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Subject: Re: [PATCH v1 1/1] kernel.h: Split out panic and oops helpers
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
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References: <20210406133158.73700-1-andriy.shevchenko@linux.intel.com>
From:   Rasmus Villemoes <linux@rasmusvillemoes.dk>
Message-ID: <03be4ed9-8e8d-e2c2-611d-ac09c61d84f9@rasmusvillemoes.dk>
Date:   Thu, 8 Apr 2021 14:45:12 +0200
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On 06/04/2021 15.31, Andy Shevchenko wrote:
> kernel.h is being used as a dump for all kinds of stuff for a long time.
> Here is the attempt to start cleaning it up by splitting out panic and
> oops helpers.

Yay.

Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>

> At the same time convert users in header and lib folder to use new header.
> Though for time being include new header back to kernel.h to avoid twisted
> indirected includes for existing users.

I think it would be good to have some place to note that "This #include
is just for backwards compatibility, it will go away RealSoonNow, so if
you rely on something from linux/panic.h, include that explicitly
yourself TYVM. And if you're looking for a janitorial task, write a
script to check that every file that uses some identifier defined in
panic.h actually includes that file. When all offenders are found and
dealt with, remove the #include and this note.".

> +
> +struct taint_flag {
> +	char c_true;	/* character printed when tainted */
> +	char c_false;	/* character printed when not tainted */
> +	bool module;	/* also show as a per-module taint flag */
> +};
> +
> +extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT];

While you're doing this, nothing outside of kernel/panic.c cares about
the definition of struct taint_flag or use the taint_flags array, so
could you make the definition private to that file and make the array
static? (Another patch, of course.)

> +enum lockdep_ok {
> +	LOCKDEP_STILL_OK,
> +	LOCKDEP_NOW_UNRELIABLE,
> +};
> +
> +extern const char *print_tainted(void);
> +extern void add_taint(unsigned flag, enum lockdep_ok);
> +extern int test_taint(unsigned flag);
> +extern unsigned long get_taint(void);

I know you're just moving code, but it would be a nice opportunity to
drop the redundant externs.

Rasmus