term/ns8250-spcr: return if redirection is disabled

Compared to previous commit, this is a better approach to handle SPCR null base
address indicating no redirection, doing the null check on the caller instead of
the callee.

Resolves: #RHEL-68622
Signed-off-by: Leo Sandoval <lsandova@redhat.com>

0284-term-ns8250-return-null-in-case-of-a-null-address.patch

@@ -1,29 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Leo Sandoval <lsandova@redhat.com>
-Date: Wed, 8 Jan 2025 10:24:26 -0600
-Subject: [PATCH] term/ns8250: return in case of a null SPCR base addresses
-
-Serial SPCR MMIO null address are invalid, so return from function, otherwise
-invalid 'mmio,0' port names are generated halting the system when running
-terminal_input|output commands.
-
-Resolves: #RHEL-68622
-Signed-off-by: Leo Sandoval <lsandova@redhat.com>
----
- grub-core/term/ns8250.c | 3 +++
- 1 file changed, 3 insertions(+)
-
-diff --git a/grub-core/term/ns8250.c b/grub-core/term/ns8250.c
-index 23e8e0904..4ac0bc06a 100644
---- a/grub-core/term/ns8250.c
-+++ b/grub-core/term/ns8250.c
-@@ -407,6 +407,9 @@ grub_serial_ns8250_add_mmio (grub_addr_t addr, unsigned int acc_size,
-   struct grub_serial_port *p;
-   unsigned i;
- 
-+  if (addr == NULL)
-+    return NULL;
-+
-   for (i = 0; i < GRUB_SERIAL_PORT_NUM; i++)
-     if (com_ports[i].use_mmio == true && com_ports[i].mmio.base == addr)
-       {

0284-term-ns8250-spcr-return-if-redirection-is-disabled.patch

@@ -0,0 +1,35 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
+Date: Thu, 16 Jan 2025 10:22:48 -0600
+Subject: [PATCH] term/ns8250-spcr: return if redirection is disabled
+
+The Microsoft spec for SPCR says "The base address of the Serial Port register
+set described using the ACPI Generic Address Structure, or 0 if console
+redirection is disabled." so return if disable (base address = 0). If this check
+is not done, we may get invalid ports for those particular machines that
+redirection is disabled and at some point hanging the booting execution when
+reading the grub.cfg configuration file.
+
+Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
+Reviewed-by: Leo Sandoval <lsandova@redhat.com>
+---
+ grub-core/term/ns8250-spcr.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/grub-core/term/ns8250-spcr.c b/grub-core/term/ns8250-spcr.c
+index d52b52c26..86f1aa078 100644
+--- a/grub-core/term/ns8250-spcr.c
++++ b/grub-core/term/ns8250-spcr.c
+@@ -75,6 +75,11 @@ grub_ns8250_spcr_init (void)
+         config.speed = 115200;
+         break;
+     };
++
++  /* if base address is 0, it means redirection is disable, so return it */
++  if (spcr->base_addr.addr == 0)
++    return NULL;
++
+   switch (spcr->base_addr.space_id)
+     {
+       case GRUB_ACPI_GENADDR_MEM_SPACE:
+

grub.patches

@@ -281,4 +281,4 @@ Patch0280: 0280-grub2-mkconfig-Pass-all-boot-params-when-used-by-ana.patch
 Patch0281: 0281-10_linux.in-escape-semicolon-and-ampersand-on-BLS-up.patch
 Patch0282: 0282-acpi-Fix-out-of-bounds-access-in-grub_acpi_xsdt_find.patch
 Patch0283: 0283-fs-xfs-Fix-large-extent-counters-incompat-feature-su.patch
-Patch0284: 0284-term-ns8250-return-null-in-case-of-a-null-address.patch
+Patch0284: 0284-term-ns8250-spcr-return-if-redirection-is-disabled.patch

grub2.spec

@@ -17,7 +17,7 @@
 Name:		grub2
 Epoch:		1
 Version:	2.12
-Release:	6%{?dist}
+Release:	7%{?dist}
 Summary:	Bootloader with support for Linux, Multiboot and more
 License:	GPL-3.0-or-later
 URL:		http://www.gnu.org/software/grub/
@@ -583,6 +583,10 @@ mv ${EFI_HOME}/grub.cfg.stb ${EFI_HOME}/grub.cfg
 %endif
 
 %changelog
+* Fri Jan 17 2025 Leo Sandoval <lsandova@redhat.com> 2.12-7
+- term/ns8250-spcr: return if redirection is disabled
+- Resolves: #RHEL-68622
+
 * Mon Jan 13 2025 Leo Sandoval <lsandova@redhat.com> 2.12-6
 - term/ns8250: return in case of a null SPCR base addresses
 - Resolves: #RHEL-68622