[Makedumpfile Patch 5/6] makedumpfile: Correct the calculation of kvaddr in set_kcore_vmcoreinfo

Pratyush Anand panand at redhat.com
Mon Feb 6 04:01:50 PST 2017

From: Baoquan He <bhe at redhat.com>

In set_kcore_vmcoreinfo, we calculate the virtual address of vmcoreinfo
by OR operation as below:

	kvaddr = (ulong)vmcoreinfo_addr | PAGE_OFFSET;

When mm sections kaslr is not enabled, this is correct since the starting
address of direct mapping section is 0xffff880000000000 which 1T aligned.
Usually system with memory below 1T won't cause problem.

However with mm section kaslr enabled, the starting address of direct
mapping is 1G aligned. The above code makes kvaddr unsure.

So change it to adding operation:
	kvaddr = (ulong)vmcoreinfo_addr + PAGE_OFFSET;

Signed-off-by: Baoquan He <bhe at redhat.com>
 elf_info.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/elf_info.c b/elf_info.c
index c5743b3cab28..100272f83c48 100644
--- a/elf_info.c
+++ b/elf_info.c
@@ -372,7 +372,7 @@ int set_kcore_vmcoreinfo(uint64_t vmcoreinfo_addr, uint64_t vmcoreinfo_len)
 	off_t offset_desc;
-	kvaddr = (ulong)vmcoreinfo_addr | PAGE_OFFSET;
+	kvaddr = (ulong)vmcoreinfo_addr + PAGE_OFFSET;
 	for (i = 0; i < num_pt_loads; ++i) {
 		struct pt_load_segment *p = &pt_loads[i];

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