Messages in this thread | | | Subject | Re: [PATCH v2] lib: Use PFN_PHYS() in devmem_is_allowed() | From | Kefeng Wang <> | Date | Fri, 30 Jul 2021 15:04:05 +0800 |
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On 2021/7/30 14:49, Liang Wang wrote: > The physical address may exceed 32 bits on ARM(when ARM_LPAE enabled), > use PFN_PHYS() in devmem_is_allowed(), or the physical address may > overflow and be truncated. > > This bug was initially introduced from v2.6.37, and the function was moved > to lib when v5.10. > > Fixes: 087aaffcdf9c ("ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem") > Fixes: 527701eda5f1 ("lib: Add a generic version of devmem_is_allowed()") > Cc: stable@vger.kernel.org # v2.6.37 > Signed-off-by: Liang Wang <wangliang101@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > v2: update subject and changelog > lib/devmem_is_allowed.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/devmem_is_allowed.c b/lib/devmem_is_allowed.c > index c0d67c541849..60be9e24bd57 100644 > --- a/lib/devmem_is_allowed.c > +++ b/lib/devmem_is_allowed.c > @@ -19,7 +19,7 @@ > */ > int devmem_is_allowed(unsigned long pfn) > { > - if (iomem_is_exclusive(pfn << PAGE_SHIFT)) > + if (iomem_is_exclusive(PFN_PHYS(pfn))) > return 0; > if (!page_is_ram(pfn)) > return 1;
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