[PATCH] prctl: add PR_[GS]ET_KILLABLE
From: Jürg Billeter <hidden>
Date: 2018-07-30 08:01:13
Also in:
lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
PR_SET_KILLABLE clears the SIGNAL_UNKILLABLE flag. This allows CLONE_NEWPID tasks to restore normal signal behavior, opting out of the special signal protection for init processes. This is required for job control in a shell that uses CLONE_NEWPID for child processes. This prctl does not allow setting the SIGNAL_UNKILLABLE flag, only clearing. Signed-off-by: Jürg Billeter <redacted> --- include/uapi/linux/prctl.h | 4 ++++ kernel/sys.c | 11 +++++++++++ 2 files changed, 15 insertions(+)
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
index c0d7ea0bf5b6..92afb63da727 100644
--- a/include/uapi/linux/prctl.h
+++ b/include/uapi/linux/prctl.h@@ -219,4 +219,8 @@ struct prctl_mm_map { # define PR_SPEC_DISABLE (1UL << 2) # define PR_SPEC_FORCE_DISABLE (1UL << 3) +/* Control SIGNAL_UNKILLABLE */ +#define PR_GET_KILLABLE 54 +#define PR_SET_KILLABLE 55 + #endif /* _LINUX_PRCTL_H */
diff --git a/kernel/sys.c b/kernel/sys.c
index 38509dc1f77b..264de630d548 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c@@ -2484,6 +2484,17 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, return -EINVAL; error = arch_prctl_spec_ctrl_set(me, arg2, arg3); break; + case PR_GET_KILLABLE: + if (arg3 || arg4 || arg5) + return -EINVAL; + error = put_user(!(me->signal->flags & SIGNAL_UNKILLABLE), + (int __user *)arg2); + break; + case PR_SET_KILLABLE: + if (arg2 != 1 || arg3 || arg4 || arg5) + return -EINVAL; + me->signal->flags &= ~SIGNAL_UNKILLABLE; + break; default: error = -EINVAL; break;
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2.18.0