A new trace-cmd record option is added: "--user". When it is set with
combination of option -F, the traced process is executed in the context
of the specified user.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
---
Documentation/trace-cmd-record.1.txt | 3 ++
tracecmd/trace-record.c | 49 ++++++++++++++++++++++++++--
tracecmd/trace-usage.c | 1 +
3 files changed, 50 insertions(+), 3 deletions(-)
diff --git a/Documentation/trace-cmd-record.1.txt b/Documentation/trace-cmd-record.1.txt
index e697f03..bb18e88 100644
--- a/Documentation/trace-cmd-record.1.txt
+++ b/Documentation/trace-cmd-record.1.txt
@@ -119,6 +119,9 @@ OPTIONS
Used with either *-F* (or *-P* if kernel supports it) to trace the process'
children too.
+*--user*::
+ Execute the specified *command* as given user.
+
*-C* 'clock'::
Set the trace clock to "clock".
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 4a20339..9b7357f 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -33,6 +33,8 @@
#include <errno.h>
#include <limits.h>
#include <libgen.h>
+#include <pwd.h>
+#include <grp.h>
#include "version.h"
#include "trace-local.h"
@@ -208,6 +210,7 @@ struct common_record_context {
struct buffer_instance *instance;
const char *output;
char *date2ts;
+ char *user;
int data_flags;
int record_all;
@@ -1457,7 +1460,34 @@ static void trace_or_sleep(enum trace_type type)
sleep(10);
}
-static void run_cmd(enum trace_type type, int argc, char **argv)
+static int change_user(const char *user)
+{
+ struct passwd *pwd;
+
+ if (!user)
+ return 0;
+
+ pwd = getpwnam(user);
+ if (!pwd)
+ return -1;
+ if (initgroups(user, pwd->pw_gid) < 0)
+ return -1;
+ if (setgid(pwd->pw_gid) < 0)
+ return -1;
+ if (setuid(pwd->pw_uid) < 0)
+ return -1;
+
+ if (setenv("HOME", pwd->pw_dir, 1) < 0)
+ return -1;
+ if (setenv("USER", pwd->pw_name, 1) < 0)
+ return -1;
+ if (setenv("LOGNAME", pwd->pw_name, 1) < 0)
+ return -1;
+
+ return 0;
+}
+
+static void run_cmd(enum trace_type type, const char *user, int argc, char **argv)
{
int status;
int pid;
@@ -1478,6 +1508,10 @@ static void run_cmd(enum trace_type type, int argc, char **argv)
dup2(save_stdout, 1);
close(save_stdout);
}
+
+ if (change_user(user) < 0)
+ die("Failed to change user to %s", user);
+
if (execvp(argv[0], argv)) {
fprintf(stderr, "\n********************\n");
fprintf(stderr, " Unable to exec %s\n", argv[0]);
@@ -4592,6 +4626,7 @@ void update_first_instance(struct buffer_instance *instance, int topt)
}
enum {
+ OPT_user = 243,
OPT_procmap = 244,
OPT_quiet = 245,
OPT_debug = 246,
@@ -4824,6 +4859,7 @@ static void parse_record_options(int argc,
{"quiet", no_argument, NULL, OPT_quiet},
{"help", no_argument, NULL, '?'},
{"proc-map", no_argument, NULL, OPT_procmap},
+ {"user", required_argument, NULL, OPT_user},
{"module", required_argument, NULL, OPT_module},
{NULL, 0, NULL, 0}
};
@@ -5056,6 +5092,11 @@ static void parse_record_options(int argc,
case 'i':
ignore_event_not_found = 1;
break;
+ case OPT_user:
+ ctx->user = strdup(optarg);
+ if (!ctx->user)
+ die("Failed to allocate user name");
+ break;
case OPT_procmap:
get_procmap = 1;
break;
@@ -5139,7 +5180,9 @@ static void parse_record_options(int argc,
"Did you mean 'record'?");
ctx->run_command = 1;
}
-
+ if (ctx->user && !ctx->run_command)
+ warning("--user %s is ignored, no command is specified",
+ ctx->user);
if (get_procmap) {
if (!ctx->run_command && !nr_filter_pids)
warning("--proc-map is ignored, no command or filtered PIDs are specified.");
@@ -5287,7 +5330,7 @@ static void record_trace(int argc, char **argv,
}
if (ctx->run_command)
- run_cmd(type, (argc - optind) - 1, &argv[optind + 1]);
+ run_cmd(type, ctx->user, (argc - optind) - 1, &argv[optind + 1]);
else {
update_task_filter();
tracecmd_enable_tracing();
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 7a67784..20cb66f 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -58,6 +58,7 @@ static struct usage_help usage_help[] = {
" --max-graph-depth limit function_graph depth\n"
" --no-filter include trace-cmd threads in the trace\n"
" --proc-map save the traced processes address map into the trace.dat file\n"
+ " --user execute the specified [command ...] as given user\n"
},
{
"start",
--
2.21.0
|