Commit-ID: 4eea6aa581abfeb2695ebe9f9d4672597e1bdd4b
Gitweb: http://git.kernel.org/tip/4eea6aa581abfeb2695ebe9f9d4672597e1bdd4b
Author: Jacob Shin <jacob.shin@xxxxxxx>
AuthorDate: Fri, 16 Nov 2012 19:38:47 -0800
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Sat, 17 Nov 2012 11:59:08 -0800
x86, mm: if kernel .text .data .bss are not marked as E820_RAM, complain and fix
There could be cases where user supplied memmap=exactmap memory
mappings do not mark the region where the kernel .text .data and
.bss reside as E820_RAM, as reported here:
https://lkml.org/lkml/2012/8/14/86
Handle it by complaining, and adding the range back into the e820.
Signed-off-by: Jacob Shin <jacob.shin@xxxxxxx>
Link: http://lkml.kernel.org/r/1353123563-3103-11-git-send-email-yinghai@xxxxxxxxxx
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/setup.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 4bd8921..d85cbd9 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -832,6 +832,20 @@ void __init setup_arch(char **cmdline_p)
insert_resource(&iomem_resource, &data_resource);
insert_resource(&iomem_resource, &bss_resource);
+ /*
+ * Complain if .text .data and .bss are not marked as E820_RAM and
+ * attempt to fix it by adding the range. We may have a confused BIOS,
+ * or the user may have incorrectly supplied it via memmap=exactmap. If
+ * we really are running on top non-RAM, we will crash later anyways.
+ */
+ if (!e820_all_mapped(code_resource.start, __pa(__brk_limit), E820_RAM)) {
+ pr_warn(".text .data .bss are not marked as E820_RAM!\n");
+
+ e820_add_region(code_resource.start,
+ __pa(__brk_limit) - code_resource.start + 1,
+ E820_RAM);
+ }
+
trim_bios_range();
#ifdef CONFIG_X86_32
if (ppro_with_ram_bug()) {
--
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