selftests/mm: skip uprobe vma merge test if uprobes are not enabled

If uprobes are not enabled, the test currently fails with:

7151 12:46:54.627936  # # #  RUN           merge.handle_uprobe_upon_merged_vma ...
7152 12:46:54.639014  # # f /sys/bus/event_source/devices/uprobe/type
7153 12:46:54.639306  # # fopen: No such file or directory
7154 12:46:54.650451  # # # merge.c:473:handle_uprobe_upon_merged_vma:Expected
read_sysfs("/sys/bus/event_source/devices/uprobe/type", &type) (1) == 0 (0)
7155 12:46:54.650730  # # # handle_uprobe_upon_merged_vma: Test terminated by assertion
7156 12:46:54.661750  # # #          FAIL  merge.handle_uprobe_upon_merged_vma
7157 12:46:54.662030  # # not ok 8 merge.handle_uprobe_upon_merged_vma

Skipping is a more sane and friendly behavior here.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: efe99fa ("selftests/mm: add test about uprobe pte be orphan during vma merge")
Signed-off-by: Pedro Falcato <[email protected]>
Reported-by: Aishwarya <[email protected]>
Closes: https://lore.kernel.org/linux-mm/[email protected]/
Reviewed-by: Lorenzo Stoakes <[email protected]>
Tested-by : Donet Tom <[email protected]>
Reviewed-by : Donet Tom <[email protected]>
Reviewed-by: Dev Jain <[email protected]>
Reviewed-by: Pu Lehui <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: heatd

tools/testing/selftests/mm/merge.c

@@ -470,7 +470,9 @@ TEST_F(merge, handle_uprobe_upon_merged_vma)
 	ASSERT_GE(fd, 0);
 
 	ASSERT_EQ(ftruncate(fd, page_size), 0);
-	ASSERT_EQ(read_sysfs("/sys/bus/event_source/devices/uprobe/type", &type), 0);
+	if (read_sysfs("/sys/bus/event_source/devices/uprobe/type", &type) != 0) {
+		SKIP(goto out, "Failed to read uprobe sysfs file, skipping");
+	}
 
 	memset(&attr, 0, attr_sz);
 	attr.size = attr_sz;
@@ -491,6 +493,7 @@ TEST_F(merge, handle_uprobe_upon_merged_vma)
 	ASSERT_NE(mremap(ptr2, page_size, page_size,
 			 MREMAP_MAYMOVE | MREMAP_FIXED, ptr1), MAP_FAILED);
 
+out:
 	close(fd);
 	remove(probe_file);
 }