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Zachary Amsden authored
APM BIOSes have many bugs regarding proper representation of the appropriate segment limits for calling the BIOS. By default, APM_RELAX_SEGMENTS is always turned on to support running the APM BIOS on these buggy machines. Keeping 64k limits poses very little danger to the kernel, because the pages where the APM BIOS is located will always be in low physical memory BIOS areas, which should already be marked reserved, and only buggy BIOSes would possibly overstep the segment bounds with writes to data anyway. Since forcing stricter limits breaks many machines and is not default behavior, it seems reasonable to deprecate the older code which may cause APM BIOS to fault. If you really have a badly enough broken APM BIOS that you have to turn off APM_RELAX_SEGMENTS, seems like the best recourse here would be to disable the APM BIOS and / or not compile it into your kernel to begin with, and / or add your system to the known bad list. The reason I want to deprecate this code is there is underlying brokenness with the set_limit macros, and getting rid of many of the call sites rather than rewriting them seems to be the simplest and most correct course of action. Signed-off-by: Zachary Amsden <zach@vmware.com> Acked-by: "Seth, Rohit" <rohit.seth@intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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