From f2cf1cc716216308a8a6d07e3afab23be07a6b02 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 7 Aug 2017 18:45:33 +0200 Subject: [PATCH] noexec: set comm field for noexecs function old new delta set_task_comm - 18 +18 tryexec 152 159 +7 pseudo_exec_argv 321 328 +7 main 106 97 -9 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 3/2 up/down: 34/-13) Total: 23 bytes Signed-off-by: Denys Vlasenko --- include/libbb.h | 5 +++++ libbb/appletlib.c | 13 ++++++++++--- libbb/vfork_daemon_rexec.c | 7 +++++-- shell/ash.c | 5 ++++- shell/hush.c | 5 ++++- 5 files changed, 28 insertions(+), 7 deletions(-) diff --git a/include/libbb.h b/include/libbb.h index 51e8f27a5..e4a19ac04 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -1116,6 +1116,11 @@ int run_nofork_applet(int applet_no, char **argv) FAST_FUNC; extern int find_applet_by_name(const char *name) FAST_FUNC; extern void run_applet_no_and_exit(int a, const char *name, char **argv) NORETURN FAST_FUNC; #endif +#if defined(__linux__) +void set_task_comm(const char *comm) FAST_FUNC; +#else +# define set_task_comm(name) ((void)0) +#endif /* Helpers for daemonization. * diff --git a/libbb/appletlib.c b/libbb/appletlib.c index fa28d433b..ce259446b 100644 --- a/libbb/appletlib.c +++ b/libbb/appletlib.c @@ -911,6 +911,14 @@ int busybox_main(int argc UNUSED_PARAM, char **argv) } # endif +#if defined(__linux__) && (NUM_APPLETS > 1) +void FAST_FUNC set_task_comm(const char *comm) +{ + /* okay if too long (truncates) */ + prctl(PR_SET_NAME, (long)comm, 0, 0, 0); +} +#endif + # if NUM_APPLETS > 0 void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv) { @@ -1064,15 +1072,14 @@ int main(int argc UNUSED_PARAM, char **argv) applet_name++; applet_name = bb_basename(applet_name); -# if defined(__linux__) /* If we are a result of execv("/proc/self/exe"), fix ugly comm of "exe" */ if (ENABLE_FEATURE_SH_STANDALONE || ENABLE_FEATURE_PREFER_APPLETS || !BB_MMU ) { - prctl(PR_SET_NAME, (long)applet_name, 0, 0, 0); + if (NUM_APPLETS > 1) + set_task_comm(applet_name); } -# endif parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */ run_applet_and_exit(applet_name, argv); diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c index 50ecea762..546cc9e36 100644 --- a/libbb/vfork_daemon_rexec.c +++ b/libbb/vfork_daemon_rexec.c @@ -175,8 +175,6 @@ int FAST_FUNC spawn_and_wait(char **argv) return wait4pid(rc); /* child */ -//TODO: prctl(PR_SET_NAME, (long)argv[0], 0, 0, 0);? [think pidof, pgrep, pkill] -//Rewrite /proc/PID/cmdline? (need to save argv0 and length at init for this to work!) /* reset some state and run without execing */ /* msg_eol = "\n"; - no caller needs this reinited yet */ @@ -185,6 +183,11 @@ int FAST_FUNC spawn_and_wait(char **argv) * init, or a NOFORK applet. But none of those call us * as of yet (and that should probably always stay true). */ +//TODO: think pidof, pgrep, pkill! +//set_task_comm() makes our pidof find NOEXECs (e.g. "yes >/dev/null"), +//but one from procps-ng-3.3.10 needs more! +//Rewrite /proc/PID/cmdline? (need to save argv0 and length at init for this to work!) + set_task_comm(argv[0]); /* xfunc_error_retval and applet_name are init by: */ run_applet_no_and_exit(a, argv[0], argv); } diff --git a/shell/ash.c b/shell/ash.c index 0a323e957..507d15c90 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -7803,8 +7803,11 @@ tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) const char *cmd, char **argv, c while (*envp) putenv(*envp++); popredir(/*drop:*/ 1); -//TODO: prctl(PR_SET_NAME, (long)argv[0], 0, 0, 0);? [think pidof, pgrep, pkill] +//TODO: think pidof, pgrep, pkill! +//set_task_comm() makes our pidof find NOEXECs (e.g. "yes >/dev/null"), +//but one from procps-ng-3.3.10 needs more! //Rewrite /proc/PID/cmdline? (need to save argv0 and length at init for this to work!) + set_task_comm(argv[0]); run_applet_no_and_exit(applet_no, cmd, argv); } /* re-exec ourselves with the new arguments */ diff --git a/shell/hush.c b/shell/hush.c index b4fe7146b..021c1f0ff 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -7387,8 +7387,11 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save, /* Without this, "rm -i FILE" can't be ^C'ed: */ switch_off_special_sigs(G.special_sig_mask); debug_printf_exec("running applet '%s'\n", argv[0]); -//TODO: prctl(PR_SET_NAME, (long)argv[0], 0, 0, 0);? [think pidof, pgrep, pkill] +//TODO: think pidof, pgrep, pkill! +//set_task_comm() makes our pidof find NOEXECs (e.g. "yes >/dev/null"), +//but one from procps-ng-3.3.10 needs more! //Rewrite /proc/PID/cmdline? (need to save argv0 and length at init for this to work!) + set_task_comm(argv[0]); run_applet_no_and_exit(a, argv[0], argv); } # endif -- 2.25.1