From 39f690e459461b73b177853a1e36d2a7aef9581e Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@google.com>
Date: Thu, 1 Oct 2020 20:22:52 +0200
Subject: [PATCH] Revert "selftests/ptrace: add test cases for dead-locks"

This reverts commit 2f7a0de4e5da7223902d48a30833bc67ef45a02b which is
commit 2de4e82318c7f9d34f4b08599a612cd4cd10bf0b upstream.

It breaks the API and we don't need it right now in the 5.4 tree.

Bug: 161946584
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ic49ab9374cf94f4e091acc130f39c20c9542cf3b
---
 tools/testing/selftests/ptrace/Makefile   |  4 +-
 tools/testing/selftests/ptrace/vmaccess.c | 86 -----------------------
 2 files changed, 2 insertions(+), 88 deletions(-)
 delete mode 100644 tools/testing/selftests/ptrace/vmaccess.c

diff --git a/tools/testing/selftests/ptrace/Makefile b/tools/testing/selftests/ptrace/Makefile
index 2f1f532c39db..c0b7f89f0930 100644
--- a/tools/testing/selftests/ptrace/Makefile
+++ b/tools/testing/selftests/ptrace/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
-CFLAGS += -std=c99 -pthread -iquote../../../../include/uapi -Wall
+CFLAGS += -iquote../../../../include/uapi -Wall
 
-TEST_GEN_PROGS := get_syscall_info peeksiginfo vmaccess
+TEST_GEN_PROGS := get_syscall_info peeksiginfo
 
 include ../lib.mk
diff --git a/tools/testing/selftests/ptrace/vmaccess.c b/tools/testing/selftests/ptrace/vmaccess.c
deleted file mode 100644
index 4db327b44586..000000000000
--- a/tools/testing/selftests/ptrace/vmaccess.c
+++ /dev/null
@@ -1,86 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Copyright (c) 2020 Bernd Edlinger <bernd.edlinger@hotmail.de>
- * All rights reserved.
- *
- * Check whether /proc/$pid/mem can be accessed without causing deadlocks
- * when de_thread is blocked with ->cred_guard_mutex held.
- */
-
-#include "../kselftest_harness.h"
-#include <stdio.h>
-#include <fcntl.h>
-#include <pthread.h>
-#include <signal.h>
-#include <unistd.h>
-#include <sys/ptrace.h>
-
-static void *thread(void *arg)
-{
-	ptrace(PTRACE_TRACEME, 0, 0L, 0L);
-	return NULL;
-}
-
-TEST(vmaccess)
-{
-	int f, pid = fork();
-	char mm[64];
-
-	if (!pid) {
-		pthread_t pt;
-
-		pthread_create(&pt, NULL, thread, NULL);
-		pthread_join(pt, NULL);
-		execlp("true", "true", NULL);
-	}
-
-	sleep(1);
-	sprintf(mm, "/proc/%d/mem", pid);
-	f = open(mm, O_RDONLY);
-	ASSERT_GE(f, 0);
-	close(f);
-	f = kill(pid, SIGCONT);
-	ASSERT_EQ(f, 0);
-}
-
-TEST(attach)
-{
-	int s, k, pid = fork();
-
-	if (!pid) {
-		pthread_t pt;
-
-		pthread_create(&pt, NULL, thread, NULL);
-		pthread_join(pt, NULL);
-		execlp("sleep", "sleep", "2", NULL);
-	}
-
-	sleep(1);
-	k = ptrace(PTRACE_ATTACH, pid, 0L, 0L);
-	ASSERT_EQ(errno, EAGAIN);
-	ASSERT_EQ(k, -1);
-	k = waitpid(-1, &s, WNOHANG);
-	ASSERT_NE(k, -1);
-	ASSERT_NE(k, 0);
-	ASSERT_NE(k, pid);
-	ASSERT_EQ(WIFEXITED(s), 1);
-	ASSERT_EQ(WEXITSTATUS(s), 0);
-	sleep(1);
-	k = ptrace(PTRACE_ATTACH, pid, 0L, 0L);
-	ASSERT_EQ(k, 0);
-	k = waitpid(-1, &s, 0);
-	ASSERT_EQ(k, pid);
-	ASSERT_EQ(WIFSTOPPED(s), 1);
-	ASSERT_EQ(WSTOPSIG(s), SIGSTOP);
-	k = ptrace(PTRACE_DETACH, pid, 0L, 0L);
-	ASSERT_EQ(k, 0);
-	k = waitpid(-1, &s, 0);
-	ASSERT_EQ(k, pid);
-	ASSERT_EQ(WIFEXITED(s), 1);
-	ASSERT_EQ(WEXITSTATUS(s), 0);
-	k = waitpid(-1, NULL, 0);
-	ASSERT_EQ(k, -1);
-	ASSERT_EQ(errno, ECHILD);
-}
-
-TEST_HARNESS_MAIN