From 18d565ea95fe553f442c5bbc5050415bab3c3fa4 Mon Sep 17 00:00:00 2001 From: Yuntao Wang Date: Sun, 17 Dec 2023 11:35:27 +0800 Subject: [PATCH] kexec_file: fix incorrect temp_start value in locate_mem_hole_top_down() temp_end represents the address of the last available byte. Therefore, the starting address of the memory segment with temp_end as its last available byte and a size of `kbuf->memsz`, that is, the value of temp_start, should be `temp_end - kbuf->memsz + 1` instead of `temp_end - kbuf->memsz`. Additionally, use the ALIGN_DOWN macro instead of open-coding it directly in locate_mem_hole_top_down() to improve code readability. Link: https://lkml.kernel.org/r/20231217033528.303333-3-ytcoode@gmail.com Signed-off-by: Yuntao Wang Acked-by: Baoquan He Cc: Borislav Petkov (AMD) Cc: Dave Hansen Cc: "Eric W. Biederman" Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- kernel/kexec_file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index aca5f3668f4c..bef2f6f2571b 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -434,11 +434,11 @@ static int locate_mem_hole_top_down(unsigned long start, unsigned long end, unsigned long temp_start, temp_end; temp_end = min(end, kbuf->buf_max); - temp_start = temp_end - kbuf->memsz; + temp_start = temp_end - kbuf->memsz + 1; do { /* align down start */ - temp_start = temp_start & (~(kbuf->buf_align - 1)); + temp_start = ALIGN_DOWN(temp_start, kbuf->buf_align); if (temp_start < start || temp_start < kbuf->buf_min) return 0;