tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2024.05.30a
head: 3d08b2c4a149fdf966e1b0768c14bbf4048e4070
commit: 6ba3d5014d24a46ed329fc567e554c218eb62cfa [5/50] ARM: Emulate one-byte cmpxchg
config: arm-randconfig-r052-20240603 (https://download.01.org/0day-ci/archive/20240603/[email protected]/config)
compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240603/[email protected]/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Note: the paulmck-rcu/dev.2024.05.30a HEAD 3d08b2c4a149fdf966e1b0768c14bbf4048e4070 builds fine.
It only hurts bisectability.
All errors (new ones prefixed by >>):
In file included from kernel/bounds.c:13:
In file included from include/linux/log2.h:12:
In file included from include/linux/bitops.h:63:
In file included from arch/arm/include/asm/bitops.h:245:
In file included from include/asm-generic/bitops/lock.h:5:
In file included from include/linux/atomic.h:7:
In file included from arch/arm/include/asm/atomic.h:16:
>> arch/arm/include/asm/cmpxchg.h:167:12: error: call to undeclared function 'cmpxchg_emu_u8'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
oldval = cmpxchg_emu_u8((volatile u8 *)ptr, old, new);
^
1 error generated.
make[3]: *** [scripts/Makefile.build:117: kernel/bounds.s] Error 1
make[3]: Target 'prepare' not remade because of errors.
make[2]: *** [Makefile:1208: prepare0] Error 2
make[2]: Target 'prepare' not remade because of errors.
make[1]: *** [Makefile:240: __sub-make] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:240: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +/cmpxchg_emu_u8 +167 arch/arm/include/asm/cmpxchg.h
152
153 /*
154 * cmpxchg only support 32-bits operands on ARMv6.
155 */
156
157 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
158 unsigned long new, int size)
159 {
160 unsigned long oldval, res;
161
162 prefetchw((const void *)ptr);
163
164 switch (size) {
165 #ifdef CONFIG_CPU_V6 /* min ARCH >= ARMv6K */
166 case 1:
> 167 oldval = cmpxchg_emu_u8((volatile u8 *)ptr, old, new);
168 break;
169 #else
170 case 1:
171 do {
172 asm volatile("@ __cmpxchg1\n"
173 " ldrexb %1, [%2]\n"
174 " mov %0, #0\n"
175 " teq %1, %3\n"
176 " strexbeq %0, %4, [%2]\n"
177 : "=&r" (res), "=&r" (oldval)
178 : "r" (ptr), "Ir" (old), "r" (new)
179 : "memory", "cc");
180 } while (res);
181 break;
182 case 2:
183 do {
184 asm volatile("@ __cmpxchg1\n"
185 " ldrexh %1, [%2]\n"
186 " mov %0, #0\n"
187 " teq %1, %3\n"
188 " strexheq %0, %4, [%2]\n"
189 : "=&r" (res), "=&r" (oldval)
190 : "r" (ptr), "Ir" (old), "r" (new)
191 : "memory", "cc");
192 } while (res);
193 break;
194 #endif
195 case 4:
196 do {
197 asm volatile("@ __cmpxchg4\n"
198 " ldrex %1, [%2]\n"
199 " mov %0, #0\n"
200 " teq %1, %3\n"
201 " strexeq %0, %4, [%2]\n"
202 : "=&r" (res), "=&r" (oldval)
203 : "r" (ptr), "Ir" (old), "r" (new)
204 : "memory", "cc");
205 } while (res);
206 break;
207 default:
208 __bad_cmpxchg(ptr, size);
209 oldval = 0;
210 }
211
212 return oldval;
213 }
214
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki