From b263b31e8ad65cdbfa5a7f739460f350554a2dc1 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 27 Feb 2012 15:15:25 -0800 Subject: x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls Specify the data structures for the 64-bit ioctls with explicit sizing and padding so that the x32 kernel will correctly use the 64-bit forms of these ioctls. Note that these ioctls are bogus in both forms on both 32 and 64 bits; even on 64 bits the maximum MTRR size is only 44 bits long. Note that nothing really is supposed to use these ioctls and that the preferred interface is text strings on /proc/mtrr, or better yet, nothing at all (use /sys/bus/pci/devices/*/resource*_wc for write combining; that uses PAT not MTRRs.) Signed-off-by: H. Peter Anvin Cc: H. J. Lu Tested-by: Nitin A. Kamble Link: http://lkml.kernel.org/n/tip-vwvnlu3hjmtkwvij4qxtm90l@git.kernel.org Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/mtrr/if.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c index 79289632cb27..a041e094b8b9 100644 --- a/arch/x86/kernel/cpu/mtrr/if.c +++ b/arch/x86/kernel/cpu/mtrr/if.c @@ -167,6 +167,7 @@ mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg) { int err = 0; mtrr_type type; + unsigned long base; unsigned long size; struct mtrr_sentry sentry; struct mtrr_gentry gentry; @@ -267,14 +268,14 @@ mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg) #endif if (gentry.regnum >= num_var_ranges) return -EINVAL; - mtrr_if->get(gentry.regnum, &gentry.base, &size, &type); + mtrr_if->get(gentry.regnum, &base, &size, &type); /* Hide entries that go above 4GB */ - if (gentry.base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)) + if (base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)) || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))) gentry.base = gentry.size = gentry.type = 0; else { - gentry.base <<= PAGE_SHIFT; + gentry.base = base << PAGE_SHIFT; gentry.size = size << PAGE_SHIFT; gentry.type = type; } @@ -321,11 +322,12 @@ mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg) #endif if (gentry.regnum >= num_var_ranges) return -EINVAL; - mtrr_if->get(gentry.regnum, &gentry.base, &size, &type); + mtrr_if->get(gentry.regnum, &base, &size, &type); /* Hide entries that would overflow */ if (size != (__typeof__(gentry.size))size) gentry.base = gentry.size = gentry.type = 0; else { + gentry.base = base; gentry.size = size; gentry.type = type; } -- cgit v1.2.3