In preparation for module support for kunit and kunit tests, we need a way of retrieving non-exported symbols from the core kernel and modules. kunit_find_symbol() supports this.
Signed-off-by: Alan Maguire alan.maguire@oracle.com Signed-off-by: Knut Omang knut.omang@oracle.com --- include/kunit/test.h | 8 ++++++++ lib/kunit/test-test.c | 19 +++++++++++++++++++ lib/kunit/test.c | 36 ++++++++++++++++++++++++++++++++++++ 3 files changed, 63 insertions(+)
diff --git a/include/kunit/test.h b/include/kunit/test.h index dba4830..c645d18 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -339,6 +339,14 @@ static inline void *kunit_kzalloc(struct kunit *test, size_t size, gfp_t gfp)
void kunit_cleanup(struct kunit *test);
+/** + * kunit_find_symbol() - lookup un-exported symbol in kernel or modules. + * @sym: symbol name. + * + * Returns symbol or ERR_PTR value on error. + */ +void *kunit_find_symbol(const char *sym); + #define kunit_printk(lvl, test, fmt, ...) \ printk(lvl "\t# %s: " fmt, (test)->name, ##__VA_ARGS__)
diff --git a/lib/kunit/test-test.c b/lib/kunit/test-test.c index c4162a9..7f09dd0 100644 --- a/lib/kunit/test-test.c +++ b/lib/kunit/test-test.c @@ -330,3 +330,22 @@ static void kunit_resource_test_exit(struct kunit *test) .test_cases = kunit_resource_test_cases, }; kunit_test_suite(kunit_resource_test_suite); + +/* + * Find non-exported kernel symbol; we use the modules list as a safe + * choice that should always be present. + */ +static void kunit_find_symbol_kernel(struct kunit *test) +{ + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, kunit_find_symbol("modules")); +} + +static struct kunit_case kunit_find_symbol_test_cases[] = { + KUNIT_CASE(kunit_find_symbol_kernel), +}; + +static struct kunit_suite kunit_find_symbol_test_suite = { + .name = "kunit-find-symbol", + .test_cases = kunit_find_symbol_test_cases, +}; +kunit_test_suite(kunit_find_symbol_test_suite); diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 49ac5fe..a2b1b46 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -8,6 +8,7 @@
#include <kunit/test.h> #include <kunit/try-catch.h> +#include <linux/kallsyms.h> #include <linux/kernel.h> #include <linux/sched/debug.h> #include "string-stream-impl.h" @@ -478,3 +479,38 @@ void kunit_cleanup(struct kunit *test) kunit_resource_free(test, resource); } } + +/* + * Support for looking up kernel/module internal symbols to enable testing. + */ +void *kunit_find_symbol(const char *sym) +{ + unsigned long (*modlookup)(const char *name); + unsigned long addr = 0; + + if (!sym || strlen(sym) > KSYM_NAME_LEN) + return ERR_PTR(-EINVAL); + + /* + * Try for kernel-internal symbol first; fall back to modules + * if that fails. + */ + addr = kallsyms_lookup_name(sym); + if (addr) + return (void *)addr; + modlookup = (void *)kallsyms_lookup_name("module_kallsyms_lookup_name"); + if (modlookup) + addr = modlookup(sym); + if (addr) + return (void *)addr; + +#ifndef CONFIG_KALLSYMS_ALL + WARN_ONCE(true, + "CONFIG_KALLSYMS_ALL is not set, so unexported symbols like '%s' are not available\n", + sym); + return ERR_PTR(-ENOTSUPP); +#else + WARN_ONCE(true, "symbol '%s' is not available\n", sym); +#endif + return ERR_PTR(-ENOENT); +}