This is a note to let you know that I've just added the patch titled
kernel/crash_core: suppress unknown crashkernel parameter warning
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kernel-crash_core-suppress-unknown-crashkernel-param.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0238da7eb34a4f2f7f70f1d29717bb89b1d93d25
Author: Philipp Rudo <prudo@xxxxxxxxxx>
Date: Fri Dec 24 21:12:39 2021 -0800
kernel/crash_core: suppress unknown crashkernel parameter warning
[ Upstream commit 71d2bcec2d4d69ff109c497e6611d6c53c8926d4 ]
When booting with crashkernel= on the kernel command line a warning
similar to
Kernel command line: ro console=ttyS0 crashkernel=256M
Unknown kernel command line parameters "crashkernel=256M", will be passed to user space.
is printed.
This comes from crashkernel= being parsed independent from the kernel
parameter handling mechanism. So the code in init/main.c doesn't know
that crashkernel= is a valid kernel parameter and prints this incorrect
warning.
Suppress the warning by adding a dummy early_param handler for
crashkernel=.
Link: https://lkml.kernel.org/r/20211208133443.6867-1-prudo@xxxxxxxxxx
Fixes: 86d1919a4fb0 ("init: print out unknown kernel parameters")
Signed-off-by: Philipp Rudo <prudo@xxxxxxxxxx>
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
Cc: Andrew Halaney <ahalaney@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index eb53f5ec62c90..256cf6db573cd 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -6,6 +6,7 @@
#include <linux/buildid.h>
#include <linux/crash_core.h>
+#include <linux/init.h>
#include <linux/utsname.h>
#include <linux/vmalloc.h>
@@ -295,6 +296,16 @@ int __init parse_crashkernel_low(char *cmdline,
"crashkernel=", suffix_tbl[SUFFIX_LOW]);
}
+/*
+ * Add a dummy early_param handler to mark crashkernel= as a known command line
+ * parameter and suppress incorrect warnings in init/main.c.
+ */
+static int __init parse_crashkernel_dummy(char *arg)
+{
+ return 0;
+}
+early_param("crashkernel", parse_crashkernel_dummy);
+
Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
void *data, size_t data_len)
{
