This exercises most of the format specifiers when things go well.
Signed-off-by: Florent Revest <[email protected]>
---
.../selftests/bpf/prog_tests/snprintf.c | 65 +++++++++++++++++++
.../selftests/bpf/progs/test_snprintf.c | 59 +++++++++++++++++
2 files changed, 124 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/snprintf.c
create mode 100644 tools/testing/selftests/bpf/progs/test_snprintf.c
diff --git a/tools/testing/selftests/bpf/prog_tests/snprintf.c b/tools/testing/selftests/bpf/prog_tests/snprintf.c
new file mode 100644
index 000000000000..948a05e6b2cb
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/snprintf.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Google LLC. */
+
+#include <test_progs.h>
+#include "test_snprintf.skel.h"
+
+#define EXP_NUM_OUT "-8 9 96 -424242 1337 DABBAD00"
+#define EXP_NUM_RET sizeof(EXP_NUM_OUT)
+
+#define EXP_IP_OUT "127.000.000.001 0000:0000:0000:0000:0000:0000:0000:0001"
+#define EXP_IP_RET sizeof(EXP_IP_OUT)
+
+/* The third specifier, %pB, depends on compiler inlining so don't check it */
+#define EXP_SYM_OUT "schedule schedule+0x0/"
+#define MIN_SYM_RET sizeof(EXP_SYM_OUT)
+
+/* The third specifier, %p, is a hashed pointer which changes on every reboot */
+#define EXP_ADDR_OUT "0000000000000000 ffff00000add4e55 "
+#define EXP_ADDR_RET sizeof(EXP_ADDR_OUT "unknownhashedptr")
+
+#define EXP_STR_OUT "str1 longstr"
+#define EXP_STR_RET sizeof(EXP_STR_OUT)
+
+#define EXP_OVER_OUT "%over"
+#define EXP_OVER_RET 10
+
+void test_snprintf(void)
+{
+ char exp_addr_out[] = EXP_ADDR_OUT;
+ char exp_sym_out[] = EXP_SYM_OUT;
+ struct test_snprintf *skel;
+
+ skel = test_snprintf__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel_open"))
+ return;
+
+ if (!ASSERT_OK(test_snprintf__attach(skel), "skel_attach"))
+ goto cleanup;
+
+ /* trigger tracepoint */
+ usleep(1);
+
+ ASSERT_STREQ(skel->bss->num_out, EXP_NUM_OUT, "num_out");
+ ASSERT_EQ(skel->bss->num_ret, EXP_NUM_RET, "num_ret");
+
+ ASSERT_STREQ(skel->bss->ip_out, EXP_IP_OUT, "ip_out");
+ ASSERT_EQ(skel->bss->ip_ret, EXP_IP_RET, "ip_ret");
+
+ ASSERT_OK(memcmp(skel->bss->sym_out, exp_sym_out,
+ sizeof(exp_sym_out) - 1), "sym_out");
+ ASSERT_LT(MIN_SYM_RET, skel->bss->sym_ret, "sym_ret");
+
+ ASSERT_OK(memcmp(skel->bss->addr_out, exp_addr_out,
+ sizeof(exp_addr_out) - 1), "addr_out");
+ ASSERT_EQ(skel->bss->addr_ret, EXP_ADDR_RET, "addr_ret");
+
+ ASSERT_STREQ(skel->bss->str_out, EXP_STR_OUT, "str_out");
+ ASSERT_EQ(skel->bss->str_ret, EXP_STR_RET, "str_ret");
+
+ ASSERT_STREQ(skel->bss->over_out, EXP_OVER_OUT, "over_out");
+ ASSERT_EQ(skel->bss->over_ret, EXP_OVER_RET, "over_ret");
+
+cleanup:
+ test_snprintf__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_snprintf.c b/tools/testing/selftests/bpf/progs/test_snprintf.c
new file mode 100644
index 000000000000..e18709055fad
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_snprintf.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Google LLC. */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_endian.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char num_out[64] = {};
+long num_ret = 0;
+
+char ip_out[64] = {};
+long ip_ret = 0;
+
+char sym_out[64] = {};
+long sym_ret = 0;
+
+char addr_out[64] = {};
+long addr_ret = 0;
+
+char str_out[64] = {};
+long str_ret = 0;
+
+char over_out[6] = {};
+long over_ret = 0;
+
+SEC("raw_tp/sys_enter")
+int handler(const void *ctx)
+{
+ /* Convenient values to pretty-print */
+ const __u8 ex_ipv4[] = {127, 0, 0, 1};
+ const __u8 ex_ipv6[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
+ const char str1[] = "str1";
+ const char longstr[] = "longstr";
+ extern const void schedule __ksym;
+
+ /* Integer types */
+ num_ret = BPF_SNPRINTF(num_out, sizeof(num_out),
+ "%d %u %x %li %llu %lX",
+ -8, 9, 150, -424242, 1337, 0xDABBAD00);
+ /* IP addresses */
+ ip_ret = BPF_SNPRINTF(ip_out, sizeof(ip_out), "%pi4 %pI6",
+ &ex_ipv4, &ex_ipv6);
+ /* Symbol lookup formatting */
+ sym_ret = BPF_SNPRINTF(sym_out, sizeof(sym_out), "%ps %pS %pB",
+ &schedule, &schedule, &schedule);
+ /* Kernel pointers */
+ addr_ret = BPF_SNPRINTF(addr_out, sizeof(addr_out), "%pK %px %p",
+ 0, 0xFFFF00000ADD4E55, 0xFFFF00000ADD4E55);
+ /* Strings embedding */
+ str_ret = BPF_SNPRINTF(str_out, sizeof(str_out), "%s %+05s",
+ str1, longstr);
+ /* Overflow */
+ over_ret = BPF_SNPRINTF(over_out, sizeof(over_out), "%%overflow");
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.31.0.291.g576ba9dcdaf-goog
On Tue, Mar 23, 2021 at 7:23 PM Florent Revest <[email protected]> wrote:
>
> This exercises most of the format specifiers when things go well.
>
> Signed-off-by: Florent Revest <[email protected]>
> ---
Looks good. Please add a no-argument test case as well.
Acked-by: Andrii Nakryiko <[email protected]>
> .../selftests/bpf/prog_tests/snprintf.c | 65 +++++++++++++++++++
> .../selftests/bpf/progs/test_snprintf.c | 59 +++++++++++++++++
> 2 files changed, 124 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/snprintf.c
> create mode 100644 tools/testing/selftests/bpf/progs/test_snprintf.c
>
[...]
> +
> +SEC("raw_tp/sys_enter")
> +int handler(const void *ctx)
> +{
> + /* Convenient values to pretty-print */
> + const __u8 ex_ipv4[] = {127, 0, 0, 1};
> + const __u8 ex_ipv6[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
> + const char str1[] = "str1";
> + const char longstr[] = "longstr";
> + extern const void schedule __ksym;
oh, fancy. I'd move it out of this function into global space, though,
to make it more apparent. I almost missed that it's a special one.
> +
> + /* Integer types */
> + num_ret = BPF_SNPRINTF(num_out, sizeof(num_out),
> + "%d %u %x %li %llu %lX",
> + -8, 9, 150, -424242, 1337, 0xDABBAD00);
> + /* IP addresses */
> + ip_ret = BPF_SNPRINTF(ip_out, sizeof(ip_out), "%pi4 %pI6",
> + &ex_ipv4, &ex_ipv6);
> + /* Symbol lookup formatting */
> + sym_ret = BPF_SNPRINTF(sym_out, sizeof(sym_out), "%ps %pS %pB",
> + &schedule, &schedule, &schedule);
> + /* Kernel pointers */
> + addr_ret = BPF_SNPRINTF(addr_out, sizeof(addr_out), "%pK %px %p",
> + 0, 0xFFFF00000ADD4E55, 0xFFFF00000ADD4E55);
> + /* Strings embedding */
> + str_ret = BPF_SNPRINTF(str_out, sizeof(str_out), "%s %+05s",
> + str1, longstr);
> + /* Overflow */
> + over_ret = BPF_SNPRINTF(over_out, sizeof(over_out), "%%overflow");
> +
> + return 0;
> +}
> +
> +char _license[] SEC("license") = "GPL";
> --
> 2.31.0.291.g576ba9dcdaf-goog
>
On Sat, Mar 27, 2021 at 12:05 AM Andrii Nakryiko
<[email protected]> wrote:
>
> On Tue, Mar 23, 2021 at 7:23 PM Florent Revest <[email protected]> wrote:
> >
> > This exercises most of the format specifiers when things go well.
> >
> > Signed-off-by: Florent Revest <[email protected]>
> > ---
>
> Looks good. Please add a no-argument test case as well.
Agreed
> Acked-by: Andrii Nakryiko <[email protected]>
>
> > .../selftests/bpf/prog_tests/snprintf.c | 65 +++++++++++++++++++
> > .../selftests/bpf/progs/test_snprintf.c | 59 +++++++++++++++++
> > 2 files changed, 124 insertions(+)
> > create mode 100644 tools/testing/selftests/bpf/prog_tests/snprintf.c
> > create mode 100644 tools/testing/selftests/bpf/progs/test_snprintf.c
> >
>
> [...]
>
> > +
> > +SEC("raw_tp/sys_enter")
> > +int handler(const void *ctx)
> > +{
> > + /* Convenient values to pretty-print */
> > + const __u8 ex_ipv4[] = {127, 0, 0, 1};
> > + const __u8 ex_ipv6[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
> > + const char str1[] = "str1";
> > + const char longstr[] = "longstr";
> > + extern const void schedule __ksym;
>
> oh, fancy. I'd move it out of this function into global space, though,
> to make it more apparent. I almost missed that it's a special one.
Just schedule? Alright.