Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.7 19/31] x86/boot: Fix kdump, cleanup aborted E820_PRAM max_pfn manipulation | Date | Fri, 14 Oct 2016 14:55:03 +0200 |
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4.7-stable review patch. If anyone has any objections, please let me know.
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From: Dan Williams <dan.j.williams@intel.com>
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However, that approach was abandoned when Christoph ported the patches [1], and that functionality has since been replaced by devm_memremap_pages().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@redhat.com> Reported-by: Jeff Moyer <jmoyer@redhat.com> Tested-by: Zhang Yi <yizhan@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-nvdimm@lists.01.org Fixes: ec776ef6bbe1 ("x86/mm: Add support for the non-standard protected e820 type") Link: http://lkml.kernel.org/r/147448744538.34910.11287693517367139607.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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)
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