Re: [PATCH] tools: Use fputc() calls in some functions
From: bot+bpf-ci@kernel.org
Date: 2026-07-23 15:07:32
Also in:
bpf, kernel-janitors, kvm, linux-acpi, linux-gpio, linux-kselftest, linux-mm, linux-perf-users, linux-pm, linux-trace-kernel, lkml, mptcp, netdev, platform-driver-x86, virtualization
quoted hunk ↗ jump to hunk
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c@@ -53,7 +53,7 @@ void p_err(const char *fmt, ...) } else { fprintf(stderr, "Error: "); vfprintf(stderr, fmt, ap); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
^^^^^^
The fputc() arguments are reversed. The C standard signature is
`int fputc(int c, FILE *stream)` - the character comes first, the stream
second. This passes the FILE* stderr as the int c parameter and '\n' as
the FILE* stream parameter.
Correct form is `fputc('\n', stderr)`.
This constraint violation triggers a -Werror=int-conversion diagnostic and
breaks the build. If it compiled, at runtime fputc would dereference
(FILE*)10, crashing the program.
The same argument reversal occurs in 67 conversions across this patch.
quoted hunk ↗ jump to hunk
@@ -67,7 +67,7 @@ void p_info(const char *fmt, ...) va_start(ap, fmt); vfprintf(stderr, fmt, ap); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
^^^^^^ Same reversed-argument bug.
quoted hunk ↗ jump to hunk
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c@@ -273,7 +273,7 @@ void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep) if (!i) /* nothing */; else if (!(i % 16)) - fprintf(f, "\n"); + fputc(f, '\n');
Arguments reversed: `fputc(f, '\n')` should be `fputc('\n', f)`.
quoted hunk ↗ jump to hunk
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c@@ -1266,7 +1266,7 @@ static void hex_print(void *data, unsigned int size, FILE *f) fprintf(f, "%c%s", c, j == i + 7 ? " " : ""); } - fprintf(f, "\n"); + fputc(f, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/include/nolibc/err.h b/tools/include/nolibc/err.h --- a/tools/include/nolibc/err.h +++ b/tools/include/nolibc/err.h@@ -27,7 +27,7 @@ void vwarnx(const char *fmt, va_list args) { fprintf(stderr, "%s: ", program_invocation_short_name); vfprintf(stderr, fmt, args); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed. This is in a nolibc header - nolibc's fputc (tools/include/nolibc/stdio.h) does `write(fileno(stream), &ch, 1)`. With stream==(FILE*)10 fileno dereferences a bogus pointer and crashes.
quoted hunk ↗ jump to hunk
diff --git a/tools/mm/page_owner_sort.c b/tools/mm/page_owner_sort.c --- a/tools/mm/page_owner_sort.c +++ b/tools/mm/page_owner_sort.c@@ -867,7 +867,7 @@ struct option longopts[] = { } if (cull & CULL_STACKTRACE) fprintf(fout, ":\n%s", list[i].stacktrace); - fprintf(fout, "\n"); + fputc(fout, '\n');
Arguments reversed: should be `fputc('\n', fout)`.
quoted hunk ↗ jump to hunk
diff --git a/tools/net/ynl/ynltool/main.c b/tools/net/ynl/ynltool/main.c --- a/tools/net/ynl/ynltool/main.c +++ b/tools/net/ynl/ynltool/main.c@@ -156,7 +156,7 @@ void p_err(const char *fmt, ...) } else { fprintf(stderr, "Error: "); vfprintf(stderr, fmt, ap); - fprintf(stderr, "\n"); + fputc(stderr, '\n'); } va_end(ap); }@@ -170,7 +170,7 @@ void p_info(const char *fmt, ...) va_start(ap, fmt); vfprintf(stderr, fmt, ap); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Both conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c@@ -297,7 +297,7 @@ int make_backup(void) fprintf(stderr, " %s", arg); } - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed. objtool runs during the kernel build, so a build failure or crash here breaks the build.
quoted hunk ↗ jump to hunk
diff --git a/tools/objtool/disas.c b/tools/objtool/disas.c --- a/tools/objtool/disas.c +++ b/tools/objtool/disas.c@@ -537,7 +537,7 @@ void disas_print_insn(FILE *stream, struct disas_context *dctx, return; if (strcmp(format, "\n") == 0) { - fprintf(stream, "\n"); + fputc(stream, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c --- a/tools/perf/builtin-c2c.c +++ b/tools/perf/builtin-c2c.c@@ -2511,7 +2511,7 @@ struct perf_hpp hpp = { hists__fprintf_headers(&c2c_hists->hists, out); once = true; } else { - fprintf(out, "\n"); + fputc(out, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -2590,15 +2590,15 @@ static void perf_c2c__hists_fprintf(FILE *out, struct perf_session *session) setup_pager(); print_c2c__display_stats(out); - fprintf(out, "\n"); + fputc(out, '\n'); print_shared_cacheline_info(out); - fprintf(out, "\n"); + fputc(out, '\n'); print_c2c_info(out, session); if (c2c.stats_only) return; - fprintf(out, "\n"); + fputc(out, '\n');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -2606,7 +2606,7 @@ static void perf_c2c__hists_fprintf(FILE *out, struct perf_session *session) hists__fprintf(&c2c.hists.hists, true, 0, 0, 0, stdout, true); - fprintf(out, "\n"); + fputc(out, '\n');
All four conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c --- a/tools/perf/builtin-daemon.c +++ b/tools/perf/builtin-daemon.c@@ -691,7 +691,7 @@ static int cmd_session_list(struct daemon *daemon, union cmd *cmd, FILE *out) /* session up time */ csv_sep, (uint64_t)((curr - daemon->start) / 60)); - fprintf(out, "\n"); + fputc(out, '\n'); } else {
[ ... ]
quoted hunk ↗ jump to hunk
@@ -730,7 +730,7 @@ /* session up time */ csv_sep, (uint64_t)((curr - session->start) / 60)); - fprintf(out, "\n"); + fputc(out, '\n');
Both conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c@@ -1319,9 +1319,9 @@ static void print_result(void) list_for_each_entry(key, &lock_keys, list) { key->print(key, st); - fprintf(lock_output, " "); + fputc(lock_output, ' '); } - fprintf(lock_output, "\n"); + fputc(lock_output, '\n');
Both `fputc(lock_output, ' ')` and `fputc(lock_output, '\n')` reverse the
arguments. Correct form: `fputc(' ', lock_output)` and
`fputc('\n', lock_output)`.
quoted hunk ↗ jump to hunk
@@ -1598,7 +1598,7 @@ static void print_header_csv(const char *sep) fprintf(lock_output, "%s%s %s", "type", sep, "caller"); if (verbose > 0) fprintf(lock_output, "%s %s", sep, "stacktrace"); - fprintf(lock_output, "\n"); + fputc(lock_output, '\n');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -1629,7 +1629,7 @@ static void print_lock_stat_stdio(struct lock_contention *con, struct lock_stat *st) list_for_each_entry(key, &lock_keys, list) { key->print(key, st); - fprintf(lock_output, " "); + fputc(lock_output, ' '); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -1687,7 +1687,7 @@ static void print_lock_stat_csv(struct lock_contention *con, struct lock_stat *st, case LOCK_AGGR_CALLER: fprintf(lock_output, "%s%s %s", get_type_flags_name(st->flags), sep, st->name); if (verbose <= 0) - fprintf(lock_output, "\n"); + fputc(lock_output, '\n');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -1721,7 +1721,7 @@ static void print_lock_stat_csv(struct lock_contention *con, struct lock_stat *st, get_symbol_name_offset(kmap, sym, ip, buf, sizeof(buf)); fprintf(lock_output, "%s %#lx %s", i ? ":" : sep, (unsigned long) ip, buf); } - fprintf(lock_output, "\n"); + fputc(lock_output, '\n'); } }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -1781,7 +1781,7 @@ static void print_footer_csv(int total, int bad, struct lock_contention_fails *fails, for (i = 0; i < BROKEN_MAX; i++) fprintf(lock_output, "%s bad_%s=%d", sep, name[i], bad_hist[i]); } - fprintf(lock_output, "\n"); + fputc(lock_output, '\n');
All six conversions in builtin-lock.c reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c@@ -2561,7 +2561,7 @@ perf_sample__fprintf_ipc(sample, evsel, fp); - fprintf(fp, "\n"); + fputc(fp, '\n');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -2815,7 +2815,7 @@ cursor, symbol_conf.bt_stop_list, fp); } - fprintf(fp, "\n"); + fputc(fp, '\n');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -3271,11 +3271,11 @@ static int list_available_languages_cb(struct scripting_ops *ops, const char *spec) static void list_available_languages(void) { - fprintf(stderr, "\n"); + fputc(stderr, '\n'); fprintf(stderr, "Scripting language extensions (used in " "perf script -s [spec:]script.[spec]):\n\n"); script_spec__for_each(&list_available_languages_cb); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
All four conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/ui/gtk/util.c b/tools/perf/ui/gtk/util.c --- a/tools/perf/ui/gtk/util.c +++ b/tools/perf/ui/gtk/util.c@@ -37,7 +37,7 @@ static int perf_gtk__error(const char *format, va_list args) vasprintf(&msg, format, args) < 0) { fprintf(stderr, "Error:\n"); vfprintf(stderr, format, args); - fprintf(stderr, "\n"); + fputc(stderr, '\n'); return -1; }@@ -62,7 +62,7 @@ static int perf_gtk__warning_info_bar(const char *format, va_list args) vasprintf(&msg, format, args) < 0) { fprintf(stderr, "Warning:\n"); vfprintf(stderr, format, args); - fprintf(stderr, "\n"); + fputc(stderr, '\n'); return -1; }@@ -83,7 +83,7 @@ static int perf_gtk__warning_statusbar(const char *format, va_list args) vasprintf(&msg, format, args) < 0) { fprintf(stderr, "Warning:\n"); vfprintf(stderr, format, args); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
All three conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c --- a/tools/perf/ui/stdio/hist.c +++ b/tools/perf/ui/stdio/hist.c@@ -691,7 +691,7 @@ } next_line: - fprintf(fp, "\n"); + fputc(fp, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -783,7 +783,7 @@ hists__fprintf_standard_headers(struct hists *hists, if (line) fprintf(fp, "# "); fprintf_line(hists, hpp, line, fp); - fprintf(fp, "\n"); + fputc(fp, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -806,10 +806,10 @@ hists__fprintf_standard_headers(struct hists *hists, width = fmt->width(fmt, hpp, hists); for (i = 0; i < width; i++) - fprintf(fp, "."); + fputc(fp, '.'); } - fprintf(fp, "\n"); + fputc(fp, '\n');
All four conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c --- a/tools/perf/util/debug.c +++ b/tools/perf/util/debug.c@@ -350,7 +350,7 @@ void __dump_stack(FILE *file, void **stackdump, size_t stackdump_size) fprintf(file, " #%zd %p ", i, stackdump[i]); map__fprintf_srcline(al.map, al.addr, "", file); - fprintf(file, "\n"); + fputc(file, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c@@ -2454,7 +2454,7 @@ static void __print_pmu_caps(FILE *fp, int nr_caps, char **caps, char *pmu_name) delimiter = ", "; } - fprintf(fp, "\n"); + fputc(fp, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -2513,7 +2513,7 @@ static void print_pmu_mappings(struct feat_fd *ff, FILE *fp) pmu_num--; } - fprintf(fp, "\n"); + fputc(fp, '\n');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -4349,7 +4349,7 @@ int perf_header__fprintf_info(struct perf_session *session, FILE *fp, bool full) fprintf(fp, "%s ", feat_ops[bit].name); } - fprintf(fp, "\n"); + fputc(fp, '\n');
All three conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-log.c b/tools/perf/util/intel-pt-decoder/intel-pt-log.c --- a/tools/perf/util/intel-pt-decoder/intel-pt-log.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-log.c@@ -70,14 +70,14 @@ static void intel_pt_print_data(const unsigned char *buf, int len, uint64_t pos, int i; for (i = 0; i < indent; i++) - fprintf(f, " "); + fputc(f, ' '); fprintf(f, " %08" PRIx64 ": ", pos); for (i = 0; i < len; i++) fprintf(f, " %02x", buf[i]); for (; i < 16; i++) fprintf(f, " "); - fprintf(f, " "); + fputc(f, ' '); } static void intel_pt_print_no_data(uint64_t pos, int indent)@@ -85,12 +85,12 @@ static void intel_pt_print_no_data(uint64_t pos, int indent) int i; for (i = 0; i < indent; i++) - fprintf(f, " "); + fputc(f, ' '); fprintf(f, " %08" PRIx64 ": ", pos); for (i = 0; i < 16; i++) fprintf(f, " "); - fprintf(f, " "); + fputc(f, ' '); }
All four conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/util/libbfd.c b/tools/perf/util/libbfd.c --- a/tools/perf/util/libbfd.c +++ b/tools/perf/util/libbfd.c@@ -603,7 +603,7 @@ } else srcline = NULL; - fprintf(s, "\n"); + fputc(s, '\n');
Arguments reversed. The variable s is an open_memstream() stream.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c --- a/tools/perf/util/stat-display.c +++ b/tools/perf/util/stat-display.c@@ -529,7 +529,7 @@ static void print_metric_json(struct perf_stat_config *config __maybe_unused, } } if (!config->metric_only) - fprintf(out, "}"); + fputc(out, '}'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -1316,7 +1316,7 @@ static void print_header_std(struct perf_stat_config *config, FILE *output = config->output; int i; - fprintf(output, "\n"); + fputc(output, '\n'); fprintf(output, " Performance counter stats for ");
[ ... ]
quoted hunk ↗ jump to hunk
@@ -1333,7 +1333,7 @@ static void print_header_std(struct perf_stat_config *config, else fprintf(output, "thread id \'%s", _target->tid); - fprintf(output, "\'"); + fputc(output, '\'');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -1406,9 +1406,9 @@ static void print_table(struct perf_stat_config *config, FILE *output, double avg) fprintf(output, " %17.9f (%+.9f) ", run, run - avg); for (h = 0; h < n; h++) - fprintf(output, "#"); + fputc(output, '#'); - fprintf(output, "\n"); + fputc(output, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -1428,7 +1428,7 @@ static void print_footer(struct perf_stat_config *config) return; if (!config->null_run) - fprintf(output, "\n"); + fputc(output, '\n');
All six conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/perf/util/values.c b/tools/perf/util/values.c --- a/tools/perf/util/values.c +++ b/tools/perf/util/values.c@@ -217,7 +217,7 @@ static void perf_read_values__display_pretty(FILE *fp, fprintf(fp, "# %*s %*s", pidwidth, "PID", tidwidth, "TID"); for (j = 0; j < values->num_counters; j++) fprintf(fp, " %*s", counterwidth[j], evsel__name(values->counters[j])); - fprintf(fp, "\n"); + fputc(fp, '\n');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -225,7 +225,7 @@ static void perf_read_values__display_pretty(FILE *fp, for (j = 0; j < values->num_counters; j++) fprintf(fp, " %*" PRIu64, counterwidth[j], values->value[i][j]); - fprintf(fp, "\n"); + fputc(fp, '\n');
Both conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/power/acpi/tools/acpidump/apdump.c b/tools/power/acpi/tools/acpidump/apdump.c --- a/tools/power/acpi/tools/acpidump/apdump.c +++ b/tools/power/acpi/tools/acpidump/apdump.c@@ -171,7 +171,7 @@ ap_dump_table_buffer(struct acpi_table_header *table, acpi_ut_dump_buffer_to_file(gbl_output_file, ACPI_CAST_PTR(u8, table), table_length, DB_BYTE_DISPLAY, 0); - fprintf(gbl_output_file, "\n"); + fputc(gbl_output_file, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/power/x86/intel-speed-select/isst-display.c b/tools/power/x86/intel-speed-select/isst-display.c --- a/tools/power/x86/intel-speed-select/isst-display.c +++ b/tools/power/x86/intel-speed-select/isst-display.c@@ -122,7 +122,7 @@ static void format_and_print(FILE *outf, int level, char *header, char *value) if (level == 0) { if (header) - fprintf(outf, "{"); + fputc(outf, '{');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -138,7 +138,7 @@ static void format_and_print(FILE *outf, int level, char *header, char *value) if (value) { if (last_level != level) - fprintf(outf, "\n"); + fputc(outf, '\n');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -156,7 +156,7 @@ static void format_and_print(FILE *outf, int level, char *header, char *value) fprintf(outf, "\n%s}", delimiters); } if (abs(last_level - level) < 3) - fprintf(outf, "\n"); + fputc(outf, '\n');
All three conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c@@ -9099,7 +9099,7 @@ void dump_cpuid_hypervisor(void) dump_word_chars(ebx); dump_word_chars(ecx); dump_word_chars(edx); - fprintf(outf, "\n"); + fputc(outf, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -9749,7 +9749,7 @@ fprintf(outf, " siblings"); for (ht_id = 0; ht_id <= MAX_HT_ID; ++ht_id) fprintf(outf, " %d", cpus[i].ht_sibling_cpu_id[ht_id]); - fprintf(outf, "\n"); + fputc(outf, '\n');
Both conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c --- a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c +++ b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c@@ -148,7 +148,7 @@ static const struct htab_mem_use_case *htab_mem_find_use_case_or_exit(const char *name) fprintf(stderr, "available use case:"); for (i = 0; i < ARRAY_SIZE(use_cases); i++) fprintf(stderr, " %s", use_cases[i].name); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/bpf/jit_disasm_helpers.c b/tools/testing/selftests/bpf/jit_disasm_helpers.c --- a/tools/testing/selftests/bpf/jit_disasm_helpers.c +++ b/tools/testing/selftests/bpf/jit_disasm_helpers.c@@ -228,7 +228,7 @@ struct bpf_prog_info info = {}; for (pc = 0, i = 0; i < jited_funcs; ++i) { fprintf(text_out, "func #%d:\n", i); disasm_one_func(text_out, image + pc, func_lens[i]); - fprintf(text_out, "\n"); + fputc(text_out, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c@@ -383,7 +383,7 @@ static void print_test_result(const struct prog_test_def *test, const struct test_state *test_state) else fprintf(env.stdout_saved, "OK (SKIP: %d/%d)", skipped_cnt, subtests_cnt); - fprintf(env.stdout_saved, "\n"); + fputc(env.stdout_saved, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -391,7 +391,7 @@ static void print_test_log(char *log_buf, size_t log_cnt) log_buf[log_cnt] = '\0'; fprintf(env.stdout_saved, "%s", log_buf); if (log_buf[log_cnt - 1] != '\n') - fprintf(env.stdout_saved, "\n"); + fputc(env.stdout_saved, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -409,7 +409,7 @@ static void print_subtest_name(int test_num, int subtest_num, if (result) fprintf(env.stdout_saved, ":%s", result); - fprintf(env.stdout_saved, "\n"); + fputc(env.stdout_saved, '\n');
All three conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/drivers/net/hw/ncdevmem.c b/tools/testing/selftests/drivers/net/hw/ncdevmem.c --- a/tools/testing/selftests/drivers/net/hw/ncdevmem.c +++ b/tools/testing/selftests/drivers/net/hw/ncdevmem.c@@ -135,7 +135,7 @@ static void pr_err(const char *fmt, ...) if (errno != 0) fprintf(stderr, ": %s", strerror(errno)); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/kvm/s390/keyop.c b/tools/testing/selftests/kvm/s390/keyop.c --- a/tools/testing/selftests/kvm/s390/keyop.c +++ b/tools/testing/selftests/kvm/s390/keyop.c@@ -117,7 +117,7 @@ static void dump_sk(const unsigned char skeys[], const char *descr) fprintf(stderr, "# %3d: ", i); for (j = 0; j < 32; j++) fprintf(stderr, "%02x ", skeys[i + j]); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c --- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c +++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c@@ -208,7 +208,7 @@ } if (server_side) fprintf(stderr, ",server_side:1"); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/net/psock_tpacket.c b/tools/testing/selftests/net/psock_tpacket.c --- a/tools/testing/selftests/net/psock_tpacket.c +++ b/tools/testing/selftests/net/psock_tpacket.c@@ -116,7 +116,7 @@ static int pfsocket(int ver) static void status_bar_update(void) { if (total_packets % 10 == 0) { - fprintf(stderr, "."); + fputc(stderr, '.');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -825,7 +825,7 @@ static int test_tpacket(int version, int type) unmap_ring(sock, &ring); close(sock); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Both conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/net/txtimestamp.c b/tools/testing/selftests/net/txtimestamp.c --- a/tools/testing/selftests/net/txtimestamp.c +++ b/tools/testing/selftests/net/txtimestamp.c@@ -200,10 +200,10 @@ static void __print_timestamp(const char *name, struct timespec *cur, ts_delta = timespec_to_ns64(cur) - timespec_to_ns64(&ts_usr); fprintf(stderr, " (USR +"); __print_ts_delta_formatted(ts_delta); - fprintf(stderr, ")"); + fputc(stderr, ')'); } - fprintf(stderr, "\n"); + fputc(stderr, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -254,7 +254,7 @@ static void print_timing_event(char *name, struct timing_event *te) __print_ts_delta_formatted(te->min); fprintf(stderr, ", max="); __print_ts_delta_formatted(te->max); - fprintf(stderr, "\n"); + fputc(stderr, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -271,7 +271,7 @@ static void print_payload(char *data, int len) fprintf(stderr, "payload: "); for (i = 0; i < len; i++) fprintf(stderr, "%02hhx ", data[i]); - fprintf(stderr, "\n"); + fputc(stderr, '\n'); }
[ ... ]
quoted hunk ↗ jump to hunk
@@ -933,7 +933,7 @@ int main(int argc, char **argv) fprintf(stderr, "protocol: %s\n", sock_names[cfg_proto]); fprintf(stderr, "payload: %u\n", cfg_payload_len); fprintf(stderr, "server port: %u\n", dest_port); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
All four conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c b/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c --- a/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c +++ b/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c@@ -363,7 +363,7 @@ goto err3; fprintf(stderr, "%02x ", tmp[i]); if (i == 5) - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/assert.h b/tools/testing/selftests/vfio/lib/include/libvfio/assert.h --- a/tools/testing/selftests/vfio/lib/include/libvfio/assert.h +++ b/tools/testing/selftests/vfio/lib/include/libvfio/assert.h@@ -10,7 +10,7 @@ #define SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_ASSERT_H #define VFIO_LOG_AND_EXIT(...) do { \ fprintf(stderr, " " __VA_ARGS__); \ - fprintf(stderr, "\n"); \ + fputc(stderr, '\n'); \
Arguments reversed in a widely-used macro. Every expansion of this macro is broken.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/vfio/lib/libvfio.c b/tools/testing/selftests/vfio/lib/libvfio.c --- a/tools/testing/selftests/vfio/lib/libvfio.c +++ b/tools/testing/selftests/vfio/lib/libvfio.c@@ -60,16 +60,16 @@ char **vfio_selftests_get_bdfs(int *argc, char *argv[], int *nr_bdfs) } fprintf(stderr, "Unable to determine which device(s) to use, skipping test.\n"); - fprintf(stderr, "\n"); + fputc(stderr, '\n'); fprintf(stderr, "To pass the device address via environment variable:\n"); - fprintf(stderr, "\n"); + fputc(stderr, '\n'); fprintf(stderr, " export VFIO_SELFTESTS_BDF=\"segment:bus:device.function\"\n"); fprintf(stderr, " %s [options]\n", argv[0]); - fprintf(stderr, "\n"); + fputc(stderr, '\n'); fprintf(stderr, "To pass the device address(es) via argv:\n"); - fprintf(stderr, "\n"); + fputc(stderr, '\n'); fprintf(stderr, " %s [options] segment:bus:device.function ...\n", argv[0]); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
All five conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/vsock/vsock_diag_test.c b/tools/testing/vsock/vsock_diag_test.c --- a/tools/testing/vsock/vsock_diag_test.c +++ b/tools/testing/vsock/vsock_diag_test.c@@ -86,7 +86,7 @@ static void print_vsock_addr(FILE *fp, unsigned int cid, unsigned int port) fprintf(fp, "%u:", cid); if (port == VMADDR_PORT_ANY) - fprintf(fp, "*"); + fputc(fp, '*');
[ ... ]
quoted hunk ↗ jump to hunk
@@ -94,7 +94,7 @@ static void print_vsock_addr(FILE *fp, unsigned int cid, unsigned int port) static void print_vsock_stat(FILE *fp, struct vsock_stat *st) { print_vsock_addr(fp, st->msg.vdiag_src_cid, st->msg.vdiag_src_port); - fprintf(fp, " "); + fputc(fp, ' ');
Both conversions reverse the arguments.
quoted hunk ↗ jump to hunk
diff --git a/tools/thermal/tmon/sysfs.c b/tools/thermal/tmon/sysfs.c --- a/tools/thermal/tmon/sysfs.c +++ b/tools/thermal/tmon/sysfs.c@@ -522,7 +522,7 @@ int update_thermal_data() } if (tmon_log) { - fprintf(tmon_log, "\n"); + fputc(tmon_log, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/thermal/tmon/tmon.c b/tools/thermal/tmon/tmon.c --- a/tools/thermal/tmon/tmon.c +++ b/tools/thermal/tmon/tmon.c@@ -199,7 +199,7 @@ fprintf(tmon_log, "%s%d ", ptdata.cdi[i].type, ptdata.cdi[i].instance); - fprintf(tmon_log, "\n"); + fputc(tmon_log, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/tracing/latency/latency-collector.c b/tools/tracing/latency/latency-collector.c --- a/tools/tracing/latency/latency-collector.c +++ b/tools/tracing/latency/latency-collector.c@@ -1999,7 +1999,7 @@ "been enabled. Random sleep is intended for the following tracers:\n"); for (i = 0; random_tracers[i]; i++) fprintf(stderr, "%s\n", random_tracers[i]); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/tracing/rtla/src/common.c b/tools/tracing/rtla/src/common.c --- a/tools/tracing/rtla/src/common.c +++ b/tools/tracing/rtla/src/common.c@@ -449,7 +449,7 @@ void common_usage(const char *tool, const char *mode, fprintf(stderr, "%s [-h] ", mode); print_msg_array(start_msgs); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/tracing/rtla/src/utils.c b/tools/tracing/rtla/src/utils.c --- a/tools/tracing/rtla/src/utils.c +++ b/tools/tracing/rtla/src/utils.c@@ -67,7 +67,7 @@ void fatal(const char *fmt, ...) va_start(ap, fmt); vfprintf(stderr, fmt, ap); va_end(ap); - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/usb/ffs-test.c b/tools/usb/ffs-test.c --- a/tools/usb/ffs-test.c +++ b/tools/usb/ffs-test.c@@ -562,7 +562,7 @@ empty_out_buf(struct thread *ignore, const void *buf, size_t nbytes) fprintf(stderr, "%4zd:", len); fprintf(stderr, " %02x", *p); if (31 == (len % 32)) - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed.
quoted hunk ↗ jump to hunk
diff --git a/tools/verification/rv/src/in_kernel.c b/tools/verification/rv/src/in_kernel.c --- a/tools/verification/rv/src/in_kernel.c +++ b/tools/verification/rv/src/in_kernel.c@@ -667,7 +667,7 @@ static void ikm_usage_print_reactors(void) end = strstr(start, "\n"); } - fprintf(stderr, "\n"); + fputc(stderr, '\n');
Arguments reversed. Looking at the lore discussion by Andi Kleen and Steven Rostedt, they raised a concern that GCC already performs this fprintf->fputc optimization automatically, making the patch unnecessary code churn. The author has not responded to this feedback. Beyond the optimization question, the technical implementation has a systematic bug: every fputc() conversion in this patch reverses the argument order. --- AI reviewed your patch. Please fix the bug or email reply why it's not a bug. See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md CI run summary: https://github.com/kernel-patches/bpf/actions/runs/30016526959