selftests/x86: Add a fork() to entry_from_vm86 to catch fork bugs

amluto · KAGA-KOKO · commit 226f1f729ce2 · 2015-10-31T09:50:25.000+01:00
Mere possession of vm86 state is strange. Make sure that nothing gets corrupted if we fork after calling vm86(). Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Stas Sergeev <stsp@list.ru> Link: http://lkml.kernel.org/r/08f83295460a80e41dc5e3e81ec40d6844d316f5.1446270067.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/tools/testing/selftests/x86/entry_from_vm86.c b/tools/testing/selftests/x86/entry_from_vm86.c
@@ -230,5 +230,9 @@ int main(void)
 	}
 	clearhandler(SIGSEGV);
 
+	/* Make sure nothing explodes if we fork. */
+	if (fork() > 0)
+		return 0;
+
 	return (nerrs == 0 ? 0 : 1);
 }

Original file line number	Diff line number	Diff line change
`@@ -230,5 +230,9 @@ int main(void)`
`230`	`230`	`}`
`231`	`231`	`clearhandler(SIGSEGV);`
`232`	`232`
	`233`	`+ /* Make sure nothing explodes if we fork. */`
	`234`	`+ if (fork() > 0)`
	`235`	`+ return 0;`
	`236`	`+`
`233`	`237`	`return (nerrs == 0 ? 0 : 1);`
`234`	`238`	`}`