linux-kernel - RE: [PATCH] x86/alternative: Support relocations in alternatives

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Message-ID: <693ce771113d49da92235a0f6d2e395f@AcuMS.aculab.com>
Date:   Wed, 8 Feb 2023 12:29:38 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Peter Zijlstra' <peterz@...radead.org>,
        "x86@...nel.org" <x86@...nel.org>, Borislav Petkov <bp@...en8.de>
CC:     Masami Hiramatsu <mhiramat@...nel.org>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Andrew Cooper <Andrew.Cooper3@...rix.com>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] x86/alternative: Support relocations in alternatives

From: Peter Zijlstra
> Sent: 06 February 2023 15:06
...
> +#define apply_reloc_n(n_, p_, d_)				\
> +	do {							\
> +		s32 v = *(s##n_ *)(p_);				\

You've added '_' suffixes to the parameters.
But these only refer to the body of the #define
so are never a problem.

OTOH the local 'v' will cause confusion if one of the
actual parameters is 'v'.
Which is why it is common to prefix locals with '_'.
(Which doesn't help with recursive expansions.)

Since this is only actually expended in the one .c file
it is unlikely to cause a problem.

	David

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