From: Nick Desaulniers <ndesaulniers@google.com>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Marc Zyngier <maz@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
LKML <linux-kernel@vger.kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: [PATCH] irqchip/gic-v3: fix OF_BAD_ADDR error handling
Date: Tue, 23 Mar 2021 15:06:22 -0700 [thread overview]
Message-ID: <CAKwvOdkBEQdVC73_datkwa+meitAGskDgTEr5LzX6AEnE4xd-w@mail.gmail.com> (raw)
In-Reply-To: <20210323131842.2773094-1-arnd@kernel.org>
On Tue, Mar 23, 2021 at 6:18 AM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> When building with extra warnings enabled, clang points out a
> mistake in the error handling:
>
> drivers/irqchip/irq-gic-v3-mbi.c:306:21: error: result of comparison of constant 18446744073709551615 with expression of type 'phys_addr_t' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
Looks like based on CONFIG_PHYS_ADDR_T_64BIT, phys_addr_t can be u64
or u32, but of_translate_address always returns a u64. This is fine
for the current value of OF_BAD_ADDR, but I think there's a risk of
losing the top 32b of the return value of of_translate_address() here?
> if (mbi_phys_base == OF_BAD_ADDR) {
>
> Truncate the constant to the same type as the variable it gets compared
> to, to shut make the check work and void the warning.
>
> Fixes: 505287525c24 ("irqchip/gic-v3: Add support for Message Based Interrupts as an MSI controller")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> drivers/irqchip/irq-gic-v3-mbi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-mbi.c b/drivers/irqchip/irq-gic-v3-mbi.c
> index 563a9b366294..e81e89a81cb5 100644
> --- a/drivers/irqchip/irq-gic-v3-mbi.c
> +++ b/drivers/irqchip/irq-gic-v3-mbi.c
> @@ -303,7 +303,7 @@ int __init mbi_init(struct fwnode_handle *fwnode, struct irq_domain *parent)
> reg = of_get_property(np, "mbi-alias", NULL);
> if (reg) {
> mbi_phys_base = of_translate_address(np, reg);
> - if (mbi_phys_base == OF_BAD_ADDR) {
> + if (mbi_phys_base == (phys_addr_t)OF_BAD_ADDR) {
> ret = -ENXIO;
> goto err_free_mbi;
> }
> --
> 2.29.2
>
--
Thanks,
~Nick Desaulniers
next prev parent reply other threads:[~2021-03-23 22:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-23 13:18 [PATCH] irqchip/gic-v3: fix OF_BAD_ADDR error handling Arnd Bergmann
2021-03-23 22:06 ` Nick Desaulniers [this message]
2021-03-24 10:14 ` Marc Zyngier
2021-03-24 10:55 ` Arnd Bergmann
2021-04-07 12:31 ` Marc Zyngier
2021-04-07 12:38 ` [irqchip: irq/irqchip-next] irqchip/gic-v3: Fix " irqchip-bot for Arnd Bergmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAKwvOdkBEQdVC73_datkwa+meitAGskDgTEr5LzX6AEnE4xd-w@mail.gmail.com \
--to=ndesaulniers@google.com \
--cc=arnd@arndb.de \
--cc=arnd@kernel.org \
--cc=clang-built-linux@googlegroups.com \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=nathan@kernel.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).