Messages in this thread | | | From | Ard Biesheuvel <> | Date | Tue, 6 Dec 2016 09:13:10 +0000 | Subject | Re: [PATCH 1/1] arm/module: maximum utilization of module area. |
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On 6 December 2016 at 08:29, Maninder Singh <maninder1.s@samsung.com> wrote: > 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@samsung.com> > Signed-off-by: Maninder Singh <maninder1.s@samsung.com> > Reviewed-by: Ajeet Yadav <ajeet.y@samsung.com> > --- > 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)
On a multi_v7_defconfig kernel, the text size is >8 MB, which means you are only adding ~7 MB to the module area, while consuming 16 MB of additional address space. Given that 20 MB modules are very uncommon, I think it is better to enable CONFIG_ARM_MODULE_PLTS instead. That way, there is no need to update these defaults for everyone.
> +#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 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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