From: Jacob Shin Date: Sat, 17 Nov 2012 03:38:47 +0000 (-0800) Subject: x86, mm: if kernel .text .data .bss are not marked as E820_RAM, complain and fix X-Git-Tag: firefly_0821_release~3680^2~1058^2~82 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4eea6aa581abfeb2695ebe9f9d4672597e1bdd4b;p=firefly-linux-kernel-4.4.55.git 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 Link: http://lkml.kernel.org/r/1353123563-3103-11-git-send-email-yinghai@kernel.org Signed-off-by: Yinghai Lu Reviewed-by: Pekka Enberg Signed-off-by: H. Peter Anvin --- diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 4bd89218cbc3..d85cbd96525d 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()) {