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Date:      Thu, 16 Feb 2017 13:32:15 +0000 (UTC)
From:      Edward Tomasz Napierala <trasz@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r313809 - in head/sys: amd64/linux modules/linux64
Message-ID:  <201702161332.v1GDWFO9034492@repo.freebsd.org>

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Author: trasz
Date: Thu Feb 16 13:32:15 2017
New Revision: 313809
URL: https://svnweb.freebsd.org/changeset/base/313809

Log:
  Implement linux version of ptrace(2).  It's nowhere near complete,
  but it allows to use 64 bit linux strace(1) on 64 bit linux binaries.
  
  Reviewed by:	dchagin (earlier version)
  MFC after:	2 weeks
  Sponsored by:	DARPA, AFRL
  Differential Revision:	https://reviews.freebsd.org/D9406

Added:
  head/sys/amd64/linux/linux_ptrace.c   (contents, props changed)
Modified:
  head/sys/amd64/linux/linux_dummy.c
  head/sys/modules/linux64/Makefile

Modified: head/sys/amd64/linux/linux_dummy.c
==============================================================================
--- head/sys/amd64/linux/linux_dummy.c	Thu Feb 16 12:56:10 2017	(r313808)
+++ head/sys/amd64/linux/linux_dummy.c	Thu Feb 16 13:32:15 2017	(r313809)
@@ -45,7 +45,6 @@ LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
 
 DUMMY(mincore);
 DUMMY(sendfile);
-DUMMY(ptrace);
 DUMMY(syslog);
 DUMMY(setfsuid);
 DUMMY(setfsgid);

Added: head/sys/amd64/linux/linux_ptrace.c
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/sys/amd64/linux/linux_ptrace.c	Thu Feb 16 13:32:15 2017	(r313809)
@@ -0,0 +1,414 @@
+/*-
+ * Copyright (c) 2017 Edward Tomasz Napierala <trasz@FreeBSD.org>
+ * All rights reserved.
+ *
+ * This software was developed by SRI International and the University of
+ * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
+ * ("CTSRD"), as part of the DARPA CRASH research programme.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/ptrace.h>
+#include <sys/syscallsubr.h>
+
+#include <machine/pcb.h>
+#include <machine/reg.h>
+
+#include <amd64/linux/linux.h>
+#include <amd64/linux/linux_proto.h>
+#include <compat/linux/linux_signal.h>
+
+#define	LINUX_PTRACE_TRACEME		0
+#define	LINUX_PTRACE_PEEKTEXT		1
+#define	LINUX_PTRACE_PEEKDATA		2
+#define	LINUX_PTRACE_PEEKUSER		3
+#define	LINUX_PTRACE_POKETEXT		4
+#define	LINUX_PTRACE_POKEDATA		5
+#define	LINUX_PTRACE_POKEUSER		6
+#define	LINUX_PTRACE_CONT		7
+#define	LINUX_PTRACE_KILL		8
+#define	LINUX_PTRACE_SINGLESTEP		9
+#define	LINUX_PTRACE_GETREGS		12
+#define	LINUX_PTRACE_SETREGS		13
+#define	LINUX_PTRACE_GETFPREGS		14
+#define	LINUX_PTRACE_SETFPREGS		15
+#define	LINUX_PTRACE_ATTACH		16
+#define	LINUX_PTRACE_DETACH		17
+#define	LINUX_PTRACE_SYSCALL		24
+#define	LINUX_PTRACE_SETOPTIONS		0x4200
+#define	LINUX_PTRACE_GETREGSET		0x4204
+#define	LINUX_PTRACE_SEIZE		0x4206
+
+#define	LINUX_PTRACE_O_TRACESYSGOOD	1
+#define	LINUX_PTRACE_O_TRACEFORK	2
+#define	LINUX_PTRACE_O_TRACEVFORK	4
+#define	LINUX_PTRACE_O_TRACECLONE	8
+#define	LINUX_PTRACE_O_TRACEEXEC	16
+#define	LINUX_PTRACE_O_TRACEVFORKDONE	32
+#define	LINUX_PTRACE_O_TRACEEXIT	64
+#define	LINUX_PTRACE_O_TRACESECCOMP	128
+#define	LINUX_PTRACE_O_EXITKILL		1048576 
+#define	LINUX_PTRACE_O_SUSPEND_SECCOMP	2097152
+
+#define	LINUX_NT_PRSTATUS		1
+
+#define	LINUX_PTRACE_O_MASK	(LINUX_PTRACE_O_TRACESYSGOOD |	\
+    LINUX_PTRACE_O_TRACEFORK | LINUX_PTRACE_O_TRACEVFORK |	\
+    LINUX_PTRACE_O_TRACECLONE | LINUX_PTRACE_O_TRACEEXEC |	\
+    LINUX_PTRACE_O_TRACEVFORKDONE | LINUX_PTRACE_O_TRACEEXIT |	\
+    LINUX_PTRACE_O_TRACESECCOMP | LINUX_PTRACE_O_EXITKILL |	\
+    LINUX_PTRACE_O_SUSPEND_SECCOMP)
+
+static int
+map_signum(int lsig, int *bsigp)
+{
+	int bsig;
+
+	if (lsig == 0) {
+		*bsigp = 0;
+		return (0);
+	}
+
+	if (lsig < 0 || lsig > LINUX_SIGRTMAX)
+		return (EINVAL);
+
+	bsig = linux_to_bsd_signal(lsig);
+	if (bsig == SIGSTOP)
+		bsig = 0;
+
+	*bsigp = bsig;
+	return (0);
+}
+
+struct linux_pt_reg {
+	l_ulong	r15;
+	l_ulong	r14;
+	l_ulong	r13;
+	l_ulong	r12;
+	l_ulong	rbp;
+	l_ulong	rbx;
+	l_ulong	r11;
+	l_ulong	r10;
+	l_ulong	r9;
+	l_ulong	r8;
+	l_ulong	rax;
+	l_ulong	rcx;
+	l_ulong	rdx;
+	l_ulong	rsi;
+	l_ulong	rdi;
+	l_ulong	orig_rax;
+	l_ulong	rip;
+	l_ulong	cs;
+	l_ulong	eflags;
+	l_ulong	rsp;
+	l_ulong	ss;
+};
+
+/*
+ * Translate amd64 ptrace registers between Linux and FreeBSD formats.
+ * The translation is pretty straighforward, for all registers but
+ * orig_rax on Linux side and r_trapno and r_err in FreeBSD.
+ */
+static void
+map_regs_to_linux(struct reg *b_reg, struct linux_pt_reg *l_reg)
+{
+
+	l_reg->r15 = b_reg->r_r15;
+	l_reg->r14 = b_reg->r_r14;
+	l_reg->r13 = b_reg->r_r13;
+	l_reg->r12 = b_reg->r_r12;
+	l_reg->rbp = b_reg->r_rbp;
+	l_reg->rbx = b_reg->r_rbx;
+	l_reg->r11 = b_reg->r_r11;
+	l_reg->r10 = b_reg->r_r10;
+	l_reg->r9 = b_reg->r_r9;
+	l_reg->r8 = b_reg->r_r8;
+	l_reg->rax = b_reg->r_rax;
+	l_reg->rcx = b_reg->r_rcx;
+	l_reg->rdx = b_reg->r_rdx;
+	l_reg->rsi = b_reg->r_rsi;
+	l_reg->rdi = b_reg->r_rdi;
+	l_reg->orig_rax = b_reg->r_rax;
+	l_reg->rip = b_reg->r_rip;
+	l_reg->cs = b_reg->r_cs;
+	l_reg->eflags = b_reg->r_rflags;
+	l_reg->rsp = b_reg->r_rsp;
+	l_reg->ss = b_reg->r_ss;
+}
+
+static void
+map_regs_from_linux(struct reg *b_reg, struct linux_pt_reg *l_reg)
+{
+	b_reg->r_r15 = l_reg->r15;
+	b_reg->r_r14 = l_reg->r14;
+	b_reg->r_r13 = l_reg->r13;
+	b_reg->r_r12 = l_reg->r12;
+	b_reg->r_r11 = l_reg->r11;
+	b_reg->r_r10 = l_reg->r10;
+	b_reg->r_r9 = l_reg->r9;
+	b_reg->r_r8 = l_reg->r8;
+	b_reg->r_rdi = l_reg->rdi;
+	b_reg->r_rsi = l_reg->rsi;
+	b_reg->r_rbp = l_reg->rbp;
+	b_reg->r_rbx = l_reg->rbx;
+	b_reg->r_rdx = l_reg->rdx;
+	b_reg->r_rcx = l_reg->rcx;
+	b_reg->r_rax = l_reg->rax;
+
+	/*
+	 * XXX: Are zeroes the right thing to put here?
+	 */
+	b_reg->r_trapno = 0;
+	b_reg->r_fs = 0;
+	b_reg->r_gs = 0;
+	b_reg->r_err = 0;
+	b_reg->r_es = 0;
+	b_reg->r_ds = 0;
+
+	b_reg->r_rip = l_reg->rip;
+	b_reg->r_cs = l_reg->cs;
+	b_reg->r_rflags = l_reg->eflags;
+	b_reg->r_rsp = l_reg->rsp;
+	b_reg->r_ss = l_reg->ss;
+}
+
+static int
+linux_ptrace_peek(struct thread *td, pid_t pid, void *addr, void *data)
+{
+	int error;
+
+	error = kern_ptrace(td, PT_READ_I, pid, addr, 0);
+	if (error == 0)
+		error = copyout(td->td_retval, data, sizeof(l_int));
+	td->td_retval[0] = error;
+
+	return (error);
+}
+
+static int
+linux_ptrace_setoptions(struct thread *td, pid_t pid, l_ulong data)
+{
+	int mask;
+
+	mask = 0;
+
+	if (data & ~LINUX_PTRACE_O_MASK) {
+		printf("%s: unknown ptrace option %lx set; "
+		    "returning EINVAL\n",
+		    __func__, data & ~LINUX_PTRACE_O_MASK);
+		return (EINVAL);
+	}
+
+	/*
+	 * PTRACE_O_EXITKILL is ignored, we do that by default.
+	 */
+
+	if (data & LINUX_PTRACE_O_TRACESYSGOOD) {
+		printf("%s: PTRACE_O_TRACESYSGOOD not implemented; "
+		    "returning EINVAL\n", __func__);
+		return (EINVAL);
+	}
+
+	if (data & LINUX_PTRACE_O_TRACEFORK)
+		mask |= PTRACE_FORK;
+
+ 	if (data & LINUX_PTRACE_O_TRACEVFORK)
+		mask |= PTRACE_VFORK;
+
+	if (data & LINUX_PTRACE_O_TRACECLONE)
+		mask |= PTRACE_VFORK;
+
+	if (data & LINUX_PTRACE_O_TRACEEXEC)
+		mask |= PTRACE_EXEC;
+
+	if (data & LINUX_PTRACE_O_TRACEVFORKDONE)
+		mask |= PTRACE_VFORK; /* XXX: Close enough? */
+
+	if (data & LINUX_PTRACE_O_TRACEEXIT) {
+		printf("%s: PTRACE_O_TRACEEXIT not implemented; "
+		    "returning EINVAL\n", __func__);
+		return (EINVAL);
+	}
+
+	return (kern_ptrace(td, PT_SET_EVENT_MASK, pid, &mask, sizeof(mask)));
+}
+
+static int
+linux_ptrace_getregs(struct thread *td, pid_t pid, void *data)
+{
+	struct ptrace_lwpinfo lwpinfo;
+	struct reg b_reg;
+	struct linux_pt_reg l_reg;
+	int error;
+
+	error = kern_ptrace(td, PT_GETREGS, pid, &b_reg, 0);
+	if (error != 0)
+		return (error);
+
+	map_regs_to_linux(&b_reg, &l_reg);
+
+	/*
+	 * The strace(1) utility depends on RAX being set to -ENOSYS
+	 * on syscall entry.
+	 */
+	error = kern_ptrace(td, PT_LWPINFO, pid, &lwpinfo, sizeof(lwpinfo));
+	if (error != 0) {
+		printf("%s: PT_LWPINFO failed with error %d\n", __func__, error);
+		return (error);
+	}
+	if (lwpinfo.pl_flags & PL_FLAG_SCE)
+		l_reg.rax = -38; // XXX: Don't hardcode?
+
+	error = copyout(&l_reg, (void *)data, sizeof(l_reg));
+	return (error);
+}
+
+static int
+linux_ptrace_setregs(struct thread *td, pid_t pid, void *data)
+{
+	struct reg b_reg;
+	struct linux_pt_reg l_reg;
+	int error;
+
+	error = copyin(data, &l_reg, sizeof(l_reg));
+	if (error != 0)
+		return (error);
+	map_regs_from_linux(&b_reg, &l_reg);
+	error = kern_ptrace(td, PT_SETREGS, pid, &b_reg, 0);
+	return (error);
+}
+
+static int
+linux_ptrace_getregset(struct thread *td, pid_t pid, l_ulong addr, l_ulong data)
+{
+
+	switch (addr) {
+	case LINUX_NT_PRSTATUS:
+		printf("%s: NT_PRSTATUS not implemented; returning EINVAL\n",
+		    __func__);
+		return (EINVAL);
+	default:
+		printf("%s: PTRACE_GETREGSET request %ld not implemented; "
+		    "returning EINVAL\n", __func__, addr);
+		return (EINVAL);
+	}
+}
+
+static int
+linux_ptrace_seize(struct thread *td, pid_t pid, l_ulong addr, l_ulong data)
+{
+
+	printf("%s: PTRACE_SEIZE not implemented; returning EINVAL\n", __func__);
+	return (EINVAL);
+}
+
+int
+linux_ptrace(struct thread *td, struct linux_ptrace_args *uap)
+{
+	void *addr;
+	pid_t pid;
+	int error, sig;
+
+	pid  = (pid_t)uap->pid;
+	addr = (void *)uap->addr;
+
+	switch (uap->req) {
+	case LINUX_PTRACE_TRACEME:
+		error = kern_ptrace(td, PT_TRACE_ME, 0, 0, 0);
+		break;
+	case LINUX_PTRACE_PEEKTEXT:
+	case LINUX_PTRACE_PEEKDATA:
+		error = linux_ptrace_peek(td, pid, addr, (void *)uap->data);
+		if (error != 0)
+			return (error);
+		/*
+		 * Linux expects this syscall to read 64 bits, not 32.
+		 */
+		error = linux_ptrace_peek(td, pid,
+		    (void *)(uap->addr + 4), (void *)(uap->data + 4));
+		break;
+	case LINUX_PTRACE_POKETEXT:
+		error = kern_ptrace(td, PT_WRITE_I, pid, addr, uap->data);
+		break;
+	case LINUX_PTRACE_POKEDATA:
+		error = kern_ptrace(td, PT_WRITE_D, pid, addr, uap->data);
+		break;
+	case LINUX_PTRACE_CONT:
+		error = map_signum(uap->data, &sig);
+		if (error != 0)
+			break;
+		error = kern_ptrace(td, PT_CONTINUE, pid, (void *)1, sig);
+		break;
+	case LINUX_PTRACE_KILL:
+		error = kern_ptrace(td, PT_KILL, pid, addr, uap->data);
+		break;
+	case LINUX_PTRACE_SINGLESTEP:
+		error = map_signum(uap->data, &sig);
+		if (error != 0)
+			break;
+		error = kern_ptrace(td, PT_STEP, pid, (void *)1, sig);
+		break;
+	case LINUX_PTRACE_GETREGS:
+		error = linux_ptrace_getregs(td, pid, (void *)uap->data);
+		break;
+	case LINUX_PTRACE_SETREGS:
+		error = linux_ptrace_setregs(td, pid, (void *)uap->data);
+		break;
+	case LINUX_PTRACE_ATTACH:
+		error = kern_ptrace(td, PT_ATTACH, pid, addr, uap->data);
+		break;
+	case LINUX_PTRACE_DETACH:
+		error = map_signum(uap->data, &sig);
+		if (error != 0)
+			break;
+		error = kern_ptrace(td, PT_DETACH, pid, (void *)1, sig);
+		break;
+	case LINUX_PTRACE_SYSCALL:
+		error = map_signum(uap->data, &sig);
+		if (error != 0)
+			break;
+		error = kern_ptrace(td, PT_SYSCALL, pid, (void *)1, sig);
+		break;
+	case LINUX_PTRACE_SETOPTIONS:
+		error = linux_ptrace_setoptions(td, pid, uap->data);
+		break;
+	case LINUX_PTRACE_GETREGSET:
+		error = linux_ptrace_getregset(td, pid, uap->addr, uap->data);
+		break;
+	case LINUX_PTRACE_SEIZE:
+		error = linux_ptrace_seize(td, pid, uap->addr, uap->data);
+		break;
+	default:
+		printf("%s: ptrace(%ld, ...) not implemented; returning EINVAL\n",
+		    __func__, uap->req);
+		error = EINVAL;
+		break;
+	}
+
+	return (error);
+}

Modified: head/sys/modules/linux64/Makefile
==============================================================================
--- head/sys/modules/linux64/Makefile	Thu Feb 16 12:56:10 2017	(r313808)
+++ head/sys/modules/linux64/Makefile	Thu Feb 16 13:32:15 2017	(r313809)
@@ -7,7 +7,7 @@ VDSO=	linux_vdso
 KMOD=	linux64
 SRCS=	linux_fork.c linux_dummy.c linux_file.c linux_event.c \
 	linux_futex.c linux_getcwd.c linux_ioctl.c linux_ipc.c \
-	linux_machdep.c linux_misc.c linux_signal.c \
+	linux_machdep.c linux_misc.c linux_ptrace.c linux_signal.c \
 	linux_socket.c linux_stats.c linux_sysctl.c linux_sysent.c \
 	linux_sysvec.c linux_time.c linux_vdso.c linux_timer.c \
 	opt_inet6.h opt_compat.h opt_posix.h opt_usb.h \



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