x86, iommu: Fix IOMMU_INIT alignment rules

This boot crash was observed:

 DMA-API: preallocated 32768 debug entries
 DMA-API: debugging enabled by kernel config
 BUG: unable to handle kernel paging request at 19da8955
 IP: [<f4ffffff>] 0xf4ffffff
 *pde = 00000000

The crux of the failure was that even if we did not use any
of the .iommu_table section, the linker would still insert it
in the vmlinux file. This patch fixes that and also fixes the
runtime crash where we would try to access the array.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
LKML-Reference: <1283191802-25086-1-git-send-email-konrad.wilk@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 3f07c370f76150e988b276d1161d8b1d06b83ed5..38e2b67807e14928290f32361a4a8eeb9dda33fe 100644 (file)
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -285,10 +285,9 @@ SECTIONS
        .iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) {
                __iommu_table = .;
                *(.iommu_table)
-               . = ALIGN(8);
                __iommu_table_end = .;
        }
-
+       . = ALIGN(8);
        /*
         * .exit.text is discard at runtime, not link time, to deal with
         *  references from .altinstructions and .eh_frame