From e82f2d8eab210dc7eb0dba2bd8e3c64ad485442b Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Wed, 30 May 2018 16:15:35 +0200
Subject: [PATCH] powerpc: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/powerpc/include/asm/kvm_host.h          |    3 --
 arch/powerpc/kernel/fadump.c                 |    9 +-----
 arch/powerpc/kernel/setup-common.c           |    3 --
 arch/powerpc/kernel/traps.c                  |   27 ++++---------------
 arch/powerpc/kvm/book3s_64_mmu_hv.c          |    5 +--
 arch/powerpc/kvm/book3s_64_mmu_radix.c       |    5 +--
 arch/powerpc/kvm/book3s_hv.c                 |    9 +-----
 arch/powerpc/kvm/timing.c                    |   11 +-------
 arch/powerpc/platforms/4xx/ocm.c             |   14 +---------
 arch/powerpc/platforms/cell/axon_msi.c       |    6 ----
 arch/powerpc/platforms/powernv/memtrace.c    |    7 -----
 arch/powerpc/platforms/powernv/opal-imc.c    |   28 +++++---------------
 arch/powerpc/platforms/powernv/pci-ioda.c    |    5 ---
 arch/powerpc/platforms/powernv/vas-debug.c   |   37 ++-------------------------
 arch/powerpc/platforms/pseries/dtl.c         |   36 +++-----------------------
 arch/powerpc/platforms/pseries/hvCall_inst.c |   12 ++------
 arch/powerpc/sysdev/scom.c                   |    8 -----
 17 files changed, 38 insertions(+), 187 deletions(-)

--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -295,8 +295,6 @@ struct kvm_arch {
 	pgd_t *pgtable;
 	u64 process_table;
 	struct dentry *debugfs_dir;
-	struct dentry *htab_dentry;
-	struct dentry *radix_dentry;
 	struct kvm_resize_hpt *resize_hpt; /* protected by kvm->lock */
 #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
 #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
@@ -809,7 +807,6 @@ struct kvm_vcpu_arch {
 	struct kvmhv_tb_accumulator cede_time;	/* time napping inside guest */
 
 	struct dentry *debugfs_dir;
-	struct dentry *debugfs_timings;
 #endif /* CONFIG_KVM_BOOK3S_HV_EXIT_TIMING */
 };
 
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -1650,7 +1650,6 @@ DEFINE_SHOW_ATTRIBUTE(fadump_region);
 
 static void fadump_init_files(void)
 {
-	struct dentry *debugfs_file;
 	int rc = 0;
 
 	rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
@@ -1663,12 +1662,8 @@ static void fadump_init_files(void)
 		printk(KERN_ERR "fadump: unable to create sysfs file"
 			" fadump_registered (%d)\n", rc);
 
-	debugfs_file = debugfs_create_file("fadump_region", 0444,
-					powerpc_debugfs_root, NULL,
-					&fadump_region_fops);
-	if (!debugfs_file)
-		printk(KERN_ERR "fadump: unable to create debugfs file"
-				" fadump_region\n");
+	debugfs_create_file("fadump_region", 0444, powerpc_debugfs_root, NULL,
+			    &fadump_region_fops);
 
 	if (fw_dump.dump_active) {
 		rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -771,8 +771,7 @@ EXPORT_SYMBOL(powerpc_debugfs_root);
 static int powerpc_debugfs_init(void)
 {
 	powerpc_debugfs_root = debugfs_create_dir("powerpc", NULL);
-
-	return powerpc_debugfs_root == NULL;
+	return 0;
 }
 arch_initcall(powerpc_debugfs_init);
 #endif
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -2265,35 +2265,20 @@ void ppc_warn_emulated_print(const char
 
 static int __init ppc_warn_emulated_init(void)
 {
-	struct dentry *dir, *d;
+	struct dentry *dir;
 	unsigned int i;
 	struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
 
-	if (!powerpc_debugfs_root)
-		return -ENODEV;
-
 	dir = debugfs_create_dir("emulated_instructions",
 				 powerpc_debugfs_root);
-	if (!dir)
-		return -ENOMEM;
 
-	d = debugfs_create_u32("do_warn", 0644, dir,
-			       &ppc_warn_emulated);
-	if (!d)
-		goto fail;
-
-	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) {
-		d = debugfs_create_u32(entries[i].name, 0644, dir,
-				       (u32 *)&entries[i].val.counter);
-		if (!d)
-			goto fail;
-	}
+	debugfs_create_u32("do_warn", 0644, dir, &ppc_warn_emulated);
 
-	return 0;
+	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++)
+		debugfs_create_u32(entries[i].name, 0644, dir,
+				   (u32 *)&entries[i].val.counter);
 
-fail:
-	debugfs_remove_recursive(dir);
-	return -ENOMEM;
+	return 0;
 }
 
 device_initcall(ppc_warn_emulated_init);
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -2160,9 +2160,8 @@ static const struct file_operations debu
 
 void kvmppc_mmu_debugfs_init(struct kvm *kvm)
 {
-	kvm->arch.htab_dentry = debugfs_create_file("htab", 0400,
-						    kvm->arch.debugfs_dir, kvm,
-						    &debugfs_htab_fops);
+	debugfs_create_file("htab", 0400, kvm->arch.debugfs_dir, kvm,
+			    &debugfs_htab_fops);
 }
 
 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -1361,9 +1361,8 @@ static const struct file_operations debu
 
 void kvmhv_radix_debugfs_init(struct kvm *kvm)
 {
-	kvm->arch.radix_dentry = debugfs_create_file("radix", 0400,
-						     kvm->arch.debugfs_dir, kvm,
-						     &debugfs_radix_fops);
+	debugfs_create_file("radix", 0400, kvm->arch.debugfs_dir, kvm,
+			    &debugfs_radix_fops);
 }
 
 int kvmppc_radix_init(void)
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2161,14 +2161,9 @@ static void debugfs_vcpu_init(struct kvm
 	struct kvm *kvm = vcpu->kvm;
 
 	snprintf(buf, sizeof(buf), "vcpu%u", id);
-	if (IS_ERR_OR_NULL(kvm->arch.debugfs_dir))
-		return;
 	vcpu->arch.debugfs_dir = debugfs_create_dir(buf, kvm->arch.debugfs_dir);
-	if (IS_ERR_OR_NULL(vcpu->arch.debugfs_dir))
-		return;
-	vcpu->arch.debugfs_timings =
-		debugfs_create_file("timings", 0444, vcpu->arch.debugfs_dir,
-				    vcpu, &debugfs_timings_ops);
+	debugfs_create_file("timings", 0444, vcpu->arch.debugfs_dir, vcpu,
+			    &debugfs_timings_ops);
 }
 
 #else /* CONFIG_KVM_BOOK3S_HV_EXIT_TIMING */
--- a/arch/powerpc/kvm/timing.c
+++ b/arch/powerpc/kvm/timing.c
@@ -218,19 +218,12 @@ static const struct file_operations kvmp
 void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id)
 {
 	static char dbg_fname[50];
-	struct dentry *debugfs_file;
 
 	snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%u_timing",
 		 current->pid, id);
-	debugfs_file = debugfs_create_file(dbg_fname, 0666,
-					kvm_debugfs_dir, vcpu,
-					&kvmppc_exit_timing_fops);
+	debugfs_create_file(dbg_fname, 0666, kvm_debugfs_dir, vcpu,
+			    &kvmppc_exit_timing_fops);
 
-	if (!debugfs_file) {
-		printk(KERN_ERR"%s: error creating debugfs file %s\n",
-			__func__, dbg_fname);
-		return;
-	}
 
 	vcpu->arch.debugfs_exit_timing = debugfs_file;
 }
--- a/arch/powerpc/platforms/4xx/ocm.c
+++ b/arch/powerpc/platforms/4xx/ocm.c
@@ -280,22 +280,12 @@ static const struct file_operations ocm_
 	.release = single_release,
 };
 
-static int ocm_debugfs_init(void)
+static void ocm_debugfs_init(void)
 {
 	struct dentry *junk;
 
 	junk = debugfs_create_dir("ppc4xx_ocm", 0);
-	if (!junk) {
-		printk(KERN_ALERT "debugfs ppc4xx ocm: failed to create dir\n");
-		return -1;
-	}
-
-	if (debugfs_create_file("info", 0644, junk, NULL, &ocm_debugfs_fops)) {
-		printk(KERN_ALERT "debugfs ppc4xx ocm: failed to create file\n");
-		return -1;
-	}
-
-	return 0;
+	debugfs_create_file("info", 0644, junk, NULL, &ocm_debugfs_fops);
 }
 
 void *ppc4xx_ocm_alloc(phys_addr_t *phys, int size, int align,
--- a/arch/powerpc/platforms/cell/axon_msi.c
+++ b/arch/powerpc/platforms/cell/axon_msi.c
@@ -484,10 +484,6 @@ void axon_msi_debug_setup(struct device_
 
 	snprintf(name, sizeof(name), "msic_%d", of_node_to_nid(dn));
 
-	if (!debugfs_create_file(name, 0600, powerpc_debugfs_root,
-				 msic, &fops_msic)) {
-		pr_devel("axon_msi: debugfs_create_file failed!\n");
-		return;
-	}
+	debugfs_create_file(name, 0600, powerpc_debugfs_root, msic, &fops_msic);
 }
 #endif /* DEBUG */
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -191,11 +191,6 @@ static int memtrace_init_debugfs(void)
 
 		snprintf(ent->name, 16, "%08x", ent->nid);
 		dir = debugfs_create_dir(ent->name, memtrace_debugfs_dir);
-		if (!dir) {
-			pr_err("Failed to create debugfs directory for node %d\n",
-				ent->nid);
-			return -1;
-		}
 
 		ent->dir = dir;
 		debugfs_create_file("trace", 0400, dir, ent, &memtrace_fops);
@@ -319,8 +314,6 @@ static int memtrace_init(void)
 {
 	memtrace_debugfs_dir = debugfs_create_dir("memtrace",
 						  powerpc_debugfs_root);
-	if (!memtrace_debugfs_dir)
-		return -1;
 
 	debugfs_create_file("enable", 0600, memtrace_debugfs_dir,
 			    NULL, &memtrace_init_fops);
--- a/arch/powerpc/platforms/powernv/opal-imc.c
+++ b/arch/powerpc/platforms/powernv/opal-imc.c
@@ -39,11 +39,10 @@ static int imc_mem_set(void *data, u64 v
 }
 DEFINE_DEBUGFS_ATTRIBUTE(fops_imc_x64, imc_mem_get, imc_mem_set, "0x%016llx\n");
 
-static struct dentry *imc_debugfs_create_x64(const char *name, umode_t mode,
-					     struct dentry *parent, u64  *value)
+static void imc_debugfs_create_x64(const char *name, umode_t mode,
+				   struct dentry *parent, u64  *value)
 {
-	return debugfs_create_file_unsafe(name, mode, parent,
-					  value, &fops_imc_x64);
+	debugfs_create_file_unsafe(name, mode, parent, value, &fops_imc_x64);
 }
 
 /*
@@ -63,13 +62,6 @@ static void export_imc_mode_and_cmd(stru
 
 	imc_debugfs_parent = debugfs_create_dir("imc", powerpc_debugfs_root);
 
-	/*
-	 * Return here, either because 'imc' directory already exists,
-	 * Or failed to create a new one.
-	 */
-	if (!imc_debugfs_parent)
-		return;
-
 	if (of_property_read_u32(node, "cb_offset", &cb_offset))
 		cb_offset = IMC_CNTL_BLK_OFFSET;
 
@@ -77,21 +69,15 @@ static void export_imc_mode_and_cmd(stru
 		loc = (u64)(pmu_ptr->mem_info[chip].vbase) + cb_offset;
 		imc_mode_addr = (u64 *)(loc + IMC_CNTL_BLK_MODE_OFFSET);
 		sprintf(mode, "imc_mode_%d", nid);
-		if (!imc_debugfs_create_x64(mode, 0600, imc_debugfs_parent,
-					    imc_mode_addr))
-			goto err;
+		imc_debugfs_create_x64(mode, 0600, imc_debugfs_parent,
+				       imc_mode_addr);
 
 		imc_cmd_addr = (u64 *)(loc + IMC_CNTL_BLK_CMD_OFFSET);
 		sprintf(cmd, "imc_cmd_%d", nid);
-		if (!imc_debugfs_create_x64(cmd, 0600, imc_debugfs_parent,
-					    imc_cmd_addr))
-			goto err;
+		imc_debugfs_create_x64(cmd, 0600, imc_debugfs_parent,
+				       imc_cmd_addr);
 		chip++;
 	}
-	return;
-
-err:
-	debugfs_remove_recursive(imc_debugfs_parent);
 }
 
 /*
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -3108,11 +3108,6 @@ static void pnv_pci_ioda_create_dbgfs(vo
 
 		sprintf(name, "PCI%04x", hose->global_number);
 		phb->dbgfs = debugfs_create_dir(name, powerpc_debugfs_root);
-		if (!phb->dbgfs) {
-			pr_warn("%s: Error on creating debugfs on PHB#%x\n",
-				__func__, hose->global_number);
-			continue;
-		}
 
 		debugfs_create_file("dump_diag_regs", 0200, phb->dbgfs, hose,
 				    &pnv_pci_diag_data_fops);
--- a/arch/powerpc/platforms/powernv/vas-debug.c
+++ b/arch/powerpc/platforms/powernv/vas-debug.c
@@ -119,7 +119,7 @@ void vas_window_free_dbgdir(struct vas_w
 
 void vas_window_init_dbgdir(struct vas_window *window)
 {
-	struct dentry *f, *d;
+	struct dentry *d;
 
 	if (!window->vinst->dbgdir)
 		return;
@@ -131,28 +131,10 @@ void vas_window_init_dbgdir(struct vas_w
 	snprintf(window->dbgname, 16, "w%d", window->winid);
 
 	d = debugfs_create_dir(window->dbgname, window->vinst->dbgdir);
-	if (IS_ERR(d))
-		goto free_name;
-
 	window->dbgdir = d;
 
-	f = debugfs_create_file("info", 0444, d, window, &info_fops);
-	if (IS_ERR(f))
-		goto remove_dir;
-
-	f = debugfs_create_file("hvwc", 0444, d, window, &hvwc_fops);
-	if (IS_ERR(f))
-		goto remove_dir;
-
-	return;
-
-remove_dir:
-	debugfs_remove_recursive(window->dbgdir);
-	window->dbgdir = NULL;
-
-free_name:
-	kfree(window->dbgname);
-	window->dbgname = NULL;
+	debugfs_create_file("info", 0444, d, window, &info_fops);
+	debugfs_create_file("hvwc", 0444, d, window, &hvwc_fops);
 }
 
 void vas_instance_init_dbgdir(struct vas_instance *vinst)
@@ -160,8 +142,6 @@ void vas_instance_init_dbgdir(struct vas
 	struct dentry *d;
 
 	vas_init_dbgdir();
-	if (!vas_debugfs)
-		return;
 
 	vinst->dbgname = kzalloc(16, GFP_KERNEL);
 	if (!vinst->dbgname)
@@ -170,16 +150,7 @@ void vas_instance_init_dbgdir(struct vas
 	snprintf(vinst->dbgname, 16, "v%d", vinst->vas_id);
 
 	d = debugfs_create_dir(vinst->dbgname, vas_debugfs);
-	if (IS_ERR(d))
-		goto free_name;
-
 	vinst->dbgdir = d;
-	return;
-
-free_name:
-	kfree(vinst->dbgname);
-	vinst->dbgname = NULL;
-	vinst->dbgdir = NULL;
 }
 
 /*
@@ -195,6 +166,4 @@ void vas_init_dbgdir(void)
 
 	first_time = false;
 	vas_debugfs = debugfs_create_dir("vas", NULL);
-	if (IS_ERR(vas_debugfs))
-		vas_debugfs = NULL;
 }
--- a/arch/powerpc/platforms/pseries/dtl.c
+++ b/arch/powerpc/platforms/pseries/dtl.c
@@ -32,7 +32,6 @@
 
 struct dtl {
 	struct dtl_entry	*buf;
-	struct dentry		*file;
 	int			cpu;
 	int			buf_entries;
 	u64			last_idx;
@@ -332,22 +331,16 @@ static const struct file_operations dtl_
 
 static struct dentry *dtl_dir;
 
-static int dtl_setup_file(struct dtl *dtl)
+static void dtl_setup_file(struct dtl *dtl)
 {
 	char name[10];
 
 	sprintf(name, "cpu-%d", dtl->cpu);
-
-	dtl->file = debugfs_create_file(name, 0400, dtl_dir, dtl, &dtl_fops);
-	if (!dtl->file)
-		return -ENOMEM;
-
-	return 0;
+	debugfs_create_file(name, 0400, dtl_dir, dtl, &dtl_fops);
 }
 
 static int dtl_init(void)
 {
-	struct dentry *event_mask_file, *buf_entries_file;
 	int rc, i;
 
 	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
@@ -357,21 +350,9 @@ static int dtl_init(void)
 
 	rc = -ENOMEM;
 	dtl_dir = debugfs_create_dir("dtl", powerpc_debugfs_root);
-	if (!dtl_dir) {
-		printk(KERN_WARNING "%s: can't create dtl root dir\n",
-				__func__);
-		goto err;
-	}
 
-	event_mask_file = debugfs_create_x8("dtl_event_mask", 0600,
-				dtl_dir, &dtl_event_mask);
-	buf_entries_file = debugfs_create_u32("dtl_buf_entries", 0400,
-				dtl_dir, &dtl_buf_entries);
-
-	if (!event_mask_file || !buf_entries_file) {
-		printk(KERN_WARNING "%s: can't create dtl files\n", __func__);
-		goto err_remove_dir;
-	}
+	debugfs_create_x8("dtl_event_mask", 0600, dtl_dir, &dtl_event_mask);
+	debugfs_create_u32("dtl_buf_entries", 0400, dtl_dir, &dtl_buf_entries);
 
 	/* set up the per-cpu log structures */
 	for_each_possible_cpu(i) {
@@ -379,16 +360,9 @@ static int dtl_init(void)
 		spin_lock_init(&dtl->lock);
 		dtl->cpu = i;
 
-		rc = dtl_setup_file(dtl);
-		if (rc)
-			goto err_remove_dir;
+		dtl_setup_file(dtl);
 	}
 
 	return 0;
-
-err_remove_dir:
-	debugfs_remove_recursive(dtl_dir);
-err:
-	return rc;
 }
 machine_arch_initcall(pseries, dtl_init);
--- a/arch/powerpc/platforms/pseries/hvCall_inst.c
+++ b/arch/powerpc/platforms/pseries/hvCall_inst.c
@@ -142,7 +142,6 @@ static void probe_hcall_exit(void *ignor
 static int __init hcall_inst_init(void)
 {
 	struct dentry *hcall_root;
-	struct dentry *hcall_file;
 	char cpu_name_buf[CPU_NAME_BUF_SIZE];
 	int cpu;
 
@@ -158,17 +157,12 @@ static int __init hcall_inst_init(void)
 	}
 
 	hcall_root = debugfs_create_dir(HCALL_ROOT_DIR, NULL);
-	if (!hcall_root)
-		return -ENOMEM;
 
 	for_each_possible_cpu(cpu) {
 		snprintf(cpu_name_buf, CPU_NAME_BUF_SIZE, "cpu%d", cpu);
-		hcall_file = debugfs_create_file(cpu_name_buf, 0444,
-						 hcall_root,
-						 per_cpu(hcall_stats, cpu),
-						 &hcall_inst_seq_fops);
-		if (!hcall_file)
-			return -ENOMEM;
+		debugfs_create_file(cpu_name_buf, 0444, hcall_root,
+				    per_cpu(hcall_stats, cpu),
+				    &hcall_inst_seq_fops);
 	}
 
 	return 0;
--- a/arch/powerpc/sysdev/scom.c
+++ b/arch/powerpc/sysdev/scom.c
@@ -198,12 +198,6 @@ static int scom_debug_init_one(struct de
 	ent->path.size = strlen((char *)ent->path.data);
 
 	dir = debugfs_create_dir(ent->name, root);
-	if (!dir) {
-		of_node_put(dn);
-		kfree(ent->path.data);
-		kfree(ent);
-		return -1;
-	}
 
 	debugfs_create_blob("devspec", 0400, dir, &ent->path);
 	debugfs_create_file("access", 0600, dir, ent, &scom_debug_fops);
@@ -218,8 +212,6 @@ static int scom_debug_init(void)
 	int i, rc;
 
 	root = debugfs_create_dir("scom", powerpc_debugfs_root);
-	if (!root)
-		return -1;
 
 	i = rc = 0;
 	for_each_node_with_property(dn, "scom-controller") {