[PATCH v2] EISA: Increase length of device names

[Kees Cook <kees@kernel.org>]

GCC 15's -Wunterminated-string-initialization warned about truncated
name strings. Instead of marking them with the "nonstring" attribute[1],
increase their length to correctly include enough space for the
terminating NUL character, as they are used with %s format specifiers
when showing resource allocations in /proc/ioports:

        seq_printf(m, "%*s%0*llx-%0*llx : %s\n", ..., r->name);

The strings in eisa.ids have a max length of 73, and the 50 limit was an
arbitrary limit that was removed back in 2008 with commit ca52a49846f1
("driver core: remove DEVICE_NAME_SIZE define"). Change the limit to 74
so nothing is truncated any more.

Additionally fix the Makefile to use "if_changed" instead of "cmd"
to detect changes to the command line used to generate the target,
otherwise devlist.h won't be rebuilt.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Alejandro Colomar <alx@kernel.org>
Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Azeem Shaikh <azeemshaikh38@gmail.com>
Cc: Alex Elder <elder@kernel.org>
Cc: Sumit Garg <sumit.garg@kernel.org>

 v2: crank length to 74 for full coverage and fix Makefile too
 v1: https://lore.kernel.org/lkml/20250310222424.work.107-kees@kernel.org/
---
 drivers/eisa/Makefile   | 11 ++++-------
 drivers/eisa/eisa-bus.c |  2 +-
 include/linux/eisa.h    |  5 ++++-
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/eisa/Makefile b/drivers/eisa/Makefile
index a1dd0eaec2d4..f0d6cf7d1f32 100644
--- a/drivers/eisa/Makefile
+++ b/drivers/eisa/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 # Makefile for the Linux device tree
 
-obj-$(CONFIG_EISA)	        += eisa-bus.o
+obj-$(CONFIG_EISA)	        += devlist.h eisa-bus.o
 obj-${CONFIG_EISA_PCI_EISA}     += pci_eisa.o
 
 # virtual_root.o should be the last EISA root device to initialize,
@@ -9,14 +9,11 @@ obj-${CONFIG_EISA_PCI_EISA}     += pci_eisa.o
 obj-${CONFIG_EISA_VIRTUAL_ROOT} += virtual_root.o
 
 
-# Ugly hack to get DEVICE_NAME_SIZE value...
-DEVICE_NAME_SIZE = 50
-
 $(obj)/eisa-bus.o: $(obj)/devlist.h
 
 quiet_cmd_eisaid = GEN     $@
-      cmd_eisaid = sed -e '/^\#/D' -e 's/^\([[:alnum:]]\{7\}\) \+"\([^"]\{1,$(DEVICE_NAME_SIZE)\}\).*"/EISA_DEVINFO ("\1", "\2"),/' $< > $@
+      cmd_eisaid = sed -e '/^\#/D' -e 's/^\([[:alnum:]]\{7\}\) \+"\([^"]*\)"/EISA_DEVINFO ("\1", "\2"),/' $< > $@
 
 clean-files := devlist.h
-$(obj)/devlist.h: $(src)/eisa.ids include/linux/device.h
-	$(call cmd,eisaid)
+$(obj)/devlist.h: $(src)/eisa.ids include/linux/device.h FORCE
+	$(call if_changed,eisaid)
diff --git a/drivers/eisa/eisa-bus.c b/drivers/eisa/eisa-bus.c
index cb586a362944..edceea083b98 100644
--- a/drivers/eisa/eisa-bus.c
+++ b/drivers/eisa/eisa-bus.c
@@ -21,7 +21,7 @@
 
 struct eisa_device_info {
 	struct eisa_device_id id;
-	char name[50];
+	char name[EISA_DEVICE_INFO_NAME_SIZE];
 };
 
 #ifdef CONFIG_EISA_NAMES
diff --git a/include/linux/eisa.h b/include/linux/eisa.h
index f98200cae637..21a2ecc1e538 100644
--- a/include/linux/eisa.h
+++ b/include/linux/eisa.h
@@ -28,6 +28,9 @@
 #define EISA_CONFIG_ENABLED         1
 #define EISA_CONFIG_FORCED          2
 
+/* Chosen to hold the longest string in eisa.ids. */
+#define EISA_DEVICE_INFO_NAME_SIZE 74
+
 /* There is not much we can say about an EISA device, apart from
  * signature, slot number, and base address. dma_mask is set by
  * default to parent device mask..*/
@@ -41,7 +44,7 @@ struct eisa_device {
 	u64                   dma_mask;
 	struct device         dev; /* generic device */
 #ifdef CONFIG_EISA_NAMES
-	char		      pretty_name[50];
+	char		      pretty_name[EISA_DEVICE_INFO_NAME_SIZE];
 #endif
 };
 
-- 
2.34.1