grub2/0003-tpm2-resend-the-command-on-TPM_RC_RETRY.patch

From dcfb996d872a750fc42cb627627a5ac3f6d89a23 Mon Sep 17 00:00:00 2001
From: Gary Lin <glin@suse.com>
Date: Thu, 9 Feb 2023 14:56:05 +0800
Subject: [PATCH 03/13] tpm2: resend the command on TPM_RC_RETRY

Sometimes TPM may return TPM_RC_RETRY for some reason, and the only
thing we can do is to send the command again. To avoid pending in the
while loop indefinitely, just try to send the command 3 times.

Signed-off-by: Gary Lin <glin@suse.com>
---
 grub-core/tpm2/tpm2.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/grub-core/tpm2/tpm2.c b/grub-core/tpm2/tpm2.c
index 5377ad2c7..083d59d02 100644
--- a/grub-core/tpm2/tpm2.c
+++ b/grub-core/tpm2/tpm2.c
@@ -25,11 +25,11 @@
 #include <grub/types.h>
 
 static TPM_RC
-grub_tpm2_submit_command (TPMI_ST_COMMAND_TAG tag,
-                          TPM_CC commandCode,
-                          TPM_RC* responseCode,
-                          const struct grub_tpm2_buffer* in,
-                          struct grub_tpm2_buffer* out)
+grub_tpm2_submit_command_real (const TPMI_ST_COMMAND_TAG tag,
+                               const TPM_CC commandCode,
+                               TPM_RC *responseCode,
+                               const struct grub_tpm2_buffer *in,
+                               struct grub_tpm2_buffer *out)
 {
   grub_err_t err;
   struct grub_tpm2_buffer buf;
@@ -75,6 +75,29 @@ grub_tpm2_submit_command (TPMI_ST_COMMAND_TAG tag,
   return TPM_RC_SUCCESS;
 }
 
+static TPM_RC
+grub_tpm2_submit_command (const TPMI_ST_COMMAND_TAG tag,
+                          const TPM_CC commandCode,
+                          TPM_RC *responseCode,
+                          const struct grub_tpm2_buffer *in,
+                          struct grub_tpm2_buffer *out)
+{
+  TPM_RC err;
+  int retry_cnt = 0;
+
+  /* Catch TPM_RC_RETRY and send the command again */
+  do {
+    err = grub_tpm2_submit_command_real (tag, commandCode, responseCode,
+                                         in, out);
+    if (*responseCode != TPM_RC_RETRY)
+      break;
+
+    retry_cnt++;
+  } while (retry_cnt < 3);
+
+  return err;
+}
+
 TPM_RC
 TPM2_CreatePrimary (const TPMI_RH_HIERARCHY primaryHandle,
                     const TPMS_AUTH_COMMAND *authCommand,
-- 
2.35.3