The architecture specific information of the running processes
could be useful to the userland. Add /proc/<pid>/arch_status
interface support to examine process architecture specific
information externally.
Signed-off-by: Aubrey Li <aubrey.li@xxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Linux API <linux-api@xxxxxxxxxxxxxxx>
---
arch/x86/Kconfig | 1 +
fs/proc/Kconfig | 10 ++++++++++
fs/proc/base.c | 23 +++++++++++++++++++++++
3 files changed, 34 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5ad92419be19..d5a9c5ddd453 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -208,6 +208,7 @@ config X86
select USER_STACKTRACE_SUPPORT
select VIRT_TO_BUS
select X86_FEATURE_NAMES if PROC_FS
+ select PROC_PID_ARCH_STATUS if PROC_FS
config INSTRUCTION_DECODER
def_bool y
diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig
index 817c02b13b1d..101bf5054e81 100644
--- a/fs/proc/Kconfig
+++ b/fs/proc/Kconfig
@@ -97,3 +97,13 @@ config PROC_CHILDREN
Say Y if you are running any user-space software which takes benefit from
this interface. For example, rkt is such a piece of software.
+
+config PROC_PID_ARCH_STATUS
+ bool "Enable /proc/<pid>/arch_status file"
+ default n
+ help
+ Provides a way to examine process architecture specific information.
+ See <file:Documentation/filesystems/proc.txt> for more information.
+
+ Say Y if you are running any user-space software which wants to obtain
+ process architecture specific information from this interface.
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 6a803a0b75df..a890d9f12851 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -94,6 +94,7 @@
#include <linux/sched/debug.h>
#include <linux/sched/stat.h>
#include <linux/posix-timers.h>
+#include <linux/processor.h>
#include <trace/events/oom.h>
#include "internal.h"
#include "fd.h"
@@ -2957,6 +2958,22 @@ static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
}
#endif /* CONFIG_STACKLEAK_METRICS */
+/*
+ * Add support for task architecture specific output in /proc/pid/arch_status.
+ * task_arch_status() must be defined in asm/processor.h
+ */
+#ifdef CONFIG_PROC_PID_ARCH_STATUS
+# ifndef task_arch_status
+# define task_arch_status(m, task)
+# endif
+static int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ task_arch_status(m, task);
+ return 0;
+}
+#endif /* CONFIG_PROC_PID_ARCH_STATUS */
+
/*
* Thread groups
*/
@@ -3061,6 +3078,9 @@ static const struct pid_entry tgid_base_stuff[] = {
#ifdef CONFIG_STACKLEAK_METRICS
ONE("stack_depth", S_IRUGO, proc_stack_depth),
#endif
+#ifdef CONFIG_PROC_PID_ARCH_STATUS
+ ONE("arch_status", S_IRUGO, proc_pid_arch_status),
+#endif
};
static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
@@ -3449,6 +3469,9 @@ static const struct pid_entry tid_base_stuff[] = {
#ifdef CONFIG_LIVEPATCH
ONE("patch_state", S_IRUSR, proc_pid_patch_state),
#endif
+#ifdef CONFIG_PROC_PID_ARCH_STATUS
+ ONE("arch_status", S_IRUGO, proc_pid_arch_status),
+#endif
};
static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
--
2.17.1
