Unverified Commit 37233169 authored by Miquel Sabaté Solà's avatar Miquel Sabaté Solà Committed by Palmer Dabbelt
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riscv: Prevent a bad reference count on CPU nodes 



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: default avatarMiquel Sabaté Solà <mikisabate@gmail.com>
Reviewed-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Reviewed-by: default avatarSunil V L <sunilvl@ventanamicro.com>
Reviewed-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Fixes: 604f32ea ("riscv: cacheinfo: initialize cacheinfo's level and  type from ACPI PPTT")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240913080053.36636-1-mikisabate@gmail.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent d41373a4

arch/riscv/kernel/cacheinfo.c

+5 −2
Original line number Diff line number Diff line
@@ -80,8 +80,7 @@ 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) {
@@ -105,6 +104,10 @@ 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"))