From: Dmitry V. Levin <ldv@altlinux.org>
Date: Wed, 5 Dec 2018 18:37:34 +0000 (+0000)
Subject: upoke: workaround crippled x32
X-Git-Tag: v4.26~57
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5be511bf862faca836862d0f06c0bcb4f3f41f27;p=strace

upoke: workaround crippled x32

As PTRACE_POKEUSER is crippled on x32 by design from the very first
linux kernel commit v3.4-rc1~33^2~2 when it was introduced,
workaround this by using the raw x86_64 syscall instead.

* linux/ptrace_pokeuser.c: New file.
* linux/x32/ptrace_pokeuser.c: Likewise.
* Makefile.am (EXTRA_DIST): Add them.
* upoke.c: Include "ptrace_pokeuser.c".
(upoke): Use ptrace_pokeuser instead of ptrace.
---

diff --git a/Makefile.am b/Makefile.am
index 7da98a36..cfcbe7c9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -699,6 +699,7 @@ EXTRA_DIST =				\
 	linux/powerpc64/syscallent.h	\
 	linux/powerpc64/syscallent1.h	\
 	linux/powerpc64/userent.h	\
+	linux/ptrace_pokeuser.c		\
 	linux/raw_syscall.h		\
 	linux/riscv/arch_defs_.h	\
 	linux/riscv/arch_regs.c		\
@@ -856,6 +857,7 @@ EXTRA_DIST =				\
 	linux/x32/ioctls_arch1.h	\
 	linux/x32/ioctls_inc0.h		\
 	linux/x32/ioctls_inc1.h		\
+	linux/x32/ptrace_pokeuser.c	\
 	linux/x32/raw_syscall.h		\
 	linux/x32/rt_sigframe.h		\
 	linux/x32/set_error.c		\
diff --git a/linux/ptrace_pokeuser.c b/linux/ptrace_pokeuser.c
new file mode 100644
index 00000000..d4c981c4
--- /dev/null
+++ b/linux/ptrace_pokeuser.c
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2018 The strace developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+static long
+ptrace_pokeuser(int pid, unsigned long off, kernel_ulong_t val)
+{
+	return ptrace(PTRACE_POKEUSER, pid, off, val);
+}
diff --git a/linux/x32/ptrace_pokeuser.c b/linux/x32/ptrace_pokeuser.c
new file mode 100644
index 00000000..a49d74ce
--- /dev/null
+++ b/linux/x32/ptrace_pokeuser.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2018 The strace developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+static long
+ptrace_pokeuser(int pid, unsigned long off, kernel_ulong_t val)
+{
+	/*
+	 * As PTRACE_POKEUSER is crippled on x32 by design from the very first
+	 * linux kernel commit v3.4-rc1~33^2~2 when it was introduced,
+	 * workaround this by using the raw x86_64 syscall instead.
+	 */
+	return syscall(101, PTRACE_POKEUSER, pid, off, val);
+}
diff --git a/upoke.c b/upoke.c
index f7987903..0bbc8427 100644
--- a/upoke.c
+++ b/upoke.c
@@ -28,11 +28,12 @@
 
 #include "defs.h"
 #include "ptrace.h"
+#include "ptrace_pokeuser.c"
 
 int
 upoke(struct tcb *tcp, unsigned long off, kernel_ulong_t val)
 {
-	if (ptrace(PTRACE_POKEUSER, tcp->pid, off, val)) {
+	if (ptrace_pokeuser(tcp->pid, off, val) < 0) {
 		if (errno != ESRCH)
 			perror_msg("upoke: PTRACE_POKEUSER pid:%d @%#lx)",
 				   tcp->pid, off);