From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Metcalf Subject: [PATCH v7 04/11] task_isolation: provide strict mode configurable signal Date: Mon, 28 Sep 2015 11:17:19 -0400 Message-ID: <1443453446-7827-5-git-send-email-cmetcalf@ezchip.com> References: <1443453446-7827-1-git-send-email-cmetcalf@ezchip.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1443453446-7827-1-git-send-email-cmetcalf@ezchip.com> Sender: linux-doc-owner@vger.kernel.org To: Gilad Ben Yossef , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Andrew Morton , Rik van Riel , Tejun Heo , Frederic Weisbecker , Thomas Gleixner , "Paul E. McKenney" , Christoph Lameter , Viresh Kumar , Catalin Marinas , Will Deacon , Andy Lutomirski , linux-doc@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Chris Metcalf List-Id: linux-api@vger.kernel.org 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 --- 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 2b8038b0d1e1..a5582ace987f 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -202,5 +202,7 @@ struct prctl_mm_map { #define PR_GET_TASK_ISOLATION 49 # 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 3779ba670472..44bafcd08bca 100644 --- a/kernel/isolation.c +++ b/kernel/isolation.c @@ -77,14 +77,23 @@ 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; + /* RCU should have been enabled prior to this point. */ RCU_LOCKDEP_WARN(!rcu_is_watching(), "kernel entry without RCU"); 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); } /* @@ -103,7 +112,7 @@ 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); } /* @@ -114,5 +123,5 @@ 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