linux-kernel - Re: [PATCH v2 3/3] arm64: Silence first allocation with CONFIG_ARM64_MODULE

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Date:   Thu, 27 Apr 2017 19:07:25 +0100
From:   Ard Biesheuvel <ard.biesheuvel@...aro.org>
To:     Florian Fainelli <f.fainelli@...il.com>
Cc:     linux-arm-kernel@...ts.infradead.org,
        Russell King <linux@...linux.org.uk>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michal Hocko <mhocko@...e.com>, zijun_hu <zijun_hu@....com>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        open list <linux-kernel@...r.kernel.org>,
        "open list:MEMORY MANAGEMENT" <linux-mm@...ck.org>,
        angus@...usclark.org
Subject: Re: [PATCH v2 3/3] arm64: Silence first allocation with CONFIG_ARM64_MODULE_PLTS=y


> On 27 Apr 2017, at 18:39, Florian Fainelli <f.fainelli@...il.com> wrote:
> 
> When CONFIG_ARM64_MODULE_PLTS is enabled, the first allocation using the
> module space fails, because the module is too big, and then the module
> allocation is attempted from vmalloc space. Silence the first allocation
> failure in that case by setting __GFP_NOWARN.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
> ---
> arch/arm64/kernel/module.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
> index 7f316982ce00..58bd5cfdd544 100644
> --- a/arch/arm64/kernel/module.c
> +++ b/arch/arm64/kernel/module.c
> @@ -32,11 +32,16 @@
> 
> void *module_alloc(unsigned long size)
> {
> +    gfp_t gfp_mask = GFP_KERNEL;
>    void *p;
> 
> +#if IS_ENABLED(CONFIG_ARM64_MODULE_PLTS)
> +    /* Silence the initial allocation */
> +    gfp_mask |= __GFP_NOWARN;
> +#endif

Please use IS_ENABLED() instead here

>    p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
>                module_alloc_base + MODULES_VSIZE,
> -                GFP_KERNEL, PAGE_KERNEL_EXEC, 0,
> +                gfp_mask, PAGE_KERNEL_EXEC, 0,
>                NUMA_NO_NODE, __builtin_return_address(0));
> 
>    if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
> -- 
> 2.9.3
> 

Other than that, and with Michal's nit addressed:

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>