[PATCH RFCv4 4/4] lib/test_printf.c: add test cases for '%pD'

[Jia He <justin.he@xxxxxxx>]

After the behaviour of specifier '%pD' is changed to print full path
of struct file, the related test cases are also updated.

Given the string of '%pD' is prepended from the end of the buffer, the
check of "wrote beyond the nul-terminator" should be skipped.

Signed-off-by: Jia He <justin.he@xxxxxxx>
---
 lib/test_printf.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/lib/test_printf.c b/lib/test_printf.c
index d1d2f898ebae..9f851a82b3af 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -16,6 +16,7 @@
 
 #include <linux/bitmap.h>
 #include <linux/dcache.h>
+#include <linux/fs.h>
 #include <linux/socket.h>
 #include <linux/in.h>
 
@@ -34,6 +35,7 @@ KSTM_MODULE_GLOBALS();
 
 static char *test_buffer __initdata;
 static char *alloced_buffer __initdata;
+static bool is_prepended_buf __initdata;
 
 extern bool no_hash_pointers;
 
@@ -78,7 +80,7 @@ do_test(int bufsize, const char *expect, int elen,
 		return 1;
 	}
 
-	if (memchr_inv(test_buffer + written + 1, FILL_CHAR, bufsize - (written + 1))) {
+	if (!is_prepended_buf && memchr_inv(test_buffer + written + 1, FILL_CHAR, bufsize - (written + 1))) {
 		pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
 			bufsize, fmt);
 		return 1;
@@ -501,6 +503,27 @@ dentry(void)
 	test("  bravo/alfa|  bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
 }
 
+static struct vfsmount test_vfsmnt __initdata = {};
+
+static struct file test_file __initdata = {
+	.f_path = { .dentry = &test_dentry[2],
+		    .mnt = &test_vfsmnt,
+	},
+};
+
+static void __init
+f_d_path(void)
+{
+	test("(null)", "%pD", NULL);
+	test("(efault)", "%pD", PTR_INVALID);
+
+	is_prepended_buf = true;
+	test("/bravo/alfa   |/bravo/alfa   ", "%-14pD|%*pD", &test_file, -14, &test_file);
+	test("   /bravo/alfa|   /bravo/alfa", "%14pD|%*pD", &test_file, 14, &test_file);
+	test("   /bravo/alfa|/bravo/alfa   ", "%14pD|%-14pD", &test_file, &test_file);
+	is_prepended_buf = false;
+}
+
 static void __init
 struct_va_format(void)
 {
@@ -784,6 +807,7 @@ test_pointer(void)
 	ip();
 	uuid();
 	dentry();
+	f_d_path();
 	struct_va_format();
 	time_and_date();
 	struct_clk();
-- 
2.17.1