linux-kernel - [PATCH] ARM: xip: Use correct symbol for end of ROM marker

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 11 Nov 2015 09:17:35 -0500
From:	Chris Brandt <chris.brandt@...esas.com>
To:	linux@....linux.org.uk, arnd@...db.de
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linux-sh@...r.kernel.org, Chris Brandt <chris.brandt@...esas.com>
Subject: [PATCH] ARM: xip: Use correct symbol for end of ROM marker

For an XIP build, _edata_loc, not _etext, represents the end of the
binary image that will be programmed into ROM and mapped into the
MODULES_VADDR area.
With an XIP kernel, nothing is loaded into RAM before boot, meaning
you have to take into account the size of the entire binary image
that was programmed, including the init data values that will be copied
to RAM during kernel boot.

This fixes the bug where you might lose the end of your kernel area
after page table setup is complete.


Signed-off-by: Chris Brandt <chris.brandt@...esas.com>
---
 arch/arm/mm/mmu.c              |    4 ++--
 include/asm-generic/sections.h |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 4867f5d..dd5a56b 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1210,7 +1210,7 @@ static inline void prepare_page_table(void)
 
 #ifdef CONFIG_XIP_KERNEL
 	/* The XIP kernel is mapped in the module area -- skip over it */
-	addr = ((unsigned long)_etext + PMD_SIZE - 1) & PMD_MASK;
+	addr = ((unsigned long)_edata_loc + PMD_SIZE - 1) & PMD_MASK;
 #endif
 	for ( ; addr < PAGE_OFFSET; addr += PMD_SIZE)
 		pmd_clear(pmd_off_k(addr));
@@ -1292,7 +1292,7 @@ static void __init devicemaps_init(const struct machine_desc *mdesc)
 #ifdef CONFIG_XIP_KERNEL
 	map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);
 	map.virtual = MODULES_VADDR;
-	map.length = ((unsigned long)_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;
+	map.length = ((unsigned long)_edata_loc - map.virtual + ~SECTION_MASK) & SECTION_MASK;
 	map.type = MT_ROM;
 	create_mapping(&map);
 #endif
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index b58fd66..195554d 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -26,7 +26,7 @@
  *	__ctors_start, __ctors_end
  */
 extern char _text[], _stext[], _etext[];
-extern char _data[], _sdata[], _edata[];
+extern char _data[], _sdata[], _edata[], _edata_loc[];
 extern char __bss_start[], __bss_stop[];
 extern char __init_begin[], __init_end[];
 extern char _sinittext[], _einittext[];
-- 
1.7.9.5


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/