The patch titled
Subject: kexec: modify the meaning of the end parameter in kimage_is_destination_range()
has been added to the -mm mm-nonmm-unstable branch. Its filename is
kexec-modify-the-meaning-of-the-end-parameter-in-kimage_is_destination_range.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kexec-modify-the-meaning-of-the-end-parameter-in-kimage_is_destination_range.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Yuntao Wang <ytcoode@xxxxxxxxx>
Subject: kexec: modify the meaning of the end parameter in kimage_is_destination_range()
Date: Sun, 17 Dec 2023 11:35:26 +0800
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@xxxxxxxxx
Signed-off-by: Yuntao Wang <ytcoode@xxxxxxxxx>
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/kexec_core.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/kernel/kexec_core.c~kexec-modify-the-meaning-of-the-end-parameter-in-kimage_is_destination_range
+++ a/kernel/kexec_core.c
@@ -278,8 +278,8 @@ int kimage_is_destination_range(struct k
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_
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(st
/* 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;
/*
_
Patches currently in -mm which might be from ytcoode@xxxxxxxxx are
kexec-use-align-macro-instead-of-open-coding-it.patch
x86-kexec-simplify-the-logic-of-mem_region_callback.patch
x86-crash-remove-the-unused-image-parameter-from-prepare_elf_headers.patch
x86-crash-use-sz_1m-macro-instead-of-hardcoded-value.patch
crash_core-fix-and-simplify-the-logic-of-crash_exclude_mem_range.patch
x86-crash-fix-potential-cmem-ranges-array-overflow.patch
kexec-modify-the-meaning-of-the-end-parameter-in-kimage_is_destination_range.patch
kexec_file-fix-incorrect-temp_start-value-in-locate_mem_hole_top_down.patch
