Cover the member a rejected by-value kfunc return type is blamed on. The existing case for a struct carrying a pointer now also checks that the verifier names the member, and two cases are added: a pointer inside a nested member struct, which has to be named by its path rather than by its own name, and a type nested deeper than the walk descends, which has no single member to blame and reports the depth instead. Signed-off-by: Yonghong Song --- .../selftests/bpf/progs/aggregate_ret_kfunc.c | 34 +++++++++++++++++++ .../selftests/bpf/test_kmods/bpf_testmod.c | 16 +++++++++ .../bpf/test_kmods/bpf_testmod_kfunc.h | 21 ++++++++++++ 3 files changed, 71 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc.c b/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc.c index f10e5cf6fd89..e9c82df8efb2 100644 --- a/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc.c +++ b/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc.c @@ -18,6 +18,8 @@ void __kfunc_btf_root(void) : "r"(&bpf_kfunc_call_test_i128), "r"(&bpf_kfunc_call_test_ret_fastcall), "r"(&bpf_kfunc_call_test_ret_ptr), + "r"(&bpf_kfunc_call_test_ret_nested), + "r"(&bpf_kfunc_call_test_ret_deep), "r"(&bpf_kfunc_call_test_ret_ii), "r"(&bpf_kfunc_call_test_ret_big)); } @@ -72,6 +74,7 @@ __naked int aggregate_ret_kfunc_fastcall_fail(void) SEC("tc") __arch_x86_64 __arch_arm64 __failure __msg("is not composed of scalars or arena pointers") +__msg("member 'p' has type PTR") __naked int aggregate_ret_kfunc_ptr_fail(void) { asm volatile ( @@ -84,6 +87,37 @@ __naked int aggregate_ret_kfunc_ptr_fail(void) : __clobber_all); } +SEC("tc") +__arch_x86_64 __arch_arm64 +__failure __msg("is not composed of scalars or arena pointers") +__msg("member 'in.p' has type PTR") +__naked int aggregate_ret_kfunc_nested_ptr_fail(void) +{ + asm volatile ( + "r1 = 0;" + "call %[bpf_kfunc_call_test_ret_nested];" + "r0 = 0;" + "exit;" + : + : __imm(bpf_kfunc_call_test_ret_nested) + : __clobber_all); +} + +SEC("tc") +__arch_x86_64 __arch_arm64 +__failure __msg("max struct nesting depth exceeded") +__naked int aggregate_ret_kfunc_too_deep_fail(void) +{ + asm volatile ( + "r1 = 0;" + "call %[bpf_kfunc_call_test_ret_deep];" + "r0 = 0;" + "exit;" + : + : __imm(bpf_kfunc_call_test_ret_deep) + : __clobber_all); +} + SEC("tc") __arch_x86_64 __arch_arm64 __failure __msg("R2 !read_ok") diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c index 850cf4f830c4..76acbe29054a 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c @@ -981,6 +981,20 @@ __bpf_kfunc struct prog_test_ret_ptr bpf_kfunc_call_test_ret_ptr(u64 tag) return r; } +__bpf_kfunc struct prog_test_ret_nested bpf_kfunc_call_test_ret_nested(u64 tag) +{ + struct prog_test_ret_nested r = { .in = { .p = NULL }, .tag = tag }; + + return r; +} + +__bpf_kfunc struct prog_test_ret_deep bpf_kfunc_call_test_ret_deep(u64 v) +{ + struct prog_test_ret_deep r = { .l1 = { .l2 = { .l3 = { .l4 = { .v = v } } } } }; + + return r; +} + __bpf_kfunc struct prog_test_ret_ii bpf_kfunc_call_test_ret_ii(int a, int b) { struct prog_test_ret_ii r = { .a = a, .b = b }; @@ -1539,6 +1553,8 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test_i128) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_pair) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_fastcall, KF_FASTCALL) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_ptr) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_nested) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_deep) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_ii) #endif BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_big) diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h index 65e693ada736..52227129a49e 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h @@ -70,6 +70,25 @@ struct prog_test_ret_ptr { /* 16 bytes: contains a pointer */ __u64 tag; }; +struct prog_test_ret_nested { /* 16 bytes: the pointer hides one level down */ + struct { + void *p; + } in; + __u64 tag; +}; + +struct prog_test_ret_deep { /* 8 bytes, but nested past the 4-level walk limit */ + struct { + struct { + struct { + struct { + __u64 v; + } l4; + } l3; + } l2; + } l1; +}; + struct prog_test_ret_big { /* 24 bytes: too large for R0:R2 */ __u64 a; __u64 b; @@ -159,6 +178,8 @@ struct prog_test_ret_pair bpf_kfunc_call_test_ret_pair(__u64 a, __u64 b) __ksym; struct prog_test_ret_pair bpf_kfunc_call_test_ret_fastcall(__u64 a, __u64 b) __ksym; struct prog_test_ret_ii bpf_kfunc_call_test_ret_ii(int a, int b) __ksym; struct prog_test_ret_ptr bpf_kfunc_call_test_ret_ptr(__u64 tag) __ksym; +struct prog_test_ret_nested bpf_kfunc_call_test_ret_nested(__u64 tag) __ksym; +struct prog_test_ret_deep bpf_kfunc_call_test_ret_deep(__u64 v) __ksym; struct prog_test_ret_big bpf_kfunc_call_test_ret_big(void) __ksym; __u64 bpf_kfunc_call_stack_arg(__u64 a, __u64 b, __u64 c, __u64 d, __u64 e, __u64 f, __u64 g, __u64 h, -- 2.53.0-Meta