Hi Marek,
On 20.11.25 05:15, Marek Vasut wrote:
If CONFIG_OF_PLATDATA=y , then the udevice has no valid OF node associated
with it and ofnode_valid(node) evaluates to 0. The dev_read_u32_default()
call ultimately reaches ofnode_read_u32_index() which invokes fdt_getprop()
and passes result of ofnode_to_offset(node) as an offset parameter into it.
The ofnode_to_offset(node) returns -1 for invalid node, which leads to an
fdt_getprop(..., -1, ...) invocation, which will crash sandbox with SIGSEGV
because libfdt can not handle negative node offsets without full tree check,
which U-Boot inhibits to keep size lower.
Since i2c_child_post_bind() already calls dev_has_ofnode(dev), reuse the
same call and assign i2c->speed_hz = I2C_SPEED_STANDARD_RATE in case the
device has no valid node associated with it, and do not call any of the
dev_read_*() functions for devices without valid nodes.
Signed-off-by: Marek Vasut <[email protected]>
---
Cc: Heiko Schocher <[email protected]>
Cc: Tom Rini <[email protected]>
Cc: [email protected]
---
drivers/i2c/i2c-uclass.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c
index 380a9f8f3ad..d0e9dad7202 100644
--- a/drivers/i2c/i2c-uclass.c
+++ b/drivers/i2c/i2c-uclass.c
@@ -749,8 +749,11 @@ static int i2c_post_probe(struct udevice *dev)
#if CONFIG_IS_ENABLED(OF_REAL)
struct dm_i2c_bus *i2c = dev_get_uclass_priv(dev);
- i2c->speed_hz = dev_read_u32_default(dev, "clock-frequency",
- I2C_SPEED_STANDARD_RATE);
+ if (!dev_has_ofnode(dev))
+ i2c->speed_hz = I2C_SPEED_STANDARD_RATE;
+ else
+ i2c->speed_hz = dev_read_u32_default(dev, "clock-frequency",
+ I2C_SPEED_STANDARD_RATE);
return dm_i2c_set_bus_speed(dev, i2c->speed_hz);
#else
This sounds more as a bug of dev_read_u32_default() to me and should
be fixed there, else we need to make this check around each call of
dev_read_u32_default() ...
And looking into u-boot:/drivers/core/read.c there are more
candidates for such a fix (all with "default" in function name?)
and such a fix would also make the dev_has_ofnode(dev) check in
i2c_child_post_bind() obsolete.
Or may we fix the default functions in drivers/core/ofnode.c ?
Something like that:
"""
hs@threadripper:u-boot [master] $ git diff
diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index cf1cf8abfbe..400512c1a30 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -401,7 +401,9 @@ int ofnode_read_u32(ofnode node, const char *propname, u32
*outp)
u32 ofnode_read_u32_default(ofnode node, const char *propname, u32 def)
{
- assert(ofnode_valid(node));
+ if (!ofnode_valid(node))
+ return def;
+
ofnode_read_u32_index(node, propname, 0, &def);
return def;
"""
I would interprete a default function in a way, that whatever happens,
it returns the default value... but may I oversee something obvious?
bye,
Heiko
--
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E-Mail: [email protected]
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