From: Tomas Glozar Date: Tue, 2 Jun 2026 12:55:06 +0000 (+0200) Subject: rtla: Fix parsing of multi-character short options X-Git-Tag: v7.1~24^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e9e41d3035032ed6053d8bad7b7077e1cb3a6540;p=thirdparty%2Flinux.git rtla: Fix parsing of multi-character short options A bug was reported where the parsing of multi-character short options, be it a short option with an argument specified without space (e.g. "-p100") or multiple short options in one argument (e.g. -un), ignores options specific to individual tools. Furthermore, if the rest of the option is supposed to be an argument, it gets reinterpreted as a string of options. For example, -p100 gets interpreted as -100, which is due to hackish implementation read as --no-thread --no-irq --no-irq with timerlat hist, causing rtla to error out: $ rtla timerlat hist -p100 no-irq and no-thread set, there is nothing to do here This behavior is caused by getopt_long() being called twice on each argument, once in common_parse_options(), once in [tool]_parse_args(): - common_parse_options() calls getopt_long() with an array of options common for all rtla tools, while suppressing errors (opterr = 0). - If the option fails to parse, common_parse_options() returns 0. - If 0 is returned from common_parse_options(), [tool]_parse_args() calls getopt_long() again, with its own set of options. * [tool] means one of {osnoise,timerlat}_{top,hist} At least in glibc, getopt_long() increments its internal nextchar variable even if the option is not recognized. That means that in the case of "-p100", common_parse_options() sets nextchar pointing to '1', and timerlat_hist_parse_args() sees '1', not 'p'; the same then repeats for the first and second '0'. As there is no way to restore the correct internal state of getopt_long() reliably, fix the issue by merging the common options back to the longopt array and option string of the [tool]_parse_args() functions using a macro; only the switch part is left in the original function, which is renamed to set_common_option(). Fixes: 850cd24cb6d6 ("tools/rtla: Add common_parse_options()") Reported-by: John Kacur Tested-by: John Kacur Link: https://lore.kernel.org/r/20260602125506.3325345-1-tglozar@redhat.com Signed-off-by: Tomas Glozar --- diff --git a/tools/tracing/rtla/src/common.c b/tools/tracing/rtla/src/common.c index 35e3d3aa922e2..bc9d01ddd1029 100644 --- a/tools/tracing/rtla/src/common.c +++ b/tools/tracing/rtla/src/common.c @@ -84,37 +84,20 @@ int getopt_auto(int argc, char **argv, const struct option *long_opts) } /* - * common_parse_options - parse common command line options + * set_common_option - set common options * + * @c: option character * @argc: argument count * @argv: argument vector * @common: common parameters structure * * Parse command line options that are common to all rtla tools. * - * Returns: non zero if a common option was parsed, or 0 - * if the option should be handled by tool-specific parsing. + * Returns: 1 if the option was set, 0 otherwise. */ -int common_parse_options(int argc, char **argv, struct common_params *common) +int set_common_option(int c, int argc, char **argv, struct common_params *common) { struct trace_events *tevent; - int saved_state = optind; - int c; - - static struct option long_options[] = { - {"cpus", required_argument, 0, 'c'}, - {"cgroup", optional_argument, 0, 'C'}, - {"debug", no_argument, 0, 'D'}, - {"duration", required_argument, 0, 'd'}, - {"event", required_argument, 0, 'e'}, - {"house-keeping", required_argument, 0, 'H'}, - {"priority", required_argument, 0, 'P'}, - {0, 0, 0, 0} - }; - - opterr = 0; - c = getopt_auto(argc, argv, long_options); - opterr = 1; switch (c) { case 'c': @@ -154,11 +137,10 @@ int common_parse_options(int argc, char **argv, struct common_params *common) common->set_sched = 1; break; default: - optind = saved_state; return 0; } - return c; + return 1; } /* diff --git a/tools/tracing/rtla/src/common.h b/tools/tracing/rtla/src/common.h index 51665db4ffce8..8921807bda988 100644 --- a/tools/tracing/rtla/src/common.h +++ b/tools/tracing/rtla/src/common.h @@ -178,7 +178,17 @@ int osnoise_set_stop_total_us(struct osnoise_context *context, long long stop_total_us); int getopt_auto(int argc, char **argv, const struct option *long_opts); -int common_parse_options(int argc, char **argv, struct common_params *common); + +#define COMMON_OPTIONS \ + {"cpus", required_argument, 0, 'c'},\ + {"cgroup", optional_argument, 0, 'C'},\ + {"debug", no_argument, 0, 'D'},\ + {"duration", required_argument, 0, 'd'},\ + {"event", required_argument, 0, 'e'},\ + {"house-keeping", required_argument, 0, 'H'},\ + {"priority", required_argument, 0, 'P'} +int set_common_option(int c, int argc, char **argv, struct common_params *common); + int common_apply_config(struct osnoise_tool *tool, struct common_params *params); int top_main_loop(struct osnoise_tool *tool); int hist_main_loop(struct osnoise_tool *tool); diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c index 8ad816b80265d..cb4ce58c59879 100644 --- a/tools/tracing/rtla/src/osnoise_hist.c +++ b/tools/tracing/rtla/src/osnoise_hist.c @@ -475,6 +475,7 @@ static struct common_params while (1) { static struct option long_options[] = { + COMMON_OPTIONS, {"auto", required_argument, 0, 'a'}, {"bucket-size", required_argument, 0, 'b'}, {"entries", required_argument, 0, 'E'}, @@ -498,15 +499,15 @@ static struct common_params {0, 0, 0, 0} }; - if (common_parse_options(argc, argv, ¶ms->common)) - continue; - c = getopt_auto(argc, argv, long_options); /* detect the end of the options. */ if (c == -1) break; + if (set_common_option(c, argc, argv, ¶ms->common)) + continue; + switch (c) { case 'a': /* set sample stop to auto_thresh */ diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c index 244bdce022ad3..e65312ec26c43 100644 --- a/tools/tracing/rtla/src/osnoise_top.c +++ b/tools/tracing/rtla/src/osnoise_top.c @@ -328,6 +328,7 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv) while (1) { static struct option long_options[] = { + COMMON_OPTIONS, {"auto", required_argument, 0, 'a'}, {"help", no_argument, 0, 'h'}, {"period", required_argument, 0, 'p'}, @@ -346,15 +347,15 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv) {0, 0, 0, 0} }; - if (common_parse_options(argc, argv, ¶ms->common)) - continue; - c = getopt_auto(argc, argv, long_options); /* Detect the end of the options. */ if (c == -1) break; + if (set_common_option(c, argc, argv, ¶ms->common)) + continue; + switch (c) { case 'a': /* set sample stop to auto_thresh */ diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c index 79142af4f5662..4b6708e333b8f 100644 --- a/tools/tracing/rtla/src/timerlat_hist.c +++ b/tools/tracing/rtla/src/timerlat_hist.c @@ -785,6 +785,7 @@ static struct common_params while (1) { static struct option long_options[] = { + COMMON_OPTIONS, {"auto", required_argument, 0, 'a'}, {"bucket-size", required_argument, 0, 'b'}, {"entries", required_argument, 0, 'E'}, @@ -819,11 +820,11 @@ static struct common_params {0, 0, 0, 0} }; - if (common_parse_options(argc, argv, ¶ms->common)) - continue; - c = getopt_auto(argc, argv, long_options); + if (set_common_option(c, argc, argv, ¶ms->common)) + continue; + /* detect the end of the options. */ if (c == -1) break; diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c index 64cbdcc878b0d..91f88bbebad9e 100644 --- a/tools/tracing/rtla/src/timerlat_top.c +++ b/tools/tracing/rtla/src/timerlat_top.c @@ -549,6 +549,7 @@ static struct common_params while (1) { static struct option long_options[] = { + COMMON_OPTIONS, {"auto", required_argument, 0, 'a'}, {"help", no_argument, 0, 'h'}, {"irq", required_argument, 0, 'i'}, @@ -577,11 +578,11 @@ static struct common_params {0, 0, 0, 0} }; - if (common_parse_options(argc, argv, ¶ms->common)) - continue; - c = getopt_auto(argc, argv, long_options); + if (set_common_option(c, argc, argv, ¶ms->common)) + continue; + /* detect the end of the options. */ if (c == -1) break;