[PATCH v3 5/6] fs: provide function to report enum strings

[Kees Cook <keescook@chromium.org>]

Providing human-readable (and audit-parsable) strings for the READING_*
enums is needed by some LSMs.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
v3:
- add general use function, zohar
---
 fs/exec.c          | 19 +++++++++++++++++++
 include/linux/fs.h |  1 +
 2 files changed, 20 insertions(+)

diff --git a/fs/exec.c b/fs/exec.c
index c4010b8207a1..05e71b6c0ef0 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -819,6 +819,25 @@ struct file *open_exec(const char *name)
 }
 EXPORT_SYMBOL(open_exec);
 
+const char *kernel_read_file_id_str(enum kernel_read_file_id id)
+{
+	switch (id) {
+	case READING_FIRMWARE:
+		return "firmware";
+	case READING_MODULE:
+		return "kernel-module";
+	case READING_KEXEC_IMAGE:
+		return "kexec-image";
+	case READING_KEXEC_INITRAMFS:
+		return "kexec-initramfs";
+	case READING_POLICY:
+		return "security-policy";
+	default:
+		return "unknown";
+	}
+}
+EXPORT_SYMBOL(kernel_read_file_id_str);
+
 int kernel_read(struct file *file, loff_t offset,
 		char *addr, unsigned long count)
 {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 304991a80e23..596b403d5a28 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2589,6 +2589,7 @@ enum kernel_read_file_id {
 	READING_MAX_ID
 };
 
+extern const char *kernel_read_file_id_str(enum kernel_read_file_id id);
 extern int kernel_read(struct file *, loff_t, char *, unsigned long);
 extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
 			    enum kernel_read_file_id);
-- 
2.6.3