CHROMIUM: alt-syscall: Whitelist signalfd4(2) for Android.

signalfd4(2) is used by init to detect SIGTERM.

BUG=b:65415372
TEST=init can start
Signed-off-by: Luis Hector Chavez <lhchavez@chromium.org>
Change-Id: If49b2cc6ff9da2c6642f10094cf557807f08eef9
Reviewed-on: https://chromium-review.googlesource.com/657966
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
diff --git a/security/chromiumos/alt-syscall.c b/security/chromiumos/alt-syscall.c
index fbde26e..a7aca9e 100644
--- a/security/chromiumos/alt-syscall.c
+++ b/security/chromiumos/alt-syscall.c
@@ -344,6 +344,7 @@
 #define __NR_compat_settimeofday	__NR_ia32_settimeofday
 #define __NR_compat_setuid	__NR_ia32_setuid
 #define __NR_compat_setxattr	__NR_ia32_setxattr
+#define __NR_compat_signalfd4	__NR_ia32_signalfd4
 #define __NR_compat_sigaltstack	__NR_ia32_sigaltstack
 #define __NR_compat_socketcall	__NR_ia32_socketcall
 #define __NR_compat_splice	__NR_ia32_splice
@@ -792,6 +793,7 @@
 	SYSCALL_ENTRY(setsid),
 	SYSCALL_ENTRY(settimeofday),
 	SYSCALL_ENTRY(setxattr),
+	SYSCALL_ENTRY(signalfd4),
 	SYSCALL_ENTRY(sigaltstack),
 	SYSCALL_ENTRY(splice),
 	SYSCALL_ENTRY(statfs),
@@ -1322,6 +1324,7 @@
 	COMPAT_SYSCALL_ENTRY(setsid),
 	COMPAT_SYSCALL_ENTRY(settimeofday),
 	COMPAT_SYSCALL_ENTRY(setxattr),
+	COMPAT_SYSCALL_ENTRY(signalfd4),
 	COMPAT_SYSCALL_ENTRY(sigaltstack),
 	COMPAT_SYSCALL_ENTRY(splice),
 	COMPAT_SYSCALL_ENTRY(stat),