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efi/unaccepted: Fix off-by-one when checking for overlapping ranges

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[ Upstream commit 01b1e3ca0e5ce47bbae8217d47376ad01b331b07 ]

When a task needs to accept memory it will scan the accepting_list
to see if any ranges already being processed by other tasks overlap
with its range. Due to an off-by-one in the range comparisons, a task
might falsely determine that an overlapping range is being accepted,
leading to an unnecessary delay before it begins processing the range.

Fix the off-by-one in the range comparison to prevent this and slightly
improve performance.

Fixes: 50e782a86c98 ("efi/unaccepted: Fix soft lockups caused by parallel memory acceptance")
Link: https://lore.kernel.org/linux-mm/20231101004523.vseyi5bezgfaht5i@amd.com/T/#me2eceb9906fcae5fe958b3fe88e41f920f8335b6
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Michael Roth 2023-11-03 10:13:54 -05:00 committed by Greg Kroah-Hartman
parent 9e23c7f75b
commit 589959bf46
1 changed files with 1 additions and 1 deletions
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2
drivers/firmware/efi/unaccepted_memory.c
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@ -100,7 +100,7 @@ retry:
* overlap on physical address level.
*/
list_for_each_entry(entry, &accepting_list, list) {
if (entry->end < range.start)
if (entry->end <= range.start)
continue;
if (entry->start >= range.end)
continue;