Re: [PATCH 3/3 v2] x86: Use tracepoint_enabled() for msr tracepoints instead of open coding it

kernel test robot
2020-09-26T06:57:18Z

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Hi Steven,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on tip/master]
[also build test ERROR on linux/master tip/perf/core tip/x86/core linus/master v5.9-rc6 next-20200925]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Steven-Rostedt/tracing-mm-Add-tracepoint_enabled-helper-function-for-headers/20200926-051950
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 0248dedd12d43035bf53c326633f0610a49d7134
config: x86_64-randconfig-a003-20200925 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project a83eb048cb9a75da7a07a9d5318bbdbf54885c87)
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 x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://github.com/0day-ci/linux/commit/7a9f7773ebb9b2d4be989415cfa2cee5788201ea
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Steven-Rostedt/tracing-mm-Add-tracepoint_enabled-helper-function-for-headers/20200926-051950
git checkout 7a9f7773ebb9b2d4be989415cfa2cee5788201ea
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

In file included from arch/x86/kernel/asm-offsets.c:9:
In file included from include/linux/crypto.h:20:
In file included from include/linux/slab.h:15:
In file included from include/linux/gfp.h:6:
In file included from include/linux/mmzone.h:8:
In file included from include/linux/spinlock.h:51:
In file included from include/linux/preempt.h:78:
In file included from arch/x86/include/asm/preempt.h:7:
In file included from include/linux/thread_info.h:38:
In file included from arch/x86/include/asm/thread_info.h:53:
In file included from arch/x86/include/asm/cpufeature.h:5:
In file included from arch/x86/include/asm/processor.h:22:
>> arch/x86/include/asm/msr.h:129:6: error: implicit declaration of function 'tracepoint_enabled' [-Werror,-Wimplicit-function-declaration]
if (tracepoint_enabled(read_msr))
^
>> arch/x86/include/asm/msr.h:129:25: error: use of undeclared identifier 'read_msr'
if (tracepoint_enabled(read_msr))
^
arch/x86/include/asm/msr.h:151:6: error: implicit declaration of function 'tracepoint_enabled' [-Werror,-Wimplicit-function-declaration]
if (tracepoint_enabled(read_msr))
^
arch/x86/include/asm/msr.h:151:25: error: use of undeclared identifier 'read_msr'
if (tracepoint_enabled(read_msr))
^
arch/x86/include/asm/msr.h:162:6: error: implicit declaration of function 'tracepoint_enabled' [-Werror,-Wimplicit-function-declaration]
if (tracepoint_enabled(write_msr))
^
>> arch/x86/include/asm/msr.h:162:25: error: use of undeclared identifier 'write_msr'
if (tracepoint_enabled(write_msr))
^
arch/x86/include/asm/msr.h:182:6: error: implicit declaration of function 'tracepoint_enabled' [-Werror,-Wimplicit-function-declaration]
if (tracepoint_enabled(write_msr))
^
arch/x86/include/asm/msr.h:182:25: error: use of undeclared identifier 'write_msr'
if (tracepoint_enabled(write_msr))
^
arch/x86/include/asm/msr.h:249:6: error: implicit declaration of function 'tracepoint_enabled' [-Werror,-Wimplicit-function-declaration]
if (tracepoint_enabled(rdpmc))
^
>> arch/x86/include/asm/msr.h:249:25: error: use of undeclared identifier 'rdpmc'; did you mean 'rdtsc'?
if (tracepoint_enabled(rdpmc))
^~~~~
rdtsc
arch/x86/include/asm/msr.h:199:43: note: 'rdtsc' declared here
static __always_inline unsigned long long rdtsc(void)
^
10 errors generated.
make[2]: *** [scripts/Makefile.build:117: arch/x86/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1198: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:185: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.

vim +/tracepoint_enabled +129 arch/x86/include/asm/msr.h

115
116 #define native_wrmsr(msr, low, high) \
117 __wrmsr(msr, low, high)
118
119 #define native_wrmsrl(msr, val) \
120 __wrmsr((msr), (u32)((u64)(val)), \
121 (u32)((u64)(val) >> 32))
122
123 static inline unsigned long long native_read_msr(unsigned int msr)
124 {
125 unsigned long long val;
126
127 val = __rdmsr(msr);
128
> 129 if (tracepoint_enabled(read_msr))
130 do_trace_read_msr(msr, val, 0);
131
132 return val;
133 }
134
135 static inline unsigned long long native_read_msr_safe(unsigned int msr,
136 int *err)
137 {
138 DECLARE_ARGS(val, low, high);
139
140 asm volatile("2: rdmsr ; xor %[err],%[err]\n"
141 "1:\n\t"
142 ".section .fixup,\"ax\"\n\t"
143 "3: mov %[fault],%[err]\n\t"
144 "xorl %%eax, %%eax\n\t"
145 "xorl %%edx, %%edx\n\t"
146 "jmp 1b\n\t"
147 ".previous\n\t"
148 _ASM_EXTABLE(2b, 3b)
149 : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
150 : "c" (msr), [fault] "i" (-EIO));
151 if (tracepoint_enabled(read_msr))
152 do_trace_read_msr(msr, EAX_EDX_VAL(val, low, high), *err);
153 return EAX_EDX_VAL(val, low, high);
154 }
155
156 /* Can be uninlined because referenced by paravirt */
157 static inline void notrace
158 native_write_msr(unsigned int msr, u32 low, u32 high)
159 {
160 __wrmsr(msr, low, high);
161
> 162 if (tracepoint_enabled(write_msr))
163 do_trace_write_msr(msr, ((u64)high << 32 | low), 0);
164 }
165
166 /* Can be uninlined because referenced by paravirt */
167 static inline int notrace
168 native_write_msr_safe(unsigned int msr, u32 low, u32 high)
169 {
170 int err;
171
172 asm volatile("2: wrmsr ; xor %[err],%[err]\n"
173 "1:\n\t"
174 ".section .fixup,\"ax\"\n\t"
175 "3: mov %[fault],%[err] ; jmp 1b\n\t"
176 ".previous\n\t"
177 _ASM_EXTABLE(2b, 3b)
178 : [err] "=a" (err)
179 : "c" (msr), "0" (low), "d" (high),
180 [fault] "i" (-EIO)
181 : "memory");
182 if (tracepoint_enabled(write_msr))
183 do_trace_write_msr(msr, ((u64)high << 32 | low), err);
184 return err;
185 }
186
187 extern int rdmsr_safe_regs(u32 regs[8]);
188 extern int wrmsr_safe_regs(u32 regs[8]);
189
190 /**
191 * rdtsc() - returns the current TSC without ordering constraints
192 *
193 * rdtsc() returns the result of RDTSC as a 64-bit integer. The
194 * only ordering constraint it supplies is the ordering implied by
195 * "asm volatile": it will put the RDTSC in the place you expect. The
196 * CPU can and will speculatively execute that RDTSC, though, so the
197 * results can be non-monotonic if compared on different CPUs.
198 */
199 static __always_inline unsigned long long rdtsc(void)
200 {
201 DECLARE_ARGS(val, low, high);
202
203 asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
204
205 return EAX_EDX_VAL(val, low, high);
206 }
207
208 /**
209 * rdtsc_ordered() - read the current TSC in program order
210 *
211 * rdtsc_ordered() returns the result of RDTSC as a 64-bit integer.
212 * It is ordered like a load to a global in-memory counter. It should
213 * be impossible to observe non-monotonic rdtsc_unordered() behavior
214 * across multiple CPUs as long as the TSC is synced.
215 */
216 static __always_inline unsigned long long rdtsc_ordered(void)
217 {
218 DECLARE_ARGS(val, low, high);
219
220 /*
221 * The RDTSC instruction is not ordered relative to memory
222 * access. The Intel SDM and the AMD APM are both vague on this
223 * point, but empirically an RDTSC instruction can be
224 * speculatively executed before prior loads. An RDTSC
225 * immediately after an appropriate barrier appears to be
226 * ordered as a normal load, that is, it provides the same
227 * ordering guarantees as reading from a global memory location
228 * that some other imaginary CPU is updating continuously with a
229 * time stamp.
230 *
231 * Thus, use the preferred barrier on the respective CPU, aiming for
232 * RDTSCP as the default.
233 */
234 asm volatile(ALTERNATIVE_2("rdtsc",
235 "lfence; rdtsc", X86_FEATURE_LFENCE_RDTSC,
236 "rdtscp", X86_FEATURE_RDTSCP)
237 : EAX_EDX_RET(val, low, high)
238 /* RDTSCP clobbers ECX with MSR_TSC_AUX. */
239 :: "ecx");
240
241 return EAX_EDX_VAL(val, low, high);
242 }
243
244 static inline unsigned long long native_read_pmc(int counter)
245 {
246 DECLARE_ARGS(val, low, high);
247
248 asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
> 249 if (tracepoint_enabled(rdpmc))
250 do_trace_rdpmc(counter, EAX_EDX_VAL(val, low, high), 0);
251 return EAX_EDX_VAL(val, low, high);
252 }
253

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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