From 71166900c7ab552fec678cb77beed5c5762f76cf Mon Sep 17 00:00:00 2001
From: David Smith <dsmith@redhat.com>
Date: Mon, 25 Nov 2013 14:00:51 -0600
Subject: [PATCH] PR16207 partial fix: Fix the 'dup' [nd_]syscall.exp tests on
 rawhide.

* tapset/linux/syscalls.stp: Split the syscall.dup2 probe into
  syscall.dup2 and syscall.dup3.
* tapset/linux/nd_syscalls.stp: Split the nd_syscall.dup2 probe into
  nd_syscall.dup2 and nd_syscall.dup3.
* runtime/linux/compat_unistd.h: Added the __NR_compat_dup3 define.
* testsuite/buildok/syscalls-detailed.stp: Added dup3 test.
* testsuite/buildok/nd_syscalls-detailed.stp: Ditto.
---
 runtime/linux/compat_unistd.h              |   5 +
 tapset/linux/nd_syscalls.stp               | 105 ++++-----------------
 tapset/linux/syscalls.stp                  |  46 +++------
 testsuite/buildok/nd_syscalls-detailed.stp |   4 +-
 testsuite/buildok/syscalls-detailed.stp    |   4 +-
 5 files changed, 38 insertions(+), 126 deletions(-)

diff --git a/runtime/linux/compat_unistd.h b/runtime/linux/compat_unistd.h
index 0138ec5e0..47e259dac 100644
--- a/runtime/linux/compat_unistd.h
+++ b/runtime/linux/compat_unistd.h
@@ -15,6 +15,9 @@
 
 // On older kernels (like RHEL5), we have to define our own 32-bit
 // syscall numbers.
+#ifndef __NR_ia32_dup3
+#define __NR_ia32_dup3 330
+#endif
 #ifndef __NR_ia32_faccessat
 #define __NR_ia32_faccessat 307
 #endif
@@ -34,6 +37,7 @@
 #define __NR_ia32_symlinkat 304
 #endif
 
+#define __NR_compat_dup3		__NR_ia32_dup3
 #define __NR_compat_faccessat		__NR_ia32_faccessat
 #define __NR_compat_fchmodat		__NR_ia32_fchmodat
 #define __NR_compat_fchownat		__NR_ia32_fchownat
@@ -48,6 +52,7 @@
 // On the ppc64 and s390x, the 32-bit syscalls use the same number
 // as the 64-bit syscalls.
 
+#define __NR_compat_dup3		__NR_dup3
 #define __NR_compat_faccessat		__NR_faccessat
 #define __NR_compat_fchmodat		__NR_fchmodat
 #define __NR_compat_fchownat		__NR_fchownat
diff --git a/tapset/linux/nd_syscalls.stp b/tapset/linux/nd_syscalls.stp
index 3d2aa69b0..a55e3f23e 100644
--- a/tapset/linux/nd_syscalls.stp
+++ b/tapset/linux/nd_syscalls.stp
@@ -690,122 +690,51 @@ probe nd_syscall.dup.return = kprobe.function("sys_dup").return ?
 
 # dup2 _______________________________________________________
 # long sys_dup2(unsigned int oldfd, unsigned int newfd)
-# Only handles corner case, others handled by dup3.
 probe nd_syscall.dup2 = kprobe.function("sys_dup2")
 {
-	// if ($oldfd != $newfd) next;
-	// name = "dup2"
+	name = "dup2"
 	// oldfd = $oldfd
 	// newfd = $newfd
+	// # The dup2 syscall doesn't have a 'flags' argument. But, the
+	// # syscall.dup2 and syscall.dup3 probes used to be combined, so
+	// # both probes need a 'flags' variable.
 	// flags = 0
 	// argstr = sprintf("%d, %d", $oldfd, $newfd)
 	asmlinkage()
 	oldfd = int_arg(1)
 	newfd = int_arg(2)
-	if (oldfd != newfd) next;
-
-	name = "dup2"
+	# The dup2 syscall doesn't have a 'flags' argument. But, the
+	# syscall.dup2 and syscall.dup3 probes used to be combined, so
+	# both probes need a 'flags' variable.
 	flags = 0
 	argstr = sprintf("%d, %d", oldfd, newfd)
 }
 probe nd_syscall.dup2.return = kprobe.function("sys_dup2").return
 {
-	// if ($oldfd != $newfd) next;
-	// name = "dup2"
-	// retstr = return_str(1, $return)
-	if (@entry(__asmlinkage_int_arg(1)) != @entry(int_arg(2))) next;
 	name = "dup2"
 	retstr = returnstr(1)
 }
 
-# dup3 (handles both dup2 and dup3 except for corner case)___________
-# long sys_dup2(unsigned int oldfd, unsigned int newfd)
+# dup3 _______________________________________________________
 # SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags)
-probe nd_syscall.dup2 = __nd_syscall.dup3 !, __nd_syscall.dup2
-{
-}
-probe __nd_syscall.dup3 = kprobe.function("sys_dup3")
+probe nd_syscall.dup3 = kprobe.function("sys_dup3") ?
 {
+	@__syscall_compat_gate(%{ __NR_dup3 %}, %{ __NR_compat_dup3 %})
+	name = "dup3";
 	// oldfd = $oldfd
 	// newfd = $newfd
-	// flags = @defined($flags) ? $flags : 0;
+	// flags = $flags
+	// argstr = sprintf("%d, %d, %s", $oldfd, $newfd, _dup3_flag_str(flags));
 	asmlinkage()
 	oldfd = int_arg(1)
 	newfd = int_arg(2)
 	flags = int_arg(3)
-
-	# Corner case handled by dup2
-	// if ($oldfd == $newfd && flags == 0) next
-	if (oldfd == newfd && flags == 0) next
-
-	// if (flags == 0) {
-	// 	name = "dup2";
-	// 	argstr = sprintf("%d, %d", $oldfd, $newfd);
-	// } else {
-	// 	name = "dup3";
-	// 	argstr = sprintf("%d, %d, %s", $oldfd, $newfd,
-	// 			 _dup3_flag_str(flags));
-	// }
-	if (flags == 0) {
-		name = "dup2";
-		argstr = sprintf("%d, %d", oldfd, newfd);
-	} else {
-		name = "dup3";
-		argstr = sprintf("%d, %d, %s", oldfd, newfd,
-				 _dup3_flag_str(flags));
-	}
+	argstr = sprintf("%d, %d, %s", oldfd, newfd, _dup3_flag_str(flags));
 }
-probe __nd_syscall.dup2 = kprobe.function("sys_dup2")
+probe nd_syscall.dup3.return = kprobe.function("sys_dup3").return ?
 {
-	// oldfd = $oldfd
-	// newfd = $newfd
-	// flags = @defined($flags) ? $flags : 0;
-	asmlinkage()
-	oldfd = int_arg(1)
-	newfd = int_arg(2)
-	flags = 0
-
-	# Corner case handled by dup2
-	// if ($oldfd == $newfd && flags == 0) next
-	if (oldfd == newfd) next
-
-	// if (flags == 0) {
-	// 	name = "dup2";
-	// 	argstr = sprintf("%d, %d", $oldfd, $newfd);
-	// } else {
-	// 	name = "dup3";
-	// 	argstr = sprintf("%d, %d, %s", $oldfd, $newfd,
-	// 			 _dup3_flag_str(flags));
-	// }
-	name = "dup2";
-	argstr = sprintf("%d, %d", oldfd, newfd);
-}
-probe nd_syscall.dup2.return = __nd_syscall.dup3.return !,
-                               __nd_syscall.dup2.return
-{
-}
-probe __nd_syscall.dup3.return = kprobe.function("sys_dup3").return
-{
-	// flags = @defined($flags) ? $flags : 0;
-	flags = @entry(__asmlinkage_int_arg(3))
-
-	# Corner case handled by dup2
-	// if ($oldfd == $newfd && flags == 0) next
-	if (@entry(int_arg(1)) == @entry(int_arg(2)) && flags == 0) next
-
-	name = flags == 0 ? "dup2" : "dup3";
-	// retstr = return_str(1, $return)
-	retstr = returnstr(1)
-}
-probe __nd_syscall.dup2.return = kprobe.function("sys_dup2").return
-{
-	# Corner case handled by dup2
-	// if ($oldfd == $newfd && flags == 0) next
-	if (@entry(__asmlinkage_int_arg(1)) == @entry(int_arg(2))) next
-
-	// name = flags == 0 ? "dup2" : "dup3";
-	// retstr = return_str(1, $return)
-	name = "dup2"
+	@__syscall_compat_gate(%{ __NR_dup3 %}, %{ __NR_compat_dup3 %})
+	name = "dup3"
 	retstr = returnstr(1)
 }
 
diff --git a/tapset/linux/syscalls.stp b/tapset/linux/syscalls.stp
index e2fd8dabe..40495ca1e 100644
--- a/tapset/linux/syscalls.stp
+++ b/tapset/linux/syscalls.stp
@@ -553,62 +553,40 @@ probe syscall.dup.return = kernel.function("sys_dup").return
 	retstr = return_str(1, $return)
 }
 
-# Notice there are two syscall.dup2 probe aliases. This is
-# intentional, to handle dup2/dup3 properly (and all their corner
-# cases).  See commit 816395 for details (and a testcase).
-#
 # dup2 _______________________________________________________
 # long sys_dup2(unsigned int oldfd, unsigned int newfd)
-# Only handles corner case, others handled by dup3.
 probe syscall.dup2 = kernel.function("sys_dup2").call
 {
-	if ($oldfd != $newfd) next;
-
 	name = "dup2"
 	oldfd = $oldfd
 	newfd = $newfd
+	# The dup2 syscall doesn't have a 'flags' argument. But, the
+	# syscall.dup2 and syscall.dup3 probes used to be combined, so
+	# both probes need a 'flags' variable.
 	flags = 0
 	argstr = sprintf("%d, %d", $oldfd, $newfd)
 }
 probe syscall.dup2.return = kernel.function("sys_dup2").return
 {
-	if ($oldfd != $newfd) next;
-
 	name = "dup2"
 	retstr = return_str(1, $return)
 }
 
-# dup3 (handles both dup2 and dup3 except for corner case)___________
-# long sys_dup2(unsigned int oldfd, unsigned int newfd)
+# dup3 _______________________________________________________
 # SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags)
-probe syscall.dup2 = kernel.function("sys_dup3").call !,
-                     kernel.function("sys_dup2").call
+probe syscall.dup3 = kernel.function("sys_dup3").call ?
 {
+	@__syscall_compat_gate(%{ __NR_dup3 %}, %{ __NR_compat_dup3 %})
+	name = "dup3";
 	oldfd = $oldfd
 	newfd = $newfd
-	flags = @choose_defined($flags, 0);
-
-	# Corner case handled by dup2
-	if ($oldfd == $newfd && flags == 0) next
-
-	if (flags == 0) {
-		name = "dup2";
-		argstr = sprintf("%d, %d", $oldfd, $newfd);
-	} else {
-		name = "dup3";
-		argstr = sprintf("%d, %d, %s", $oldfd, $newfd,
-				 _dup3_flag_str(flags));
-	}
+	flags = $flags
+	argstr = sprintf("%d, %d, %s", $oldfd, $newfd, _dup3_flag_str(flags));
 }
-probe syscall.dup2.return = kernel.function("sys_dup3").return !,
-                            kernel.function("sys_dup2").return
+probe syscall.dup3.return = kernel.function("sys_dup3").return ?
 {
-	flags = @choose_defined($flags, 0);
-
-	# Corner case handled by dup2
-	if ($oldfd == $newfd && flags == 0) next
-
-	name = flags == 0 ? "dup2" : "dup3";
+	@__syscall_compat_gate(%{ __NR_dup3 %}, %{ __NR_compat_dup3 %})
+	name = "dup3"
 	retstr = return_str(1, $return)
 }
 
diff --git a/testsuite/buildok/nd_syscalls-detailed.stp b/testsuite/buildok/nd_syscalls-detailed.stp
index 8152f8d5f..b3489e16e 100755
--- a/testsuite/buildok/nd_syscalls-detailed.stp
+++ b/testsuite/buildok/nd_syscalls-detailed.stp
@@ -231,12 +231,12 @@ probe nd_syscall.dup.return
 	printf("%s, %s\n", name, retstr)
 }
 
-probe nd_syscall.dup2
+probe nd_syscall.dup2, nd_syscall.dup3 ?
 {
 	printf("%s, %s\n", name, argstr)
 	printf("%d, %d, %d\n", oldfd, newfd, flags)
 }
-probe nd_syscall.dup2.return
+probe nd_syscall.dup2.return, nd_syscall.dup3.return ?
 {
 	printf("%s, %s\n", name, retstr)
 }
diff --git a/testsuite/buildok/syscalls-detailed.stp b/testsuite/buildok/syscalls-detailed.stp
index e1c626c74..1d47d623d 100755
--- a/testsuite/buildok/syscalls-detailed.stp
+++ b/testsuite/buildok/syscalls-detailed.stp
@@ -231,12 +231,12 @@ probe syscall.dup.return
 	printf("%s, %s\n", name, retstr)
 }
 
-probe syscall.dup2
+probe syscall.dup2, syscall.dup3 ?
 {
 	printf("%s, %s\n", name, argstr)
 	printf("%d, %d, %d\n", oldfd, newfd, flags)
 }
-probe syscall.dup2.return
+probe syscall.dup2.return, syscall.dup3.return ?
 {
 	printf("%s, %s\n", name, retstr)
 }
-- 
2.43.5