[PATCH v3 2/3] fs/proc/array: Add Syscall User Dispatch to proc status

From: Gregory Price
Date: Fri Jan 20 2023 - 09:45:25 EST


If a dispatch selector has been configured for Syscall User Dispatch,
report Syscall User Dispath as configured in proc/status.

This provides an indicator to userland checkpoint/restart software that
it much manage special signal conditions (similar to SECCOMP)

Signed-off-by: Gregory Price <gregory.price@xxxxxxxxxxxx>
---
fs/proc/array.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 49283b8103c7..c85cdb4c137c 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -428,6 +428,13 @@ static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm)
seq_printf(m, "THP_enabled:\t%d\n", thp_enabled);
}

+static inline void task_syscall_user_dispatch(struct seq_file *m,
+ struct task_struct *p)
+{
+ seq_put_decimal_ull(m, "\nSyscall_user_dispatch:\t",
+ (p->syscall_dispatch.selector != NULL));
+}
+
int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
@@ -451,6 +458,7 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
task_cpus_allowed(m, task);
cpuset_task_status_allowed(m, task);
task_context_switch_counts(m, task);
+ task_syscall_user_dispatch(m, task);
return 0;
}

--
2.39.0