gcc trunk fails to build kernel on PowerPC64 due to oprofile warnings

From e5490da918186cbd42b8609da146946fbdadf0e5 Mon Sep 17 00:00:00 2001
From: William Cohen <wcohen@redhat.com>
Date: Thu, 2 Feb 2017 12:02:51 -0500
Subject: [PATCH] Avoid hypthetical string truncation in various oprofile
 buffers
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Increased the size of internal oprofile driver buffers ensuring that
the strings were never truncated for any possible values to avoid
warning/errors like the following GCC 7 compiler error on ppc when
building the kernel:

linux/arch/powerpc/oprofile/../../../drivers/oprofile/oprofile_stats.c: In function ‘oprofile_create_stats_files’:
linux/arch/powerpc/oprofile/../../../drivers/oprofile/oprofile_stats.c:55:25: error: ‘%d’ directive output may be truncated writing between 1 and 11 bytes into a region of size 7 [-Werror=format-truncation=]
   snprintf(buf, 10, "cpu%d", i);
                         ^~
linux/arch/powerpc/oprofile/../../../drivers/oprofile/oprofile_stats.c:55:21: note: using the range [1, -2147483648] for directive argument
   snprintf(buf, 10, "cpu%d", i);
                     ^~~~~~~
linux/arch/powerpc/oprofile/../../../drivers/oprofile/oprofile_stats.c:55:3: note: format output between 5 and 15 bytes into a destination of size 10
   snprintf(buf, 10, "cpu%d", i);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  LD      crypto/async_tx/built-in.o
  CC      lib/random32.o
cc1: all warnings being treated as errors

Signed-off-by: William Cohen <wcohen@redhat.com>
---
 arch/alpha/oprofile/common.c         | 4 ++--
 arch/avr32/oprofile/op_model_avr32.c | 2 +-
 arch/mips/oprofile/common.c          | 4 ++--
 arch/powerpc/oprofile/common.c       | 4 ++--
 arch/x86/oprofile/nmi_int.c          | 2 +-
 drivers/oprofile/oprofile_perf.c     | 4 ++--
 drivers/oprofile/oprofile_stats.c    | 4 ++--
 7 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/alpha/oprofile/common.c b/arch/alpha/oprofile/common.c
index 310a4ce..a1704ee 100644
--- a/arch/alpha/oprofile/common.c
+++ b/arch/alpha/oprofile/common.c
@@ -112,9 +112,9 @@  op_axp_create_files(struct dentry *root)
 
 	for (i = 0; i < model->num_counters; ++i) {
 		struct dentry *dir;
-		char buf[4];
+		char buf[32];
 
-		snprintf(buf, sizeof buf, "%d", i);
+		snprintf(buf, sizeof(buf), "%d", i);
 		dir = oprofilefs_mkdir(root, buf);
 
 		oprofilefs_create_ulong(dir, "enabled", &ctr[i].enabled);
diff --git a/arch/avr32/oprofile/op_model_avr32.c b/arch/avr32/oprofile/op_model_avr32.c
index 08308be..af1249b 100644
--- a/arch/avr32/oprofile/op_model_avr32.c
+++ b/arch/avr32/oprofile/op_model_avr32.c
@@ -101,7 +101,7 @@  static int avr32_perf_counter_create_files(struct dentry *root)
 {
 	struct dentry *dir;
 	unsigned int i;
-	char filename[4];
+	char filename[32];
 
 	for (i = 0; i < NR_counter; i++) {
 		snprintf(filename, sizeof(filename), "%u", i);
diff --git a/arch/mips/oprofile/common.c b/arch/mips/oprofile/common.c
index 2f33992..20583cd 100644
--- a/arch/mips/oprofile/common.c
+++ b/arch/mips/oprofile/common.c
@@ -41,9 +41,9 @@  static int op_mips_create_files(struct dentry *root)
 
 	for (i = 0; i < model->num_counters; ++i) {
 		struct dentry *dir;
-		char buf[4];
+		char buf[32];
 
-		snprintf(buf, sizeof buf, "%d", i);
+		snprintf(buf, sizeof(buf), "%d", i);
 		dir = oprofilefs_mkdir(root, buf);
 
 		oprofilefs_create_ulong(dir, "enabled", &ctr[i].enabled);
diff --git a/arch/powerpc/oprofile/common.c b/arch/powerpc/oprofile/common.c
index bf094c5..5ac7b88 100644
--- a/arch/powerpc/oprofile/common.c
+++ b/arch/powerpc/oprofile/common.c
@@ -157,9 +157,9 @@  static int op_powerpc_create_files(struct dentry *root)
 
 	for (i = 0; i < model->num_counters; ++i) {
 		struct dentry *dir;
-		char buf[4];
+		char buf[32];
 
-		snprintf(buf, sizeof buf, "%d", i);
+		snprintf(buf, sizeof(buf), "%d", i);
 		dir = oprofilefs_mkdir(root, buf);
 
 		oprofilefs_create_ulong(dir, "enabled", &ctr[i].enabled);
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index ffdbc48..dec2fd0 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -416,7 +416,7 @@  static int nmi_create_files(struct dentry *root)
 
 	for (i = 0; i < model->num_virt_counters; ++i) {
 		struct dentry *dir;
-		char buf[4];
+		char buf[32];
 
 		/* quick little hack to _not_ expose a counter if it is not
 		 * available for use.  This should protect userspace app.
diff --git a/drivers/oprofile/oprofile_perf.c b/drivers/oprofile/oprofile_perf.c
index d5b2732..acc74c4 100644
--- a/drivers/oprofile/oprofile_perf.c
+++ b/drivers/oprofile/oprofile_perf.c
@@ -144,9 +144,9 @@  static int oprofile_perf_create_files(struct dentry *root)
 
 	for (i = 0; i < num_counters; i++) {
 		struct dentry *dir;
-		char buf[4];
+		char buf[32];
 
-		snprintf(buf, sizeof buf, "%d", i);
+		snprintf(buf, sizeof(buf), "%d", i);
 		dir = oprofilefs_mkdir(root, buf);
 		oprofilefs_create_ulong(dir, "enabled", &counter_config[i].enabled);
 		oprofilefs_create_ulong(dir, "event", &counter_config[i].event);
diff --git a/drivers/oprofile/oprofile_stats.c b/drivers/oprofile/oprofile_stats.c
index 59659ce..14d0585 100644
--- a/drivers/oprofile/oprofile_stats.c
+++ b/drivers/oprofile/oprofile_stats.c
@@ -43,7 +43,7 @@  void oprofile_create_stats_files(struct dentry *root)
 	struct oprofile_cpu_buffer *cpu_buf;
 	struct dentry *cpudir;
 	struct dentry *dir;
-	char buf[10];
+	char buf[32];
 	int i;
 
 	dir = oprofilefs_mkdir(root, "stats");
@@ -52,7 +52,7 @@  void oprofile_create_stats_files(struct dentry *root)
 
 	for_each_possible_cpu(i) {
 		cpu_buf = &per_cpu(op_cpu_buffer, i);
-		snprintf(buf, 10, "cpu%d", i);
+		snprintf(buf, sizeof(buf), "cpu%d", i);
 		cpudir = oprofilefs_mkdir(dir, buf);
 
 		/* Strictly speaking access to these ulongs is racy,
-- 
2.9.3