x86: Fix ioremap off by one BUG

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Jean Delvare's machine triggered this BUG

acpi_os_map_memory phys ffff0000 size 65535
------------[ cut here ]------------
kernel BUG at arch/x86/mm/pat.c:233!

with ACPI in the backtrace.

Adding some debugging output showed that ACPI calls

acpi_os_map_memory phys ffff0000 size 65535

And ioremap/PAT does this check in 32bit, so addr+size wraps and the BUG
in reserve_memtype() triggers incorrectly.

        BUG_ON(start >= end); /* end is exclusive */

But reserve_memtype already uses u64:

int reserve_memtype(u64 start, u64 end,

so the 32bit truncation must happen in the caller. Presumably in ioremap
when it passes this information to reserve_memtype().

This patch does this computation in 64bit.

http://bugzilla.kernel.org/show_bug.cgi?id=11346

Signed-off-by: Andi Kleen <ak@linux.intel.com>

...

This commit is contained in:

Andi Kleen 2008-08-15 18:12:47 +02:00

parent b635acec48

commit e213e87785

1 changed files with 1 additions and 1 deletions

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arch/x86/mm/ioremap.c

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