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* Re: New linux-next KCFLAGS
       [not found] <CAGXu5jL9WDRVCzPP0V2cvFHWfwAfd74kBNX9O+0frFkD26ti1Q@mail.gmail.com>
@ 2018-11-25 21:48 ` Stephen Rothwell
  2018-11-26  5:46   ` Kees Cook
  0 siblings, 1 reply; 6+ messages in thread
From: Stephen Rothwell @ 2018-11-25 21:48 UTC (permalink / raw)
  To: Kees Cook; +Cc: PowerPC

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Hi Kees,

On Fri, 26 Oct 2018 01:34:33 +0100 Kees Cook <keescook@google.com> wrote:
>
> So, if you it's possible to "seed" some new flags for linux-next, I'd
> be interested in making sure no new instances of warnings from
> -Wimplicit-fallthrough (gcc 7.1 and later) appear. VLAs will be gone
> in a couple days, so I'm currently only interested in killing implicit
> fallthroughs[1] now. There are hundreds of cases remaining, so ignore
> those on the first build, but anything NEW is what I'd like to get
> maintainer nags sent for (CCing myself and Gustavo Silva would be
> especially nice, too).

I don't know Gustavo's email address ...

> Thanks!
> 
> [1] Gustavo has fixed lots of actual bugs as part of this work:
>      https://lkml.kernel.org/r/1f64449a-ef19-20c8-f8cb-7e629f8fe71b@embeddedor.com

I finally got around to this.  I have added the following patch to my
fixes tree (which is merged immediately after Linus' tree).

commit 4d8360ade996cf1823e570544791c9d7bd660ffb
Author: Stephen Rothwell <sfr@canb.auug.org.au>
Date:   Mon Nov 26 07:58:34 2018 +1100

    Check for new cases of implict fallthrough
    
    for Kees
    
    Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

diff --git a/Makefile b/Makefile
index ddbf627cad8f..380164f590bc 100644
--- a/Makefile
+++ b/Makefile
@@ -804,6 +804,9 @@ KBUILD_CFLAGS += -Wdeclaration-after-statement
 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 KBUILD_CFLAGS += $(call cc-option,-Wvla)
 
+# Check for implict fallthroughs
+KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough)
+
 # disable pointer signed / unsigned warnings in gcc 4.0
 KBUILD_CFLAGS += -Wno-pointer-sign
 

Unfortunately, some of the kernel is built with -Werror, so I have had
to add the following patch as well just to build Linus' tree:

(I just marked them as "fall through", I am not sure if that is the
correct resolution.)

From: Stephen Rothwell <sfr@canb.auug.org.au>
Date: Mon, 26 Nov 2018 08:32:39 +1100
Subject: [PATCH] powerpc: tag implicit fall throughs

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
 arch/powerpc/kernel/nvram_64.c            | 1 +
 arch/powerpc/platforms/powermac/feature.c | 1 +
 arch/powerpc/xmon/xmon.c                  | 1 +
 3 files changed, 3 insertions(+)

diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
index 22e9d281324d..06e2eda2430e 100644
--- a/arch/powerpc/kernel/nvram_64.c
+++ b/arch/powerpc/kernel/nvram_64.c
@@ -809,6 +809,7 @@ static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
 #ifdef CONFIG_PPC_PMAC
 	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
 		printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
+		/* fall through */
 	case IOC_NVRAM_GET_OFFSET: {
 		int part, offset;
 
diff --git a/arch/powerpc/platforms/powermac/feature.c b/arch/powerpc/platforms/powermac/feature.c
index ed2f54b3f173..a7ec06876b53 100644
--- a/arch/powerpc/platforms/powermac/feature.c
+++ b/arch/powerpc/platforms/powermac/feature.c
@@ -1471,6 +1471,7 @@ static long g5_i2s_enable(struct device_node *node, long param, long value)
 	case 2:
 		if (macio->type == macio_shasta)
 			break;
+		/* fall through */
 	default:
 		return -ENODEV;
 	}
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 36b8dc47a3c3..308326f8b7ed 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -4033,6 +4033,7 @@ static int do_spu_cmd(void)
 		subcmd = inchar();
 		if (isxdigit(subcmd) || subcmd == '\n')
 			termch = subcmd;
+		/* fall through */
 	case 'f':
 		scanhex(&num);
 		if (num >= XMON_NUM_SPUS || !spu_info[num].spu) {
-- 
2.19.1

-- 
Cheers,
Stephen Rothwell

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^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: New linux-next KCFLAGS
  2018-11-25 21:48 ` New linux-next KCFLAGS Stephen Rothwell
@ 2018-11-26  5:46   ` Kees Cook
  2018-11-26  6:49     ` Stephen Rothwell
  0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2018-11-26  5:46 UTC (permalink / raw)
  To: Stephen Rothwell; +Cc: Gustavo A. R. Silva, PowerPC

On Sun, Nov 25, 2018 at 1:48 PM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi Kees,
>
> On Fri, 26 Oct 2018 01:34:33 +0100 Kees Cook <keescook@google.com> wrote:
> >
> > So, if you it's possible to "seed" some new flags for linux-next, I'd
> > be interested in making sure no new instances of warnings from
> > -Wimplicit-fallthrough (gcc 7.1 and later) appear. VLAs will be gone
> > in a couple days, so I'm currently only interested in killing implicit
> > fallthroughs[1] now. There are hundreds of cases remaining, so ignore
> > those on the first build, but anything NEW is what I'd like to get
> > maintainer nags sent for (CCing myself and Gustavo Silva would be
> > especially nice, too).
>
> I don't know Gustavo's email address ...
>
> > Thanks!
> >
> > [1] Gustavo has fixed lots of actual bugs as part of this work:
> >      https://lkml.kernel.org/r/1f64449a-ef19-20c8-f8cb-7e629f8fe71b@embeddedor.com
>
> I finally got around to this.  I have added the following patch to my
> fixes tree (which is merged immediately after Linus' tree).

Excellent! (Though, wait, does this mean everyone _else_ will see this
too? I'm worried that will be way too noisy...)

> FYI, I am currently ignoring 659 such warnings in Linus' tree ...

That sound about right. Before Gustavo started there maybe 1000 more. (!) :)

Thanks!

-Kees

> commit 4d8360ade996cf1823e570544791c9d7bd660ffb
> Author: Stephen Rothwell <sfr@canb.auug.org.au>
> Date:   Mon Nov 26 07:58:34 2018 +1100
>
>     Check for new cases of implict fallthrough
>
>     for Kees
>
>     Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
>
> diff --git a/Makefile b/Makefile
> index ddbf627cad8f..380164f590bc 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -804,6 +804,9 @@ KBUILD_CFLAGS += -Wdeclaration-after-statement
>  # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
>  KBUILD_CFLAGS += $(call cc-option,-Wvla)
>
> +# Check for implict fallthroughs
> +KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough)
> +
>  # disable pointer signed / unsigned warnings in gcc 4.0
>  KBUILD_CFLAGS += -Wno-pointer-sign
>
>
> Unfortunately, some of the kernel is built with -Werror, so I have had
> to add the following patch as well just to build Linus' tree:
>
> (I just marked them as "fall through", I am not sure if that is the
> correct resolution.)
>
> From: Stephen Rothwell <sfr@canb.auug.org.au>
> Date: Mon, 26 Nov 2018 08:32:39 +1100
> Subject: [PATCH] powerpc: tag implicit fall throughs
>
> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
> ---
>  arch/powerpc/kernel/nvram_64.c            | 1 +
>  arch/powerpc/platforms/powermac/feature.c | 1 +
>  arch/powerpc/xmon/xmon.c                  | 1 +
>  3 files changed, 3 insertions(+)
>
> diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
> index 22e9d281324d..06e2eda2430e 100644
> --- a/arch/powerpc/kernel/nvram_64.c
> +++ b/arch/powerpc/kernel/nvram_64.c
> @@ -809,6 +809,7 @@ static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
>  #ifdef CONFIG_PPC_PMAC
>         case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
>                 printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
> +               /* fall through */
>         case IOC_NVRAM_GET_OFFSET: {
>                 int part, offset;
>
> diff --git a/arch/powerpc/platforms/powermac/feature.c b/arch/powerpc/platforms/powermac/feature.c
> index ed2f54b3f173..a7ec06876b53 100644
> --- a/arch/powerpc/platforms/powermac/feature.c
> +++ b/arch/powerpc/platforms/powermac/feature.c
> @@ -1471,6 +1471,7 @@ static long g5_i2s_enable(struct device_node *node, long param, long value)
>         case 2:
>                 if (macio->type == macio_shasta)
>                         break;
> +               /* fall through */
>         default:
>                 return -ENODEV;
>         }
> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> index 36b8dc47a3c3..308326f8b7ed 100644
> --- a/arch/powerpc/xmon/xmon.c
> +++ b/arch/powerpc/xmon/xmon.c
> @@ -4033,6 +4033,7 @@ static int do_spu_cmd(void)
>                 subcmd = inchar();
>                 if (isxdigit(subcmd) || subcmd == '\n')
>                         termch = subcmd;
> +               /* fall through */
>         case 'f':
>                 scanhex(&num);
>                 if (num >= XMON_NUM_SPUS || !spu_info[num].spu) {
> --
> 2.19.1
>
> --
> Cheers,
> Stephen Rothwell



-- 
Kees Cook

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: New linux-next KCFLAGS
  2018-11-26  5:46   ` Kees Cook
@ 2018-11-26  6:49     ` Stephen Rothwell
  2018-11-26  6:56       ` Stephen Rothwell
  2018-11-26 14:00       ` Stephen Rothwell
  0 siblings, 2 replies; 6+ messages in thread
From: Stephen Rothwell @ 2018-11-26  6:49 UTC (permalink / raw)
  To: Kees Cook; +Cc: Gustavo A. R. Silva, PowerPC

[-- Attachment #1: Type: text/plain, Size: 372 bytes --]

Hi Kees,

On Sun, 25 Nov 2018 21:46:20 -0800 Kees Cook <keescook@google.com> wrote:
>
> Excellent! (Though, wait, does this mean everyone _else_ will see this
> too? I'm worried that will be way too noisy...)

Ah, yes, you may be right.  everyone will see them :-(

I may have to figure out another way to do this for tomorrow.

-- 
Cheers,
Stephen Rothwell

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: New linux-next KCFLAGS
  2018-11-26  6:49     ` Stephen Rothwell
@ 2018-11-26  6:56       ` Stephen Rothwell
  2018-11-26 14:00       ` Stephen Rothwell
  1 sibling, 0 replies; 6+ messages in thread
From: Stephen Rothwell @ 2018-11-26  6:56 UTC (permalink / raw)
  To: Kees Cook; +Cc: Gustavo A. R. Silva, PowerPC

[-- Attachment #1: Type: text/plain, Size: 629 bytes --]

Hi Kees,

On Mon, 26 Nov 2018 17:49:26 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> On Sun, 25 Nov 2018 21:46:20 -0800 Kees Cook <keescook@google.com> wrote:
> >
> > Excellent! (Though, wait, does this mean everyone _else_ will see this
> > too? I'm worried that will be way too noisy...)  
> 
> Ah, yes, you may be right.  everyone will see them :-(
> 
> I may have to figure out another way to do this for tomorrow.

For today, I will just revert the commit that adds the flag at the
end or my merging run.  People will only see the warnings if they are
bisecting.

-- 
Cheers,
Stephen Rothwell

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: New linux-next KCFLAGS
  2018-11-26  6:49     ` Stephen Rothwell
  2018-11-26  6:56       ` Stephen Rothwell
@ 2018-11-26 14:00       ` Stephen Rothwell
  2018-11-26 14:25         ` Gustavo A. R. Silva
  1 sibling, 1 reply; 6+ messages in thread
From: Stephen Rothwell @ 2018-11-26 14:00 UTC (permalink / raw)
  To: Kees Cook; +Cc: Gustavo A. R. Silva, PowerPC

[-- Attachment #1: Type: text/plain, Size: 589 bytes --]

Hi all,

On Mon, 26 Nov 2018 17:49:26 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> On Sun, 25 Nov 2018 21:46:20 -0800 Kees Cook <keescook@google.com> wrote:
> >
> > Excellent! (Though, wait, does this mean everyone _else_ will see this
> > too? I'm worried that will be way too noisy...)  
> 
> Ah, yes, you may be right.  everyone will see them :-(
> 
> I may have to figure out another way to do this for tomorrow.

OK, starting tomorrow (later today), I have just added
-Wimplicit-fallthrough to KCFLAGS in my build scripts.

-- 
Cheers,
Stephen Rothwell

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: New linux-next KCFLAGS
  2018-11-26 14:00       ` Stephen Rothwell
@ 2018-11-26 14:25         ` Gustavo A. R. Silva
  0 siblings, 0 replies; 6+ messages in thread
From: Gustavo A. R. Silva @ 2018-11-26 14:25 UTC (permalink / raw)
  To: Stephen Rothwell, Kees Cook; +Cc: PowerPC



On 11/26/18 8:00 AM, Stephen Rothwell wrote:
> Hi all,
> 
> On Mon, 26 Nov 2018 17:49:26 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>>
>> On Sun, 25 Nov 2018 21:46:20 -0800 Kees Cook <keescook@google.com> wrote:
>>>
>>> Excellent! (Though, wait, does this mean everyone _else_ will see this
>>> too? I'm worried that will be way too noisy...)
>>
>> Ah, yes, you may be right.  everyone will see them :-(
>>
>> I may have to figure out another way to do this for tomorrow.
> 
> OK, starting tomorrow (later today), I have just added
> -Wimplicit-fallthrough to KCFLAGS in my build scripts.
> 

Awesome!

Thank you, Stephen. :)
--
Gustavo

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2018-11-26 14:49 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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     [not found] <CAGXu5jL9WDRVCzPP0V2cvFHWfwAfd74kBNX9O+0frFkD26ti1Q@mail.gmail.com>
2018-11-25 21:48 ` New linux-next KCFLAGS Stephen Rothwell
2018-11-26  5:46   ` Kees Cook
2018-11-26  6:49     ` Stephen Rothwell
2018-11-26  6:56       ` Stephen Rothwell
2018-11-26 14:00       ` Stephen Rothwell
2018-11-26 14:25         ` Gustavo A. R. Silva

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