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| author | Yihan Ding <dingyihan@uniontech.com> | 2026-04-16 20:01:41 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-04-16 15:53:32 -0700 |
| commit | b960430ea8862ef37ce53c8bf74a8dc79d3f2404 (patch) | |
| tree | 4a590bcf0ca967d54d750615f96f3f49f62aa846 /tools | |
| parent | 766bf026d0da242a329b402c436c8e4cfa2008d8 (diff) | |
| download | lwn-b960430ea8862ef37ce53c8bf74a8dc79d3f2404.tar.gz lwn-b960430ea8862ef37ce53c8bf74a8dc79d3f2404.zip | |
bpf: allow UTF-8 literals in bpf_bprintf_prepare()
bpf_bprintf_prepare() only needs ASCII parsing for conversion
specifiers. Plain text can safely carry bytes >= 0x80, so allow
UTF-8 literals outside '%' sequences while keeping ASCII control
bytes rejected and format specifiers ASCII-only.
This keeps existing parsing rules for format directives unchanged,
while allowing helpers such as bpf_trace_printk() to emit UTF-8
literal text.
Update test_snprintf_negative() in the same commit so selftests keep
matching the new plain-text vs format-specifier split during bisection.
Fixes: 48cac3f4a96d ("bpf: Implement formatted output helpers with bstr_printf")
Signed-off-by: Yihan Ding <dingyihan@uniontech.com>
Acked-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/20260416120142.1420646-2-dingyihan@uniontech.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/snprintf.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/snprintf.c b/tools/testing/selftests/bpf/prog_tests/snprintf.c index 594441acb707..4e4a82d54f79 100644 --- a/tools/testing/selftests/bpf/prog_tests/snprintf.c +++ b/tools/testing/selftests/bpf/prog_tests/snprintf.c @@ -114,7 +114,8 @@ static void test_snprintf_negative(void) ASSERT_ERR(load_single_snprintf("%--------"), "invalid specifier 5"); ASSERT_ERR(load_single_snprintf("%lc"), "invalid specifier 6"); ASSERT_ERR(load_single_snprintf("%llc"), "invalid specifier 7"); - ASSERT_ERR(load_single_snprintf("\x80"), "non ascii character"); + ASSERT_OK(load_single_snprintf("\x80"), "non ascii plain text"); + ASSERT_ERR(load_single_snprintf("%\x80"), "non ascii in specifier"); ASSERT_ERR(load_single_snprintf("\x1"), "non printable character"); ASSERT_ERR(load_single_snprintf("%p%"), "invalid specifier 8"); ASSERT_ERR(load_single_snprintf("%s%"), "invalid specifier 9"); |