2012-08-14 14:06:46

by Cyrill Gorcunov

Subject: [patch 8/8] fdinfo: Show sigmask for signalfd fd

Signed-off-by: Pavel Emelyanov <[email protected]>
Signed-off-by: Cyrill Gorcunov <[email protected]>
---
fs/proc/array.c | 2 -
fs/signalfd.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/proc_fs.h | 3 ++
3 files changed, 67 insertions(+), 1 deletion(-)

Index: linux-2.6.git/fs/proc/array.c
===================================================================
--- linux-2.6.git.orig/fs/proc/array.c
+++ linux-2.6.git/fs/proc/array.c
@@ -220,7 +220,7 @@ static inline void task_state(struct seq
seq_putc(m, '\n');
}

-static void render_sigset_t(struct seq_file *m, const char *header,
+void render_sigset_t(struct seq_file *m, const char *header,
sigset_t *set)
{
int i;
Index: linux-2.6.git/fs/signalfd.c
===================================================================
--- linux-2.6.git.orig/fs/signalfd.c
+++ linux-2.6.git/fs/signalfd.c
@@ -29,6 +29,7 @@
#include <linux/anon_inodes.h>
#include <linux/signalfd.h>
#include <linux/syscalls.h>
+#include <linux/proc_fs.h>

void signalfd_cleanup(struct sighand_struct *sighand)
{
@@ -46,6 +47,7 @@ void signalfd_cleanup(struct sighand_str
}

struct signalfd_ctx {
+ seqcount_t cnt;
sigset_t sigmask;
};

@@ -259,6 +261,7 @@ SYSCALL_DEFINE4(signalfd4, int, ufd, sig
return -ENOMEM;

ctx->sigmask = sigmask;
+ seqcount_init(&ctx->cnt);

/*
* When we call this, the initialization must be complete, since
@@ -279,7 +282,9 @@ SYSCALL_DEFINE4(signalfd4, int, ufd, sig
return -EINVAL;
}
spin_lock_irq(&current->sighand->siglock);
+ write_seqcount_begin(&ctx->cnt);
ctx->sigmask = sigmask;
+ write_seqcount_end(&ctx->cnt);
spin_unlock_irq(&current->sighand->siglock);

wake_up(&current->sighand->signalfd_wqh);
@@ -294,3 +299,61 @@ SYSCALL_DEFINE3(signalfd, int, ufd, sigs
{
return sys_signalfd4(ufd, user_mask, sizemask, 0);
}
+
+#if defined(CONFIG_PROC_FS) && defined(CONFIG_CHECKPOINT_RESTORE)
+
+static void *seq_start(struct seq_file *m, loff_t *pos)
+{
+ struct proc_fdinfo_extra *extra = m->private;
+ return *pos == 0 ? extra->f_file : NULL;
+}
+
+static void *seq_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ ++*pos;
+ return NULL;
+}
+
+static int seq_show(struct seq_file *m, void *v)
+{
+ struct signalfd_ctx *ctx = ((struct file *)v)->private_data;
+ sigset_t sigmask;
+ unsigned seq;
+
+ do {
+ seq = read_seqcount_begin(&ctx->cnt);
+ sigmask = ctx->sigmask;
+ } while (read_seqcount_retry(&ctx->cnt, seq));
+
+ signotset(&sigmask);
+ render_sigset_t(m, "sigmask:\t", &sigmask);
+ return 0;
+}
+
+static void seq_stop(struct seq_file *p, void *v) { }
+
+static const struct seq_operations signalfd_fdinfo_ops = {
+ .start = seq_start,
+ .next = seq_next,
+ .stop = seq_stop,
+ .show = seq_show,
+};
+
+static int is_signalfd_file(struct file *file)
+{
+ return file->f_op == &signalfd_fops;
+}
+
+static struct proc_fdinfo_driver signalfd_fdinfo = {
+ .name = "signalfd",
+ .ops = &signalfd_fdinfo_ops,
+ .probe = is_signalfd_file,
+};
+
+static int __init signalfd_init(void)
+{
+ return proc_register_fdinfo_driver(&signalfd_fdinfo);
+}
+fs_initcall(signalfd_init);
+
+#endif /* CONFIG_PROC_FS && CONFIG_CHECKPOINT_RESTORE */
Index: linux-2.6.git/include/linux/proc_fs.h
===================================================================
--- linux-2.6.git.orig/include/linux/proc_fs.h
+++ linux-2.6.git/include/linux/proc_fs.h
@@ -316,4 +316,7 @@ static inline struct net *PDE_NET(struct
return pde->parent->data;
}

+#include <asm/signal.h>
+
+void render_sigset_t(struct seq_file *m, const char *header, sigset_t *set);
#endif /* _LINUX_PROC_FS_H */