From 37233169a6ea912020c572f870075a63293b786a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Miquel=20Sabat=C3=A9=20Sol=C3=A0?= Date: Fri, 13 Sep 2024 10:00:52 +0200 Subject: [PATCH] riscv: Prevent a bad reference count on CPU nodes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Sudeep Holla Reviewed-by: Sunil V L Reviewed-by: Alexandre Ghiti Fixes: 604f32ea6909 ("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: Palmer Dabbelt --- arch/riscv/kernel/cacheinfo.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c index b320b1d9aa01..2d40736fc37c 100644 --- a/arch/riscv/kernel/cacheinfo.c +++ b/arch/riscv/kernel/cacheinfo.c @@ -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"))