Re: [PATCH] reboot: Fix variable assignments in type_store

From: Petr Mladek
Date: Fri Nov 13 2020 - 10:57:03 EST


On Wed 2020-11-11 20:50:23, Nathan Chancellor wrote:
> Clang warns:
>
> kernel/reboot.c:707:17: warning: implicit conversion from enumeration
> type 'enum reboot_type' to different enumeration type 'enum reboot_mode'
> [-Wenum-conversion]
> reboot_mode = BOOT_TRIPLE;
> ~ ^~~~~~~~~~~
> kernel/reboot.c:709:17: warning: implicit conversion from enumeration
> type 'enum reboot_type' to different enumeration type 'enum reboot_mode'
> [-Wenum-conversion]
> reboot_mode = BOOT_KBD;
> ~ ^~~~~~~~
> kernel/reboot.c:711:17: warning: implicit conversion from enumeration
> type 'enum reboot_type' to different enumeration type 'enum reboot_mode'
> [-Wenum-conversion]
> reboot_mode = BOOT_BIOS;
> ~ ^~~~~~~~~
> kernel/reboot.c:713:17: warning: implicit conversion from enumeration
> type 'enum reboot_type' to different enumeration type 'enum reboot_mode'
> [-Wenum-conversion]
> reboot_mode = BOOT_ACPI;
> ~ ^~~~~~~~~
> kernel/reboot.c:715:17: warning: implicit conversion from enumeration
> type 'enum reboot_type' to different enumeration type 'enum reboot_mode'
> [-Wenum-conversion]
> reboot_mode = BOOT_EFI;
> ~ ^~~~~~~~
> kernel/reboot.c:717:17: warning: implicit conversion from enumeration
> type 'enum reboot_type' to different enumeration type 'enum reboot_mode'
> [-Wenum-conversion]
> reboot_mode = BOOT_CF9_FORCE;
> ~ ^~~~~~~~~~~~~~
> kernel/reboot.c:719:17: warning: implicit conversion from enumeration
> type 'enum reboot_type' to different enumeration type 'enum reboot_mode'
> [-Wenum-conversion]
> reboot_mode = BOOT_CF9_SAFE;
> ~ ^~~~~~~~~~~~~
> 7 warnings generated.
>
> It seems that these assignment should be to reboot_type, not
> reboot_mode. Fix it so there are no more warnings and the code works
> properly.
>
> Fixes: eab8da48579d ("reboot: allow to specify reboot mode via sysfs")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1197
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> ---
> kernel/reboot.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/kernel/reboot.c b/kernel/reboot.c
> index deba133a071b..8599d0d44aec 100644
> --- a/kernel/reboot.c
> +++ b/kernel/reboot.c
> @@ -704,19 +704,19 @@ static ssize_t type_store(struct kobject *kobj, struct kobj_attribute *attr,
> return -EPERM;
>
> if (!strncmp(buf, BOOT_TRIPLE_STR, strlen(BOOT_TRIPLE_STR)))
> - reboot_mode = BOOT_TRIPLE;
> + reboot_type = BOOT_TRIPLE;
> else if (!strncmp(buf, BOOT_KBD_STR, strlen(BOOT_KBD_STR)))
> - reboot_mode = BOOT_KBD;
> + reboot_type = BOOT_KBD;
> else if (!strncmp(buf, BOOT_BIOS_STR, strlen(BOOT_BIOS_STR)))
> - reboot_mode = BOOT_BIOS;
> + reboot_type = BOOT_BIOS;
> else if (!strncmp(buf, BOOT_ACPI_STR, strlen(BOOT_ACPI_STR)))
> - reboot_mode = BOOT_ACPI;
> + reboot_type = BOOT_ACPI;
> else if (!strncmp(buf, BOOT_EFI_STR, strlen(BOOT_EFI_STR)))
> - reboot_mode = BOOT_EFI;
> + reboot_type = BOOT_EFI;
> else if (!strncmp(buf, BOOT_CF9_FORCE_STR, strlen(BOOT_CF9_FORCE_STR)))
> - reboot_mode = BOOT_CF9_FORCE;
> + reboot_type = BOOT_CF9_FORCE;
> else if (!strncmp(buf, BOOT_CF9_SAFE_STR, strlen(BOOT_CF9_SAFE_STR)))
> - reboot_mode = BOOT_CF9_SAFE;
> + reboot_type = BOOT_CF9_SAFE;
> else
> return -EINVAL;

Great catch! I guess that it has been a cut&paste mistake when writing
the code.

I feel shame that I have missed it. I think that I have even tested it
but I probably tried only mode_store() and mode_read().

Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>

Best Regards,
Petr