[RFC PATCH bpf-next 3/7] selftests/bpf: stop using static variables for passing data to/from user-space
From: Andrii Nakryiko <andrii@kernel.org>
Date: 2021-05-07 05:41:42
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Shuah Khan, Linus Torvalds
In preparation of skipping emitting static variables in BPF skeletons, switch all current selftests uses of static variables to pass data between BPF and user-space to use global variables. All non-read-only `static volatile` variables become just plain global variables by dropping `static volatile` part. Read-only `static volatile const` variables, though, still require `volatile` modifier, otherwise compiler will ignore whatever values are set from user-space. Few static linker tests are using name-conflicting static variables to validate that static linker still properly handles static variables and doesn't trip up on name conflicts. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> --- tools/testing/selftests/bpf/prog_tests/send_signal.c | 2 +- tools/testing/selftests/bpf/prog_tests/skeleton.c | 6 ++---- tools/testing/selftests/bpf/prog_tests/static_linked.c | 5 ----- tools/testing/selftests/bpf/progs/bpf_iter_test_kern4.c | 4 ++-- tools/testing/selftests/bpf/progs/kfree_skb.c | 4 ++-- tools/testing/selftests/bpf/progs/tailcall3.c | 2 +- tools/testing/selftests/bpf/progs/tailcall4.c | 2 +- tools/testing/selftests/bpf/progs/tailcall5.c | 2 +- tools/testing/selftests/bpf/progs/tailcall_bpf2bpf2.c | 2 +- tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c | 2 +- tools/testing/selftests/bpf/progs/test_check_mtu.c | 4 ++-- tools/testing/selftests/bpf/progs/test_cls_redirect.c | 4 ++-- tools/testing/selftests/bpf/progs/test_global_func_args.c | 2 +- tools/testing/selftests/bpf/progs/test_rdonly_maps.c | 6 +++--- tools/testing/selftests/bpf/progs/test_skeleton.c | 4 ++-- tools/testing/selftests/bpf/progs/test_snprintf_single.c | 2 +- tools/testing/selftests/bpf/progs/test_sockmap_listen.c | 4 ++-- tools/testing/selftests/bpf/progs/test_static_linked1.c | 8 ++++---- tools/testing/selftests/bpf/progs/test_static_linked2.c | 8 ++++---- 19 files changed, 33 insertions(+), 40 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/send_signal.c b/tools/testing/selftests/bpf/prog_tests/send_signal.c
index 7043e6ded0e6..a1eade51d440 100644
--- a/tools/testing/selftests/bpf/prog_tests/send_signal.c
+++ b/tools/testing/selftests/bpf/prog_tests/send_signal.c@@ -2,7 +2,7 @@ #include <test_progs.h> #include "test_send_signal_kern.skel.h" -static volatile int sigusr1_received = 0; +int sigusr1_received = 0; static void sigusr1_handler(int signum) {
diff --git a/tools/testing/selftests/bpf/prog_tests/skeleton.c b/tools/testing/selftests/bpf/prog_tests/skeleton.c
index fe87b77af459..f6f130c99b8c 100644
--- a/tools/testing/selftests/bpf/prog_tests/skeleton.c
+++ b/tools/testing/selftests/bpf/prog_tests/skeleton.c@@ -82,10 +82,8 @@ void test_skeleton(void) CHECK(data->out2 != 2, "res2", "got %lld != exp %d\n", data->out2, 2); CHECK(bss->out3 != 3, "res3", "got %d != exp %d\n", (int)bss->out3, 3); CHECK(bss->out4 != 4, "res4", "got %lld != exp %d\n", bss->out4, 4); - CHECK(bss->handler_out5.a != 5, "res5", "got %d != exp %d\n", - bss->handler_out5.a, 5); - CHECK(bss->handler_out5.b != 6, "res6", "got %lld != exp %d\n", - bss->handler_out5.b, 6); + CHECK(bss->out5.a != 5, "res5", "got %d != exp %d\n", bss->out5.a, 5); + CHECK(bss->out5.b != 6, "res6", "got %lld != exp %d\n", bss->out5.b, 6); CHECK(bss->out6 != 14, "res7", "got %d != exp %d\n", bss->out6, 14); CHECK(bss->bpf_syscall != kcfg->CONFIG_BPF_SYSCALL, "ext1",
diff --git a/tools/testing/selftests/bpf/prog_tests/static_linked.c b/tools/testing/selftests/bpf/prog_tests/static_linked.c
index 46556976dccc..ab6acbaf9d8c 100644
--- a/tools/testing/selftests/bpf/prog_tests/static_linked.c
+++ b/tools/testing/selftests/bpf/prog_tests/static_linked.c@@ -14,12 +14,7 @@ void test_static_linked(void) return; skel->rodata->rovar1 = 1; - skel->bss->static_var1 = 2; - skel->bss->static_var11 = 3; - skel->rodata->rovar2 = 4; - skel->bss->static_var2 = 5; - skel->bss->static_var22 = 6; err = test_static_linked__load(skel); if (!ASSERT_OK(err, "skel_load"))
diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_test_kern4.c b/tools/testing/selftests/bpf/progs/bpf_iter_test_kern4.c
index ee49493dc125..400fdf8d6233 100644
--- a/tools/testing/selftests/bpf/progs/bpf_iter_test_kern4.c
+++ b/tools/testing/selftests/bpf/progs/bpf_iter_test_kern4.c@@ -9,8 +9,8 @@ __u32 map1_id = 0, map2_id = 0; __u32 map1_accessed = 0, map2_accessed = 0; __u64 map1_seqnum = 0, map2_seqnum1 = 0, map2_seqnum2 = 0; -static volatile const __u32 print_len; -static volatile const __u32 ret1; +volatile const __u32 print_len; +volatile const __u32 ret1; SEC("iter/bpf_map") int dump_bpf_map(struct bpf_iter__bpf_map *ctx)
diff --git a/tools/testing/selftests/bpf/progs/kfree_skb.c b/tools/testing/selftests/bpf/progs/kfree_skb.c
index a46a264ce24e..55e283050cab 100644
--- a/tools/testing/selftests/bpf/progs/kfree_skb.c
+++ b/tools/testing/selftests/bpf/progs/kfree_skb.c@@ -109,10 +109,10 @@ int BPF_PROG(trace_kfree_skb, struct sk_buff *skb, void *location) return 0; } -static volatile struct { +struct { bool fentry_test_ok; bool fexit_test_ok; -} result; +} result = {}; SEC("fentry/eth_type_trans") int BPF_PROG(fentry_eth_type_trans, struct sk_buff *skb, struct net_device *dev,
diff --git a/tools/testing/selftests/bpf/progs/tailcall3.c b/tools/testing/selftests/bpf/progs/tailcall3.c
index 739dc2a51e74..910858fe078a 100644
--- a/tools/testing/selftests/bpf/progs/tailcall3.c
+++ b/tools/testing/selftests/bpf/progs/tailcall3.c@@ -10,7 +10,7 @@ struct { __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); -static volatile int count; +int count = 0; SEC("classifier/0") int bpf_func_0(struct __sk_buff *skb)
diff --git a/tools/testing/selftests/bpf/progs/tailcall4.c b/tools/testing/selftests/bpf/progs/tailcall4.c
index f82075b47d7d..bd4be135c39d 100644
--- a/tools/testing/selftests/bpf/progs/tailcall4.c
+++ b/tools/testing/selftests/bpf/progs/tailcall4.c@@ -10,7 +10,7 @@ struct { __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); -static volatile int selector; +int selector = 0; #define TAIL_FUNC(x) \ SEC("classifier/" #x) \
diff --git a/tools/testing/selftests/bpf/progs/tailcall5.c b/tools/testing/selftests/bpf/progs/tailcall5.c
index ce5450744fd4..adf30a33064e 100644
--- a/tools/testing/selftests/bpf/progs/tailcall5.c
+++ b/tools/testing/selftests/bpf/progs/tailcall5.c@@ -10,7 +10,7 @@ struct { __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); -static volatile int selector; +int selector = 0; #define TAIL_FUNC(x) \ SEC("classifier/" #x) \
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf2.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf2.c
index 7b1c04183824..3cc4c12817b5 100644
--- a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf2.c
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf2.c@@ -20,7 +20,7 @@ int subprog_tail(struct __sk_buff *skb) return 1; } -static volatile int count; +int count = 0; SEC("classifier/0") int bpf_func_0(struct __sk_buff *skb)
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c
index 9a1b166b7fbe..77df6d4db895 100644
--- a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c@@ -9,7 +9,7 @@ struct { __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); -static volatile int count; +int count = 0; __noinline int subprog_tail_2(struct __sk_buff *skb)
diff --git a/tools/testing/selftests/bpf/progs/test_check_mtu.c b/tools/testing/selftests/bpf/progs/test_check_mtu.c
index c4a9bae96e75..71184af57749 100644
--- a/tools/testing/selftests/bpf/progs/test_check_mtu.c
+++ b/tools/testing/selftests/bpf/progs/test_check_mtu.c@@ -11,8 +11,8 @@ char _license[] SEC("license") = "GPL"; /* Userspace will update with MTU it can see on device */ -static volatile const int GLOBAL_USER_MTU; -static volatile const __u32 GLOBAL_USER_IFINDEX; +volatile const int GLOBAL_USER_MTU; +volatile const __u32 GLOBAL_USER_IFINDEX; /* BPF-prog will update these with MTU values it can see */ __u32 global_bpf_mtu_xdp = 0;
diff --git a/tools/testing/selftests/bpf/progs/test_cls_redirect.c b/tools/testing/selftests/bpf/progs/test_cls_redirect.c
index 3c1e042962e6..e2a5acc4785c 100644
--- a/tools/testing/selftests/bpf/progs/test_cls_redirect.c
+++ b/tools/testing/selftests/bpf/progs/test_cls_redirect.c@@ -39,8 +39,8 @@ char _license[] SEC("license") = "Dual BSD/GPL"; /** * Destination port and IP used for UDP encapsulation. */ -static volatile const __be16 ENCAPSULATION_PORT; -static volatile const __be32 ENCAPSULATION_IP; +volatile const __be16 ENCAPSULATION_PORT; +volatile const __be32 ENCAPSULATION_IP; typedef struct { uint64_t processed_packets_total;
diff --git a/tools/testing/selftests/bpf/progs/test_global_func_args.c b/tools/testing/selftests/bpf/progs/test_global_func_args.c
index cae309538a9e..e712bf77daae 100644
--- a/tools/testing/selftests/bpf/progs/test_global_func_args.c
+++ b/tools/testing/selftests/bpf/progs/test_global_func_args.c@@ -8,7 +8,7 @@ struct S { int v; }; -static volatile struct S global_variable; +struct S global_variable = {}; struct { __uint(type, BPF_MAP_TYPE_ARRAY);
diff --git a/tools/testing/selftests/bpf/progs/test_rdonly_maps.c b/tools/testing/selftests/bpf/progs/test_rdonly_maps.c
index ecbeea2df259..fc8e8a34a3db 100644
--- a/tools/testing/selftests/bpf/progs/test_rdonly_maps.c
+++ b/tools/testing/selftests/bpf/progs/test_rdonly_maps.c@@ -5,7 +5,7 @@ #include <linux/bpf.h> #include <bpf/bpf_helpers.h> -static volatile const struct { +const struct { unsigned a[4]; /* * if the struct's size is multiple of 16, compiler will put it into
@@ -15,11 +15,11 @@ static volatile const struct { char _y; } rdonly_values = { .a = {2, 3, 4, 5} }; -static volatile struct { +struct { unsigned did_run; unsigned iters; unsigned sum; -} res; +} res = {}; SEC("raw_tracepoint/sys_enter:skip_loop") int skip_loop(struct pt_regs *ctx)
diff --git a/tools/testing/selftests/bpf/progs/test_skeleton.c b/tools/testing/selftests/bpf/progs/test_skeleton.c
index 374ccef704e1..441fa1c552c8 100644
--- a/tools/testing/selftests/bpf/progs/test_skeleton.c
+++ b/tools/testing/selftests/bpf/progs/test_skeleton.c@@ -38,11 +38,11 @@ extern int LINUX_KERNEL_VERSION __kconfig; bool bpf_syscall = 0; int kern_ver = 0; +struct s out5 = {}; + SEC("raw_tp/sys_enter") int handler(const void *ctx) { - static volatile struct s out5; - out1 = in1; out2 = in2; out3 = in3;
diff --git a/tools/testing/selftests/bpf/progs/test_snprintf_single.c b/tools/testing/selftests/bpf/progs/test_snprintf_single.c
index 402adaf344f9..3095837334d3 100644
--- a/tools/testing/selftests/bpf/progs/test_snprintf_single.c
+++ b/tools/testing/selftests/bpf/progs/test_snprintf_single.c@@ -5,7 +5,7 @@ #include <bpf/bpf_helpers.h> /* The format string is filled from the userspace such that loading fails */ -static const char fmt[10]; +const char fmt[10]; SEC("raw_tp/sys_enter") int handler(const void *ctx)
diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_listen.c b/tools/testing/selftests/bpf/progs/test_sockmap_listen.c
index a39eba9f5201..a1cc58b10c7c 100644
--- a/tools/testing/selftests/bpf/progs/test_sockmap_listen.c
+++ b/tools/testing/selftests/bpf/progs/test_sockmap_listen.c@@ -28,8 +28,8 @@ struct { __type(value, unsigned int); } verdict_map SEC(".maps"); -static volatile bool test_sockmap; /* toggled by user-space */ -static volatile bool test_ingress; /* toggled by user-space */ +bool test_sockmap = false; /* toggled by user-space */ +bool test_ingress = false; /* toggled by user-space */ SEC("sk_skb/stream_parser") int prog_stream_parser(struct __sk_buff *skb)
diff --git a/tools/testing/selftests/bpf/progs/test_static_linked1.c b/tools/testing/selftests/bpf/progs/test_static_linked1.c
index ea1a6c4c7172..cae304045d9c 100644
--- a/tools/testing/selftests/bpf/progs/test_static_linked1.c
+++ b/tools/testing/selftests/bpf/progs/test_static_linked1.c@@ -4,9 +4,9 @@ #include <linux/bpf.h> #include <bpf/bpf_helpers.h> -/* 8-byte aligned .bss */ -static volatile long static_var1; -static volatile int static_var11; +/* 8-byte aligned .data */ +static volatile long static_var1 = 2; +static volatile int static_var2 = 3; int var1 = 0; /* 4-byte aligned .rodata */ const volatile int rovar1;
@@ -21,7 +21,7 @@ static __noinline int subprog(int x) SEC("raw_tp/sys_enter") int handler1(const void *ctx) { - var1 = subprog(rovar1) + static_var1 + static_var11; + var1 = subprog(rovar1) + static_var1 + static_var2; return 0; }
diff --git a/tools/testing/selftests/bpf/progs/test_static_linked2.c b/tools/testing/selftests/bpf/progs/test_static_linked2.c
index 54d8d1ab577c..c54c4e865ed8 100644
--- a/tools/testing/selftests/bpf/progs/test_static_linked2.c
+++ b/tools/testing/selftests/bpf/progs/test_static_linked2.c@@ -4,9 +4,9 @@ #include <linux/bpf.h> #include <bpf/bpf_helpers.h> -/* 4-byte aligned .bss */ -static volatile int static_var2; -static volatile int static_var22; +/* 4-byte aligned .data */ +static volatile int static_var1 = 5; +static volatile int static_var2 = 6; int var2 = 0; /* 8-byte aligned .rodata */ const volatile long rovar2;
@@ -21,7 +21,7 @@ static __noinline int subprog(int x) SEC("raw_tp/sys_enter") int handler2(const void *ctx) { - var2 = subprog(rovar2) + static_var2 + static_var22; + var2 = subprog(rovar2) + static_var1 + static_var2; return 0; }
--
2.30.2