The patch titled
Subject: kdump: write correct address of mem_section into vmcoreinfo
has been added to the -mm tree. Its filename is
kdump-write-a-correct-address-of-mem_section-into-vmcoreinfo.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kdump-write-a-correct-address-of-mem_section-into-vmcoreinfo.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kdump-write-a-correct-address-of-mem_section-into-vmcoreinfo.patch
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------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: kdump: write correct address of mem_section into vmcoreinfo
Depending on configuration mem_section can now be an array or a pointer to
an array allocated dynamically. In most cases, we can continue to refer
to it as 'mem_section' regardless of what it is.
But there's one exception: '&mem_section' means "address of the array" if
mem_section is an array, but if mem_section is a pointer, it would mean
"address of the pointer".
We've stepped onto this in kdump code. VMCOREINFO_SYMBOL(mem_section)
writes down address of pointer into vmcoreinfo, not array as we wanted.
Let's introduce VMCOREINFO_SYMBOL_ARRAY() that would handle the situation
correctly for both cases.
Link: http://lkml.kernel.org/r/20180112162532.35896-1-kirill.shutemov@xxxxxxxxxxxxxxx
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Fixes: 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y")
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
Acked-by: Dave Young <dyoung@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/crash_core.h | 2 ++
kernel/crash_core.c | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff -puN include/linux/crash_core.h~kdump-write-a-correct-address-of-mem_section-into-vmcoreinfo include/linux/crash_core.h
--- a/include/linux/crash_core.h~kdump-write-a-correct-address-of-mem_section-into-vmcoreinfo
+++ a/include/linux/crash_core.h
@@ -42,6 +42,8 @@ phys_addr_t paddr_vmcoreinfo_note(void);
vmcoreinfo_append_str("PAGESIZE=%ld\n", value)
#define VMCOREINFO_SYMBOL(name) \
vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name)
+#define VMCOREINFO_SYMBOL_ARRAY(name) \
+ vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)name)
#define VMCOREINFO_SIZE(name) \
vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
(unsigned long)sizeof(name))
diff -puN kernel/crash_core.c~kdump-write-a-correct-address-of-mem_section-into-vmcoreinfo kernel/crash_core.c
--- a/kernel/crash_core.c~kdump-write-a-correct-address-of-mem_section-into-vmcoreinfo
+++ a/kernel/crash_core.c
@@ -410,7 +410,7 @@ static int __init crash_save_vmcoreinfo_
VMCOREINFO_SYMBOL(contig_page_data);
#endif
#ifdef CONFIG_SPARSEMEM
- VMCOREINFO_SYMBOL(mem_section);
+ VMCOREINFO_SYMBOL_ARRAY(mem_section);
VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
VMCOREINFO_STRUCT_SIZE(mem_section);
VMCOREINFO_OFFSET(mem_section, section_mem_map);
_
Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are
kdump-write-a-correct-address-of-mem_section-into-vmcoreinfo.patch
asm-generic-provide-generic_pmdp_establish.patch
arc-use-generic_pmdp_establish-as-pmdp_establish.patch
arm-mm-provide-pmdp_establish-helper.patch
mips-use-generic_pmdp_establish-as-pmdp_establish.patch
x86-mm-provide-pmdp_establish-helper.patch
mm-do-not-lose-dirty-and-access-bits-in-pmdp_invalidate.patch
mm-use-updated-pmdp_invalidate-interface-to-track-dirty-accessed-bits.patch