sigaction_signum
 llseek
diff --git a/tests/Makefile.am b/tests/Makefile.am
index dfffb8c2c..6cb13c28f 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -249,6 +249,7 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	ksysent \
 	landlock_create_ruleset-success \
 	landlock_create_ruleset-success-y \
+	link-P \
 	list_sigaction_signum \
 	localtime \
 	looping_threads \
diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index 6432e3409..cf5bf17b2 100644
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -479,7 +479,8 @@ landlock_restrict_self -a29
 landlock_restrict_self-y -a29 -y -e trace=landlock_restrict_self 7>/dev/full
 lchown	-a30
 lchown32	-a32
-link
+link	-a17
+link-P	-a17 -e trace=link -P link_sample_old
 linkat
 linkat--secontext	--secontext -e trace=linkat
 linkat--secontext_full	--secontext=full -e trace=linkat
diff --git a/tests/link-P.c b/tests/link-P.c
new file mode 100644
index 000000000..08eb1f0e4
--- /dev/null
+++ b/tests/link-P.c
@@ -0,0 +1,2 @@
+#define PATH_TRACING
+#include "link.c"
diff --git a/tests/link.c b/tests/link.c
index 468086fe5..299211e87 100644
--- a/tests/link.c
+++ b/tests/link.c
@@ -11,17 +11,55 @@
 #ifdef __NR_link
 
 # include <stdio.h>
+# include <string.h>
 # include <unistd.h>
 
 int
 main(void)
 {
-	static const char sample_1[] = "link_sample_old";
-	static const char sample_2[] = "link_sample_new";
+	static const char sample_1_str[] = "link_sample_old";
+	static const char sample_2_str[] = "link_sample_new";
 
-	long rc = syscall(__NR_link, sample_1, sample_2);
+	TAIL_ALLOC_OBJECT_CONST_ARR(char, sample_1, sizeof(sample_1_str));
+	TAIL_ALLOC_OBJECT_CONST_ARR(char, sample_2, sizeof(sample_2_str));
+	TAIL_ALLOC_OBJECT_CONST_ARR(char, short_1, sizeof(sample_1_str) - 1);
+	TAIL_ALLOC_OBJECT_CONST_ARR(char, short_2, sizeof(sample_2_str) - 1);
+
+	long rc;
+
+	memcpy(sample_1, sample_1_str, sizeof(sample_1_str));
+	memcpy(sample_2, sample_2_str, sizeof(sample_2_str));
+	memcpy(short_1, sample_1_str, sizeof(sample_1_str) - 1);
+	memcpy(short_2, sample_2_str, sizeof(sample_2_str) - 1);
+
+	rc = syscall(__NR_link, NULL, NULL);
+# ifndef PATH_TRACING
+	printf("link(NULL, NULL) = %ld %s (%m)\n", rc, errno2name());
+# endif
+
+	rc = syscall(__NR_link, short_1, NULL);
+# ifndef PATH_TRACING
+	printf("link(%p, NULL) = %ld %s (%m)\n",
+	       short_1, rc, errno2name());
+# endif
+
+	rc = syscall(__NR_link, NULL, sample_1);
+	printf("link(NULL, \"%s\") = %ld %s (%m)\n",
+	       sample_1_str, rc, errno2name());
+
+	rc = syscall(__NR_link, sample_1, short_2);
+	printf("link(\"%s\", %p) = %ld %s (%m)\n",
+	       sample_1_str, short_2, rc, errno2name());
+
+	rc = syscall(__NR_link, short_1, sample_2);
+# ifndef PATH_TRACING
+	printf("link(%p, \"%s\") = %ld %s (%m)\n",
+	       short_1, sample_2_str, rc, errno2name());
+# endif
+
+	rc = syscall(__NR_link, sample_1, sample_2);
 	printf("link(\"%s\", \"%s\") = %ld %s (%m)\n",
-	       sample_1, sample_2, rc, errno2name());
+	       sample_1_str, sample_2_str, rc, errno2name());
 
 	puts("+++ exited with 0 +++");
 	return 0;