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authorZachary Amsden <zach@vmware.com>2006-01-06 00:11:55 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-06 08:33:35 -0800
commit5fe9fe3c6f9a1ae7aa224bb7a66eb9aad9e4abef (patch)
treeec120ce6e72700fe49720127bc76228c51bd406b /include/asm-i386
parent3fae1c37eea98097de34ba665796fea93b29f4aa (diff)
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[PATCH] x86: Pnp byte granularity
The one remaining caller of set_limit, the PnP BIOS code, calls into the PnP BIOS, passing kernel parameters in and out. These parameteres may be passed from arbitrary kernel virtual memory, so they deserve strict protection to stop a bad BIOS from smashing beyond the object size. Unfortunately, the use of set_limit was badly botching this by setting the limit in terms of pages, when it really should have byte granularity. When doing this, I discovered my BIOS had the buggy code during the "get system device node" call: mov ax, es:[bx] Which is harmless, but has a trivial workaround. Signed-off-by: Zachary Amsden <zach@vmware.com> Cc: "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>
Diffstat (limited to 'include/asm-i386')
-rw-r--r--include/asm-i386/system.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h
index 24cc0c8..9c0593b 100644
--- a/include/asm-i386/system.h
+++ b/include/asm-i386/system.h
@@ -54,7 +54,7 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \
); } while(0)
#define set_base(ldt,base) _set_base( ((char *)&(ldt)) , (base) )
-#define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , ((limit)-1)>>12 )
+#define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , ((limit)-1) )
/*
* Load a segment. Fall back on loading the zero
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