From: Andrew Halaney <ahala...@redhat.com>

redhat/configs/common: Turn on CONFIG_IKCONFIG_PROC

Some users expect to check /proc/config.gz instead of
/boot/config-$(uname -r), and both are valid approaches. In fact, one
could argue it is easier to trust the contents of /proc/config.gz than
it is to trust the config install at /boot/.

There's a cost to kernel size (mainly the gzipped size of the config
file), but ~50 KB isn't much compared to the size of the ~30 MB kernel
image I just compiled using the fedora aarch64 configs.

bloat-o-meter output below doesn't show the increase because the config
is injected with .incbin and uses symbol labels to grab it in C code:

    [ahalaney@halaney-x13s kernel-ark]$ ./scripts/bloat-o-meter 
vmlinux.original vmlinux.ikconfig_proc
    add/remove: 7/1 grow/shrink: 0/0 up/down: 320/-8 (312)
    Function                                     old     new   delta
    ikconfig_init                                  -     100    +100
    config_gz_proc_ops                             -      88     +88
    ikconfig_read_current                          -      68     +68
    ikconfig_cleanup                               -      40     +40
    e843419@0969_0000fd78_82f4                     -       8      +8
    e843419@08a0_0000e7d2_a58                      -       8      +8
    e843419@074e_0000bea9_8988                     -       8      +8
    e843419@0170_000025c9_53a8                     8       -      -8
    Total: Before=31935449, After=31935761, chg +0.00%
    [ahalaney@halaney-x13s kernel-ark]$ echo "31935761 - 31935449" | bc
    312
    [ahalaney@halaney-x13s kernel-ark]$

But you can still grab that bit too with a little more work:

    [ahalaney@halaney-x13s kernel-ark]$ nm vmlinux.ikconfig_proc| grep 
kernel_config_data
    ffff800008c78540 D kernel_config_data
    ffff800008c8257e D kernel_config_data_end
    [ahalaney@halaney-x13s kernel-ark]$ echo 'ibase=16; 8C8257E - 8C78540' | bc
    41022
    [ahalaney@halaney-x13s kernel-ark]$ ls -la kernel/config_data.gz
    -rw-r--r-- 1 ahalaney ahalaney 41022 Sep 30 15:43 kernel/config_data.gz
    [ahalaney@halaney-x13s kernel-ark]$

All in all that's not that much of a difference in the image size, so
let's enable this feature.

Signed-off-by: Andrew Halaney <ahala...@redhat.com>

diff --git a/redhat/configs/common/generic/CONFIG_IKCONFIG 
b/redhat/configs/common/generic/CONFIG_IKCONFIG
index blahblah..blahblah 100644
--- a/redhat/configs/common/generic/CONFIG_IKCONFIG
+++ b/redhat/configs/common/generic/CONFIG_IKCONFIG
@@ -1 +1 @@
-# CONFIG_IKCONFIG is not set
+CONFIG_IKCONFIG=y
diff --git a/redhat/configs/common/generic/CONFIG_IKCONFIG_PROC 
b/redhat/configs/common/generic/CONFIG_IKCONFIG_PROC
new file mode 100644
index blahblah..blahblah 100644
--- /dev/null
+++ b/redhat/configs/common/generic/CONFIG_IKCONFIG_PROC
@@ -0,0 +1 @@
+CONFIG_IKCONFIG_PROC=y

--
https://gitlab.com/cki-project/kernel-ark/-/merge_requests/2041
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