Commit 4198ff31 authored by Yihan Ding's avatar Yihan Ding Committed by Alexei Starovoitov
Browse files

selftests/bpf: cover UTF-8 trace_printk output 



Extend trace_printk coverage to verify that UTF-8 literal text is
emitted successfully and that '%' parsing still rejects non-ASCII
bytes once format parsing starts.

Use an explicitly invalid format string for the negative case so the
ASCII-only parser expectation is visible from the test code itself.

Signed-off-by: default avatarYihan Ding <dingyihan@uniontech.com>
Acked-by: default avatarPaul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/20260416120142.1420646-3-dingyihan@uniontech.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent b960430e

tools/testing/selftests/bpf/prog_tests/trace_printk.c

+22 −6
Original line number Diff line number Diff line
@@ -6,18 +6,21 @@ 
#include "trace_printk.lskel.h"



#define SEARCHMSG	"testing,testing"

#define SEARCHMSG_UTF8	"中文,测试"



static void trace_pipe_cb(const char *str, void *data)

{

	if (strstr(str, SEARCHMSG) != NULL)

		(*(int *)data)++;

		((int *)data)[0]++;

	if (strstr(str, SEARCHMSG_UTF8))

		((int *)data)[1]++;

}



void serial_test_trace_printk(void)

{

	struct trace_printk_lskel__bss *bss;

	struct trace_printk_lskel *skel;

	int err = 0, found = 0;

	int err = 0, found[2] = {};



	skel = trace_printk_lskel__open();

	if (!ASSERT_OK_PTR(skel, "trace_printk__open"))
@@ -46,11 +49,24 @@ void serial_test_trace_printk(void) 
	if (!ASSERT_GT(bss->trace_printk_ret, 0, "bss->trace_printk_ret"))

		goto cleanup;



	/* verify our search string is in the trace buffer */

	ASSERT_OK(read_trace_pipe_iter(trace_pipe_cb, &found, 1000),

	if (!ASSERT_GT(bss->trace_printk_utf8_ran, 0, "bss->trace_printk_utf8_ran"))

		goto cleanup;



	if (!ASSERT_GT(bss->trace_printk_utf8_ret, 0, "bss->trace_printk_utf8_ret"))

		goto cleanup;



	if (!ASSERT_LT(bss->trace_printk_invalid_spec_ret, 0,

		       "bss->trace_printk_invalid_spec_ret"))

		goto cleanup;



	/* verify our search strings are in the trace buffer */

	ASSERT_OK(read_trace_pipe_iter(trace_pipe_cb, found, 1000),

		  "read_trace_pipe_iter");



	if (!ASSERT_EQ(found, bss->trace_printk_ran, "found"))

	if (!ASSERT_EQ(found[0], bss->trace_printk_ran, "found"))

		goto cleanup;



	if (!ASSERT_EQ(found[1], bss->trace_printk_utf8_ran, "found_utf8"))

		goto cleanup;



cleanup:

tools/testing/selftests/bpf/progs/trace_printk.c

+10 −0
Original line number Diff line number Diff line
@@ -10,13 +10,23 @@ char _license[] SEC("license") = "GPL"; 


int trace_printk_ret = 0;

int trace_printk_ran = 0;

int trace_printk_invalid_spec_ret = 0;

int trace_printk_utf8_ret = 0;

int trace_printk_utf8_ran = 0;



const char fmt[] = "Testing,testing %d\n";

static const char utf8_fmt[] = "中文,测试 %d\n";

/* Non-ASCII bytes after '%' must still be rejected. */

static const char invalid_spec_fmt[] = "%\x80\n";



SEC("fentry/" SYS_PREFIX "sys_nanosleep")

int sys_enter(void *ctx)

{

	trace_printk_ret = bpf_trace_printk(fmt, sizeof(fmt),

					    ++trace_printk_ran);

	trace_printk_utf8_ret = bpf_trace_printk(utf8_fmt, sizeof(utf8_fmt),

						 ++trace_printk_utf8_ran);

	trace_printk_invalid_spec_ret = bpf_trace_printk(invalid_spec_fmt,

							 sizeof(invalid_spec_fmt));

	return 0;

}