[PATCH 00/10] irqchip: Prevent drivers abusing irq_chip::name

From: Marc Zyngier <maz@kernel.org>
To: linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Bartosz Golaszewski <brgl@bgdev.pl>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Grygorii Strashko <grygorii.strashko@ti.com>,
	Santosh Shilimkar <ssantosh@kernel.org>,
	Kevin Hilman <khilman@kernel.org>,
	Tony Lindgren <tony@atomide.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Vladimir Zapolskiy <vz@mleia.com>, Andrew Lunn <andrew@lunn.ch>,
	Gregory Clement <gregory.clement@bootlin.com>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
	Emil Renner Berthing <kernel@esmil.dk>,
	kernel-team@android.com
Subject: [PATCH 00/10] irqchip: Prevent drivers abusing irq_chip::name
Date: Wed,  9 Feb 2022 16:25:57 +0000	[thread overview]
Message-ID: <20220209162607.1118325-1-maz@kernel.org> (raw)

Another common abuse in irqchip drivers (and derivatives) is to place
a string representing the underlying device in the irq_chip::name
field that gets displayed in /proc/interrupts while this should only
be an indication of the "type" of interrupt controller.

Not only this is pretty pointless (with hierarchical domains, you only
see the top chip), but it also gets in the way of making the irq_chip
structure const. For debug, we have a whole infrastructure that does
everything you can imagine (and stuff you don't want to).

We can't remove this name as it is visible from userspace and there is
a whole collection of CI scripts that parse /proc/interrupts for good
(and mostly bad) reasons. The solution is to use the irq_print_chip()
callback and to let it output whatever string is necessary.

Having done that, we can cleanup a few irqchip drivers and make their
irq_chip structure const (which requires touching a handful of core
functions). Whilst we're at it, we do the same for a couple of gpio
drivers.

This series relies on the one posted at [1].

Thanks,

	M.

[1] https://lore.kernel.org/r/20220201120310.878267-1-maz@kernel.org

Marc Zyngier (10):
  irqdomain: Let irq_domain_set_{info,hwirq_and_chip} take a const
    irq_chip
  genirq: Allow irq_chip registration functions to take a const irq_chip
  irqchip/gic: Switch to dynamic chip name output
  irqchip/lpc32xx: Switch to dynamic chip name output
  irqchip/mvebu-pic: Switch to dynamic chip name output
  irqchip/ts4800: Switch to dynamic chip name output
  irqchip/versatile-fpga: Switch to dynamic chip name output
  gpio: mt7621: Switch to dynamic chip name output
  gpio: omap: Switch to dynamic chip name output
  pinctrl: starfive: Switch to dynamic chip name output

 drivers/gpio/gpio-mt7621.c             |  12 ++-
 drivers/gpio/gpio-omap.c               |  28 ++++---
 drivers/irqchip/irq-ftintc010.c        |   1 -
 drivers/irqchip/irq-gic.c              | 102 +++++++++++++------------
 drivers/irqchip/irq-lpc32xx.c          |  34 ++++++---
 drivers/irqchip/irq-mvebu-pic.c        |  28 ++++---
 drivers/irqchip/irq-ts4800.c           |  25 ++++--
 drivers/irqchip/irq-versatile-fpga.c   |  46 ++++++-----
 drivers/pinctrl/pinctrl-starfive.c     |  11 ++-
 include/linux/irq.h                    |   7 +-
 include/linux/irqchip/versatile-fpga.h |  14 ----
 include/linux/irqdomain.h              |   5 +-
 kernel/irq/chip.c                      |   9 +--
 kernel/irq/irqdomain.c                 |   7 +-
 14 files changed, 189 insertions(+), 140 deletions(-)
 delete mode 100644 include/linux/irqchip/versatile-fpga.h

-- 
2.30.2