File 0001-tpm-Disable-tpm-verifier-if-tpm-is-not-pre... of Package grub2

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File 0001-tpm-Disable-tpm-verifier-if-tpm-is-not-present.patch of Package grub2

From 12378be5243c1c02ce28de2e5703e87197c69157 Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Mon, 29 Aug 2022 11:28:28 +0800
Subject: [PATCH] tpm: Disable tpm verifier if tpm is not present

This helps to prevent out of memory error when reading large files via disablig
tpm device as verifier has to read all content into memory in one chunk to
measure the hash and extend to tpm.

Signed-off-by: Michael Chang <mchang@suse.com>
---
 grub-core/commands/efi/tpm.c |   37 +++++++++++++++++++++++++++++++++++++
 grub-core/commands/tpm.c     |    4 ++++
 include/grub/tpm.h           |    1 +
 3 files changed, 42 insertions(+)

--- a/grub-core/commands/efi/tpm.c
+++ b/grub-core/commands/efi/tpm.c
@@ -349,3 +349,40 @@
 
   return result;
 }
+
+int
+grub_tpm_present ()
+{
+  grub_efi_handle_t tpm_handle;
+  grub_efi_uint8_t protocol_version;
+
+  if (!grub_tpm_handle_find (&tpm_handle, &protocol_version))
+    return 0;
+
+  if (protocol_version == 1)
+    {
+      grub_efi_tpm_protocol_t *tpm;
+
+      tpm = grub_efi_open_protocol (tpm_handle, &tpm_guid,
+				    GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+      if (!tpm)
+	{
+	  grub_dprintf ("tpm", "Cannot open TPM protocol\n");
+	  return 0;
+	}
+      return grub_tpm1_present (tpm);
+    }
+  else
+    {
+      grub_efi_tpm2_protocol_t *tpm;
+
+      tpm = grub_efi_open_protocol (tpm_handle, &tpm2_guid,
+				    GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+      if (!tpm)
+	{
+	  grub_dprintf ("tpm", "Cannot open TPM protocol\n");
+	  return 0;
+	}
+      return grub_tpm2_present (tpm);
+    }
+}
--- a/grub-core/commands/tpm.c
+++ b/grub-core/commands/tpm.c
@@ -291,6 +291,8 @@
 
 GRUB_MOD_INIT (tpm)
 {
+  if (!grub_tpm_present())
+    return;
   grub_verifier_register (&grub_tpm_verifier);
 
   cmd = grub_register_extcmd ("tpm_record_pcrs", grub_tpm_record_pcrs, 0,
@@ -301,6 +303,8 @@
 
 GRUB_MOD_FINI (tpm)
 {
+  if (!grub_tpm_present())
+    return;
   grub_verifier_unregister (&grub_tpm_verifier);
   grub_unregister_extcmd (cmd);
 }
--- a/include/grub/tpm.h
+++ b/include/grub/tpm.h
@@ -44,5 +44,6 @@
 			     grub_uint8_t pcr, const char *description);
 struct grub_tpm_digest *grub_tpm_read_pcr (grub_uint8_t index, const char *algo);
 void grub_tpm_digest_free (struct grub_tpm_digest *d);
+int grub_tpm_present (void);
 
 #endif

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File 0001-tpm-Disable-tpm-verifier-if-tpm-is-not-present.patch of Package grub2

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