From: Nathan Chancellor <natechancellor@gmail.com>
To: Matteo Croce <mcroce@linux.microsoft.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>,
linux-kernel@vger.kernel.org, Guenter Roeck <linux@roeck-us.net>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Petr Mladek <pmladek@suse.com>, Mike Rapoport <rppt@kernel.org>,
Tyler Hicks <tyhicks@linux.microsoft.com>,
ndesaulniers@google.com, clang-built-linux@googlegroups.com
Subject: Re: [PATCH] reboot: Fix variable assignments in type_store
Date: Thu, 12 Nov 2020 10:49:54 -0700 [thread overview]
Message-ID: <20201112174954.GA934563@ubuntu-m3-large-x86> (raw)
In-Reply-To: <CAFnufp2eEKW4tencrhUoYkY6C-eGB5xF_Fg5hms52zgJj68hJg@mail.gmail.com>
Hi Matteo,
On Thu, Nov 12, 2020 at 12:26:45PM +0100, Matteo Croce wrote:
> On Thu, Nov 12, 2020 at 4:50 AM Nathan Chancellor
> <natechancellor@gmail.com> 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@gmail.com>
> > ---
> > 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;
> >
> >
> > base-commit: 3e14f70c05cda4794901ed8f976de3a88deebcc0
> > --
> > 2.29.2
> >
>
> Hmm, this was introduced in v3 I think.
>
> I wonder why my compiler doesn't warn about it, the two variables are
> defined as different enum type.
> I get the same warnings with GCC and -Wenum-conversion.
What version of GCC do you have? -Wenum-conversion is a fairly new
warning in GCC I think. Although if you get it now, maybe it was some
configuration error?
Regardless, thank you for taking a look at the patch!
Cheers,
Nathan
next prev parent reply other threads:[~2020-11-12 17:50 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 20:27 [PATCH v4] reboot: allow to specify reboot mode via sysfs Matteo Croce
2020-11-12 3:50 ` [PATCH] reboot: Fix variable assignments in type_store Nathan Chancellor
2020-11-12 11:26 ` Matteo Croce
2020-11-12 17:49 ` Nathan Chancellor [this message]
2020-11-12 17:59 ` Matteo Croce
2020-11-12 18:09 ` Nathan Chancellor
2020-11-12 23:13 ` Andrew Morton
2020-11-13 0:20 ` Matteo Croce
2020-11-13 0:41 ` Matteo Croce
2020-11-13 1:18 ` Andrew Morton
2020-11-13 1:38 ` Matteo Croce
2020-11-13 2:46 ` Andrew Morton
2020-11-13 2:58 ` Matteo Croce
2020-11-13 20:06 ` Petr Mladek
2020-11-13 21:28 ` Matteo Croce
2020-11-18 11:47 ` Petr Mladek
2020-11-13 15:56 ` Petr Mladek
2021-02-22 10:03 ` [PATCH v4] reboot: allow to specify reboot mode via sysfs Pavel Machek
2021-02-22 13:12 ` Matteo Croce
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