This is a note to let you know that I've just added the patch titled x86/boot: Fix kdump, cleanup aborted E820_PRAM max_pfn manipulation to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-boot-fix-kdump-cleanup-aborted-e820_pram-max_pfn-manipulation.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 917db484dc6a69969d317b3e57add4208a8d9d42 Mon Sep 17 00:00:00 2001 From: Dan Williams <dan.j.williams@xxxxxxxxx> Date: Wed, 21 Sep 2016 12:50:45 -0700 Subject: x86/boot: Fix kdump, cleanup aborted E820_PRAM max_pfn manipulation From: Dan Williams <dan.j.williams@xxxxxxxxx> commit 917db484dc6a69969d317b3e57add4208a8d9d42 upstream. In commit: ec776ef6bbe1 ("x86/mm: Add support for the non-standard protected e820 type") Christoph references the original patch I wrote implementing pmem support. The intent of the 'max_pfn' changes in that commit were to enable persistent memory ranges to be covered by the struct page memmap by default. However, that approach was abandoned when Christoph ported the patches [1], and that functionality has since been replaced by devm_memremap_pages(). In the meantime, this max_pfn manipulation is confusing kdump [2] that assumes that everything covered by the max_pfn is "System RAM". This results in kdump hanging or crashing. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-March/000348.html [2]: https://bugzilla.redhat.com/show_bug.cgi?id=1351098 So fix it. Reported-by: Zhang Yi <yizhan@xxxxxxxxxx> Reported-by: Jeff Moyer <jmoyer@xxxxxxxxxx> Tested-by: Zhang Yi <yizhan@xxxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Boaz Harrosh <boaz@xxxxxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: linux-nvdimm@xxxxxxxxxxxx Fixes: ec776ef6bbe1 ("x86/mm: Add support for the non-standard protected e820 type") Link: http://lkml.kernel.org/r/147448744538.34910.11287693517367139607.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/e820.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -348,7 +348,7 @@ int __init sanitize_e820_map(struct e820 * continue building up new bios map based on this * information */ - if (current_type != last_type || current_type == E820_PRAM) { + if (current_type != last_type) { if (last_type != 0) { new_bios[new_bios_entry].size = change_point[chgidx]->addr - last_addr; @@ -754,7 +754,7 @@ u64 __init early_reserve_e820(u64 size, /* * Find the highest page frame number we have available */ -static unsigned long __init e820_end_pfn(unsigned long limit_pfn) +static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type) { int i; unsigned long last_pfn = 0; @@ -765,11 +765,7 @@ static unsigned long __init e820_end_pfn unsigned long start_pfn; unsigned long end_pfn; - /* - * Persistent memory is accounted as ram for purposes of - * establishing max_pfn and mem_map. - */ - if (ei->type != E820_RAM && ei->type != E820_PRAM) + if (ei->type != type) continue; start_pfn = ei->addr >> PAGE_SHIFT; @@ -794,12 +790,12 @@ static unsigned long __init e820_end_pfn } unsigned long __init e820_end_of_ram_pfn(void) { - return e820_end_pfn(MAX_ARCH_PFN); + return e820_end_pfn(MAX_ARCH_PFN, E820_RAM); } unsigned long __init e820_end_of_low_ram_pfn(void) { - return e820_end_pfn(1UL << (32-PAGE_SHIFT)); + return e820_end_pfn(1UL << (32 - PAGE_SHIFT), E820_RAM); } static void early_panic(char *msg) Patches currently in stable-queue which might be from dan.j.williams@xxxxxxxxx are queue-4.8/x86-boot-fix-kdump-cleanup-aborted-e820_pram-max_pfn-manipulation.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html