[PATCH v5 4/6] cpu_isolated: provide strict mode configurable signal
From: Chris Metcalf <hidden>
Date: 2015-07-28 19:50:18
Also in:
lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Allow userspace to override the default SIGKILL delivered when a cpu_isolated 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/time/cpu_isolated.c | 17 ++++++++++++----- 2 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
index 0c11238a84fb..ab45bd3d5799 100644
--- a/include/uapi/linux/prctl.h
+++ b/include/uapi/linux/prctl.h@@ -195,5 +195,7 @@ struct prctl_mm_map { #define PR_GET_CPU_ISOLATED 48 # define PR_CPU_ISOLATED_ENABLE (1 << 0) # define PR_CPU_ISOLATED_STRICT (1 << 1) +# define PR_CPU_ISOLATED_SET_SIG(sig) (((sig) & 0x7f) << 8) +# define PR_CPU_ISOLATED_GET_SIG(bits) (((bits) >> 8) & 0x7f) #endif /* _LINUX_PRCTL_H */
diff --git a/kernel/time/cpu_isolated.c b/kernel/time/cpu_isolated.c
index d30bf3852897..9f8fcbd97770 100644
--- a/kernel/time/cpu_isolated.c
+++ b/kernel/time/cpu_isolated.c@@ -71,11 +71,18 @@ void cpu_isolated_enter(void) } } -static void kill_cpu_isolated_strict_task(void) -{ +static void kill_cpu_isolated_strict_task(int is_syscall) + { + siginfo_t info = {}; + int sig; + dump_stack(); current->cpu_isolated_flags &= ~PR_CPU_ISOLATED_ENABLE; - send_sig(SIGKILL, current, 1); + + sig = PR_CPU_ISOLATED_GET_SIG(current->cpu_isolated_flags) ?: SIGKILL; + info.si_signo = sig; + info.si_code = is_syscall; + send_sig_info(sig, &info, current); } /*
@@ -94,7 +101,7 @@ void cpu_isolated_syscall(int syscall) pr_warn("%s/%d: cpu_isolated strict mode violated by syscall %d\n", current->comm, current->pid, syscall); - kill_cpu_isolated_strict_task(); + kill_cpu_isolated_strict_task(1); } /*
@@ -105,5 +112,5 @@ void cpu_isolated_exception(void) { pr_warn("%s/%d: cpu_isolated strict mode violated by exception\n", current->comm, current->pid); - kill_cpu_isolated_strict_task(); + kill_cpu_isolated_strict_task(0); }
--
2.1.2