[PATCH 1/1] arm/module: maximum utilization of module area.

From: Maninder Singh
Date: Tue Dec 06 2016 - 03:45:50 EST


This patch defines new macro MODULE_START to ensure kernel text
and module remains within 32 MB of address range.

Tried this patch by inserting 20 MB size module on 4.1 kernel:-

Earlier:-
==========
sh# insmod size.ko
....
insmod: ERROR: could not insert module size.ko: Cannot allocate memory
sh#

With this patch
===============
sh# insmod size.ko
...
sh# lsmod
Module Size Used by
size 20972425 0

Signed-off-by: Vaneet Narang <v.narang@xxxxxxxxxxx>
Signed-off-by: Maninder Singh <maninder1.s@xxxxxxxxxxx>
Reviewed-by: Ajeet Yadav <ajeet.y@xxxxxxxxxxx>
---
arch/arm/include/asm/memory.h | 4 ++--
arch/arm/kernel/module.c | 9 ++++++++-
2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index 76cbd9c..1a0a6e5 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -37,7 +37,7 @@
* TASK_SIZE - the maximum size of a user space task.
* TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area
*/
-#define TASK_SIZE (UL(CONFIG_PAGE_OFFSET) - UL(SZ_16M))
+#define TASK_SIZE (UL(CONFIG_PAGE_OFFSET) - UL(SZ_32M))
#define TASK_UNMAPPED_BASE ALIGN(TASK_SIZE / 3, SZ_16M)

/*
@@ -50,7 +50,7 @@
* and PAGE_OFFSET - it must be within 32MB of the kernel text.
*/
#ifndef CONFIG_THUMB2_KERNEL
-#define MODULES_VADDR (PAGE_OFFSET - SZ_16M)
+#define MODULES_VADDR (PAGE_OFFSET - SZ_32M)
#else
/* smaller range for Thumb-2 symbols relocation (2^24)*/
#define MODULES_VADDR (PAGE_OFFSET - SZ_8M)
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index 4f14b5c..b8e1f9c 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -35,12 +35,19 @@
*/
#undef MODULES_VADDR
#define MODULES_VADDR (((unsigned long)_exiprom + ~PMD_MASK) & PMD_MASK)
+#define MODULES_START MODULES_VADDR
+#else
+#ifndef CONFIG_THUMB2_KERNEL
+#define MODULES_START ALIGN((unsigned long)_etext - SZ_32M, PAGE_SIZE)
+#else
+#define MODULES_START MODULES_VADDR
+#endif
#endif

#ifdef CONFIG_MMU
void *module_alloc(unsigned long size)
{
- void *p = __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
+ void *p = __vmalloc_node_range(size, 1, MODULES_START, MODULES_END,
GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
__builtin_return_address(0));
if (!IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || p)
--
1.9.1