Messages in this thread | | | Date | Tue, 10 Jan 2023 10:01:53 +0200 | Subject | Re: [PATCH] lib/scatterlist: Fix to calculate the last_pg properly | From | Yishai Hadas <> |
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On 10/01/2023 7:08, Matthew Wilcox wrote: > On Mon, Jan 09, 2023 at 04:47:01PM +0200, Yishai Hadas wrote: >> if (sgt_append->prv) { >> + unsigned long paddr = >> + (page_to_pfn(sg_page(sgt_append->prv)) * PAGE_SIZE + > 1. page_to_pfn() * PAGE_SIZE is spelled page_to_phys() > > 2. physical addresses have type phys_addr_t. Oh, wait, paddr isn't a > physical address, it's a pfn because you divide by PAGE_SIZE at the end. > But you will get truncation on 32-bit, because page_to_pfn() has type > unsigned long. Anyway, this shouldn't be called paddr. Maybe last_pfn > or something? > >> + sgt_append->prv->offset + sgt_append->prv->length) / >> + PAGE_SIZE;
In this area of the patch I just reverted to what we had in 6.1 [1] where we were good.
I can send V1 and replace the 'paddr' to be called 'last_pfn' if it's really needed.
Alternatively, we can stay with this patch version unless you can see here any real issue.
What do you suggest ?
[1] https://elixir.bootlin.com/linux/v6.1.4/source/lib/scatterlist.c#L462
Yishai
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