Hi Greg,
On Mon, Nov 23, 2020 at 10:20:02AM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
>
> The patch below does not apply to the 4.9-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@xxxxxxxxxxxxxxx>.
Here is the backport.
--
Regards
Sudip
>From 3ef096ea5d9ec8353a23109cd4d8a326743c7905 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= <mirq-linux@xxxxxxxxxxxx>
Date: Fri, 13 Nov 2020 01:20:28 +0100
Subject: [PATCH] regulator: avoid resolve_supply() infinite recursion
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commit 4b639e254d3d4f15ee4ff2b890a447204cfbeea9 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: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
Tested-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> # stpmic1
Link: https://lore.kernel.org/r/c6171057cfc0896f950c4d8cb82df0f9f1b89ad9.1605226675.git.mirq-linux@xxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
drivers/regulator/core.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 0a0dd0aac047..89f14e301b4c 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1550,6 +1550,12 @@ 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;
+ }
+
/* Recursively resolve the supply of the supply */
ret = regulator_resolve_supply(r);
if (ret < 0) {
--
2.11.0
