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address the case where there are multiple values for the same kernel arg

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There is the case where there are multiple entries of the same parameter on
the command line, e.g.
GRUB_CMDLINE_LINUX="crashkernel=110M crashkernel=220M fadump=on crashkernel=330M".

In such an situation _update_kernel_cmdline_in_grub_etc_default only
updates/removes the last entry which is usually not what you want as the
kernel (for crashkernel) takes the last entry it can find.

Thus make sure the case with multiple entries of the same parameter is
handled properly by removing all occurrences of given parameter first.

Note
1. sed command group and conditional control has been used to get rid of
   grep.
2. Fully supporting kernel cmdline as documented in
   Documentation/admin-guide/kernel-parameters.rst is complex and in
   foreseeable future a full implementation is not needed. So simply
   document the unsupported cases instead.

Fixes: 140da74 ("rewrite reset_crashkernel to support fadump and to used by RPM scriptlet")

Reported-by: Philipp Rudo <prudo@redhat.com>
Suggested-by: Philipp Rudo <prudo@redhat.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>
This commit is contained in:
Coiby Xu 2022-02-15 13:24:19 +08:00
parent 311b5b100b
commit 37f4f2c1f6
1 changed files with 40 additions and 14 deletions
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54
kdumpctl
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@ -1399,25 +1399,49 @@ _get_all_kernels_from_grubby()
}
GRUB_ETC_DEFAULT="/etc/default/grub"
# modify the kernel command line parameter in default grub conf
# Update a kernel parameter in default grub conf
#
# If a value is specified, it will be inserted in the end. Otherwise it
# would remove given kernel parameter.
#
# Note this function doesn't address the following cases,
# 1. The kernel ignores everything on the command line after a '--'. So
# simply adding the new entry to the end will fail if the cmdline
# contains a --.
# 2. If the value for a parameter contains spaces it can be quoted using
# double quotes, for example param="value with spaces". This will
# break the [^[:space:]\"] regex for the value.
# 3. Dashes and underscores in the parameter name are equivalent. So
# some_parameter and some-parameter are identical.
# 4. Some parameters, e.g. efivar_ssdt, can be given multiple times.
# 5. Some kernel parameters, e.g. quiet, doesn't have value
#
# $1: the name of the kernel command line parameter
# $2: new value. If empty, the parameter would be removed
_update_kernel_cmdline_in_grub_etc_default()
# $2: new value. If empty, given parameter would be removed
_update_kernel_arg_in_grub_etc_default()
{
local _para=$1 _val=$2 _para_val _regex
local _para=$1 _val=$2 _para_val
if [[ -n $_val ]]; then
_para_val="$_para=$_val"
fi
_regex='^(GRUB_CMDLINE_LINUX=.*)([[:space:]"])'"$_para"'=[^[:space:]"]*(.*)$'
if grep -q -E "$_regex" "$GRUB_ETC_DEFAULT"; then
sed -i -E 's/'"$_regex"'/\1\2'"$_para_val"'\3/' "$GRUB_ETC_DEFAULT"
elif [[ -n $_para_val ]]; then
# If the kernel parameter doesn't exist, put it in the first
sed -i -E 's/^(GRUB_CMDLINE_LINUX=")/\1'"$_para_val"' /' "$GRUB_ETC_DEFAULT"
fi
# Update the command line /etc/default/grub, i.e.
# on the line that starts with 'GRUB_CMDLINE_LINUX=',
# 1) remove $para=$val if the it's the first arg
# 2) remove all occurences of $para=$val
# 3) insert $_para_val to end
# 4) remove duplicate spaces left over by 1) or 2) or 3)
# 5) remove space at the beginning of the string left over by 1) or 2) or 3)
# 6) remove space at the end of the string left over by 1) or 2) or 3)
sed -i -E "/^GRUB_CMDLINE_LINUX=/ {
s/\"${_para}=[^[:space:]\"]*/\"/g;
s/[[:space:]]+${_para}=[^[:space:]\"]*/ /g;
s/\"$/ ${_para_val}\"/
s/[[:space:]]+/ /g;
s/(\")[[:space:]]+/\1/g;
s/[[:space:]]+(\")/\1/g;
}" "$GRUB_ETC_DEFAULT"
}
reset_crashkernel()
@ -1496,10 +1520,12 @@ reset_crashkernel()
# - set the dump mode as kdump for non-ppc64le cases
# - retrieved the default crashkernel value for given dump mode
if [[ $_grubby_kernel_path == ALL && -n $_dump_mode ]]; then
_update_kernel_cmdline_in_grub_etc_default crashkernel "$_crashkernel"
_update_kernel_arg_in_grub_etc_default crashkernel "$_crashkernel"
# remove the fadump if fadump is disabled
[[ $_fadump_val == off ]] && _fadump_val=""
_update_kernel_cmdline_in_grub_etc_default fadump "$_fadump_val"
if [[ $_fadump_val == off ]]; then
_fadump_val=""
fi
_update_kernel_arg_in_grub_etc_default fadump "$_fadump_val"
fi
# If kernel-path not specified, either