include/linux/tpm_eventlog.h:165:6: warning: variable 'mapping_size' set but not used
From: kernel test robot
Date: Sun Oct 15 2023 - 12:18:30 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 9a3dad63edbe9a2ab2be1e7361a2133f519f855b
commit: c46f3405692de1ac82240d927b9c7a0f9d6a4a36 tpm: Reserve the TPM final events table
date: 4 years, 4 months ago
config: x86_64-randconfig-013-20230909 (https://download.01.org/0day-ci/archive/20231016/202310160026.eOXhKeWr-lkp@xxxxxxxxx/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231016/202310160026.eOXhKeWr-lkp@xxxxxxxxx/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 <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310160026.eOXhKeWr-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
clang-16: warning: argument unused during compilation: '-mno-global-merge' [-Wunused-command-line-argument]
In file included from drivers/char/tpm/eventlog/common.c:20:
>> include/linux/tpm_eventlog.h:165:6: warning: variable 'mapping_size' set but not used [-Wunused-but-set-variable]
int mapping_size;
^
1 warning generated.
--
clang-16: warning: argument unused during compilation: '-mno-global-merge' [-Wunused-command-line-argument]
In file included from drivers/char/tpm/eventlog/tpm1.c:24:
>> include/linux/tpm_eventlog.h:165:6: warning: variable 'mapping_size' set but not used [-Wunused-but-set-variable]
int mapping_size;
^
drivers/char/tpm/eventlog/tpm1.c:253:6: warning: variable 'len' set but not used [-Wunused-but-set-variable]
int len = 0;
^
2 warnings generated.
vim +/mapping_size +165 include/linux/tpm_eventlog.h
138
139 /**
140 * __calc_tpm2_event_size - calculate the size of a TPM2 event log entry
141 * @event: Pointer to the event whose size should be calculated
142 * @event_header: Pointer to the initial event containing the digest lengths
143 * @do_mapping: Whether or not the event needs to be mapped
144 *
145 * The TPM2 event log format can contain multiple digests corresponding to
146 * separate PCR banks, and also contains a variable length of the data that
147 * was measured. This requires knowledge of how long each digest type is,
148 * and this information is contained within the first event in the log.
149 *
150 * We calculate the length by examining the number of events, and then looking
151 * at each event in turn to determine how much space is used for events in
152 * total. Once we've done this we know the offset of the data length field,
153 * and can calculate the total size of the event.
154 *
155 * Return: size of the event on success, <0 on failure
156 */
157
158 static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
159 struct tcg_pcr_event *event_header,
160 bool do_mapping)
161 {
162 struct tcg_efi_specid_event_head *efispecid;
163 struct tcg_event_field *event_field;
164 void *mapping = NULL;
> 165 int mapping_size;
166 void *marker;
167 void *marker_start;
168 u32 halg_size;
169 size_t size;
170 u16 halg;
171 int i;
172 int j;
173
174 marker = event;
175 marker_start = marker;
176 marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type)
177 + sizeof(event->count);
178
179 /* Map the event header */
180 if (do_mapping) {
181 mapping_size = marker - marker_start;
182 mapping = TPM_MEMREMAP((unsigned long)marker_start,
183 mapping_size);
184 if (!mapping) {
185 size = 0;
186 goto out;
187 }
188 } else {
189 mapping = marker_start;
190 }
191
192 event = (struct tcg_pcr_event2_head *)mapping;
193
194 efispecid = (struct tcg_efi_specid_event_head *)event_header->event;
195
196 /* Check if event is malformed. */
197 if (event->count > efispecid->num_algs) {
198 size = 0;
199 goto out;
200 }
201
202 for (i = 0; i < event->count; i++) {
203 halg_size = sizeof(event->digests[i].alg_id);
204
205 /* Map the digest's algorithm identifier */
206 if (do_mapping) {
207 TPM_MEMUNMAP(mapping, mapping_size);
208 mapping_size = halg_size;
209 mapping = TPM_MEMREMAP((unsigned long)marker,
210 mapping_size);
211 if (!mapping) {
212 size = 0;
213 goto out;
214 }
215 } else {
216 mapping = marker;
217 }
218
219 memcpy(&halg, mapping, halg_size);
220 marker = marker + halg_size;
221
222 for (j = 0; j < efispecid->num_algs; j++) {
223 if (halg == efispecid->digest_sizes[j].alg_id) {
224 marker +=
225 efispecid->digest_sizes[j].digest_size;
226 break;
227 }
228 }
229 /* Algorithm without known length. Such event is unparseable. */
230 if (j == efispecid->num_algs) {
231 size = 0;
232 goto out;
233 }
234 }
235
236 /*
237 * Map the event size - we don't read from the event itself, so
238 * we don't need to map it
239 */
240 if (do_mapping) {
241 TPM_MEMUNMAP(mapping, mapping_size);
242 mapping_size += sizeof(event_field->event_size);
243 mapping = TPM_MEMREMAP((unsigned long)marker,
244 mapping_size);
245 if (!mapping) {
246 size = 0;
247 goto out;
248 }
249 } else {
250 mapping = marker;
251 }
252
253 event_field = (struct tcg_event_field *)mapping;
254
255 marker = marker + sizeof(event_field->event_size)
256 + event_field->event_size;
257 size = marker - marker_start;
258
259 if ((event->event_type == 0) && (event_field->event_size == 0))
260 size = 0;
261 out:
262 if (do_mapping)
263 TPM_MEMUNMAP(mapping, mapping_size);
264 return size;
265 }
266
--
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