Allow tkill
tkill and tgkill are syscalls that do not have glibc wrappers, but
they are required in order to send a signal to a specific thread.
Non-android software may call them directly with syscall(). Bionic
provides a wrapper for tgkill, so seccomp allows it, but not for
tkill. Add tkill to the whitelist.
This can be reproduced with:
sleep 1000 & sleep 1 ; strace -p $!
then hit ctrl-C, and the shell will print "Bad system call" because
the strace process died with SIGSYS
Bug: 34586922
Test: repro case is fixed
Change-Id: Ib6962a967f2cc757f2906de7905e75e1b6d6f39f
diff --git a/init/seccomp.cpp b/init/seccomp.cpp
index b7744b6..d632302 100644
--- a/init/seccomp.cpp
+++ b/init/seccomp.cpp
@@ -170,6 +170,9 @@
// Needed for trusty
AllowSyscall(f, __NR_syncfs);
+ // Needed for strace
+ AllowSyscall(f, __NR_tkill); // __NR_tkill
+
// Needed for kernel to restart syscalls
AllowSyscall(f, __NR_restart_syscall);
@@ -204,6 +207,9 @@
// Syscalls needed to run GFXBenchmark
AllowSyscall(f, 190); // __NR_vfork
+ // Needed for strace
+ AllowSyscall(f, 238); // __NR_tkill
+
// Needed for kernel to restart syscalls
AllowSyscall(f, 0); // __NR_restart_syscall