[Buildroot] [PATCH] support/testing: test_lxc: bump kernel version to 5.15.38 for complete pidfds support

[Romain Naour]

As reported by [1], the lxc test is broken since lxc >= 4.0.11.
A patch was added to lxc 4.0.11 to use the new mount api for devpts
setup [2] but the fall back code doesn't work when this new mount
API is not supported. This API was added in kernel 5.6.

(kernel 5.5)
DEBUG conf - conf.c:lxc_setup_devpts_child:1682 - No new devpts instance will be
mounted since no pts devices are required
lxc-start lxc_iperf3  DEBUG conf - conf.c:lxc_setup_dev_console:1966 - Cleared
all (0) mounts from "/dev/console"
lxc-start lxc_iperf3  ERROR mount_utils - mount_utils.c:mount_at:661 - No such
file or directory - Failed to mount "/proc/self/fd/44" to "/proc/self/fd/43"
lxc-start lxc_iperf3  ERROR conf - conf.c:lxc_setup_dev_console:1988 - No such
file or directory - Failed to mount "10(/dev/pts/0)" on "43"
lxc-start lxc_iperf3  ERROR conf - conf.c:lxc_setup_console:2143 - No such file
or directory - Failed to setup console

(kernel 5.6)
lxc-start lxc_iperf3  TRACE mount_utils - mount_utils.c:can_use_mount_api:582 -
Kernel supports mount api
lxc-start lxc_iperf3  TRACE mount_utils - mount_utils.c:move_detached_mount:328
- Attach detached mount 45 to filesystem at 43
lxc-start lxc_iperf3  TRACE conf - conf.c:lxc_setup_dev_console:1990 - Setup
console "/dev/pts/0"

Bump the kernel to the current LTS 5.15.38 version that fully support the
mount API needed by lxc.

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/2429013708

[1] http://lists.busybox.net/pipermail/buildroot/2022-January/635251.html
[2] https://github.com/lxc/lxc/commit/be606e16fd0fa967219d890745a425625eafe251

Signed-off-by: Romain Naour <romain.naour at gmail.com>
Cc: Fabrice Fontaine <fontaine.fabrice at gmail.com>
---
 support/testing/tests/package/test_lxc.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/support/testing/tests/package/test_lxc.py b/support/testing/tests/package/test_lxc.py
index d98bed8761..f66b31f3ba 100644
--- a/support/testing/tests/package/test_lxc.py
+++ b/support/testing/tests/package/test_lxc.py
@@ -12,7 +12,7 @@ class TestLxc(infra.basetest.BRTest):
             BR2_TOOLCHAIN_EXTERNAL=y
             BR2_LINUX_KERNEL=y
             BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-            BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.19.204"
+            BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.15.38"
             BR2_LINUX_KERNEL_DEFCONFIG="vexpress"
             BR2_LINUX_KERNEL_DTS_SUPPORT=y
             BR2_LINUX_KERNEL_INTREE_DTS_NAME="vexpress-v2p-ca9"
-- 
2.35.1