Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
objtool/klp: Disable unsupported pr_debug() usage
Instead of erroring out on unsupported pr_debug() (e.g., when patching a
module), issue a warning and make it inert, similar to how unsupported
tracepoints are currently handled.
Reviewed-and-tested-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/3a7db3a5b7d4abf9b2534803a74e2e7231322738.1770759954.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
+15
-8
+15
-8
tools/objtool/klp-diff.c
+15
-8
tools/objtool/klp-diff.c
···
1334
1334
* be applied after static branch/call init, resulting in code corruption.
1335
1335
*
1336
1336
* Validate a special section entry to avoid that. Note that an inert
1337
-
* tracepoint is harmless enough, in that case just skip the entry and print a
1338
-
* warning. Otherwise, return an error.
1337
+
* tracepoint or pr_debug() is harmless enough, in that case just skip the
1338
+
* entry and print a warning. Otherwise, return an error.
1339
1339
*
1340
-
* This is only a temporary limitation which will be fixed when livepatch adds
1341
-
* support for submodules: fully self-contained modules which are embedded in
1342
-
* the top-level livepatch module's data and which can be loaded on demand when
1343
-
* their corresponding to-be-patched module gets loaded. Then klp relocs can
1344
-
* be retired.
1340
+
* TODO: This is only a temporary limitation which will be fixed when livepatch
1341
+
* adds support for submodules: fully self-contained modules which are embedded
1342
+
* in the top-level livepatch module's data and which can be loaded on demand
1343
+
* when their corresponding to-be-patched module gets loaded. Then klp relocs
1344
+
* can be retired.
1345
1345
*
1346
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* Return:
1347
1347
* -1: error: validation failed
1348
-
* 1: warning: tracepoint skipped
1348
+
* 1: warning: disabled tracepoint or pr_debug()
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* 0: success
1350
1350
*/
1351
1351
static int validate_special_section_klp_reloc(struct elfs *e, struct symbol *sym)
···
1399
1399
if (strstarts(reloc->sym->name, "__tracepoint_")) {
1400
1400
WARN("%s: disabling unsupported tracepoint %s",
1401
1401
code_sym->name, reloc->sym->name + 13);
1402
+
ret = 1;
1403
+
continue;
1404
+
}
1405
+
1406
+
if (strstr(reloc->sym->name, "__UNIQUE_ID_ddebug_")) {
1407
+
WARN("%s: disabling unsupported pr_debug()",
1408
+
code_sym->name);
1402
1409
ret = 1;
1403
1410
continue;
1404
1411
}