From 816d334afa85c836080b41bb6238aea845615ad9 Mon Sep 17 00:00:00 2001 From: Yuntao Wang Date: Sun, 17 Dec 2023 11:35:26 +0800 Subject: kexec: modify the meaning of the end parameter in kimage_is_destination_range() The end parameter received by kimage_is_destination_range() should be the last valid byte address of the target memory segment plus 1. However, in the locate_mem_hole_bottom_up() and locate_mem_hole_top_down() functions, the corresponding value passed to kimage_is_destination_range() is the last valid byte address of the target memory segment, which is 1 less. There are two ways to fix this bug. We can either correct the logic of the locate_mem_hole_bottom_up() and locate_mem_hole_top_down() functions, or we can fix kimage_is_destination_range() by making the end parameter represent the last valid byte address of the target memory segment. Here, we choose the second approach. Due to the modification to kimage_is_destination_range(), we also need to adjust its callers, such as kimage_alloc_normal_control_pages() and kimage_alloc_page(). Link: https://lkml.kernel.org/r/20231217033528.303333-2-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_core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 6e0f022987ff..2f039a7d9af9 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -278,8 +278,8 @@ int kimage_is_destination_range(struct kimage *image, unsigned long mstart, mend; mstart = image->segment[i].mem; - mend = mstart + image->segment[i].memsz; - if ((end > mstart) && (start < mend)) + mend = mstart + image->segment[i].memsz - 1; + if ((end >= mstart) && (start <= mend)) return 1; } @@ -372,7 +372,7 @@ static struct page *kimage_alloc_normal_control_pages(struct kimage *image, pfn = page_to_boot_pfn(pages); epfn = pfn + count; addr = pfn << PAGE_SHIFT; - eaddr = epfn << PAGE_SHIFT; + eaddr = (epfn << PAGE_SHIFT) - 1; if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) || kimage_is_destination_range(image, addr, eaddr)) { list_add(&pages->lru, &extra_pages); @@ -718,7 +718,7 @@ static struct page *kimage_alloc_page(struct kimage *image, /* If the page is not a destination page use it */ if (!kimage_is_destination_range(image, addr, - addr + PAGE_SIZE)) + addr + PAGE_SIZE - 1)) break; /* -- cgit