All of lore.kernel.org
 help / color / mirror / Atom feed
From: Lee Jones <lee.jones@linaro.org>
To: daniel.thompson@linaro.org, broonie@kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, arnd@arndb.de,
	linus.walleij@linaro.org, baohua@kernel.org, stephan@gerhold.net,
	Lee Jones <lee.jones@linaro.org>
Subject: [PATCH v4 05/10] mfd: mfd-core: Protect against NULL call-back function pointer
Date: Fri,  1 Nov 2019 07:45:13 +0000	[thread overview]
Message-ID: <20191101074518.26228-6-lee.jones@linaro.org> (raw)
In-Reply-To: <20191101074518.26228-1-lee.jones@linaro.org>

If a child device calls mfd_cell_{en,dis}able() without an appropriate
call-back being set, we are likely to encounter a panic.  Avoid this
by adding suitable checking.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 drivers/mfd/mfd-core.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index 23276a80e3b4..96d02b6f06fd 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -28,6 +28,11 @@ int mfd_cell_enable(struct platform_device *pdev)
 	const struct mfd_cell *cell = mfd_get_cell(pdev);
 	int err = 0;
 
+	if (!cell->enable) {
+		dev_dbg(&pdev->dev, "No .enable() call-back registered\n");
+		return 0;
+	}
+
 	/* only call enable hook if the cell wasn't previously enabled */
 	if (atomic_inc_return(cell->usage_count) == 1)
 		err = cell->enable(pdev);
@@ -45,6 +50,11 @@ int mfd_cell_disable(struct platform_device *pdev)
 	const struct mfd_cell *cell = mfd_get_cell(pdev);
 	int err = 0;
 
+	if (!cell->disable) {
+		dev_dbg(&pdev->dev, "No .disable() call-back registered\n");
+		return 0;
+	}
+
 	/* only disable if no other clients are using it */
 	if (atomic_dec_return(cell->usage_count) == 0)
 		err = cell->disable(pdev);
-- 
2.17.1


WARNING: multiple messages have this Message-ID (diff)
From: Lee Jones <lee.jones@linaro.org>
To: daniel.thompson@linaro.org, broonie@kernel.org
Cc: baohua@kernel.org, stephan@gerhold.net, arnd@arndb.de,
	linus.walleij@linaro.org, linux-kernel@vger.kernel.org,
	Lee Jones <lee.jones@linaro.org>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 05/10] mfd: mfd-core: Protect against NULL call-back function pointer
Date: Fri,  1 Nov 2019 07:45:13 +0000	[thread overview]
Message-ID: <20191101074518.26228-6-lee.jones@linaro.org> (raw)
In-Reply-To: <20191101074518.26228-1-lee.jones@linaro.org>

If a child device calls mfd_cell_{en,dis}able() without an appropriate
call-back being set, we are likely to encounter a panic.  Avoid this
by adding suitable checking.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 drivers/mfd/mfd-core.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index 23276a80e3b4..96d02b6f06fd 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -28,6 +28,11 @@ int mfd_cell_enable(struct platform_device *pdev)
 	const struct mfd_cell *cell = mfd_get_cell(pdev);
 	int err = 0;
 
+	if (!cell->enable) {
+		dev_dbg(&pdev->dev, "No .enable() call-back registered\n");
+		return 0;
+	}
+
 	/* only call enable hook if the cell wasn't previously enabled */
 	if (atomic_inc_return(cell->usage_count) == 1)
 		err = cell->enable(pdev);
@@ -45,6 +50,11 @@ int mfd_cell_disable(struct platform_device *pdev)
 	const struct mfd_cell *cell = mfd_get_cell(pdev);
 	int err = 0;
 
+	if (!cell->disable) {
+		dev_dbg(&pdev->dev, "No .disable() call-back registered\n");
+		return 0;
+	}
+
 	/* only disable if no other clients are using it */
 	if (atomic_dec_return(cell->usage_count) == 0)
 		err = cell->disable(pdev);
-- 
2.17.1


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

  parent reply	other threads:[~2019-11-01  7:45 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-01  7:45 [PATCH v4 00/10] Simplify MFD Core Lee Jones
2019-11-01  7:45 ` Lee Jones
2019-11-01  7:45 ` [PATCH v4 01/10] mfd: cs5535-mfd: Use PLATFORM_DEVID_* defines and tidy error message Lee Jones
2019-11-01  7:45   ` Lee Jones
2019-11-01  7:45 ` [PATCH v4 02/10] mfd: cs5535-mfd: Remove mfd_cell->id hack Lee Jones
2019-11-01  7:45   ` Lee Jones
2019-11-01  7:45 ` [PATCH v4 03/10] mfd: cs5535-mfd: Request shared IO regions centrally Lee Jones
2019-11-01  7:45   ` Lee Jones
2019-11-01  8:01   ` Daniel Thompson
2019-11-01  8:01     ` Daniel Thompson
2019-11-01  7:45 ` [PATCH v4 04/10] mfd: cs5535-mfd: Register clients using their own dedicated MFD cell entries Lee Jones
2019-11-01  7:45   ` Lee Jones
2019-11-01  7:45 ` Lee Jones [this message]
2019-11-01  7:45   ` [PATCH v4 05/10] mfd: mfd-core: Protect against NULL call-back function pointer Lee Jones
2019-11-01  7:45 ` [PATCH v4 06/10] mfd: mfd-core: Remove mfd_clone_cell() Lee Jones
2019-11-01  7:45   ` Lee Jones
2019-11-01  7:45 ` [PATCH v4 07/10] x86: olpc-xo1-pm: Remove invocation of MFD's .enable()/.disable() call-backs Lee Jones
2019-11-01  7:45   ` Lee Jones
2019-11-01  7:45 ` [PATCH v4 08/10] x86: olpc-xo1-sci: " Lee Jones
2019-11-01  7:45   ` Lee Jones
2019-11-01  7:45 ` [PATCH v4 09/10] mfd: mfd-core: Remove usage counting for .{en,dis}able() call-backs Lee Jones
2019-11-01  7:45   ` [PATCH v4 09/10] mfd: mfd-core: Remove usage counting for .{en, dis}able() call-backs Lee Jones
2019-11-01  7:45 ` [PATCH v4 10/10] mfd: mfd-core: Move pdev->mfd_cell creation back into mfd_add_device() Lee Jones
2019-11-01  7:45   ` Lee Jones

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=20191101074518.26228-6-lee.jones@linaro.org \
    --to=lee.jones@linaro.org \
    --cc=arnd@arndb.de \
    --cc=baohua@kernel.org \
    --cc=broonie@kernel.org \
    --cc=daniel.thompson@linaro.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=stephan@gerhold.net \
    /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.