[PATCH RFC POC 10/50] microblaze: commit fds on syscall exit

[Christian Brauner]

Add TIF_FD_SLOTS to the syscall work mask. The return path rereads
the flags after the system call and calls do_syscall_trace_leave()
for any of them which commits the reservations before audit and the
ptrace exit stop.

Signed-off-by: Christian Brauner (Amutable) <brauner@xxxxxxxxxx>
---
 arch/microblaze/include/asm/thread_info.h | 5 ++++-
 arch/microblaze/kernel/ptrace.c           | 4 ++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/microblaze/include/asm/thread_info.h b/arch/microblaze/include/asm/thread_info.h
index 0153f7c2717c..ee2f76589696 100644
--- a/arch/microblaze/include/asm/thread_info.h
+++ b/arch/microblaze/include/asm/thread_info.h
@@ -103,6 +103,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SINGLESTEP		4
 #define TIF_NOTIFY_SIGNAL	5	/* signal notifications exist */
 #define TIF_MEMDIE		6	/* is terminating due to OOM killer */
+#define TIF_FD_SLOTS		7	/* syscall prepared descriptors */
 #define TIF_SYSCALL_AUDIT	9       /* syscall auditing active */
 #define TIF_SECCOMP		10      /* secure computing */
 
@@ -118,10 +119,12 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP		(1 << TIF_SECCOMP)
+#define _TIF_FD_SLOTS		(1 << TIF_FD_SLOTS)
 
 /* work to do in syscall trace */
 #define _TIF_WORK_SYSCALL_MASK  (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
-				 _TIF_SYSCALL_AUDIT | _TIF_SECCOMP)
+				 _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
+				 _TIF_FD_SLOTS)
 
 /* work to do on interrupt/exception return */
 #define _TIF_WORK_MASK		0x0000FFFE
diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c
index 236264e932d6..e6951fea8593 100644
--- a/arch/microblaze/kernel/ptrace.c
+++ b/arch/microblaze/kernel/ptrace.c
@@ -25,6 +25,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/file.h>
 #include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
@@ -156,6 +157,9 @@ asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
 {
 	int step;
 
+	if (test_thread_flag(TIF_FD_SLOTS))
+		fd_slots_commit(regs);
+
 	audit_syscall_exit(regs);
 
 	step = test_thread_flag(TIF_SINGLESTEP);

-- 
2.53.0