From 01b1e3ca0e5ce47bbae8217d47376ad01b331b07 Mon Sep 17 00:00:00 2001 From: Michael Roth Date: Fri, 3 Nov 2023 10:13:54 -0500 Subject: efi/unaccepted: Fix off-by-one when checking for overlapping ranges 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 Signed-off-by: Michael Roth Acked-by: Vlastimil Babka Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/unaccepted_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/efi/unaccepted_memory.c b/drivers/firmware/efi/unaccepted_memory.c index 3f2f7bf6e33526..5b439d04079c84 100644 --- a/drivers/firmware/efi/unaccepted_memory.c +++ b/drivers/firmware/efi/unaccepted_memory.c @@ -101,7 +101,7 @@ 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; -- cgit 1.2.3-korg