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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 <ytcoode@gmail.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Yuntao Wang 2023-12-17 11:35:26 +08:00 committed by Andrew Morton
parent 5c28913ed0
commit 816d334afa
1 changed files with 4 additions and 4 deletions
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8
kernel/kexec_core.c
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@ -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;
/*