[PATCH v5 09/15] arch/powerpc: don't initialize kasan if it's disabled

[Sourabh Jain]

On 25/02/26 13:44, Baoquan He wrote:
> Here, kasan is disabled if specified 'kasan=off' in kernel cmdline.
>
> This includes 32bit, book3s/64 and book3e/64.
>
> Signed-off-by: Baoquan He <bhe at redhat.com>
> Cc: linuxppc-dev at lists.ozlabs.org
> ---
>   arch/powerpc/mm/kasan/init_32.c        | 6 +++++-
>   arch/powerpc/mm/kasan/init_book3e_64.c | 4 ++++
>   arch/powerpc/mm/kasan/init_book3s_64.c | 4 ++++
>   3 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/mm/kasan/init_32.c b/arch/powerpc/mm/kasan/init_32.c
> index 1d083597464f..0ea2a636c992 100644
> --- a/arch/powerpc/mm/kasan/init_32.c
> +++ b/arch/powerpc/mm/kasan/init_32.c
> @@ -141,6 +141,10 @@ void __init kasan_init(void)
>   	u64 i;
>   	int ret;
>   
> +	/* If KASAN is disabled via command line, don't initialize it. */
> +	if (kasan_arg_disabled)
> +		return;
> +
>   	for_each_mem_range(i, &base, &end) {
>   		phys_addr_t top = min(end, total_lowmem);
>   
> @@ -170,7 +174,7 @@ void __init kasan_init(void)
>   
>   void __init kasan_late_init(void)
>   {
> -	if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
> +	if (IS_ENABLED(CONFIG_KASAN_VMALLOC) && kasan_enabled())
>   		kasan_unmap_early_shadow_vmalloc();
>   }
>   
> diff --git a/arch/powerpc/mm/kasan/init_book3e_64.c b/arch/powerpc/mm/kasan/init_book3e_64.c
> index 0d3a73d6d4b0..fbe4c9a7e460 100644
> --- a/arch/powerpc/mm/kasan/init_book3e_64.c
> +++ b/arch/powerpc/mm/kasan/init_book3e_64.c
> @@ -111,6 +111,10 @@ void __init kasan_init(void)
>   	u64 i;
>   	pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL_RO);
>   
> +	/* If KASAN is disabled via command line, don't initialize it. */
> +	if (kasan_arg_disabled)
> +		return;
> +
>   	for_each_mem_range(i, &start, &end)
>   		kasan_init_phys_region(phys_to_virt(start), phys_to_virt(end));
>   
> diff --git a/arch/powerpc/mm/kasan/init_book3s_64.c b/arch/powerpc/mm/kasan/init_book3s_64.c
> index dcafa641804c..f7906f9ef9be 100644
> --- a/arch/powerpc/mm/kasan/init_book3s_64.c
> +++ b/arch/powerpc/mm/kasan/init_book3s_64.c
> @@ -54,6 +54,10 @@ void __init kasan_init(void)
>   	u64 i;
>   	pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL);
>   
> +	/* If KASAN is disabled via command line, don't initialize it. */
> +	if (kasan_arg_disabled)
> +		return;
> +
>   	if (!early_radix_enabled()) {
>   		pr_warn("KASAN not enabled as it requires radix!");
>   		return;

Should we log in the kernel log buffer that KASAN is disabled?

Right now, I don't see the kernel advertising the same.

$ dmesg | grep -i kasan
[    0.000000] Kernel command line: 
BOOT_IMAGE=(ieee1275//vdevice/v-scsi at 30000070/disk at 8100000000000000,msdos2)/vmlinuz-7.0.0-rc3+ 
crashkernel=2G kasan=off

Tested this series on powerpc Pseries platform.
So feel free to add:
Tested-by: Sourabh Jain <sourabhjain at linux.ibm.com>

- Sourabh Jain