/proc/PID/syscall
This adds /proc/PID/syscall and /proc/PID/task/TID/syscall magic files.
These use task_current_syscall() to show the task's current system call
number and argument registers, stack pointer and PC. For a task blocked
but not in a syscall, the file shows "-1" in place of the syscall number,
followed by only the SP and PC. For a task that's not blocked, it shows
"running".
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 4b74dba..81bce67 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -509,6 +509,26 @@
return count;
}
+#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
+static int proc_pid_syscall(struct task_struct *task, char *buffer)
+{
+ long nr;
+ unsigned long args[6], sp, pc;
+
+ if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
+ return sprintf(buffer, "running\n");
+
+ if (nr < 0)
+ return sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
+
+ return sprintf(buffer,
+ "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
+ nr,
+ args[0], args[1], args[2], args[3], args[4], args[5],
+ sp, pc);
+}
+#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
+
/************************************************************************/
/* Here the fs part begins */
/************************************************************************/
@@ -2478,6 +2498,9 @@
#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, pid_sched),
#endif
+#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
+ INF("syscall", S_IRUSR, pid_syscall),
+#endif
INF("cmdline", S_IRUGO, pid_cmdline),
ONE("stat", S_IRUGO, tgid_stat),
ONE("statm", S_IRUGO, pid_statm),
@@ -2810,6 +2833,9 @@
#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, pid_sched),
#endif
+#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
+ INF("syscall", S_IRUSR, pid_syscall),
+#endif
INF("cmdline", S_IRUGO, pid_cmdline),
ONE("stat", S_IRUGO, tid_stat),
ONE("statm", S_IRUGO, pid_statm),