From d963cd95bea93b7db9390a71d1e2cabbb3b2c3ea Mon Sep 17 00:00:00 2001 From: "Chen, Gong" Date: Wed, 11 Jun 2014 14:02:20 -0700 Subject: [PATCH] RAS, debugfs: Add debugfs interface for RAS subsystem Implement a new debugfs interface for RAS susbsystem. A file named daemon_active is added there accordingly. This file is used to track if user space daemon accesses perf/trace interface or not. One can track which daemon opens it via "lsof /path/to/debugfs/ras/daemon_active". Signed-off-by: Chen, Gong Link: http://lkml.kernel.org/r/1402475691-30045-5-git-send-email-gong.chen@linux.intel.com Signed-off-by: Borislav Petkov Signed-off-by: Tony Luck --- drivers/ras/Makefile | 2 +- drivers/ras/debugfs.c | 56 +++++++++++++++++++++++++++++++++++++++++++ drivers/ras/ras.c | 14 +++++++++++ include/linux/ras.h | 14 +++++++++++ 4 files changed, 85 insertions(+), 1 deletion(-) create mode 100644 drivers/ras/debugfs.c create mode 100644 include/linux/ras.h diff --git a/drivers/ras/Makefile b/drivers/ras/Makefile index 223e806fa5bf..d7f73341ced3 100644 --- a/drivers/ras/Makefile +++ b/drivers/ras/Makefile @@ -1 +1 @@ -obj-$(CONFIG_RAS) += ras.o +obj-$(CONFIG_RAS) += ras.o debugfs.o diff --git a/drivers/ras/debugfs.c b/drivers/ras/debugfs.c new file mode 100644 index 000000000000..0322acf67ea5 --- /dev/null +++ b/drivers/ras/debugfs.c @@ -0,0 +1,56 @@ +#include + +static struct dentry *ras_debugfs_dir; + +static atomic_t trace_count = ATOMIC_INIT(0); + +int ras_userspace_consumers(void) +{ + return atomic_read(&trace_count); +} +EXPORT_SYMBOL_GPL(ras_userspace_consumers); + +static int trace_show(struct seq_file *m, void *v) +{ + return atomic_read(&trace_count); +} + +static int trace_open(struct inode *inode, struct file *file) +{ + atomic_inc(&trace_count); + return single_open(file, trace_show, NULL); +} + +static int trace_release(struct inode *inode, struct file *file) +{ + atomic_dec(&trace_count); + return single_release(inode, file); +} + +static const struct file_operations trace_fops = { + .open = trace_open, + .read = seq_read, + .llseek = seq_lseek, + .release = trace_release, +}; + +int __init ras_add_daemon_trace(void) +{ + struct dentry *fentry; + + if (!ras_debugfs_dir) + return -ENOENT; + + fentry = debugfs_create_file("daemon_active", S_IRUSR, ras_debugfs_dir, + NULL, &trace_fops); + if (!fentry) + return -ENODEV; + + return 0; + +} + +void __init ras_debugfs_init(void) +{ + ras_debugfs_dir = debugfs_create_dir("ras", NULL); +} diff --git a/drivers/ras/ras.c b/drivers/ras/ras.c index b0c6ed1d8e77..4cac43a1e25c 100644 --- a/drivers/ras/ras.c +++ b/drivers/ras/ras.c @@ -5,8 +5,22 @@ * Chen, Gong */ +#include +#include + #define CREATE_TRACE_POINTS #define TRACE_INCLUDE_PATH ../../include/ras #include +static int __init ras_init(void) +{ + int rc = 0; + + ras_debugfs_init(); + rc = ras_add_daemon_trace(); + + return rc; +} +subsys_initcall(ras_init); + EXPORT_TRACEPOINT_SYMBOL_GPL(mc_event); diff --git a/include/linux/ras.h b/include/linux/ras.h new file mode 100644 index 000000000000..2aceeafd6fe5 --- /dev/null +++ b/include/linux/ras.h @@ -0,0 +1,14 @@ +#ifndef __RAS_H__ +#define __RAS_H__ + +#ifdef CONFIG_DEBUG_FS +int ras_userspace_consumers(void); +void ras_debugfs_init(void); +int ras_add_daemon_trace(void); +#else +static inline int ras_userspace_consumers(void) { return 0; } +static inline void ras_debugfs_init(void) { return; } +static inline int ras_add_daemon_trace(void) { return 0; } +#endif + +#endif -- 2.39.5