On Mon, Sep 20, 2021 at 11:55:50AM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> When CONFIG_DMI is disabled, dmi_get_system_info() returns a NULL
> pointer, which is now caught by a warning:
>
> In function 'strlen',
> inlined from 'acpi_add.part.0' at drivers/platform/x86/lg-laptop.c:658:6:
> include/linux/fortify-string.h:25:33: error: argument 1 null where non-null expected [-Werror=nonnull]
> 25 | #define __underlying_strlen __builtin_strlen
> | ^
> include/linux/fortify-string.h:60:24: note: in expansion of macro '__underlying_strlen'
> 60 | return __underlying_strlen(p);
> | ^~~~~~~~~~~~~~~~~~~
> drivers/platform/x86/lg-laptop.c: In function 'acpi_add.part.0':
> include/linux/fortify-string.h:25:33: note: in a call to built-in function '__builtin_strlen'
> 25 | #define __underlying_strlen __builtin_strlen
> | ^
> include/linux/fortify-string.h:60:24: note: in expansion of macro '__underlying_strlen'
> 60 | return __underlying_strlen(p);
> | ^~~~~~~~~~~~~~~~~~~
>
> The code in there does not appear essential, so an explicit
> NULL check should be sufficient. The string is also printed
> to the console, but printk() is able to handle NULL pointer
> arguments gracefully.
>
> Fixes: 8983bfd58d61 ("platform/x86: lg-laptop: Support for battery charge limit on newer models")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/platform/x86/lg-laptop.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/lg-laptop.c b/drivers/platform/x86/lg-laptop.c
> index 3e520d5bca07..88b551caeaaf 100644
> --- a/drivers/platform/x86/lg-laptop.c
> +++ b/drivers/platform/x86/lg-laptop.c
> @@ -655,7 +655,7 @@ static int acpi_add(struct acpi_device *device)
> goto out_platform_registered;
> }
> product = dmi_get_system_info(DMI_PRODUCT_NAME);
> - if (strlen(product) > 4)
> + if (product && strlen(product) > 4)
seems appropriate.
--mark
> switch (product[4]) {
> case '5':
> case '6':
> --
> 2.29.2
>
