kernel/tools/testing/selftests/bpf/progs/test_snprintf.c, branch linux-6.2.y

selftest/bpf: Extend the bpf_snprintf() test for "%c".

2021-08-15T07:19:10Z

This patch adds various "positive" patterns for "%c" and two "negative" patterns for wide character. Signed-off-by: Kuniyuki Iwashima Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210814015718.42704-5-kuniyu@amazon.co.jp

libbpf: Move BPF_SEQ_PRINTF and BPF_SNPRINTF to bpf_helpers.h

2021-05-26T17:45:41Z

These macros are convenient wrappers around the bpf_seq_printf and bpf_snprintf helpers. They are currently provided by bpf_tracing.h which targets low level tracing primitives. bpf_helpers.h is a better fit. The __bpf_narg and __bpf_apply are needed in both files and provided twice. __bpf_empty isn't used anywhere and is removed from bpf_tracing.h Reported-by: Andrii Nakryiko Signed-off-by: Florent Revest Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210526164643.2881368-1-revest@chromium.org

selftests/bpf: Fix the snprintf test

2021-04-30T17:36:59Z

The BPF program for the snprintf selftest runs on all syscall entries. On busy multicore systems this can cause concurrency issues. For example it was observed that sometimes the userspace part of the test reads " 4 0000" instead of " 4 000" (extra '0' at the end) which seems to happen just before snprintf on another core sets end[-1] = '\0'. This patch adds a pid filter to the test to ensure that no bpf_snprintf() will write over the test's output buffers while the userspace reads the values. Fixes: c2e39c6bdc7e ("selftests/bpf: Add a series of tests for bpf_snprintf") Reported-by: Andrii Nakryiko Signed-off-by: Florent Revest Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210428152501.1024509-1-revest@chromium.org

selftests/bpf: Add a series of tests for bpf_snprintf

2021-04-19T22:27:37Z

The "positive" part tests all format specifiers when things go well. The "negative" part makes sure that incorrect format strings fail at load time. Signed-off-by: Florent Revest Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20210419155243.1632274-7-revest@chromium.org