2023-04-12 04:34:07

by Pavan Kondeti

Subject: [PATCH] arm64: kernel: Fix kernel warning when nokaslr is passed to commandline

'Unknown kernel command line parameters "nokaslr", will be passed to
user space' message is noticed in the dmesg when nokaslr is passed to
the kernel commandline on ARM64 platform. This is because nokaslr param
is handled by early cpufeature detection infrastructure and the parameter
is never consumed by a kernel param handler. Fix this warning by
providing a dummy kernel param handler for nokaslr.

Signed-off-by: Pavankumar Kondeti <[email protected]>
---
arch/arm64/kernel/idreg-override.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
index 95133765ed29..75ceb7c07af7 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -177,6 +177,13 @@ static const struct {
{ "nokaslr", "kaslr.disabled=1" },
};

+static int __init parse_nokaslr(char *unused)
+{
+ /* nokaslr param handling is done by early cpufeature code */
+ return 0;
+}
+early_param("nokaslr", parse_nokaslr);
+
static int __init find_field(const char *cmdline,
const struct ftr_set_desc *reg, int f, u64 *v)
{
--
2.25.1

2023-04-14 14:45:11

by Will Deacon

Subject: Re: [PATCH] arm64: kernel: Fix kernel warning when nokaslr is passed to commandline

On Wed, 12 Apr 2023 10:02:58 +0530, Pavankumar Kondeti wrote:
> 'Unknown kernel command line parameters "nokaslr", will be passed to
> user space' message is noticed in the dmesg when nokaslr is passed to
> the kernel commandline on ARM64 platform. This is because nokaslr param
> is handled by early cpufeature detection infrastructure and the parameter
> is never consumed by a kernel param handler. Fix this warning by
> providing a dummy kernel param handler for nokaslr.
>
> [...]

Applied to arm64 (for-next/misc), thanks!

[1/1] arm64: kernel: Fix kernel warning when nokaslr is passed to commandline
https://git.kernel.org/arm64/c/a2a83eb40fbd

Cheers,
--
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev