Patch "sparc: Fix -Wstringop-overflow warning" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

sparc: Fix -Wstringop-overflow warning

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
sparc-fix-wstringop-overflow-warning.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Orlando Arias <[email protected]>
Date: Tue, 16 May 2017 15:34:00 -0400
Subject: sparc: Fix -Wstringop-overflow warning

From: Orlando Arias <[email protected]>

[ Upstream commit deba804c90642c8ed0f15ac1083663976d578f54 ]

Greetings,

GCC 7 introduced the -Wstringop-overflow flag to detect buffer overflows in calls to string handling functions [1][2]. Due to the way ``empty_zero_page'' is declared in arch/sparc/include/setup.h, this causes a warning to trigger at compile time in the function mem_init(), which is subsequently converted to an error. The ensuing patch fixes this issue and aligns the declaration of empty_zero_page to that of other architectures. Thank you.

Cheers,
Orlando.

[1] https://gcc.gnu.org/ml/gcc-patches/2016-10/msg02308.html
[2] https://gcc.gnu.org/gcc-7/changes.html

--------------------------------------------------------------------------------

---
 arch/sparc/include/asm/pgtable_32.h |    4 ++--
 arch/sparc/include/asm/setup.h      |    2 +-
 arch/sparc/mm/init_32.c             |    2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

@@ -91,9 +91,9 @@ extern unsigned long pfn_base;
  * ZERO_PAGE is a global shared page that is always zero: used
  * for zero-mapped memory areas etc..
  */
-extern unsigned long empty_zero_page;
+extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 
-#define ZERO_PAGE(vaddr) (virt_to_page(&empty_zero_page))
+#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
 
 /*
  * In general all page table modifications should use the V8 atomic

@@ -16,7 +16,7 @@ extern char reboot_command[];
  */
 extern unsigned char boot_cpu_id;
 
-extern unsigned long empty_zero_page;
+extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 
 extern int serial_console;
 static inline int con_is_present(void)

@@ -301,7 +301,7 @@ void __init mem_init(void)
 
 
 	/* Saves us work later. */
-	memset((void *)&empty_zero_page, 0, PAGE_SIZE);
+	memset((void *)empty_zero_page, 0, PAGE_SIZE);
 
 	i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
 	i += 1;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/sparc-fix-wstringop-overflow-warning.patch