| Message ID | 20211110205418.332403-1-vinicius.gomes@intel.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | [net,v2] bpf: Fix build when CONFIG_BPF_SYSCALL is disabled | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for net |
| netdev/fixes_present | success | Fixes tag present in non-next series |
| netdev/subject_prefix | success | Link |
| netdev/cover_letter | success | Single patches do not need cover letters |
| netdev/patch_count | success | Link |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 17 this patch: 17 |
| netdev/cc_maintainers | warning | 2 maintainers not CCed: kpsingh@kernel.org john.fastabend@gmail.com |
| netdev/build_clang | success | Errors and warnings before: 22 this patch: 22 |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/verify_fixes | success | Fixes tag looks correct |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 21 this patch: 21 |
| netdev/checkpatch | warning | CHECK: struct mutex definition without comment |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
| bpf/vmtest-bpf-next-PR | fail | PR summary |
| bpf/vmtest-bpf-next | fail | VM_Test |
| bpf/vmtest-bpf | fail | VM_Test |
| bpf/vmtest-bpf-PR | fail | PR summary |
On Thu, Nov 11, 2021 at 02:24:18AM IST, Vinicius Costa Gomes wrote: > When CONFIG_DEBUG_INFO_BTF is enabled and CONFIG_BPF_SYSCALL is > disabled, the following compilation error can be seen: > > GEN .version > CHK include/generated/compile.h > UPD include/generated/compile.h > CC init/version.o > AR init/built-in.a > LD vmlinux.o > MODPOST vmlinux.symvers > MODINFO modules.builtin.modinfo > GEN modules.builtin > LD .tmp_vmlinux.btf > ld: net/ipv4/tcp_cubic.o: in function `cubictcp_unregister': > net/ipv4/tcp_cubic.c:545: undefined reference to `bpf_tcp_ca_kfunc_list' > ld: net/ipv4/tcp_cubic.c:545: undefined reference to `unregister_kfunc_btf_id_set' > ld: net/ipv4/tcp_cubic.o: in function `cubictcp_register': > net/ipv4/tcp_cubic.c:539: undefined reference to `bpf_tcp_ca_kfunc_list' > ld: net/ipv4/tcp_cubic.c:539: undefined reference to `register_kfunc_btf_id_set' > BTF .btf.vmlinux.bin.o > pahole: .tmp_vmlinux.btf: No such file or directory > LD .tmp_vmlinux.kallsyms1 > .btf.vmlinux.bin.o: file not recognized: file format not recognized > make: *** [Makefile:1187: vmlinux] Error 1 > > 'bpf_tcp_ca_kfunc_list', 'register_kfunc_btf_id_set()' and > 'unregister_kfunc_btf_id_set()' are only defined when > CONFIG_BPF_SYSCALL is enabled. > > Fix that by moving those definitions somewhere that doesn't depend on > the bpf() syscall. > > Fixes: 14f267d95fe4 ("bpf: btf: Introduce helpers for dynamic BTF set registration") > Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> Thanks for the fix. But instead of moving this to core.c, you can probably make the btf.h declaration conditional on CONFIG_BPF_SYSCALL, since this is not useful in isolation (only used by verifier for module kfunc support). For the case of kfunc_btf_id_list variables, just define it as an empty struct and static variables, since the definition is still inside btf.c. So it becomes a noop for !CONFIG_BPF_SYSCALL. I am also not sure whether BTF is useful without BPF support, but maybe I'm missing some usecase. That's just my opinion however, I'll defer to BPF maintainers. -- Kartikeya
On Wed, Nov 10, 2021 at 1:25 PM Kumar Kartikeya Dwivedi <memxor@gmail.com> wrote: > > On Thu, Nov 11, 2021 at 02:24:18AM IST, Vinicius Costa Gomes wrote: > > When CONFIG_DEBUG_INFO_BTF is enabled and CONFIG_BPF_SYSCALL is > > disabled, the following compilation error can be seen: > > > > GEN .version > > CHK include/generated/compile.h > > UPD include/generated/compile.h > > CC init/version.o > > AR init/built-in.a > > LD vmlinux.o > > MODPOST vmlinux.symvers > > MODINFO modules.builtin.modinfo > > GEN modules.builtin > > LD .tmp_vmlinux.btf > > ld: net/ipv4/tcp_cubic.o: in function `cubictcp_unregister': > > net/ipv4/tcp_cubic.c:545: undefined reference to `bpf_tcp_ca_kfunc_list' > > ld: net/ipv4/tcp_cubic.c:545: undefined reference to `unregister_kfunc_btf_id_set' > > ld: net/ipv4/tcp_cubic.o: in function `cubictcp_register': > > net/ipv4/tcp_cubic.c:539: undefined reference to `bpf_tcp_ca_kfunc_list' > > ld: net/ipv4/tcp_cubic.c:539: undefined reference to `register_kfunc_btf_id_set' > > BTF .btf.vmlinux.bin.o > > pahole: .tmp_vmlinux.btf: No such file or directory > > LD .tmp_vmlinux.kallsyms1 > > .btf.vmlinux.bin.o: file not recognized: file format not recognized > > make: *** [Makefile:1187: vmlinux] Error 1 > > > > 'bpf_tcp_ca_kfunc_list', 'register_kfunc_btf_id_set()' and > > 'unregister_kfunc_btf_id_set()' are only defined when > > CONFIG_BPF_SYSCALL is enabled. > > > > Fix that by moving those definitions somewhere that doesn't depend on > > the bpf() syscall. > > > > Fixes: 14f267d95fe4 ("bpf: btf: Introduce helpers for dynamic BTF set registration") > > Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> > > Thanks for the fix. > > But instead of moving this to core.c, you can probably make the btf.h > declaration conditional on CONFIG_BPF_SYSCALL, since this is not useful in > isolation (only used by verifier for module kfunc support). For the case of > kfunc_btf_id_list variables, just define it as an empty struct and static > variables, since the definition is still inside btf.c. So it becomes a noop for > !CONFIG_BPF_SYSCALL. > > I am also not sure whether BTF is useful without BPF support, but maybe I'm > missing some usecase. Unlikely. I would just disallow such config instead of sprinkling the code with ifdefs.
Hi, Kumar Kartikeya Dwivedi <memxor@gmail.com> writes: > On Thu, Nov 11, 2021 at 02:24:18AM IST, Vinicius Costa Gomes wrote: >> When CONFIG_DEBUG_INFO_BTF is enabled and CONFIG_BPF_SYSCALL is >> disabled, the following compilation error can be seen: >> >> GEN .version >> CHK include/generated/compile.h >> UPD include/generated/compile.h >> CC init/version.o >> AR init/built-in.a >> LD vmlinux.o >> MODPOST vmlinux.symvers >> MODINFO modules.builtin.modinfo >> GEN modules.builtin >> LD .tmp_vmlinux.btf >> ld: net/ipv4/tcp_cubic.o: in function `cubictcp_unregister': >> net/ipv4/tcp_cubic.c:545: undefined reference to `bpf_tcp_ca_kfunc_list' >> ld: net/ipv4/tcp_cubic.c:545: undefined reference to `unregister_kfunc_btf_id_set' >> ld: net/ipv4/tcp_cubic.o: in function `cubictcp_register': >> net/ipv4/tcp_cubic.c:539: undefined reference to `bpf_tcp_ca_kfunc_list' >> ld: net/ipv4/tcp_cubic.c:539: undefined reference to `register_kfunc_btf_id_set' >> BTF .btf.vmlinux.bin.o >> pahole: .tmp_vmlinux.btf: No such file or directory >> LD .tmp_vmlinux.kallsyms1 >> .btf.vmlinux.bin.o: file not recognized: file format not recognized >> make: *** [Makefile:1187: vmlinux] Error 1 >> >> 'bpf_tcp_ca_kfunc_list', 'register_kfunc_btf_id_set()' and >> 'unregister_kfunc_btf_id_set()' are only defined when >> CONFIG_BPF_SYSCALL is enabled. >> >> Fix that by moving those definitions somewhere that doesn't depend on >> the bpf() syscall. >> >> Fixes: 14f267d95fe4 ("bpf: btf: Introduce helpers for dynamic BTF set registration") >> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> > > Thanks for the fix. > > But instead of moving this to core.c, you can probably make the btf.h > declaration conditional on CONFIG_BPF_SYSCALL, since this is not useful in > isolation (only used by verifier for module kfunc support). For the case of > kfunc_btf_id_list variables, just define it as an empty struct and static > variables, since the definition is still inside btf.c. So it becomes a noop for > !CONFIG_BPF_SYSCALL. > > I am also not sure whether BTF is useful without BPF support, but maybe I'm > missing some usecase. From my side, you are not missing anything, it was just random chance that I had a 'x86_64_defconfig + debug + BTF' .config laying around and the build broke with it. I don't have any real usecases for this combination. Cheers,
Alexei Starovoitov <alexei.starovoitov@gmail.com> writes: >> Thanks for the fix. >> >> But instead of moving this to core.c, you can probably make the btf.h >> declaration conditional on CONFIG_BPF_SYSCALL, since this is not useful in >> isolation (only used by verifier for module kfunc support). For the case of >> kfunc_btf_id_list variables, just define it as an empty struct and static >> variables, since the definition is still inside btf.c. So it becomes a noop for >> !CONFIG_BPF_SYSCALL. >> >> I am also not sure whether BTF is useful without BPF support, but maybe I'm >> missing some usecase. > > Unlikely. I would just disallow such config instead of sprinkling > the code with ifdefs. Is something like this what you have in mind? diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 6fdbf9613aec..eae860c86e26 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -316,6 +316,7 @@ config DEBUG_INFO_BTF bool "Generate BTF typeinfo" depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST + depends on BPF_SYSCALL help Generate deduplicated BTF type information from DWARF debug info. Turning this on expects presence of pahole tool, which will convert Cheers,
On Thu, Nov 11, 2021 at 05:21:53AM IST, Vinicius Costa Gomes wrote: > Alexei Starovoitov <alexei.starovoitov@gmail.com> writes: > > >> Thanks for the fix. > >> > >> But instead of moving this to core.c, you can probably make the btf.h > >> declaration conditional on CONFIG_BPF_SYSCALL, since this is not useful in > >> isolation (only used by verifier for module kfunc support). For the case of > >> kfunc_btf_id_list variables, just define it as an empty struct and static > >> variables, since the definition is still inside btf.c. So it becomes a noop for > >> !CONFIG_BPF_SYSCALL. > >> > >> I am also not sure whether BTF is useful without BPF support, but maybe I'm > >> missing some usecase. > > > > Unlikely. I would just disallow such config instead of sprinkling > > the code with ifdefs. > > Is something like this what you have in mind? > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 6fdbf9613aec..eae860c86e26 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -316,6 +316,7 @@ config DEBUG_INFO_BTF > bool "Generate BTF typeinfo" > depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED > depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST > + depends on BPF_SYSCALL > help > Generate deduplicated BTF type information from DWARF debug info. > Turning this on expects presence of pahole tool, which will convert > > BTW, you will need a little more than that, I suspect the compiler optimizes out the register/unregister call so we don't see a build failure, but adding a side effect gives me errors, so something like this should resolve the problem (since kfunc_btf_id_list variable definition is behind CONFIG_BPF_SYSCALL). diff --git a/include/linux/btf.h b/include/linux/btf.h index 203eef993d76..e9881ef9e9aa 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -254,6 +254,8 @@ void unregister_kfunc_btf_id_set(struct kfunc_btf_id_list *l, struct kfunc_btf_id_set *s); bool bpf_check_mod_kfunc_call(struct kfunc_btf_id_list *klist, u32 kfunc_id, struct module *owner); +extern struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list; +extern struct kfunc_btf_id_list prog_test_kfunc_list; #else static inline void register_kfunc_btf_id_set(struct kfunc_btf_id_list *l, struct kfunc_btf_id_set *s) @@ -268,13 +270,13 @@ static inline bool bpf_check_mod_kfunc_call(struct kfunc_btf_id_list *klist, { return false; } +struct kfunc_btf_id_list {}; +static struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list __maybe_unused; +static struct kfunc_btf_id_list prog_test_kfunc_list __maybe_unused; + #endif #define DEFINE_KFUNC_BTF_ID_SET(set, name) \ struct kfunc_btf_id_set name = { LIST_HEAD_INIT(name.list), (set), \ THIS_MODULE } - -extern struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list; -extern struct kfunc_btf_id_list prog_test_kfunc_list; - #endif -- Kartikeya
Hi Kartikeya, Kumar Kartikeya Dwivedi <memxor@gmail.com> writes: > On Thu, Nov 11, 2021 at 05:21:53AM IST, Vinicius Costa Gomes wrote: >> Alexei Starovoitov <alexei.starovoitov@gmail.com> writes: >> >> >> Thanks for the fix. >> >> >> >> But instead of moving this to core.c, you can probably make the btf.h >> >> declaration conditional on CONFIG_BPF_SYSCALL, since this is not useful in >> >> isolation (only used by verifier for module kfunc support). For the case of >> >> kfunc_btf_id_list variables, just define it as an empty struct and static >> >> variables, since the definition is still inside btf.c. So it becomes a noop for >> >> !CONFIG_BPF_SYSCALL. >> >> >> >> I am also not sure whether BTF is useful without BPF support, but maybe I'm >> >> missing some usecase. >> > >> > Unlikely. I would just disallow such config instead of sprinkling >> > the code with ifdefs. >> >> Is something like this what you have in mind? >> >> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug >> index 6fdbf9613aec..eae860c86e26 100644 >> --- a/lib/Kconfig.debug >> +++ b/lib/Kconfig.debug >> @@ -316,6 +316,7 @@ config DEBUG_INFO_BTF >> bool "Generate BTF typeinfo" >> depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED >> depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST >> + depends on BPF_SYSCALL >> help >> Generate deduplicated BTF type information from DWARF debug info. >> Turning this on expects presence of pahole tool, which will convert >> >> > > BTW, you will need a little more than that, I suspect the compiler optimizes out > the register/unregister call so we don't see a build failure, but adding a side > effect gives me errors, so something like this should resolve the problem (since > kfunc_btf_id_list variable definition is behind CONFIG_BPF_SYSCALL). > > diff --git a/include/linux/btf.h b/include/linux/btf.h > index 203eef993d76..e9881ef9e9aa 100644 > --- a/include/linux/btf.h > +++ b/include/linux/btf.h > @@ -254,6 +254,8 @@ void unregister_kfunc_btf_id_set(struct kfunc_btf_id_list *l, > struct kfunc_btf_id_set *s); > bool bpf_check_mod_kfunc_call(struct kfunc_btf_id_list *klist, u32 kfunc_id, > struct module *owner); > +extern struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list; > +extern struct kfunc_btf_id_list prog_test_kfunc_list; > #else > static inline void register_kfunc_btf_id_set(struct kfunc_btf_id_list *l, > struct kfunc_btf_id_set *s) > @@ -268,13 +270,13 @@ static inline bool bpf_check_mod_kfunc_call(struct kfunc_btf_id_list *klist, > { > return false; > } > +struct kfunc_btf_id_list {}; > +static struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list __maybe_unused; > +static struct kfunc_btf_id_list prog_test_kfunc_list __maybe_unused; > + > #endif > > #define DEFINE_KFUNC_BTF_ID_SET(set, name) \ > struct kfunc_btf_id_set name = { LIST_HEAD_INIT(name.list), (set), \ > THIS_MODULE } > - > -extern struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list; > -extern struct kfunc_btf_id_list prog_test_kfunc_list; > - > #endif > I could not reproduce the build failure here even when adding some side effects, but I didn't try very hard. As you are more familiar with the code, I would be glad if you could take it from here and propose a patch. Cheers,
On Thu, Nov 11, 2021 at 07:34:38AM IST, Vinicius Costa Gomes wrote: > Hi Kartikeya, > > Kumar Kartikeya Dwivedi <memxor@gmail.com> writes: > > > On Thu, Nov 11, 2021 at 05:21:53AM IST, Vinicius Costa Gomes wrote: > >> Alexei Starovoitov <alexei.starovoitov@gmail.com> writes: > >> > >> >> Thanks for the fix. > >> >> > >> >> But instead of moving this to core.c, you can probably make the btf.h > >> >> declaration conditional on CONFIG_BPF_SYSCALL, since this is not useful in > >> >> isolation (only used by verifier for module kfunc support). For the case of > >> >> kfunc_btf_id_list variables, just define it as an empty struct and static > >> >> variables, since the definition is still inside btf.c. So it becomes a noop for > >> >> !CONFIG_BPF_SYSCALL. > >> >> > >> >> I am also not sure whether BTF is useful without BPF support, but maybe I'm > >> >> missing some usecase. > >> > > >> > Unlikely. I would just disallow such config instead of sprinkling > >> > the code with ifdefs. > >> > >> Is something like this what you have in mind? > >> > >> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > >> index 6fdbf9613aec..eae860c86e26 100644 > >> --- a/lib/Kconfig.debug > >> +++ b/lib/Kconfig.debug > >> @@ -316,6 +316,7 @@ config DEBUG_INFO_BTF > >> bool "Generate BTF typeinfo" > >> depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED > >> depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST > >> + depends on BPF_SYSCALL > >> help > >> Generate deduplicated BTF type information from DWARF debug info. > >> Turning this on expects presence of pahole tool, which will convert > >> > >> > > > > BTW, you will need a little more than that, I suspect the compiler optimizes out > > the register/unregister call so we don't see a build failure, but adding a side > > effect gives me errors, so something like this should resolve the problem (since > > kfunc_btf_id_list variable definition is behind CONFIG_BPF_SYSCALL). > > > > diff --git a/include/linux/btf.h b/include/linux/btf.h > > index 203eef993d76..e9881ef9e9aa 100644 > > --- a/include/linux/btf.h > > +++ b/include/linux/btf.h > > @@ -254,6 +254,8 @@ void unregister_kfunc_btf_id_set(struct kfunc_btf_id_list *l, > > struct kfunc_btf_id_set *s); > > bool bpf_check_mod_kfunc_call(struct kfunc_btf_id_list *klist, u32 kfunc_id, > > struct module *owner); > > +extern struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list; > > +extern struct kfunc_btf_id_list prog_test_kfunc_list; > > #else > > static inline void register_kfunc_btf_id_set(struct kfunc_btf_id_list *l, > > struct kfunc_btf_id_set *s) > > @@ -268,13 +270,13 @@ static inline bool bpf_check_mod_kfunc_call(struct kfunc_btf_id_list *klist, > > { > > return false; > > } > > +struct kfunc_btf_id_list {}; > > +static struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list __maybe_unused; > > +static struct kfunc_btf_id_list prog_test_kfunc_list __maybe_unused; > > + > > #endif > > > > #define DEFINE_KFUNC_BTF_ID_SET(set, name) \ > > struct kfunc_btf_id_set name = { LIST_HEAD_INIT(name.list), (set), \ > > THIS_MODULE } > > - > > -extern struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list; > > -extern struct kfunc_btf_id_list prog_test_kfunc_list; > > - > > #endif > > > > I could not reproduce the build failure here even when adding some side > effects, but I didn't try very hard. > > As you are more familiar with the code, I would be glad if you could > take it from here and propose a patch. > Sure, no worries! > > Cheers, > -- > Vinicius -- Kartikeya
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index dbc3ad07e21b..cc9868376345 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6344,33 +6344,8 @@ const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { BTF_ID_LIST_GLOBAL_SINGLE(btf_task_struct_ids, struct, task_struct) -/* BTF ID set registration API for modules */ - -struct kfunc_btf_id_list { - struct list_head list; - struct mutex mutex; -}; - #ifdef CONFIG_DEBUG_INFO_BTF_MODULES -void register_kfunc_btf_id_set(struct kfunc_btf_id_list *l, - struct kfunc_btf_id_set *s) -{ - mutex_lock(&l->mutex); - list_add(&s->list, &l->list); - mutex_unlock(&l->mutex); -} -EXPORT_SYMBOL_GPL(register_kfunc_btf_id_set); - -void unregister_kfunc_btf_id_set(struct kfunc_btf_id_list *l, - struct kfunc_btf_id_set *s) -{ - mutex_lock(&l->mutex); - list_del_init(&s->list); - mutex_unlock(&l->mutex); -} -EXPORT_SYMBOL_GPL(unregister_kfunc_btf_id_set); - bool bpf_check_mod_kfunc_call(struct kfunc_btf_id_list *klist, u32 kfunc_id, struct module *owner) { @@ -6390,11 +6365,3 @@ bool bpf_check_mod_kfunc_call(struct kfunc_btf_id_list *klist, u32 kfunc_id, } #endif - -#define DEFINE_KFUNC_BTF_ID_LIST(name) \ - struct kfunc_btf_id_list name = { LIST_HEAD_INIT(name.list), \ - __MUTEX_INITIALIZER(name.mutex) }; \ - EXPORT_SYMBOL_GPL(name) - -DEFINE_KFUNC_BTF_ID_LIST(bpf_tcp_ca_kfunc_list); -DEFINE_KFUNC_BTF_ID_LIST(prog_test_kfunc_list); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 2405e39d800f..f2939a6d8199 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2456,6 +2456,43 @@ int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); EXPORT_SYMBOL(bpf_stats_enabled_key); +/* BTF ID set registration API for modules */ + +struct kfunc_btf_id_list { + struct list_head list; + struct mutex mutex; +}; + +#ifdef CONFIG_DEBUG_INFO_BTF_MODULES + +void register_kfunc_btf_id_set(struct kfunc_btf_id_list *l, + struct kfunc_btf_id_set *s) +{ + mutex_lock(&l->mutex); + list_add(&s->list, &l->list); + mutex_unlock(&l->mutex); +} +EXPORT_SYMBOL_GPL(register_kfunc_btf_id_set); + +void unregister_kfunc_btf_id_set(struct kfunc_btf_id_list *l, + struct kfunc_btf_id_set *s) +{ + mutex_lock(&l->mutex); + list_del_init(&s->list); + mutex_unlock(&l->mutex); +} +EXPORT_SYMBOL_GPL(unregister_kfunc_btf_id_set); + +#endif + +#define DEFINE_KFUNC_BTF_ID_LIST(name) \ + struct kfunc_btf_id_list name = { LIST_HEAD_INIT(name.list), \ + __MUTEX_INITIALIZER(name.mutex) }; \ + EXPORT_SYMBOL_GPL(name) + +DEFINE_KFUNC_BTF_ID_LIST(bpf_tcp_ca_kfunc_list); +DEFINE_KFUNC_BTF_ID_LIST(prog_test_kfunc_list); + /* All definitions of tracepoints related to BPF. */ #define CREATE_TRACE_POINTS #include <linux/bpf_trace.h>
When CONFIG_DEBUG_INFO_BTF is enabled and CONFIG_BPF_SYSCALL is disabled, the following compilation error can be seen: GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a LD vmlinux.o MODPOST vmlinux.symvers MODINFO modules.builtin.modinfo GEN modules.builtin LD .tmp_vmlinux.btf ld: net/ipv4/tcp_cubic.o: in function `cubictcp_unregister': net/ipv4/tcp_cubic.c:545: undefined reference to `bpf_tcp_ca_kfunc_list' ld: net/ipv4/tcp_cubic.c:545: undefined reference to `unregister_kfunc_btf_id_set' ld: net/ipv4/tcp_cubic.o: in function `cubictcp_register': net/ipv4/tcp_cubic.c:539: undefined reference to `bpf_tcp_ca_kfunc_list' ld: net/ipv4/tcp_cubic.c:539: undefined reference to `register_kfunc_btf_id_set' BTF .btf.vmlinux.bin.o pahole: .tmp_vmlinux.btf: No such file or directory LD .tmp_vmlinux.kallsyms1 .btf.vmlinux.bin.o: file not recognized: file format not recognized make: *** [Makefile:1187: vmlinux] Error 1 'bpf_tcp_ca_kfunc_list', 'register_kfunc_btf_id_set()' and 'unregister_kfunc_btf_id_set()' are only defined when CONFIG_BPF_SYSCALL is enabled. Fix that by moving those definitions somewhere that doesn't depend on the bpf() syscall. Fixes: 14f267d95fe4 ("bpf: btf: Introduce helpers for dynamic BTF set registration") Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> --- kernel/bpf/btf.c | 33 --------------------------------- kernel/bpf/core.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+), 33 deletions(-)