On Thu, Jun 17, 2021 at 03:28:10AM +0000, HAGIO KAZUHITO(萩尾 一仁) wrote:
-----Original Message-----
Kernel commit 464920104bf7adac12722035bfefb3d772eb04d8
"/proc/kcore: update physical address for kcore ram and text" sets an
invalid paddr (-1=0xffffffffffffffff) for PT_LOAD segments of not direct
mapped regions,
$ readelf -l /proc/kcore
Elf file type is CORE (Core file)
Entry point 0x0
There are 4 program headers, starting at offset 64
Program Headers:
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
NOTE 0x0000000000000120 0x0000000000000000 0x0000000000000000
0x0000000000002320 0x0000000000000000 0x0
LOAD 0x1000000000010000 0xd000000000000000 0xffffffffffffffff
^^^^^^^^^^^^^^^^^^
0x0001f80000000000 0x0001f80000000000 RWE 0x10000
LOAD 0x0000000000010000 0xc000000000000000 0x0000000000000000
0x00000003f0000000 0x00000003f0000000 RWE 0x10000
LOAD 0x3000000000010000 0xf000000000000000 0xffffffffffffffff
^^^^^^^^^^^^^^^^^^
0x0000000000fc0000 0x0000000000fc0000 RWE 0x10000
makedumple uses max_paddr to calculate the number of sections for sparse
memory model thus wrong number is obtained based on max_paddr=-1. This
error could lead to the failure of copying /proc/kcore for RHEL-8.5 on
ppc64le machine [1],
$ uname -r
4.18.0-312.el8.ppc64le
$ makedumpfile /proc/kcore vmcore1
get_mem_section: Could not validate mem_section.
get_mm_sparsemem: Can't get the address of mem_section.
makedumpfile Failed.
IIUC, makedumpfile has NOT been developed to filter /proc/kcore so far,
except for the --mem-usage option, and this is the first patch for it.
It might be more handy than crash's snap.so extension, so I applied this:
https://github.com/makedumpfile/makedumpfile/commit/38d921a2ef50ebd36258097553626443ffe27496
Thanks for applying the patch!
But please note that maybe filtering /proc/kcore with makedumpfile (and
also analyzing the dumpfile with crash) is still not mature enough for
field or production use.
Thanks for the note!
Thanks,
Kazu
Let's check if the phys_start of the segment is a valid physical address
to fix this problem.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1965267
Reported-by: Xiaoying Yan <yiyan@xxxxxxxxxx>
Signed-off-by: Coiby Xu <coxu@xxxxxxxxxx>
---
elf_info.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/elf_info.c b/elf_info.c
index e8affb7..9444847 100644
--- a/elf_info.c
+++ b/elf_info.c
@@ -628,7 +628,7 @@ get_max_paddr(void)
for (i = 0; i < num_pt_loads; i++) {
pls = &pt_loads[i];
- if (max_paddr < pls->phys_end)
+ if (pls->phys_start != NOT_PADDR && max_paddr < pls->phys_end)
max_paddr = pls->phys_end;
}
return max_paddr;
--
2.31.1
_______________________________________________
kexec mailing list
kexec@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/kexec
--
Best regards,
Coiby
_______________________________________________
kexec mailing list
kexec@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/kexec
