From 9054fc6d57e80c27c0b0632966416144f2092c2b Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 17 Nov 2021 20:07:34 +0200 Subject: [PATCH 1/3] ACPI: Get acpi_device's parent from the parent field Printk modifier %pfw is used to print the full path of the device name. This is obtained device by device until a device no longer has a parent. On ACPI getting the parent fwnode is done by calling acpi_get_parent() which tries to down() a semaphore. But local IRQs are now disabled in vprintk_store() before the mutex is acquired. This is obviously a problem. Luckily struct device, embedded in struct acpi_device, has a parent field already. Use that field to get the parent instead of relying on acpi_get_parent(). Fixes: 3bd32d6a2ee6 ("lib/vsprintf: Add %pfw conversion specifier for printing fwnode names") Cc: 5.5+ # 5.5+ Signed-off-by: Sakari Ailus Reviewed-by: Andy Shevchenko Signed-off-by: Rafael J. Wysocki --- drivers/acpi/property.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c index e312ebaed8db..781e312f4534 100644 --- a/drivers/acpi/property.c +++ b/drivers/acpi/property.c @@ -1090,15 +1090,10 @@ struct fwnode_handle *acpi_node_get_parent(const struct fwnode_handle *fwnode) /* All data nodes have parent pointer so just return that */ return to_acpi_data_node(fwnode)->parent; } else if (is_acpi_device_node(fwnode)) { - acpi_handle handle, parent_handle; + struct device *dev = to_acpi_device_node(fwnode)->dev.parent; - handle = to_acpi_device_node(fwnode)->handle; - if (ACPI_SUCCESS(acpi_get_parent(handle, &parent_handle))) { - struct acpi_device *adev; - - if (!acpi_bus_get_device(parent_handle, &adev)) - return acpi_fwnode_handle(adev); - } + if (dev) + return acpi_fwnode_handle(to_acpi_device(dev)); } return NULL; From 985e9ece1e55a94da842f6c1f9ff84d587b26267 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 17 Nov 2021 20:07:35 +0200 Subject: [PATCH 2/3] ACPI: Make acpi_node_get_parent() local acpi_node_get_parent() isn't used outside drivers/acpi/property.c. Make it local. Signed-off-by: Sakari Ailus Reviewed-by: Andy Shevchenko Signed-off-by: Rafael J. Wysocki --- drivers/acpi/property.c | 3 ++- include/linux/acpi.h | 7 ------- 2 files changed, 2 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c index 781e312f4534..2366f54d8e9c 100644 --- a/drivers/acpi/property.c +++ b/drivers/acpi/property.c @@ -1084,7 +1084,8 @@ struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode, * Returns parent node of an ACPI device or data firmware node or %NULL if * not available. */ -struct fwnode_handle *acpi_node_get_parent(const struct fwnode_handle *fwnode) +static struct fwnode_handle * +acpi_node_get_parent(const struct fwnode_handle *fwnode) { if (is_acpi_data_node(fwnode)) { /* All data nodes have parent pointer so just return that */ diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 668d007f0917..b28f8790192a 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1182,7 +1182,6 @@ int acpi_node_prop_get(const struct fwnode_handle *fwnode, const char *propname, struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode, struct fwnode_handle *child); -struct fwnode_handle *acpi_node_get_parent(const struct fwnode_handle *fwnode); struct acpi_probe_entry; typedef bool (*acpi_probe_entry_validate_subtbl)(struct acpi_subtable_header *, @@ -1287,12 +1286,6 @@ acpi_get_next_subnode(const struct fwnode_handle *fwnode, return NULL; } -static inline struct fwnode_handle * -acpi_node_get_parent(const struct fwnode_handle *fwnode) -{ - return NULL; -} - static inline struct fwnode_handle * acpi_graph_get_next_endpoint(const struct fwnode_handle *fwnode, struct fwnode_handle *prev) From 935dff305da2be7957a5ce8f07f45d6c4c1c6984 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 18 Nov 2021 14:37:38 +0100 Subject: [PATCH 3/3] ACPI: CPPC: Add NULL pointer check to cppc_get_perf() Check cpc_desc against NULL in cppc_get_perf(), so it doesn't crash down the road if cpc_desc is NULL. Fixes: 0654cf05d17b ("ACPI: CPPC: Introduce cppc_get_nominal_perf()") Reported-by: Kai-Heng Feng Signed-off-by: Rafael J. Wysocki Cc: 5.15+ # 5.15+ Tested-by: Kai-Heng Feng --- drivers/acpi/cppc_acpi.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index a85c351589be..b62c87b8ce4a 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -998,7 +998,14 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) { struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); - struct cpc_register_resource *reg = &cpc_desc->cpc_regs[reg_idx]; + struct cpc_register_resource *reg; + + if (!cpc_desc) { + pr_debug("No CPC descriptor for CPU:%d\n", cpunum); + return -ENODEV; + } + + reg = &cpc_desc->cpc_regs[reg_idx]; if (CPC_IN_PCC(reg)) { int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum);