linux-toradex.git/tools/objtool/tests/generic/test-export-symbol-for-modules.sh, branch master Linux kernel for Apalis and Colibri modules objtool/klp: Add test for EXPORT_SYMBOL_FOR_MODULES references 2026-09-21T09:12:06+00:00 Song Liu song@kernel.org 2026-09-16T18:43:25+00:00 a87892ac05098d23e855e25c7afc128b1e9973fe A symbol exported with EXPORT_SYMBOL_FOR_MODULES() is reachable only by the modules named in its namespace, and a livepatch module is never one of them. So a reference to it cannot be an ordinary relocation resolved by the module loader; it has to be a klp relocation applied at patch time. Getting this wrong is silent. The module links, loads, and reads the wrong thing, or fails to load for a reason that does not name the cause. This tests the behavior of commit 4cd3cfb8b54f ("objtool/klp: Fix relocations for EXPORT_SYMBOL_FOR_MODULES() symbols"). Which object the resulting relocation is filed under is a separate question, and one this test cannot ask: the patched object here is vmlinux, so the vmlinux section is the one produced either way. That is covered by the module case, in "objtool/klp: Add test for vmlinux relocs in a patched module". Assisted-by: Claude:claude-opus-4 Based-on-test-by: Joe Lawrence <joe.lawrence@redhat.com> Assisted-by: Claude:claude-opus-5 Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://patch.msgid.link/20260916184351.2720310-33-song@kernel.org 
A symbol exported with EXPORT_SYMBOL_FOR_MODULES() is reachable only by the
modules named in its namespace, and a livepatch module is never one of
them. So a reference to it cannot be an ordinary relocation resolved by the
module loader; it has to be a klp relocation applied at patch time.

Getting this wrong is silent.  The module links, loads, and reads the wrong
thing, or fails to load for a reason that does not name the cause.

This tests the behavior of commit 4cd3cfb8b54f ("objtool/klp: Fix
relocations for EXPORT_SYMBOL_FOR_MODULES() symbols").  Which object the
resulting relocation is filed under is a separate question, and one this
test cannot ask: the patched object here is vmlinux, so the vmlinux section
is the one produced either way.  That is covered by the module case, in
"objtool/klp: Add test for vmlinux relocs in a patched module".

Assisted-by: Claude:claude-opus-4
Based-on-test-by: Joe Lawrence <joe.lawrence@redhat.com>
Assisted-by: Claude:claude-opus-5
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20260916184351.2720310-33-song@kernel.org