Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1208831 > unrolled thread

[PATCH 0/3] Stuff for 4.2 (including a revert)

Started byAndy Lutomirski <luto@kernel.org>
First post2015-08-17 21:30 +0200
Last post2015-08-19 09:20 +0200
Articles 3 — 2 participants

Back to article view | Back to linux.kernel

Contents

  [PATCH 0/3] Stuff for 4.2 (including a revert) Andy Lutomirski <luto@kernel.org> - 2015-08-17 21:30 +0200
    [PATCH 3/3] selftests/x86: Add syscall_nt selftest Andy Lutomirski <luto@kernel.org> - 2015-08-17 21:30 +0200
      [tip:x86/asm] selftests/x86: Add syscall_nt selftest tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2015-08-19 09:20 +0200

#1208831 — [PATCH 0/3] Stuff for 4.2 (including a revert)

FromAndy Lutomirski <luto@kernel.org>
Date2015-08-17 21:30 +0200
Subject[PATCH 0/3] Stuff for 4.2 (including a revert)
Message-ID<pYygx-8f8-5@gated-at.bofh.it>
Hi all-

Patch 1 is a revert, Cc'd to stable.  I haven't tried to write a
real test for the bug, but the code definitely looks buggy.  I
intent to fix it for real as part of converting more of the syscall
entry code to C, but this is a better fix for now.

Patch 2 fixes selftests fallout from the sigcontext revert.

Patch 3 is a new test that I thought I added but apparently didn't.
It's probably 4.3 material, but it's related to patch 1, so I'm
sending them together.

Andy Lutomirski (3):
  Revert "sched/x86_64: Don't save flags on context switch"
  selftests/x86: Disable sigreturn_64
  selftests/x86: Add syscall_nt selftest

 arch/x86/include/asm/switch_to.h         | 12 +++----
 tools/testing/selftests/x86/Makefile     |  4 +--
 tools/testing/selftests/x86/syscall_nt.c | 54 ++++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 10 deletions(-)
 create mode 100644 tools/testing/selftests/x86/syscall_nt.c

-- 
2.4.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]

#1208832 — [PATCH 3/3] selftests/x86: Add syscall_nt selftest

FromAndy Lutomirski <luto@kernel.org>
Date2015-08-17 21:30 +0200
Subject[PATCH 3/3] selftests/x86: Add syscall_nt selftest
Message-ID<pYygz-8f8-39@gated-at.bofh.it>
In reply to#1208831
I've had this sitting around for a while.  Add it to the selftests
tree.  Far Cry running under Wine depends on this behavior.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 tools/testing/selftests/x86/Makefile     |  2 +-
 tools/testing/selftests/x86/syscall_nt.c | 54 ++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/x86/syscall_nt.c

diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index 1cda40be06ca..2221f2ba449d 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -4,7 +4,7 @@ include ../lib.mk
 
 .PHONY: all all_32 all_64 warn_32bit_failure clean
 
-TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs
+TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt
 TARGETS_C_32BIT_ONLY := entry_from_vm86 sigreturn
 
 TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY)
diff --git a/tools/testing/selftests/x86/syscall_nt.c b/tools/testing/selftests/x86/syscall_nt.c
new file mode 100644
index 000000000000..60c06af4646a
--- /dev/null
+++ b/tools/testing/selftests/x86/syscall_nt.c
@@ -0,0 +1,54 @@
+/*
+ * syscall_nt.c - checks syscalls with NT set
+ * Copyright (c) 2014-2015 Andrew Lutomirski
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * Some obscure user-space code requires the ability to make system calls
+ * with FLAGS.NT set.  Make sure it works.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <asm/processor-flags.h>
+
+#ifdef __x86_64__
+# define WIDTH "q"
+#else
+# define WIDTH "l"
+#endif
+
+static unsigned long get_eflags(void)
+{
+	unsigned long eflags;
+	asm volatile ("pushf" WIDTH "\n\tpop" WIDTH " %0" : "=rm" (eflags));
+	return eflags;
+}
+
+static void set_eflags(unsigned long eflags)
+{
+	asm volatile ("push" WIDTH " %0\n\tpopf" WIDTH
+		      : : "rm" (eflags) : "flags");
+}
+
+int main()
+{
+	printf("[RUN]\tSet NT and issue a syscall\n");
+	set_eflags(get_eflags() | X86_EFLAGS_NT);
+	syscall(SYS_getpid);
+	if (get_eflags() & X86_EFLAGS_NT) {
+		printf("[OK]\tThe syscall worked and NT is still set\n");
+		return 0;
+	} else {
+		printf("[FAIL]\tThe syscall worked but NT was cleared\n");
+		return 1;
+	}
+}
-- 
2.4.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1209674 — [tip:x86/asm] selftests/x86: Add syscall_nt selftest

Fromtip-bot for Andy Lutomirski <tipbot@zytor.com>
Date2015-08-19 09:20 +0200
Subject[tip:x86/asm] selftests/x86: Add syscall_nt selftest
Message-ID<pZ5Pb-7hG-1@gated-at.bofh.it>
In reply to#1208832
Commit-ID:  a9c909ce8c7853b4fc16055c50eb50d91e20cb93
Gitweb:     http://git.kernel.org/tip/a9c909ce8c7853b4fc16055c50eb50d91e20cb93
Author:     Andy Lutomirski <luto@kernel.org>
AuthorDate: Mon, 17 Aug 2015 12:22:52 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 18 Aug 2015 09:43:38 +0200

selftests/x86: Add syscall_nt selftest

I've had this sitting around for a while.  Add it to the
selftests tree.  Far Cry running under Wine depends on this
behavior.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ee4d63799a9e5294b70930618b71d04d2770eb2d.1439838962.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 tools/testing/selftests/x86/Makefile     |  2 +-
 tools/testing/selftests/x86/syscall_nt.c | 54 ++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index 986e7cb..29089b2 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -4,7 +4,7 @@ include ../lib.mk
 
 .PHONY: all all_32 all_64 warn_32bit_failure clean
 
-TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs ldt_gdt
+TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs ldt_gdt syscall_nt
 TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault sigreturn
 
 TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY)
diff --git a/tools/testing/selftests/x86/syscall_nt.c b/tools/testing/selftests/x86/syscall_nt.c
new file mode 100644
index 0000000..60c06af4
--- /dev/null
+++ b/tools/testing/selftests/x86/syscall_nt.c
@@ -0,0 +1,54 @@
+/*
+ * syscall_nt.c - checks syscalls with NT set
+ * Copyright (c) 2014-2015 Andrew Lutomirski
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * Some obscure user-space code requires the ability to make system calls
+ * with FLAGS.NT set.  Make sure it works.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <asm/processor-flags.h>
+
+#ifdef __x86_64__
+# define WIDTH "q"
+#else
+# define WIDTH "l"
+#endif
+
+static unsigned long get_eflags(void)
+{
+	unsigned long eflags;
+	asm volatile ("pushf" WIDTH "\n\tpop" WIDTH " %0" : "=rm" (eflags));
+	return eflags;
+}
+
+static void set_eflags(unsigned long eflags)
+{
+	asm volatile ("push" WIDTH " %0\n\tpopf" WIDTH
+		      : : "rm" (eflags) : "flags");
+}
+
+int main()
+{
+	printf("[RUN]\tSet NT and issue a syscall\n");
+	set_eflags(get_eflags() | X86_EFLAGS_NT);
+	syscall(SYS_getpid);
+	if (get_eflags() & X86_EFLAGS_NT) {
+		printf("[OK]\tThe syscall worked and NT is still set\n");
+		return 0;
+	} else {
+		printf("[FAIL]\tThe syscall worked but NT was cleared\n");
+		return 1;
+	}
+}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web