| Message ID | 20240806020136.3481593-1-davidgow@google.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Brendan Higgins |
| Headers | show |
| Series | kunit: Fix kunit_kstrdup_const() with modules | expand |
On Tue, Aug 06, 2024 at 10:01:34AM +0800, David Gow wrote: > In commit 7d3c33b290b1 ("kunit: Device wrappers should also manage driver name"), > the kunit_kstrdup_const() and kunit_kfree_const() were introduced as an > optimisation of kunit_kstrdup(), which only copy/free strings from the > kernel rodata. > > However, these are inline functions, and is_kernel_rodata() only works > for built-in code. This causes problems in two cases: > - If kunit is built as a module, __{start,end}_rodata is not defined. > - If a kunit test using these functions is built as a module, it will > suffer the same fate. > > Restrict the is_kernel_rodata() case to when KUnit is built as a module, > which fixes the first case, at the cost of losing the optimisation. > > Also, make kunit_{kstrdup,kfree}_const non-inline, so that other modules > using them will not accidentally depend on is_kernel_rodata(). If KUnit > is built-in, they'll benefit from the optimisation, if KUnit is not, > they won't, but the string will be properly duplicated. I wonder if this series should be refreshed: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/log/?h=devel/hardening/is_rodata We gained is_kernel_rodata() and is_kernel_ro_after_init() since this original proposal, which is what the proposed core_kernel_rodata() checks. It adds a is_module_rodata...() check, so with the is_kernel_*() checks, it's possible to do a check across the entire kernel and all modules. -Kees > > (And fix a couple of typos in the doc comment, too.) > > Reported-by: Nico Pache <npache@redhat.com> > Closes: https://lore.kernel.org/all/CAA1CXcDKht4vOL-acxrARbm6JhGna8_k8wjYJ-vHONink8aZ=w@mail.gmail.com/ > Fixes: 7d3c33b290b1 ("kunit: Device wrappers should also manage driver name") > Signed-off-by: David Gow <davidgow@google.com> > --- > include/kunit/test.h | 16 +++------------- > lib/kunit/test.c | 19 +++++++++++++++++++ > 2 files changed, 22 insertions(+), 13 deletions(-) > > diff --git a/include/kunit/test.h b/include/kunit/test.h > index da9e84de14c0..5ac237c949a0 100644 > --- a/include/kunit/test.h > +++ b/include/kunit/test.h > @@ -489,11 +489,7 @@ static inline void *kunit_kcalloc(struct kunit *test, size_t n, size_t size, gfp > * Calls kunit_kfree() only if @x is not in .rodata section. > * See kunit_kstrdup_const() for more information. > */ > -static inline void kunit_kfree_const(struct kunit *test, const void *x) > -{ > - if (!is_kernel_rodata((unsigned long)x)) > - kunit_kfree(test, x); > -} > +void kunit_kfree_const(struct kunit *test, const void *x); > > /** > * kunit_kstrdup() - Duplicates a string into a test managed allocation. > @@ -527,16 +523,10 @@ static inline char *kunit_kstrdup(struct kunit *test, const char *str, gfp_t gfp > * @gfp: flags passed to underlying kmalloc(). > * > * Calls kunit_kstrdup() only if @str is not in the rodata section. Must be freed with > - * kunit_free_const() -- not kunit_free(). > + * kunit_kfree_const() -- not kunit_kfree(). > * See kstrdup_const() and kunit_kmalloc_array() for more information. > */ > -static inline const char *kunit_kstrdup_const(struct kunit *test, const char *str, gfp_t gfp) > -{ > - if (is_kernel_rodata((unsigned long)str)) > - return str; > - > - return kunit_kstrdup(test, str, gfp); > -} > +const char *kunit_kstrdup_const(struct kunit *test, const char *str, gfp_t gfp); > > /** > * kunit_vm_mmap() - Allocate KUnit-tracked vm_mmap() area > diff --git a/lib/kunit/test.c b/lib/kunit/test.c > index e8b1b52a19ab..089c832e3cdb 100644 > --- a/lib/kunit/test.c > +++ b/lib/kunit/test.c > @@ -874,6 +874,25 @@ void kunit_kfree(struct kunit *test, const void *ptr) > } > EXPORT_SYMBOL_GPL(kunit_kfree); > > +void kunit_kfree_const(struct kunit *test, const void *x) > +{ > +#if !IS_MODULE(CONFIG_KUNIT) > + if (!is_kernel_rodata((unsigned long)x)) > +#endif > + kunit_kfree(test, x); > +} > +EXPORT_SYMBOL_GPL(kunit_kfree_const); > + > +const char *kunit_kstrdup_const(struct kunit *test, const char *str, gfp_t gfp) > +{ > +#if !IS_MODULE(CONFIG_KUNIT) > + if (is_kernel_rodata((unsigned long)str)) > + return str; > +#endif > + return kunit_kstrdup(test, str, gfp); > +} > +EXPORT_SYMBOL_GPL(kunit_kstrdup_const); > + > void kunit_cleanup(struct kunit *test) > { > struct kunit_resource *res; > -- > 2.46.0.rc2.264.g509ed76dc8-goog >
diff --git a/include/kunit/test.h b/include/kunit/test.h index da9e84de14c0..5ac237c949a0 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -489,11 +489,7 @@ static inline void *kunit_kcalloc(struct kunit *test, size_t n, size_t size, gfp * Calls kunit_kfree() only if @x is not in .rodata section. * See kunit_kstrdup_const() for more information. */ -static inline void kunit_kfree_const(struct kunit *test, const void *x) -{ - if (!is_kernel_rodata((unsigned long)x)) - kunit_kfree(test, x); -} +void kunit_kfree_const(struct kunit *test, const void *x); /** * kunit_kstrdup() - Duplicates a string into a test managed allocation. @@ -527,16 +523,10 @@ static inline char *kunit_kstrdup(struct kunit *test, const char *str, gfp_t gfp * @gfp: flags passed to underlying kmalloc(). * * Calls kunit_kstrdup() only if @str is not in the rodata section. Must be freed with - * kunit_free_const() -- not kunit_free(). + * kunit_kfree_const() -- not kunit_kfree(). * See kstrdup_const() and kunit_kmalloc_array() for more information. */ -static inline const char *kunit_kstrdup_const(struct kunit *test, const char *str, gfp_t gfp) -{ - if (is_kernel_rodata((unsigned long)str)) - return str; - - return kunit_kstrdup(test, str, gfp); -} +const char *kunit_kstrdup_const(struct kunit *test, const char *str, gfp_t gfp); /** * kunit_vm_mmap() - Allocate KUnit-tracked vm_mmap() area diff --git a/lib/kunit/test.c b/lib/kunit/test.c index e8b1b52a19ab..089c832e3cdb 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -874,6 +874,25 @@ void kunit_kfree(struct kunit *test, const void *ptr) } EXPORT_SYMBOL_GPL(kunit_kfree); +void kunit_kfree_const(struct kunit *test, const void *x) +{ +#if !IS_MODULE(CONFIG_KUNIT) + if (!is_kernel_rodata((unsigned long)x)) +#endif + kunit_kfree(test, x); +} +EXPORT_SYMBOL_GPL(kunit_kfree_const); + +const char *kunit_kstrdup_const(struct kunit *test, const char *str, gfp_t gfp) +{ +#if !IS_MODULE(CONFIG_KUNIT) + if (is_kernel_rodata((unsigned long)str)) + return str; +#endif + return kunit_kstrdup(test, str, gfp); +} +EXPORT_SYMBOL_GPL(kunit_kstrdup_const); + void kunit_cleanup(struct kunit *test) { struct kunit_resource *res;
In commit 7d3c33b290b1 ("kunit: Device wrappers should also manage driver name"), the kunit_kstrdup_const() and kunit_kfree_const() were introduced as an optimisation of kunit_kstrdup(), which only copy/free strings from the kernel rodata. However, these are inline functions, and is_kernel_rodata() only works for built-in code. This causes problems in two cases: - If kunit is built as a module, __{start,end}_rodata is not defined. - If a kunit test using these functions is built as a module, it will suffer the same fate. Restrict the is_kernel_rodata() case to when KUnit is built as a module, which fixes the first case, at the cost of losing the optimisation. Also, make kunit_{kstrdup,kfree}_const non-inline, so that other modules using them will not accidentally depend on is_kernel_rodata(). If KUnit is built-in, they'll benefit from the optimisation, if KUnit is not, they won't, but the string will be properly duplicated. (And fix a couple of typos in the doc comment, too.) Reported-by: Nico Pache <npache@redhat.com> Closes: https://lore.kernel.org/all/CAA1CXcDKht4vOL-acxrARbm6JhGna8_k8wjYJ-vHONink8aZ=w@mail.gmail.com/ Fixes: 7d3c33b290b1 ("kunit: Device wrappers should also manage driver name") Signed-off-by: David Gow <davidgow@google.com> --- include/kunit/test.h | 16 +++------------- lib/kunit/test.c | 19 +++++++++++++++++++ 2 files changed, 22 insertions(+), 13 deletions(-)