This is a note to let you know that I've just added the patch titled
riscv: Prevent a bad reference count on CPU nodes
to the 6.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
riscv-prevent-a-bad-reference-count-on-cpu-nodes.patch
and it can be found in the queue-6.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4431ae6ccacaf738fc8dca807771a7725985ae15
Author: Miquel Sabaté Solà <mikisabate@xxxxxxxxx>
Date: Fri Sep 13 10:00:52 2024 +0200
riscv: Prevent a bad reference count on CPU nodes
[ Upstream commit 37233169a6ea912020c572f870075a63293b786a ]
When populating cache leaves we previously fetched the CPU device node
at the very beginning. But when ACPI is enabled we go through a
specific branch which returns early and does not call 'of_node_put' for
the node that was acquired.
Since we are not using a CPU device node for the ACPI code anyways, we
can simply move the initialization of it just passed the ACPI block, and
we are guaranteed to have an 'of_node_put' call for the acquired node.
This prevents a bad reference count of the CPU device node.
Moreover, the previous function did not check for errors when acquiring
the device node, so a return -ENOENT has been added for that case.
Signed-off-by: Miquel Sabaté Solà <mikisabate@xxxxxxxxx>
Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Reviewed-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>
Reviewed-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Fixes: 604f32ea6909 ("riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT")
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20240913080053.36636-1-mikisabate@xxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c
index d6c108c50cba9..d32dfdba083e1 100644
--- a/arch/riscv/kernel/cacheinfo.c
+++ b/arch/riscv/kernel/cacheinfo.c
@@ -75,8 +75,7 @@ int populate_cache_leaves(unsigned int cpu)
{
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
struct cacheinfo *this_leaf = this_cpu_ci->info_list;
- struct device_node *np = of_cpu_device_node_get(cpu);
- struct device_node *prev = NULL;
+ struct device_node *np, *prev;
int levels = 1, level = 1;
if (!acpi_disabled) {
@@ -100,6 +99,10 @@ int populate_cache_leaves(unsigned int cpu)
return 0;
}
+ np = of_cpu_device_node_get(cpu);
+ if (!np)
+ return -ENOENT;
+
if (of_property_read_bool(np, "cache-size"))
ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
if (of_property_read_bool(np, "i-cache-size"))
