Messages in this thread | | | Date | Thu, 14 Nov 2002 17:16:50 +0100 | From | Florian Zumbiehl <> | Subject | Wrong size calculation in __ioremap(), various platforms |
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Hi all,
in arch/*/mm/ioremap.c, __ioremap() of several platforms there seems to be a minor mistake in the calculation of the page-aligned mapping size:
void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) { void * addr; struct vm_struct * area; unsigned long offset, last_addr;
/* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; if (!size || last_addr < phys_addr) return NULL;
/* ... code which doesn't change last_addr ... */
size = PAGE_ALIGN(last_addr) - phys_addr;
/* ... */ }
For this calculation to work, PAGE_ALIGN(last_addr) would have to be the address immediately after the last address to be mapped - if last_addr is the first address of a page however, PAGE_ALIGN() of course "returns" it unchanged.
So, the correct version IMO should look like this:
size = PAGE_ALIGN(last_addr + 1) - phys_addr;
(2.5.47?/)i386 even seems to be affected twice - bt_ioremap() contains the same piece of code.
In the hope not to have overlooked something,
Florian - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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