linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ard Biesheuvel <ardb@kernel.org>
To: linux-efi@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>
Cc: Ard Biesheuvel <ardb@kernel.org>,
	linux-kernel@vger.kernel.org,
	David Hildenbrand <david@redhat.com>,
	Heinrich Schuchardt <xypron.glpk@gmx.de>,
	Tom Lendacky <thomas.lendacky@amd.com>
Subject: [PATCH 2/6] efi/x86: Add RNG seed EFI table to unencrypted mapping check
Date: Fri, 28 Feb 2020 13:14:04 +0100	[thread overview]
Message-ID: <20200228121408.9075-3-ardb@kernel.org> (raw)
In-Reply-To: <20200228121408.9075-1-ardb@kernel.org>

From: Tom Lendacky <thomas.lendacky@amd.com>

When booting with SME active, EFI tables must be mapped unencrypted since
they were built by UEFI in unencrypted memory. Update the list of tables
to be checked during early_memremap() processing to account for the EFI
RNG seed table.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/b64385fc13e5d7ad4b459216524f138e7879234f.1582662842.git.thomas.lendacky@amd.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/x86/platform/efi/efi.c |  1 +
 drivers/firmware/efi/efi.c  | 18 ++++++++++--------
 include/linux/efi.h         |  2 ++
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 0a8117865430..aca9bdd87bca 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -90,6 +90,7 @@ static const unsigned long * const efi_tables[] = {
 #endif
 	&efi.tpm_log,
 	&efi.tpm_final_log,
+	&efi_rng_seed,
 };
 
 u64 efi_setup;		/* efi setup_data physical address */
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 69a585106d30..1e79f77d4e6c 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -45,7 +45,7 @@ struct efi __read_mostly efi = {
 };
 EXPORT_SYMBOL(efi);
 
-static unsigned long __ro_after_init rng_seed = EFI_INVALID_TABLE_ADDR;
+unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR;
 static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
 static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
 
@@ -451,7 +451,7 @@ static const efi_config_table_type_t common_tables[] __initconst = {
 	{SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
 	{EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
 	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi_mem_attr_table},
-	{LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &rng_seed},
+	{LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi_rng_seed},
 	{LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
 	{LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log},
 	{LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &mem_reserve},
@@ -519,11 +519,11 @@ int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
 	pr_cont("\n");
 	set_bit(EFI_CONFIG_TABLES, &efi.flags);
 
-	if (rng_seed != EFI_INVALID_TABLE_ADDR) {
+	if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
 		struct linux_efi_random_seed *seed;
 		u32 size = 0;
 
-		seed = early_memremap(rng_seed, sizeof(*seed));
+		seed = early_memremap(efi_rng_seed, sizeof(*seed));
 		if (seed != NULL) {
 			size = seed->size;
 			early_memunmap(seed, sizeof(*seed));
@@ -531,7 +531,8 @@ int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
 			pr_err("Could not map UEFI random seed!\n");
 		}
 		if (size > 0) {
-			seed = early_memremap(rng_seed, sizeof(*seed) + size);
+			seed = early_memremap(efi_rng_seed,
+					      sizeof(*seed) + size);
 			if (seed != NULL) {
 				pr_notice("seeding entropy pool\n");
 				add_bootloader_randomness(seed->bits, seed->size);
@@ -923,7 +924,7 @@ static int update_efi_random_seed(struct notifier_block *nb,
 	if (!kexec_in_progress)
 		return NOTIFY_DONE;
 
-	seed = memremap(rng_seed, sizeof(*seed), MEMREMAP_WB);
+	seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
 	if (seed != NULL) {
 		size = min(seed->size, EFI_RANDOM_SEED_SIZE);
 		memunmap(seed);
@@ -931,7 +932,8 @@ static int update_efi_random_seed(struct notifier_block *nb,
 		pr_err("Could not map UEFI random seed!\n");
 	}
 	if (size > 0) {
-		seed = memremap(rng_seed, sizeof(*seed) + size, MEMREMAP_WB);
+		seed = memremap(efi_rng_seed, sizeof(*seed) + size,
+				MEMREMAP_WB);
 		if (seed != NULL) {
 			seed->size = size;
 			get_random_bytes(seed->bits, seed->size);
@@ -949,7 +951,7 @@ static struct notifier_block efi_random_seed_nb = {
 
 static int __init register_update_efi_random_seed(void)
 {
-	if (rng_seed == EFI_INVALID_TABLE_ADDR)
+	if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
 		return 0;
 	return register_reboot_notifier(&efi_random_seed_nb);
 }
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 2ab33d5d6ca5..e8a08a499131 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -526,6 +526,8 @@ typedef struct {
 	efi_time_t time_of_revocation;
 } efi_cert_x509_sha256_t;
 
+extern unsigned long __ro_after_init efi_rng_seed;		/* RNG Seed table */
+
 /*
  * All runtime access to EFI goes through this structure:
  */
-- 
2.17.1


  parent reply	other threads:[~2020-02-28 12:14 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-28 12:14 [GIT PULL 0/6] More EFI updates for v5.7 Ard Biesheuvel
2020-02-28 12:14 ` [PATCH 1/6] efi/x86: Add TPM related EFI tables to unencrypted mapping checks Ard Biesheuvel
2020-02-28 12:14 ` Ard Biesheuvel [this message]
2020-02-28 12:14 ` [PATCH 3/6] efi: don't shadow i in efi_config_parse_tables() Ard Biesheuvel
2020-02-28 12:14 ` [PATCH 4/6] efi/arm: clean EFI stub exit code from cache instead of avoiding it Ard Biesheuvel
2020-02-28 12:14 ` [PATCH 5/6] efi/arm64: " Ard Biesheuvel
2020-02-28 12:14 ` [PATCH 6/6] efi: mark all EFI runtime services as unsupported on non-EFI boot Ard Biesheuvel
2020-03-04 22:48 ` [GIT PULL 0/6] More EFI updates for v5.7 Ard Biesheuvel

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200228121408.9075-3-ardb@kernel.org \
    --to=ardb@kernel.org \
    --cc=david@redhat.com \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=thomas.lendacky@amd.com \
    --cc=xypron.glpk@gmx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).