[PATCH v6 4/6] task_isolation: provide strict mode configurable signal
From: Chris Metcalf <hidden>
Date: 2015-08-25 19:57:29
Also in:
lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Allow userspace to override the default SIGKILL delivered when a task_isolation process in STRICT mode does a syscall or otherwise synchronously enters the kernel. In addition to being able to set the signal, we now also pass whether or not the interruption was from a syscall in the si_code field of the siginfo. Signed-off-by: Chris Metcalf <redacted> --- include/uapi/linux/prctl.h | 2 ++ kernel/isolation.c | 17 +++++++++++++---- 2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
index e16e13911e8a..2a4ddc890e22 100644
--- a/include/uapi/linux/prctl.h
+++ b/include/uapi/linux/prctl.h@@ -195,5 +195,7 @@ struct prctl_mm_map { #define PR_GET_TASK_ISOLATION 48 # define PR_TASK_ISOLATION_ENABLE (1 << 0) # define PR_TASK_ISOLATION_STRICT (1 << 1) +# define PR_TASK_ISOLATION_SET_SIG(sig) (((sig) & 0x7f) << 8) +# define PR_TASK_ISOLATION_GET_SIG(bits) (((bits) >> 8) & 0x7f) #endif /* _LINUX_PRCTL_H */
diff --git a/kernel/isolation.c b/kernel/isolation.c
index a89a6e9adfb4..b776aa632c8f 100644
--- a/kernel/isolation.c
+++ b/kernel/isolation.c@@ -75,11 +75,20 @@ void task_isolation_enter(void) } } -static void kill_task_isolation_strict_task(void) +static void kill_task_isolation_strict_task(int is_syscall) { + siginfo_t info = {}; + int sig; + dump_stack(); current->task_isolation_flags &= ~PR_TASK_ISOLATION_ENABLE; - send_sig(SIGKILL, current, 1); + + sig = PR_TASK_ISOLATION_GET_SIG(current->task_isolation_flags); + if (sig == 0) + sig = SIGKILL; + info.si_signo = sig; + info.si_code = is_syscall; + send_sig_info(sig, &info, current); } /*
@@ -98,7 +107,7 @@ void task_isolation_syscall(int syscall) pr_warn("%s/%d: task_isolation strict mode violated by syscall %d\n", current->comm, current->pid, syscall); - kill_task_isolation_strict_task(); + kill_task_isolation_strict_task(1); } /*
@@ -109,5 +118,5 @@ void task_isolation_exception(void) { pr_warn("%s/%d: task_isolation strict mode violated by exception\n", current->comm, current->pid); - kill_task_isolation_strict_task(); + kill_task_isolation_strict_task(0); }
--
2.1.2