Commit 0fc59d3a authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar

x86: fix init_memory_mapping() to handle small ranges

Impact: fix failed EFI bootup in certain circumstances

Ying Huang found init_memory_mapping() has problem with small ranges
less than 2M when he tried to direct map the EFI runtime code out of
max_low_pfn_mapped.

It turns out we never considered that case and didn't check the range...
Reported-by: default avatarYing Huang <ying.huang@intel.com>
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Cc: Brian Maly <bmaly@redhat.com>
LKML-Reference: <49ACDDED.1060508@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2450cf51
...@@ -714,6 +714,8 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, ...@@ -714,6 +714,8 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
pos = start_pfn << PAGE_SHIFT; pos = start_pfn << PAGE_SHIFT;
end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT) end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
<< (PMD_SHIFT - PAGE_SHIFT); << (PMD_SHIFT - PAGE_SHIFT);
if (end_pfn > (end >> PAGE_SHIFT))
end_pfn = end >> PAGE_SHIFT;
if (start_pfn < end_pfn) { if (start_pfn < end_pfn) {
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
pos = end_pfn << PAGE_SHIFT; pos = end_pfn << PAGE_SHIFT;
......
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