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Message-ID: <202210140652.nxy2MTX5-lkp@intel.com>
Date: Fri, 14 Oct 2022 06:54:50 +0800
From: kernel test robot <lkp@...el.com>
To: Palmer Dabbelt <palmer@...osinc.com>
Cc: llvm@...ts.linux.dev, kbuild-all@...ts.01.org,
Ammar Faizi <ammarfaizi2@...weeb.org>,
GNU/Weeb Mailing List <gwml@...r.gnuweeb.org>,
linux-kernel@...r.kernel.org
Subject: [ammarfaizi2-block:palmer/linux/riscv-hwprobe-v1 4/5]
arch/riscv/kernel/sys_riscv.c:229:8: warning: variable 'ret' is used
uninitialized whenever switch case is taken
tree: https://github.com/ammarfaizi2/linux-block palmer/linux/riscv-hwprobe-v1
head: ea6ba33fae4f9ca9d13f457ea2ccc8dd9f99d367
commit: 510c491cb9d87dcbdc91c63558dc704968723240 [4/5] RISC-V: hwprobe: Support probing of misaligned accesss performance
config: riscv-randconfig-r003-20221012
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 791a7ae1ba3efd6bca96338e10ffde557ba83920)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://github.com/ammarfaizi2/linux-block/commit/510c491cb9d87dcbdc91c63558dc704968723240
git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
git fetch --no-tags ammarfaizi2-block palmer/linux/riscv-hwprobe-v1
git checkout 510c491cb9d87dcbdc91c63558dc704968723240
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/kernel/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@...el.com>
All warnings (new ones prefixed by >>):
In file included from arch/riscv/kernel/sys_riscv.c:8:
In file included from include/linux/syscalls.h:88:
In file included from include/trace/syscall.h:7:
In file included from include/linux/trace_events.h:9:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/riscv/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
^
In file included from arch/riscv/kernel/sys_riscv.c:8:
In file included from include/linux/syscalls.h:88:
In file included from include/trace/syscall.h:7:
In file included from include/linux/trace_events.h:9:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/riscv/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
In file included from arch/riscv/kernel/sys_riscv.c:8:
In file included from include/linux/syscalls.h:88:
In file included from include/trace/syscall.h:7:
In file included from include/linux/trace_events.h:9:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/riscv/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:1134:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
~~~~~~~~~~ ^
>> arch/riscv/kernel/sys_riscv.c:229:8: warning: variable 'ret' is used uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
case RISCV_HWPROBE_KEY_CPUPERF_0:
^~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/riscv/include/uapi/asm/hwprobe.h:27:37: note: expanded from macro 'RISCV_HWPROBE_KEY_CPUPERF_0'
#define RISCV_HWPROBE_KEY_CPUPERF_0 5
^
arch/riscv/kernel/sys_riscv.c:234:7: note: uninitialized use occurs here
if (ret < 0)
^~~
arch/riscv/kernel/sys_riscv.c:197:11: note: initialize the variable 'ret' to silence this warning
long ret;
^
= 0
8 warnings generated.
vim +/ret +229 arch/riscv/kernel/sys_riscv.c
159
160 static
161 long do_riscv_hwprobe(struct riscv_hwprobe __user *pairs, long pair_count,
162 long key_offset, long cpu_count,
163 unsigned long __user *cpus_user, unsigned long flags)
164 {
165 size_t out, k;
166 long ret;
167 struct cpumask cpus;
168
169 /* Check the reserved flags. */
170 if (flags != 0)
171 return -EINVAL;
172
173 /*
174 * The only supported values must be the same on all CPUs, but check to
175 * make sure userspace at least tried to provide something here for
176 * future compatibility.
177 */
178 cpumask_clear(&cpus);
179 if (cpu_count > cpumask_size())
180 cpu_count = cpumask_size();
181 ret = copy_from_user(&cpus, cpus_user, cpu_count);
182 if (!ret)
183 return -EFAULT;
184
185
186 /*
187 * Userspace must provide at least one online CPU, without that there's
188 * no way to define what is supported.
189 */
190 cpumask_and(&cpus, &cpus, cpu_online_mask);
191 if (cpumask_empty(&cpus))
192 return -EINVAL;
193
194 out = 0;
195 k = key_offset;
196 while (out < pair_count && k < RISCV_HWPROBE_MAX_KEY) {
197 long ret;
198
199 switch (k) {
200 case RISCV_HWPROBE_KEY_MVENDORID:
201 case RISCV_HWPROBE_KEY_MARCHID:
202 case RISCV_HWPROBE_KEY_MIMPID:
203 ret = hwprobe_mid(pairs + out, k, &cpus);
204 break;
205
206 /*
207 * The kernel already assumes that the base single-letter ISA
208 * extensions are supported on all harts, and only supports the
209 * IMA base, so just cheat a bit here and tell that to
210 * userspace.
211 */
212 case RISCV_HWPROBE_KEY_BASE_BEHAVIOR:
213 ret = set_hwprobe(pairs + out, k,
214 RISCV_HWPROBE_BASE_BEHAVIOR_IMA);
215 break;
216
217 case RISCV_HWPROBE_KEY_IMA_EXT_0:
218 {
219 u64 val = 0;
220
221 if (has_fpu())
222 val |= RISCV_HWPROBE_IMA_FD;
223 if (elf_hwcap & RISCV_ISA_EXT_c)
224 val |= RISCV_HWPROBE_IMA_C;
225 ret = set_hwprobe(pairs + out, k, val);
226 }
227 break;
228
> 229 case RISCV_HWPROBE_KEY_CPUPERF_0:
230 set_hwprobe(pairs + out, k, hwprobe_misaligned(&cpus));
231 break;
232 }
233
234 if (ret < 0)
235 return ret;
236 if (ret == 0)
237 out++;
238 }
239
240 return out;
241
--
0-DAY CI Kernel Test Service
https://01.org/lkp
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