[PATCH RFC POC 16/50] sparc: commit fds on syscall exit

[Christian Brauner <brauner@kernel.org>]

Add TIF_FD_SLOTS and test it together with the other syscall exit
work on the way out of a system call. A task that reserved
descriptors calls syscall_trace() on sparc32 and syscall_trace_leave()
on sparc64.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---
 arch/sparc/include/asm/thread_info_32.h | 2 ++
 arch/sparc/include/asm/thread_info_64.h | 9 ++++++++-
 arch/sparc/kernel/entry.S               | 2 +-
 arch/sparc/kernel/ptrace_32.c           | 4 ++++
 arch/sparc/kernel/ptrace_64.c           | 4 ++++
 arch/sparc/kernel/syscalls.S            | 4 +++-
 6 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/arch/sparc/include/asm/thread_info_32.h b/arch/sparc/include/asm/thread_info_32.h
index fdaf7b171e0a..fbd7af6bb427 100644
--- a/arch/sparc/include/asm/thread_info_32.h
+++ b/arch/sparc/include/asm/thread_info_32.h
@@ -105,6 +105,7 @@ register struct thread_info *current_thread_info_reg asm("g6");
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_RESTORE_SIGMASK	4	/* restore signal mask in do_signal() */
 #define TIF_NOTIFY_SIGNAL	5	/* signal notifications exist */
+#define TIF_FD_SLOTS		6	/* syscall prepared descriptors */
 #define TIF_USEDFPU		8	/* FPU was used by this task
 					 * this quantum (SMP) */
 #define TIF_POLLING_NRFLAG	9	/* true if poll_idle() is polling
@@ -117,6 +118,7 @@ register struct thread_info *current_thread_info_reg asm("g6");
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
+#define _TIF_FD_SLOTS		(1<<TIF_FD_SLOTS)
 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index c8a73dff27f8..890ee65d9029 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -180,7 +180,7 @@ extern struct thread_info *current_thread_info(void);
 #define TIF_SIGPENDING		2	/* signal pending */
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_NOTIFY_SIGNAL	4	/* signal notifications exist */
-#define TIF_UNALIGNED		5	/* allowed to do unaligned accesses */
+#define TIF_FD_SLOTS		5	/* syscall prepared descriptors */
 #define TIF_UPROBE		6	/* breakpointed or singlestepped */
 #define TIF_32BIT		7	/* 32-bit binary */
 #define TIF_NOHZ		8	/* in adaptive nohz mode */
@@ -194,12 +194,14 @@ extern struct thread_info *current_thread_info(void);
 #define TIF_MCDPER		12	/* Precise MCD exception */
 #define TIF_MEMDIE		13	/* is terminating due to OOM killer */
 #define TIF_POLLING_NRFLAG	14
+#define TIF_UNALIGNED		15	/* allowed to do unaligned accesses */
 
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
+#define _TIF_FD_SLOTS		(1<<TIF_FD_SLOTS)
 #define _TIF_UNALIGNED		(1<<TIF_UNALIGNED)
 #define _TIF_UPROBE		(1<<TIF_UPROBE)
 #define _TIF_32BIT		(1<<TIF_32BIT)
@@ -209,6 +211,11 @@ extern struct thread_info *current_thread_info(void);
 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
+/* work to do in syscall_trace_leave() */
+#define _TIF_SYSCALL_EXIT_WORK	(_TIF_SYSCALL_TRACE | _TIF_SECCOMP | \
+				 _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT | \
+				 _TIF_NOHZ | _TIF_FD_SLOTS)
+
 #define _TIF_USER_WORK_MASK	((0xff << TI_FLAG_WSAVED_SHIFT) | \
 				 _TIF_DO_NOTIFY_RESUME_MASK | \
 				 _TIF_NEED_RESCHED)
diff --git a/arch/sparc/kernel/entry.S b/arch/sparc/kernel/entry.S
index ea51ef52c952..d2023b84db9e 100644
--- a/arch/sparc/kernel/entry.S
+++ b/arch/sparc/kernel/entry.S
@@ -1023,7 +1023,7 @@ ret_sys_call:
 	ld	[%sp + STACKFRAME_SZ + PT_PSR], %g3
 	set	PSR_C, %g2
 	bgeu	1f
-	 andcc	%l5, _TIF_SYSCALL_TRACE, %g0
+	 andcc	%l5, (_TIF_SYSCALL_TRACE | _TIF_FD_SLOTS), %g0
 
 	/* System call success, clear Carry condition code. */
 	andn	%g3, %g2, %g3
diff --git a/arch/sparc/kernel/ptrace_32.c b/arch/sparc/kernel/ptrace_32.c
index 5991b1731fee..042e60685418 100644
--- a/arch/sparc/kernel/ptrace_32.c
+++ b/arch/sparc/kernel/ptrace_32.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/file.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/errno.h>
@@ -437,6 +438,9 @@ asmlinkage int syscall_trace(struct pt_regs *regs, int syscall_exit_p)
 {
 	int ret = 0;
 
+	if (syscall_exit_p && test_thread_flag(TIF_FD_SLOTS))
+		fd_slots_commit(regs);
+
 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
 		if (syscall_exit_p)
 			ptrace_report_syscall_exit(regs, 0);
diff --git a/arch/sparc/kernel/ptrace_64.c b/arch/sparc/kernel/ptrace_64.c
index 825ddf55fece..499b30c505fd 100644
--- a/arch/sparc/kernel/ptrace_64.c
+++ b/arch/sparc/kernel/ptrace_64.c
@@ -12,6 +12,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/file.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
 #include <linux/mm.h>
@@ -1110,6 +1111,9 @@ asmlinkage void syscall_trace_leave(struct pt_regs *regs)
 	if (test_thread_flag(TIF_NOHZ))
 		user_exit();
 
+	if (test_thread_flag(TIF_FD_SLOTS))
+		fd_slots_commit(regs);
+
 	audit_syscall_exit(regs);
 
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
diff --git a/arch/sparc/kernel/syscalls.S b/arch/sparc/kernel/syscalls.S
index 96fe8763d70c..086fb8eaf133 100644
--- a/arch/sparc/kernel/syscalls.S
+++ b/arch/sparc/kernel/syscalls.S
@@ -269,10 +269,12 @@ ret_sys_call:
 	ldx	[%sp + PTREGS_OFF + PT_V9_TSTATE], %g3
 	mov	%ulo(TSTATE_XCARRY | TSTATE_ICARRY), %g2
 	sllx	%g2, 32, %g2
+	/* Reload the flags, the syscall may have set TIF_FD_SLOTS. */
+	ldx	[%g6 + TI_FLAGS], %l0
 
 	cmp	%o0, -ERESTART_RESTARTBLOCK
 	bgeu,pn	%xcc, 1f
-	 andcc	%l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT|_TIF_NOHZ), %g0
+	 andcc	%l0, _TIF_SYSCALL_EXIT_WORK, %g0
 	ldx	[%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
 
 2:

-- 
2.53.0