All of lore.kernel.org
 help / color / mirror / Atom feed
From: Arnd Bergmann <arnd@kernel.org>
To: Sudeep Holla <sudeep.holla@arm.com>,
	Cristian Marussi <cristian.marussi@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Bill Wendling <morbo@google.com>,
	Justin Stitt <justinstitt@google.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: [PATCH] firmware: arm_scmi: avoid returning uninialized data
Date: Fri, 16 Feb 2024 17:32:53 +0100	[thread overview]
Message-ID: <20240216163259.1927967-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

Clang notices that there is a code path through
scmi_powercap_notify_supported() that returns an
undefined value:

drivers/firmware/arm_scmi/powercap.c:821:11: error: variable 'supported' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
  821 |         else if (evt_id == SCMI_EVENT_POWERCAP_MEASUREMENTS_CHANGED)
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/firmware/arm_scmi/powercap.c:824:9: note: uninitialized use occurs here
  824 |         return supported;
      |                ^~~~~~~~~
drivers/firmware/arm_scmi/powercap.c:821:7: note: remove the 'if' if its condition is always true
  821 |         else if (evt_id == SCMI_EVENT_POWERCAP_MEASUREMENTS_CHANGED)
      |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  822 |                 supported = dom_info->notify_powercap_measurement_change;
drivers/firmware/arm_scmi/powercap.c:811:16: note: initialize the variable 'supported' to silence this warning
  811 |         bool supported;
      |                       ^

Return 'false' here, which is probably what was intended.

Fixes: c92a75fe84ce ("firmware: arm_scmi: Implement Powercap .is_notify_supported callback")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/firmware/arm_scmi/powercap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/firmware/arm_scmi/powercap.c b/drivers/firmware/arm_scmi/powercap.c
index aae91f47303e..8ee3be8776b0 100644
--- a/drivers/firmware/arm_scmi/powercap.c
+++ b/drivers/firmware/arm_scmi/powercap.c
@@ -820,6 +820,8 @@ scmi_powercap_notify_supported(const struct scmi_protocol_handle *ph,
 		supported = dom_info->notify_powercap_cap_change;
 	else if (evt_id == SCMI_EVENT_POWERCAP_MEASUREMENTS_CHANGED)
 		supported = dom_info->notify_powercap_measurement_change;
+	else
+		supported = false;
 
 	return supported;
 }
-- 
2.39.2


WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@kernel.org>
To: Sudeep Holla <sudeep.holla@arm.com>,
	Cristian Marussi <cristian.marussi@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Bill Wendling <morbo@google.com>,
	Justin Stitt <justinstitt@google.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: [PATCH] firmware: arm_scmi: avoid returning uninialized data
Date: Fri, 16 Feb 2024 17:32:53 +0100	[thread overview]
Message-ID: <20240216163259.1927967-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

Clang notices that there is a code path through
scmi_powercap_notify_supported() that returns an
undefined value:

drivers/firmware/arm_scmi/powercap.c:821:11: error: variable 'supported' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
  821 |         else if (evt_id == SCMI_EVENT_POWERCAP_MEASUREMENTS_CHANGED)
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/firmware/arm_scmi/powercap.c:824:9: note: uninitialized use occurs here
  824 |         return supported;
      |                ^~~~~~~~~
drivers/firmware/arm_scmi/powercap.c:821:7: note: remove the 'if' if its condition is always true
  821 |         else if (evt_id == SCMI_EVENT_POWERCAP_MEASUREMENTS_CHANGED)
      |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  822 |                 supported = dom_info->notify_powercap_measurement_change;
drivers/firmware/arm_scmi/powercap.c:811:16: note: initialize the variable 'supported' to silence this warning
  811 |         bool supported;
      |                       ^

Return 'false' here, which is probably what was intended.

Fixes: c92a75fe84ce ("firmware: arm_scmi: Implement Powercap .is_notify_supported callback")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/firmware/arm_scmi/powercap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/firmware/arm_scmi/powercap.c b/drivers/firmware/arm_scmi/powercap.c
index aae91f47303e..8ee3be8776b0 100644
--- a/drivers/firmware/arm_scmi/powercap.c
+++ b/drivers/firmware/arm_scmi/powercap.c
@@ -820,6 +820,8 @@ scmi_powercap_notify_supported(const struct scmi_protocol_handle *ph,
 		supported = dom_info->notify_powercap_cap_change;
 	else if (evt_id == SCMI_EVENT_POWERCAP_MEASUREMENTS_CHANGED)
 		supported = dom_info->notify_powercap_measurement_change;
+	else
+		supported = false;
 
 	return supported;
 }
-- 
2.39.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2024-02-16 16:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-16 16:32 Arnd Bergmann [this message]
2024-02-16 16:32 ` [PATCH] firmware: arm_scmi: avoid returning uninialized data Arnd Bergmann
2024-02-16 17:21 ` Cristian Marussi
2024-02-16 17:21   ` Cristian Marussi
2024-02-16 20:19   ` Arnd Bergmann
2024-02-16 20:19     ` 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=20240216163259.1927967-1-arnd@kernel.org \
    --to=arnd@kernel.org \
    --cc=arnd@arndb.de \
    --cc=cristian.marussi@arm.com \
    --cc=justinstitt@google.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=llvm@lists.linux.dev \
    --cc=morbo@google.com \
    --cc=nathan@kernel.org \
    --cc=ndesaulniers@google.com \
    --cc=sudeep.holla@arm.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.