From 493e881e51d767c98dd1d9583990aee656451510 Mon Sep 17 00:00:00 2001
From: "Lee, Chun-Yi" <jlee@suse.com>
Date: Wed, 29 Nov 2017 18:19:44 +0800
Subject: [PATCH 2/4] MODSIGN: print appropriate status message when getting
 UEFI certificates list
Patch-mainline: No, submitted https://patchwork.kernel.org/patch/10082319/
References: fate#316531, bnc#854875

When getting certificates list from UEFI variable, the original error
message shows the state number from UEFI firmware. It's hard to be read
by human. This patch changed the error message to show the appropriate
string.

The message will be showed as:

[    0.788529] MODSIGN: Couldn't get UEFI MokListRT: EFI_NOT_FOUND
[    0.788537] MODSIGN: Couldn't get UEFI MokListXRT: EFI_NOT_FOUND

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
---
 certs/load_uefi.c   |   43 ++++++++++++++++++++++++++++++-------------
 include/linux/efi.h |   25 +++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 13 deletions(-)

--- a/certs/load_uefi.c
+++ b/certs/load_uefi.c
@@ -4,6 +4,7 @@
 #include <linux/err.h>
 #include <linux/efi.h>
 #include <linux/slab.h>
+#include <linux/ucs2_string.h>
 #include <keys/asymmetric-type.h>
 #include <keys/system_keyring.h>
 #include "internal.h"
@@ -32,6 +33,24 @@ static __init bool uefi_check_ignore_db(
 	return status == EFI_SUCCESS;
 }
 
+static __init void print_get_fail(efi_char16_t *char16_str, efi_status_t status)
+{
+	char *utf8_str;
+	unsigned long utf8_size;
+
+	if (!char16_str)
+		return;
+	utf8_size = ucs2_utf8size(char16_str) + 1;
+	utf8_str = kmalloc(utf8_size, GFP_KERNEL);
+	if (!utf8_str)
+		return;
+	ucs2_as_utf8(utf8_str, char16_str, utf8_size);
+
+	pr_info("MODSIGN: Couldn't get UEFI %s: %s\n",
+		utf8_str, efi_status_to_str(status));
+	kfree(utf8_str);
+}
+
 /*
  * Get a certificate list blob from the named EFI variable.
  */
@@ -45,25 +64,29 @@ static __init void *get_cert_list(efi_ch
 
 	status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
 	if (status != EFI_BUFFER_TOO_SMALL) {
-		pr_err("Couldn't get size: 0x%lx\n", status);
-		return NULL;
+		if (status != EFI_NOT_FOUND)
+			pr_err("Couldn't get size: 0x%lx\n", status);
+		goto err;
 	}
 
 	db = kmalloc(lsize, GFP_KERNEL);
 	if (!db) {
 		pr_err("Couldn't allocate memory for uefi cert list\n");
-		return NULL;
+		goto err;
 	}
 
 	status = efi.get_variable(name, guid, NULL, &lsize, db);
 	if (status != EFI_SUCCESS) {
 		kfree(db);
 		pr_err("Error reading db var: 0x%lx\n", status);
-		return NULL;
+		goto err;
 	}
 
 	*size = lsize;
 	return db;
+err:
+	print_get_fail(name, status);
+	return NULL;
 }
 
 /*
@@ -153,9 +176,7 @@ static int __init load_uefi_certs(void)
 	 */
 	if (!uefi_check_ignore_db()) {
 		db = get_cert_list(L"db", &secure_var, &dbsize);
-		if (!db) {
-			pr_err("MODSIGN: Couldn't get UEFI db list\n");
-		} else {
+		if (db) {
 			rc = parse_efi_signature_list("UEFI:db",
 						      db, dbsize, get_handler_for_db);
 			if (rc)
@@ -165,9 +186,7 @@ static int __init load_uefi_certs(void)
 	}
 
 	dbx = get_cert_list(L"dbx", &secure_var, &dbxsize);
-	if (!dbx) {
-		pr_info("MODSIGN: Couldn't get UEFI dbx list\n");
-	} else {
+	if (dbx) {
 		rc = parse_efi_signature_list("UEFI:dbx",
 					      dbx, dbxsize,
 					      get_handler_for_dbx);
@@ -181,9 +200,7 @@ static int __init load_uefi_certs(void)
 		return 0;
 
 	mok = get_cert_list(L"MokListRT", &mok_var, &moksize);
-	if (!mok) {
-		pr_info("MODSIGN: Couldn't get UEFI MokListRT\n");
-	} else {
+	if (mok) {
 		rc = parse_efi_signature_list("UEFI:MokListRT",
 					      mok, moksize, get_handler_for_db);
 		if (rc)
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1640,4 +1640,29 @@ struct linux_efi_memreserve {
 #define EFI_MEMRESERVE_COUNT(size) (((size) - sizeof(struct linux_efi_memreserve)) \
 	/ sizeof(((struct linux_efi_memreserve *)0)->entry[0]))
 
+#define EFI_STATUS_STR(_status)				\
+	case EFI_##_status:				\
+		return "EFI_" __stringify(_status);	\
+
+static inline char *
+efi_status_to_str(efi_status_t status)
+{
+	switch (status) {
+	EFI_STATUS_STR(SUCCESS)
+	EFI_STATUS_STR(LOAD_ERROR)
+	EFI_STATUS_STR(INVALID_PARAMETER)
+	EFI_STATUS_STR(UNSUPPORTED)
+	EFI_STATUS_STR(BAD_BUFFER_SIZE)
+	EFI_STATUS_STR(BUFFER_TOO_SMALL)
+	EFI_STATUS_STR(NOT_READY)
+	EFI_STATUS_STR(DEVICE_ERROR)
+	EFI_STATUS_STR(WRITE_PROTECTED)
+	EFI_STATUS_STR(OUT_OF_RESOURCES)
+	EFI_STATUS_STR(NOT_FOUND)
+	EFI_STATUS_STR(ABORTED)
+	EFI_STATUS_STR(SECURITY_VIOLATION)
+	}
+
+	return "";
+}
 #endif /* _LINUX_EFI_H */