Patch "selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     selftests-x86-do-not-rely-on-int-0x80-in-test_mremap_vdso.c.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 2cbc0d66de0480449c75636f55697c7ff3af61fc Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Sun, 11 Feb 2018 12:10:11 +0100
Subject: selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c

From: Dominik Brodowski <linux@dominikbrodowski.net>

commit 2cbc0d66de0480449c75636f55697c7ff3af61fc upstream.

On 64-bit builds, we should not rely on "int $0x80" working (it only does if
CONFIG_IA32_EMULATION=y is enabled).

Without this patch, the move test may succeed, but the "int $0x80" causes
a segfault, resulting in a false negative output of this self-test.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kselftest@vger.kernel.org
Cc: shuah@kernel.org
Link: http://lkml.kernel.org/r/20180211111013.16888-4-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/testing/selftests/x86/test_mremap_vdso.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/tools/testing/selftests/x86/test_mremap_vdso.c
+++ b/tools/testing/selftests/x86/test_mremap_vdso.c
@@ -90,8 +90,12 @@ int main(int argc, char **argv, char **e
 			vdso_size += PAGE_SIZE;
 		}
 
+#ifdef __i386__
 		/* Glibc is likely to explode now - exit with raw syscall */
 		asm volatile ("int $0x80" : : "a" (__NR_exit), "b" (!!ret));
+#else /* __x86_64__ */
+		syscall(SYS_exit, ret);
+#endif
 	} else {
 		int status;
 


Patches currently in stable-queue which might be from linux@dominikbrodowski.net are

queue-4.9/selftests-x86-do-not-rely-on-int-0x80-in-single_step_syscall.c.patch
queue-4.9/selftests-x86-do-not-rely-on-int-0x80-in-test_mremap_vdso.c.patch