Zander671/kdumpst
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

kdumpst-load/config: Add option to use crashkernel as pstore/ram memory

Browse Source 
Currently kdumpst only allows a proper RAM buffer to be used as ramoops
memory area - this is the proper way of doing that, but there are cases
in which it's not trivial to have these buffers available:

(a) In case it's not there by default (due to kernel alignment / device-tree)
for example, there is no easy parameter to reserve such area right now
(using mem= is the way to go, but a bit complex to gather the exact size).

(b) The kernel parameter crashkernel= does something like this: reserve
a piece of memory not to be used by the kernel. It's meant for kdump, but
can be (ab)used for other purposes.

So, we hereby add a way for kdumpst to make use of crash reserved area
if the users wish so; the risks are exposed in the config file text.

Also, since we're changing this code, take the opportunity to improve the
sanitization of addresses from /proc/iomem and fix a corner case of empty
RANGE in the iomem parsing routine.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
This commit is contained in:
Guilherme G. Piccoli
2023-12-23 12:03:00 -05:00
parent acd5a64652
commit 63345d21a7
2 changed files with 17 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
kdumpst-load.sh.in
View File

@ -77,10 +77,14 @@ clear_all_initrds() {
# Next routine parses /proc/iomem to obtain the biggest RAM buffer
# available. Saves the results in 2 global variables: MEM_{SIZE,START}.
parse_ram_buffers() {
BUFFERS="$(grep "RAM buffer" /proc/iomem)"
BUFFERS="$(grep "$1" /proc/iomem)"
while read -r line
do
RANGE=$(echo "$line" | cut -f1 -d\ )
RANGE=$(echo "$line" | sed 's/^[[:space:]]*//g' | cut -f1 -d:)
if [ "${RANGE}" == '' ]; then
continue
fi
MEM_END=$(echo "$RANGE" | cut -f2 -d-)
MSTART=$(echo "$RANGE" | cut -f1 -d-)
@ -155,7 +159,11 @@ if [ "${USE_PSTORE_RAM}" -eq 1 ]; then
RECORD_SIZE="${PSTORE_RECORD_SZ}"
MEM_SIZE=0
parse_ram_buffers
parse_ram_buffers "RAM buffer"
if [ "${MEM_SIZE}" -eq 0 ] && [ "${PSTORE_RAM_USE_CRASH_MEM}" -eq 1 ]; then
parse_ram_buffers "Crash kernel"
fi
if [ "${MEM_SIZE}" -gt 0 ]; then
if modprobe ramoops mem_address=0x"${MEM_START}" mem_size="${MEM_REQUIRED}" record_size="${RECORD_SIZE}"; then