| 2009-07-03 12:30:22 |
Stefan Bader |
description |
I'm running up-to-date Jaunty, kernel 2.6.28-11.42, x86_64.
In order to circumvent bug #187671 (which is caused by a bad BIOS configuration of the MMIO regions for certain laptops) I added the kernel option "reserve=0xffb00000,0x100000" to my default kernel in /boot/grub/menu.lst, which has been reported to work on 32-bit systems (and which I have been able to verify using a 32-bit liveCD).
However, the kernel boot parameter does not work correctly on the 64-bit kernel. The option I specified is interpreted so that the following line appears at the end of /proc/iomem:
ffffffffffb00000-ffffffffffbfffff : reserved
which is clearly incorrect: it looks like the 32-bit address is being padded with ones instead of zeros. Specifying "reserve=0x00000000ffb00000,0x100000" (full-blown 64-bit address) does not change anything, the same line appears in /proc/iomem. |
SRU Justificatoin:
IMPACT: kernel parameter "reserve=" is not handled well on AMD64 and the value in /proc/iomem is not padded by 0xf in the front. The bug LP#187671 depends on this bug.
FIX: A patch from Zhang Rui fixed. The patch is also summitted to the mainline. The status on mainline bugzilla is "RESOLVED CODE_FIX". It may be merged into the mainline some day.
TEST: I tested on Karmic, Jaunty and Intrepid. The value in /proc/iomem is correct after applying this patch. The original reporter also tested on 2.6.28-11 kernel and reported to work well.
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I'm running up-to-date Jaunty, kernel 2.6.28-11.42, x86_64.
In order to circumvent bug #187671 (which is caused by a bad BIOS configuration of the MMIO regions for certain laptops) I added the kernel option "reserve=0xffb00000,0x100000" to my default kernel in /boot/grub/menu.lst, which has been reported to work on 32-bit systems (and which I have been able to verify using a 32-bit liveCD).
However, the kernel boot parameter does not work correctly on the 64-bit kernel. The option I specified is interpreted so that the following line appears at the end of /proc/iomem:
ffffffffffb00000-ffffffffffbfffff : reserved
which is clearly incorrect: it looks like the 32-bit address is being padded with ones instead of zeros. Specifying "reserve=0x00000000ffb00000,0x100000" (full-blown 64-bit address) does not change anything, the same line appears in /proc/iomem. |
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