From: Sami Tolvanen <samitolvanen@google.com>
To: Neal Liu <neal.liu@mediatek.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Thierry Reding <thierry.reding@gmail.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org,
linux-tegra@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org,
lkml <linux-kernel@vger.kernel.org>,
wsd_upstream@mediatek.com
Subject: Re: [PATCH v2] cpuidle: change enter_s2idle() prototype
Date: Tue, 7 Jul 2020 09:43:25 -0700 [thread overview]
Message-ID: <20200707164325.GA2525978@google.com> (raw)
In-Reply-To: <1594005196-16327-2-git-send-email-neal.liu@mediatek.com>
On Mon, Jul 06, 2020 at 11:13:16AM +0800, Neal Liu wrote:
> Control Flow Integrity(CFI) is a security mechanism that disallows
> changes to the original control flow graph of a compiled binary,
> making it significantly harder to perform such attacks.
>
> init_state_node() assign same function callback to different
> function pointer declarations.
>
> static int init_state_node(struct cpuidle_state *idle_state,
> const struct of_device_id *matches,
> struct device_node *state_node) { ...
> idle_state->enter = match_id->data; ...
> idle_state->enter_s2idle = match_id->data; }
>
> Function declarations:
>
> struct cpuidle_state { ...
> int (*enter) (struct cpuidle_device *dev,
> struct cpuidle_driver *drv,
> int index);
>
> void (*enter_s2idle) (struct cpuidle_device *dev,
> struct cpuidle_driver *drv,
> int index); };
>
> In this case, either enter() or enter_s2idle() would cause CFI check
> failed since they use same callee.
>
> Align function prototype of enter() since it needs return value for
> some use cases. The return value of enter_s2idle() is no
> need currently.
>
> Signed-off-by: Neal Liu <neal.liu@mediatek.com>
> ---
> drivers/acpi/processor_idle.c | 6 ++++--
> drivers/cpuidle/cpuidle-tegra.c | 8 +++++---
> drivers/idle/intel_idle.c | 6 ++++--
> include/linux/cpuidle.h | 6 +++---
> 4 files changed, 16 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 75534c5..6ffb6c9 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -655,8 +655,8 @@ static int acpi_idle_enter(struct cpuidle_device *dev,
> return index;
> }
>
> -static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
> - struct cpuidle_driver *drv, int index)
> +static int acpi_idle_enter_s2idle(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv, int index)
> {
> struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
>
> @@ -674,6 +674,8 @@ static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
> }
> }
> acpi_idle_do_entry(cx);
> +
> + return 0;
> }
>
> static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
> diff --git a/drivers/cpuidle/cpuidle-tegra.c b/drivers/cpuidle/cpuidle-tegra.c
> index 1500458..a12fb14 100644
> --- a/drivers/cpuidle/cpuidle-tegra.c
> +++ b/drivers/cpuidle/cpuidle-tegra.c
> @@ -253,11 +253,13 @@ static int tegra_cpuidle_enter(struct cpuidle_device *dev,
> return err ? -1 : index;
> }
>
> -static void tegra114_enter_s2idle(struct cpuidle_device *dev,
> - struct cpuidle_driver *drv,
> - int index)
> +static int tegra114_enter_s2idle(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index)
> {
> tegra_cpuidle_enter(dev, drv, index);
> +
> + return 0;
> }
>
> /*
> diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
> index f449584..b178da3 100644
> --- a/drivers/idle/intel_idle.c
> +++ b/drivers/idle/intel_idle.c
> @@ -175,13 +175,15 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev,
> * Invoked as a suspend-to-idle callback routine with frozen user space, frozen
> * scheduler tick and suspended scheduler clock on the target CPU.
> */
> -static __cpuidle void intel_idle_s2idle(struct cpuidle_device *dev,
> - struct cpuidle_driver *drv, int index)
> +static __cpuidle int intel_idle_s2idle(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv, int index)
> {
> unsigned long eax = flg2MWAIT(drv->states[index].flags);
> unsigned long ecx = 1; /* break on interrupt flag */
>
> mwait_idle_with_hints(eax, ecx);
> +
> + return 0;
> }
>
> /*
> diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
> index ec2ef63..bee10c0 100644
> --- a/include/linux/cpuidle.h
> +++ b/include/linux/cpuidle.h
> @@ -66,9 +66,9 @@ struct cpuidle_state {
> * suspended, so it must not re-enable interrupts at any point (even
> * temporarily) or attempt to change states of clock event devices.
> */
> - void (*enter_s2idle) (struct cpuidle_device *dev,
> - struct cpuidle_driver *drv,
> - int index);
> + int (*enter_s2idle)(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index);
> };
>
> /* Idle State Flags */
> --
> 1.7.9.5
This looks good to me, thank you for sending the patch! Please feel free
to add:
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Sami
next prev parent reply other threads:[~2020-07-07 16:43 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-06 3:13 [PATCH v2] cpuidle: Fix CFI failure Neal Liu
2020-07-06 3:13 ` [PATCH v2] cpuidle: change enter_s2idle() prototype Neal Liu
2020-07-07 16:43 ` Sami Tolvanen [this message]
2020-07-09 12:18 ` Rafael J. Wysocki
2020-07-10 3:08 ` Neal Liu
2020-07-20 8:21 ` Neal Liu
2020-07-23 19:07 ` Sami Tolvanen
2020-07-24 9:57 ` Rafael J. Wysocki
2020-07-24 10:24 ` Neal Liu
2020-07-24 11:20 ` Rafael J. Wysocki
2020-07-24 11:49 ` Neal Liu
2020-07-25 15:48 ` Rafael J. Wysocki
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=20200707164325.GA2525978@google.com \
--to=samitolvanen@google.com \
--cc=daniel.lezcano@linaro.org \
--cc=jacob.jun.pan@linux.intel.com \
--cc=jonathanh@nvidia.com \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=matthias.bgg@gmail.com \
--cc=neal.liu@mediatek.com \
--cc=rjw@rjwysocki.net \
--cc=thierry.reding@gmail.com \
--cc=wsd_upstream@mediatek.com \
/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).