Messages in this thread | | | Subject | Re: [PATCH] powerpc/mm: fix a hardcode on memory boundary checking | From | Rui Teng <> | Date | Mon, 6 Feb 2017 10:50:21 +0800 |
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On 31/01/2017 5:11 PM, Michael Ellerman wrote: > Rui Teng <rui.teng@linux.vnet.ibm.com> writes: > >> The offset of hugepage block will not be 16G, if the expected >> page is more than one. Calculate the totol size instead of the >> hardcode value. > > I assume you found this by code inspection and not by triggering an > actual bug?
Yes, I found this problem only by code inspection. We were finding the ways to enable 16G huge page besides changing the device tree. For example, provide a new interface to set these size and pages parameters. So that I think it may cause problem here.
> > cheers > >> diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c >> index 8033493..b829f8e 100644 >> --- a/arch/powerpc/mm/hash_utils_64.c >> +++ b/arch/powerpc/mm/hash_utils_64.c >> @@ -506,7 +506,7 @@ static int __init htab_dt_scan_hugepage_blocks(unsigned long node, >> printk(KERN_INFO "Huge page(16GB) memory: " >> "addr = 0x%lX size = 0x%lX pages = %d\n", >> phys_addr, block_size, expected_pages); >> - if (phys_addr + (16 * GB) <= memblock_end_of_DRAM()) { >> + if (phys_addr + block_size * expected_pages <= memblock_end_of_DRAM()) { >> memblock_reserve(phys_addr, block_size * expected_pages); >> add_gpage(phys_addr, block_size, expected_pages); >> } >> -- >> 2.9.0 >
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