From 524e58f3b2f9e4702293af66f6768755b300e8d3 Mon Sep 17 00:00:00 2001
From: Alexander Kanavin <alex@linutronix.de>
Date: Thu, 2 Mar 2023 13:59:13 +0100
Subject: [PATCH] Support procps 4.x

Upstream-Status: Submitted [https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/issues/116#note_1785522]
Signed-off-by: Alexander Kanavin <alex@linutronix.de>
---
 lib/igt_aux.c   | 238 ++++++++++++++++++++++++++++++++++++++++--------
 lib/meson.build |   7 +-
 meson.build     |  10 +-
 3 files changed, 215 insertions(+), 40 deletions(-)

diff --git a/lib/igt_aux.c b/lib/igt_aux.c
index 15e30440..d23c9a40 100644
--- a/lib/igt_aux.c
+++ b/lib/igt_aux.c
@@ -52,8 +52,16 @@
 #include <assert.h>
 #include <grp.h>
 
+#ifdef HAVE_LIBPROCPS
 #include <proc/readproc.h>
+#endif
+#ifdef HAVE_LIBPROC2
+#include <libproc2/pids.h>
+#endif
+
 #include <libudev.h>
+#include <linux/limits.h>
+#include <dirent.h>
 
 #include "drmtest.h"
 #include "i915_drm.h"
@@ -1217,6 +1225,7 @@ void igt_unlock_mem(void)
  */
 int igt_is_process_running(const char *comm)
 {
+#if HAVE_LIBPROCPS
 	PROCTAB *proc;
 	proc_t *proc_info;
 	bool found = false;
@@ -1235,6 +1244,26 @@ int igt_is_process_running(const char *comm)
 
 	closeproc(proc);
 	return found;
+#endif
+#ifdef HAVE_LIBPROC2
+	enum pids_item Item[] = { PIDS_CMD };
+	struct pids_info *info = NULL;
+	struct pids_stack *stack;
+	char *pid_comm;
+	bool found = false;
+
+	if (procps_pids_new(&info, Item, 1) < 0)
+	    return false;
+	while ((stack = procps_pids_get(info, PIDS_FETCH_TASKS_ONLY))) {
+	    pid_comm = PIDS_VAL(0, str, stack, info);
+	    if (!strncasecmp(pid_comm, comm, strlen(pid_comm))) {
+		found = true;
+		break;
+	    }
+	}
+	procps_pids_unref(&info);
+	return found;
+#endif
 }
 
 /**
@@ -1251,6 +1280,7 @@ int igt_is_process_running(const char *comm)
  */
 int igt_terminate_process(int sig, const char *comm)
 {
+#ifdef HAVE_LIBPROCPS
 	PROCTAB *proc;
 	proc_t *proc_info;
 	int err = 0;
@@ -1272,6 +1302,29 @@ int igt_terminate_process(int sig, const char *comm)
 
 	closeproc(proc);
 	return err;
+#endif
+#ifdef HAVE_LIBPROC2
+	enum pids_item Items[] = { PIDS_ID_PID, PIDS_CMD };
+	struct pids_info *info = NULL;
+	struct pids_stack *stack;
+	char *pid_comm;
+	int pid;
+	int err = 0;
+
+	if (procps_pids_new(&info, Items, 2) < 0)
+		return -errno;
+	while ((stack = procps_pids_get(info, PIDS_FETCH_TASKS_ONLY))) {
+		pid = PIDS_VAL(0, s_int, stack, info);
+		pid_comm = PIDS_VAL(1, str, stack, info);
+		if (!strncasecmp(pid_comm, comm, strlen(pid_comm))) {
+			if (kill(pid, sig) < 0)
+				err = -errno;
+			break;
+		}
+	}
+	procps_pids_unref(&info);
+	return err;
+#endif
 }
 
 struct pinfo {
@@ -1341,9 +1394,9 @@ igt_show_stat_header(void)
 }
 
 static void
-igt_show_stat(proc_t *info, int *state, const char *fn)
+igt_show_stat(const pid_t tid, const char *cmd, int *state, const char *fn)
 {
-	struct pinfo p = { .pid = info->tid, .comm = info->cmd, .fn = fn };
+	struct pinfo p = { .pid = tid, .comm = cmd, .fn = fn };
 
 	if (!*state)
 		igt_show_stat_header();
@@ -1353,7 +1406,7 @@ igt_show_stat(proc_t *info, int *state, const char *fn)
 }
 
 static void
-__igt_lsof_fds(proc_t *proc_info, int *state, char *proc_path, const char *dir)
+__igt_lsof_fds(const pid_t tid, const char *cmd, int *state, char *proc_path, const char *dir)
 {
 	struct dirent *d;
 	struct stat st;
@@ -1400,7 +1453,7 @@ again:
 		dirn = dirname(copy_fd_lnk);
 
 		if (!strncmp(dir, dirn, strlen(dir)))
-			igt_show_stat(proc_info, state, fd_lnk);
+			igt_show_stat(tid, cmd, state, fd_lnk);
 
 		free(copy_fd_lnk);
 		free(fd_lnk);
@@ -1416,13 +1469,14 @@ again:
 static void
 __igt_lsof(const char *dir)
 {
-	PROCTAB *proc;
-	proc_t *proc_info;
-
 	char path[30];
 	char *name_lnk;
 	struct stat st;
 	int state = 0;
+#ifdef HAVE_LIBPROCPS
+	PROCTAB *proc;
+	proc_t *proc_info;
+
 
 	proc = openproc(PROC_FILLCOM | PROC_FILLSTAT | PROC_FILLARG);
 	igt_assert(proc != NULL);
@@ -1456,6 +1510,44 @@ __igt_lsof(const char *dir)
 	}
 
 	closeproc(proc);
+#endif
+#ifdef HAVE_LIBPROC2
+	enum pids_item Items[] = { PIDS_ID_PID, PIDS_CMD };
+	struct pids_info *info = NULL;
+	struct pids_stack *stack;
+
+	if (procps_pids_new(&info, Items, 2) < 0)
+		return;
+	while ((stack = procps_pids_get(info, PIDS_FETCH_TASKS_ONLY))) {
+		ssize_t read;
+		int tid = PIDS_VAL(0, s_int, stack, info);
+		char *pid_comm = PIDS_VAL(1, str, stack, info);
+
+		/* check current working directory */
+		memset(path, 0, sizeof(path));
+		snprintf(path, sizeof(path), "/proc/%d/cwd", tid);
+
+		if (stat(path, &st) == -1)
+			continue;
+
+		name_lnk = malloc(st.st_size + 1);
+
+		igt_assert((read = readlink(path, name_lnk, st.st_size + 1)));
+		name_lnk[read] = '\0';
+
+		if (!strncmp(dir, name_lnk, strlen(dir)))
+			igt_show_stat(tid, pid_comm, &state, name_lnk);
+
+		/* check also fd, seems that lsof(8) doesn't look here */
+		memset(path, 0, sizeof(path));
+		snprintf(path, sizeof(path), "/proc/%d/fd", tid);
+
+		__igt_lsof_fds(tid, pid_comm, &state, path, dir);
+
+		free(name_lnk);
+	}
+	procps_pids_unref(&info);
+#endif
 }
 
 /**
@@ -1490,7 +1582,7 @@ igt_lsof(const char *dpath)
 	free(sanitized);
 }
 
-static void pulseaudio_unload_module(proc_t *proc_info)
+static void pulseaudio_unload_module(const uid_t euid, const gid_t egid)
 {
 	struct igt_helper_process pa_proc = {};
 	char xdg_dir[PATH_MAX];
@@ -1498,14 +1590,14 @@ static void pulseaudio_unload_module(proc_t *proc_info)
 	struct passwd *pw;
 
 	igt_fork_helper(&pa_proc) {
-		pw = getpwuid(proc_info->euid);
+		pw = getpwuid(euid);
 		homedir = pw->pw_dir;
-		snprintf(xdg_dir, sizeof(xdg_dir), "/run/user/%d", proc_info->euid);
+		snprintf(xdg_dir, sizeof(xdg_dir), "/run/user/%d", euid);
 
 		igt_info("Request pulseaudio to stop using audio device\n");
 
-		setgid(proc_info->egid);
-		setuid(proc_info->euid);
+		setgid(egid);
+		setuid(euid);
 		clearenv();
 		setenv("HOME", homedir, 1);
 		setenv("XDG_RUNTIME_DIR",xdg_dir, 1);
@@ -1524,10 +1616,12 @@ static void pipewire_reserve_wait(void)
 	char xdg_dir[PATH_MAX];
 	const char *homedir;
 	struct passwd *pw;
-	proc_t *proc_info;
-	PROCTAB *proc;
+	int tid=0, euid, egid;
 
+#ifdef HAVE_LIBPROCPS
 	igt_fork_helper(&pw_reserve_proc) {
+		proc_t *proc_info;
+		PROCTAB *proc;
 		igt_info("Preventing pipewire-pulse to use the audio drivers\n");
 
 		proc = openproc(PROC_FILLCOM | PROC_FILLSTAT | PROC_FILLARG);
@@ -1539,21 +1633,44 @@ static void pipewire_reserve_wait(void)
 			freeproc(proc_info);
 		}
 		closeproc(proc);
+		tid = proc_info->tid;
+		euid = proc_info->euid;
+		egid = proc_info->egid;
+		freeproc(proc_info);
+#endif
+#ifdef HAVE_LIBPROC2
+	igt_fork(child, 1) {
+		enum pids_item Items[] = { PIDS_ID_PID, PIDS_ID_EUID, PIDS_ID_EGID };
+		enum rel_items { EU_PID, EU_EUID, EU_EGID };
+		struct pids_info *info = NULL;
+		struct pids_stack *stack;
+
+		igt_info("Preventing pipewire-pulse to use the audio drivers\n");
+
+		if (procps_pids_new(&info, Items, 3) < 0)
+		    return;
+		while ((stack = procps_pids_get(info, PIDS_FETCH_TASKS_ONLY))) {
+			tid = PIDS_VAL(EU_PID, s_int, stack, info);
+			if (pipewire_pulse_pid == tid)
+				break;
+		}
+		euid = PIDS_VAL(EU_EUID, s_int, stack, info);
+		egid = PIDS_VAL(EU_EGID, s_int, stack, info);
+		procps_pids_unref(&info);
+#endif
 
 		/* Sanity check: if it can't find the process, it means it has gone */
-		if (pipewire_pulse_pid != proc_info->tid)
+		if (pipewire_pulse_pid != tid)
 			exit(0);
 
-		pw = getpwuid(proc_info->euid);
+		pw = getpwuid(euid);
 		homedir = pw->pw_dir;
-		snprintf(xdg_dir, sizeof(xdg_dir), "/run/user/%d", proc_info->euid);
-		setgid(proc_info->egid);
-		setuid(proc_info->euid);
+		snprintf(xdg_dir, sizeof(xdg_dir), "/run/user/%d", euid);
+		setgid(egid);
+		setuid(euid);
 		clearenv();
 		setenv("HOME", homedir, 1);
 		setenv("XDG_RUNTIME_DIR",xdg_dir, 1);
-		freeproc(proc_info);
-
 		/*
 		 * pw-reserve will run in background. It will only exit when
 		 * igt_kill_children() is called later on. So, it shouldn't
@@ -1570,9 +1687,7 @@ static void pipewire_reserve_wait(void)
 int pipewire_pulse_start_reserve(void)
 {
 	bool is_pw_reserve_running = false;
-	proc_t *proc_info;
 	int attempts = 0;
-	PROCTAB *proc;
 
 	if (!pipewire_pulse_pid)
 		return 0;
@@ -1584,6 +1699,10 @@ int pipewire_pulse_start_reserve(void)
 	 * pipewire version 0.3.50 or upper.
 	 */
 	for (attempts = 0; attempts < PIPEWIRE_RESERVE_MAX_TIME; attempts++) {
+#ifdef HAVE_LIBPROCPS
+		proc_t *proc_info;
+		PROCTAB *proc;
+
 		usleep(1000);
 		proc = openproc(PROC_FILLCOM | PROC_FILLSTAT | PROC_FILLARG);
 		igt_assert(proc != NULL);
@@ -1598,6 +1717,25 @@ int pipewire_pulse_start_reserve(void)
 			freeproc(proc_info);
 		}
 		closeproc(proc);
+#endif
+#ifdef HAVE_LIBPROC2
+		enum pids_item Items[] = { PIDS_ID_PID, PIDS_CMD };
+		struct pids_info *info = NULL;
+		struct pids_stack *stack;
+
+		usleep(1000);
+
+		if (procps_pids_new(&info, Items, 2) < 0)
+			return 1;
+		while ((stack = procps_pids_get(info, PIDS_FETCH_TASKS_ONLY))) {
+			if (!strcmp(PIDS_VAL(1, str, stack, info), "pw-reserve")) {
+				is_pw_reserve_running = true;
+				pipewire_pw_reserve_pid = PIDS_VAL(0, s_int, stack, info);
+				break;
+			}
+		}
+		procps_pids_unref(&info);
+#endif
 		if (is_pw_reserve_running)
 			break;
 	}
@@ -1645,7 +1783,7 @@ void pipewire_pulse_stop_reserve(void)
  * If the check fails, it means that the process can simply be killed.
  */
 static int
-__igt_lsof_audio_and_kill_proc(proc_t *proc_info, char *proc_path)
+__igt_lsof_audio_and_kill_proc(const pid_t tid, const char *cmd, const uid_t euid, const gid_t egid, char *proc_path)
 {
 	const char *audio_dev = "/dev/snd/";
 	char path[PATH_MAX * 2];
@@ -1670,10 +1808,10 @@ __igt_lsof_audio_and_kill_proc(proc_t *proc_info, char *proc_path)
 	 * 2) unload/unbind the the audio driver(s);
 	 * 3) stop the pw-reserve thread.
 	 */
-	if (!strcmp(proc_info->cmd, "pipewire-pulse")) {
+	if (!strcmp(cmd, "pipewire-pulse")) {
 		igt_info("process %d (%s) is using audio device. Should be requested to stop using them.\n",
-			 proc_info->tid, proc_info->cmd);
-		pipewire_pulse_pid = proc_info->tid;
+			 tid, cmd);
+		pipewire_pulse_pid = tid;
 		return 0;
 	}
 	/*
@@ -1685,9 +1823,9 @@ __igt_lsof_audio_and_kill_proc(proc_t *proc_info, char *proc_path)
 	 * will respawn them. So, just ignore here, they'll honor pw-reserve,
 	 * when the time comes.
 	 */
-	if (!strcmp(proc_info->cmd, "pipewire-media-session"))
+	if (!strcmp(cmd, "pipewire-media-session"))
 		return 0;
-	if (!strcmp(proc_info->cmd, "wireplumber"))
+	if (!strcmp(cmd, "wireplumber"))
 		return 0;
 
 	dp = opendir(proc_path);
@@ -1723,22 +1861,22 @@ __igt_lsof_audio_and_kill_proc(proc_t *proc_info, char *proc_path)
 		 * enough to unbind audio modules and won't cause race issues
 		 * with systemd trying to reload it.
 		 */
-		if (!strcmp(proc_info->cmd, "pulseaudio")) {
-			pulseaudio_unload_module(proc_info);
+		if (!strcmp(cmd, "pulseaudio")) {
+			pulseaudio_unload_module(euid, egid);
 			break;
 		}
 
 		/* For all other processes, just kill them */
 		igt_info("process %d (%s) is using audio device. Should be terminated.\n",
-				proc_info->tid, proc_info->cmd);
+				tid, cmd);
 
-		if (kill(proc_info->tid, SIGTERM) < 0) {
+		if (kill(tid, SIGTERM) < 0) {
 			igt_info("Fail to terminate %s (pid: %d) with SIGTERM\n",
-				proc_info->cmd, proc_info->tid);
-			if (kill(proc_info->tid, SIGABRT) < 0) {
+				cmd, tid);
+			if (kill(tid, SIGABRT) < 0) {
 				fail++;
 				igt_info("Fail to terminate %s (pid: %d) with SIGABRT\n",
-					proc_info->cmd, proc_info->tid);
+					cmd, tid);
 			}
 		}
 
@@ -1760,9 +1898,10 @@ int
 igt_lsof_kill_audio_processes(void)
 {
 	char path[PATH_MAX];
+	int fail = 0;
+#ifdef HAVE_LIBPROCPS
 	proc_t *proc_info;
 	PROCTAB *proc;
-	int fail = 0;
 
 	proc = openproc(PROC_FILLCOM | PROC_FILLSTAT | PROC_FILLARG);
 	igt_assert(proc != NULL);
@@ -1772,12 +1911,35 @@ igt_lsof_kill_audio_processes(void)
 		if (snprintf(path, sizeof(path), "/proc/%d/fd", proc_info->tid) < 1)
 			fail++;
 		else
-			fail += __igt_lsof_audio_and_kill_proc(proc_info, path);
+			fail += __igt_lsof_audio_and_kill_proc(proc_info->pid, proc_info->cmd, proc_info->euid, proc_info->egid, path);
 
 		freeproc(proc_info);
 	}
 	closeproc(proc);
+#endif
+#ifdef HAVE_LIBPROC2
+	enum pids_item Items[] = { PIDS_ID_PID, PIDS_CMD, PIDS_ID_EUID, PIDS_ID_EGID };
+	enum rel_items { EU_PID, EU_CMD, EU_EUID, EU_EGID };
+	struct pids_info *info = NULL;
+	struct pids_stack *stack;
+	pid_t tid;
+
+	if (procps_pids_new(&info, Items, 4) < 0)
+		return 1;
+	while ((stack = procps_pids_get(info, PIDS_FETCH_TASKS_ONLY))) {
+		tid = PIDS_VAL(EU_PID, s_int, stack, info);
 
+		if (snprintf(path, sizeof(path), "/proc/%d/fd", tid) < 1)
+			fail++;
+		else
+			fail += __igt_lsof_audio_and_kill_proc(tid,
+				PIDS_VAL(EU_CMD, str, stack, info),
+				PIDS_VAL(EU_EUID, s_int, stack, info),
+				PIDS_VAL(EU_EGID, s_int, stack, info),
+				path);
+	}
+	procps_pids_unref(&info);
+#endif
 	return fail;
 }
 
diff --git a/lib/meson.build b/lib/meson.build
index cc784686..90591e0e 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -105,7 +105,6 @@ lib_deps = [
 	libdrm,
 	libdw,
 	libkmod,
-	libprocps,
 	libudev,
 	math,
 	pciaccess,
@@ -169,6 +168,12 @@ if chamelium.found()
 	lib_sources += 'monitor_edids/monitor_edids_helper.c'
 endif
 
+if libprocps.found()
+	lib_deps += libprocps
+else
+	lib_deps += libproc2
+endif
+
 if get_option('srcdir') != ''
     srcdir = join_paths(get_option('srcdir'), 'tests')
 else
diff --git a/meson.build b/meson.build
index e7a68503..309b0af3 100644
--- a/meson.build
+++ b/meson.build
@@ -120,7 +120,15 @@ build_info += 'With libdrm: ' + ','.join(libdrm_info)
 
 pciaccess = dependency('pciaccess', version : '>=0.10')
 libkmod = dependency('libkmod')
-libprocps = dependency('libprocps', required : true)
+libprocps = dependency('libprocps', required : false)
+libproc2 = dependency('libproc2', required : false)
+if libprocps.found()
+  config.set('HAVE_LIBPROCPS', 1)
+elif libproc2.found()
+  config.set('HAVE_LIBPROC2', 1)
+else
+  error('Either libprocps or libproc2 is required')
+endif
 
 libunwind = dependency('libunwind', required : get_option('libunwind'))
 build_info += 'With libunwind: @0@'.format(libunwind.found())
