[Bionic][ARM64]Failure debugging linux kernel
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
gdb (Ubuntu) |
Fix Released
|
High
|
Manoj Iyer | ||
Bionic |
Fix Released
|
High
|
Unassigned |
Bug Description
[Impact]
GDB fails to debug ARM64 vmlinux debug image with proc/kcore information. For example it is unable to print values of variables like 'jiffies_64'.
[Test]
# gdb /usr/lib/
[New process 1]
Core was generated by `BOOT_IMAGE=
#0 0x0000000000000000 in ?? ()
(gdb) p jiffies_64
Cannot access memory at address 0xffff000009616980
(gdb)
[Fix]
This issue was fixed upstream (git://
8727de56b0 Fix tagged pointer support
[Regression Potential]
The risk of regression after applying this patch could be to architectures other than ARM64 due to changes to gdb/util.c. Please see comment #2 where I have tested the PPA package on a ppc64el system and found it does not introduce any regressions.
Changed in gdb (Ubuntu): | |
status: | New → In Progress |
description: | updated |
description: | updated |
Changed in gdb (Ubuntu Bionic): | |
status: | New → In Progress |
importance: | Undecided → High |
Changed in gdb (Ubuntu): | |
status: | In Progress → Fix Released |
Test package is available in PPA: gdb-lp1830796
ppa:manjo/
ubuntu@hotdog:~$ apt policy gdb ppa.launchpad. net/manjo/ gdb-lp1830796/ ubuntu bionic/main arm64 Packages dpkg/status ports.ubuntu. com/ubuntu- ports bionic/main arm64 Packages
gdb:
Installed: 8.1-0ubuntu4
Candidate: 8.1-0ubuntu4
Version table:
*** 8.1-0ubuntu4 500
500 http://
100 /var/lib/
8.1-0ubuntu3 500
500 http://
ubuntu@hotdog:~$
root@hotdog:~# gdb /usr/lib/ debug/boot/ vmlinux- 4.18.0- 20-generic /proc/kcore gnu.org/ licenses/ gpl.html> linux-gnu" . www.gnu. org/software/ gdb/bugs/>. www.gnu. org/software/ gdb/documentati on/>. debug/boot/ vmlinux- 4.18.0- 20-generic. ..done.
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Reading symbols from /usr/lib/
warning: core file may not match specified executable file. /boot/vmlinuz- 4.18.0- 20-generic root=UUID= edb5e5a7- 8272-4e13- aa25-37' .
[New process 1]
Core was generated by `BOOT_IMAGE=
#0 0x0000000000000000 in ?? ()
(gdb) p jiffies_64
$1 = 4406710034
(gdb)