regulator: avoid resolve_supply() infinite recursion

osctobe · ksacilotto · commit b22d85536757 · 2021-01-20T14:24:28.000+01:00
BugLink: https://bugs.launchpad.net/bugs/1908561 commit 4b639e2 upstream. When a regulator's name equals its supply's name the regulator_resolve_supply() recurses indefinitely. Add a check so that debugging the problem is easier. The "fixed" commit just exposed the problem. Fixes: aea6cb9 ("regulator: resolve supply after creating regulator") Cc: stable@vger.kernel.org Reported-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # stpmic1 Link: https://lore.kernel.org/r/c6171057cfc0896f950c4d8cb82df0f9f1b89ad9.1605226675.git.mirq-linux@rere.qmqm.pl Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Ian May <ian.may@canonical.com>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
@@ -1800,6 +1800,12 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
 		}
 	}
 
+	if (r == rdev) {
+		dev_err(dev, "Supply for %s (%s) resolved to itself\n",
+			rdev->desc->name, rdev->supply_name);
+		return -EINVAL;
+	}
+
 	/*
 	 * If the supply's parent device is not the same as the
 	 * regulator's parent device, then ensure the parent device

Original file line number	Diff line number	Diff line change
`@@ -1800,6 +1800,12 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)`
`1800`	`1800`	`}`
`1801`	`1801`	`}`
`1802`	`1802`
	`1803`	`+ if (r == rdev) {`
	`1804`	`+ dev_err(dev, "Supply for %s (%s) resolved to itself\n",`
	`1805`	`+ rdev->desc->name, rdev->supply_name);`
	`1806`	`+ return -EINVAL;`
	`1807`	`+ }`
	`1808`	`+`
`1803`	`1809`	`/*`
`1804`	`1810`	`* If the supply's parent device is not the same as the`
`1805`	`1811`	`* regulator's parent device, then ensure the parent device`