[PATCH v4 3/5] nohz: cpu_isolated strict mode configurable signal
From: Chris Metcalf <hidden>
Date: 2015-07-13 19:58:30
Also in:
lkml
Subsystem:
nohz, dynticks support, the rest · Maintainers:
Anna-Maria Behnsen, Frederic Weisbecker, Ingo Molnar, Thomas Gleixner, 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/tick-sched.c | 15 +++++++++++---- 2 files changed, 13 insertions(+), 4 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/tick-sched.c b/kernel/time/tick-sched.c
index 9f495c7c7dc2..c5eca9c99fad 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c@@ -447,11 +447,18 @@ void tick_nohz_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); } /*
@@ -470,7 +477,7 @@ void tick_nohz_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); } /*
@@ -481,7 +488,7 @@ void tick_nohz_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); } #endif
--
2.1.2