Merge branch 'for-next/entry' into for-next/core

* for-next/entry:
  arm64/ptrace: Return early for ptrace_report_syscall_entry() error
  arm64/ptrace: Split report_syscall()
  arm64: Remove unused _TIF_WORK_MASK
  arm64: Avoid memcpy() for syscall_get_arguments()
  syscall.h: Remove unused SYSCALL_MAX_ARGS

Author: willdeacon

arch/arm/include/asm/syscall.h

@@ -92,8 +92,6 @@ static inline void syscall_set_nr(struct task_struct *task,
 		(nr & __NR_SYSCALL_MASK);
 }
 
-#define SYSCALL_MAX_ARGS 7
-
 static inline void syscall_get_arguments(struct task_struct *task,
 					 struct pt_regs *regs,
 					 unsigned long *args)

arch/arm64/include/asm/syscall.h

@@ -77,23 +77,29 @@ static inline void syscall_set_nr(struct task_struct *task,
 	}
 }
 
-#define SYSCALL_MAX_ARGS 6
-
 static inline void syscall_get_arguments(struct task_struct *task,
 					 struct pt_regs *regs,
 					 unsigned long *args)
 {
 	args[0] = regs->orig_x0;
-	args++;
-
-	memcpy(args, &regs->regs[1], 5 * sizeof(args[0]));
+	args[1] = regs->regs[1];
+	args[2] = regs->regs[2];
+	args[3] = regs->regs[3];
+	args[4] = regs->regs[4];
+	args[5] = regs->regs[5];
 }
 
 static inline void syscall_set_arguments(struct task_struct *task,
 					 struct pt_regs *regs,
 					 const unsigned long *args)
 {
-	memcpy(&regs->regs[0], args, 6 * sizeof(args[0]));
+	regs->regs[0] = args[0];
+	regs->regs[1] = args[1];
+	regs->regs[2] = args[2];
+	regs->regs[3] = args[3];
+	regs->regs[4] = args[4];
+	regs->regs[5] = args[5];
+
 	/*
 	 * Also copy the first argument into orig_x0
 	 * so that syscall_get_arguments() would return it

arch/arm64/include/asm/thread_info.h

@@ -106,12 +106,6 @@ void arch_setup_new_exec(void);
 #define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
 #define _TIF_TSC_SIGSEGV	(1 << TIF_TSC_SIGSEGV)
 
-#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY | \
-				 _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
-				 _TIF_UPROBE | _TIF_MTE_ASYNC_FAULT | \
-				 _TIF_NOTIFY_SIGNAL | _TIF_SIGPENDING | \
-				 _TIF_PATCH_PENDING)
-
 #define _TIF_SYSCALL_WORK	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
 				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
 				 _TIF_SYSCALL_EMU)

arch/arm64/kernel/ptrace.c

@@ -2346,9 +2346,10 @@ enum ptrace_syscall_dir {
 	PTRACE_SYSCALL_EXIT,
 };
 
-static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
+static __always_inline unsigned long ptrace_save_reg(struct pt_regs *regs,
+						     enum ptrace_syscall_dir dir,
+						     int *regno)
 {
-	int regno;
 	unsigned long saved_reg;
 
 	/*
@@ -2367,15 +2368,34 @@ static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
 	 * - Syscall stops behave differently to seccomp and pseudo-step traps
 	 *   (the latter do not nobble any registers).
 	 */
-	regno = (is_compat_task() ? 12 : 7);
-	saved_reg = regs->regs[regno];
-	regs->regs[regno] = dir;
+	*regno = (is_compat_task() ? 12 : 7);
+	saved_reg = regs->regs[*regno];
+	regs->regs[*regno] = dir;
 
-	if (dir == PTRACE_SYSCALL_ENTER) {
-		if (ptrace_report_syscall_entry(regs))
-			forget_syscall(regs);
-		regs->regs[regno] = saved_reg;
-	} else if (!test_thread_flag(TIF_SINGLESTEP)) {
+	return saved_reg;
+}
+
+static int report_syscall_entry(struct pt_regs *regs)
+{
+	unsigned long saved_reg;
+	int regno, ret;
+
+	saved_reg = ptrace_save_reg(regs, PTRACE_SYSCALL_ENTER, &regno);
+	ret = ptrace_report_syscall_entry(regs);
+	if (ret)
+		forget_syscall(regs);
+	regs->regs[regno] = saved_reg;
+
+	return ret;
+}
+
+static void report_syscall_exit(struct pt_regs *regs)
+{
+	unsigned long saved_reg;
+	int regno;
+
+	saved_reg = ptrace_save_reg(regs, PTRACE_SYSCALL_EXIT, &regno);
+	if (!test_thread_flag(TIF_SINGLESTEP)) {
 		ptrace_report_syscall_exit(regs, 0);
 		regs->regs[regno] = saved_reg;
 	} else {
@@ -2393,10 +2413,11 @@ static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
 int syscall_trace_enter(struct pt_regs *regs)
 {
 	unsigned long flags = read_thread_flags();
+	int ret;
 
 	if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
-		report_syscall(regs, PTRACE_SYSCALL_ENTER);
-		if (flags & _TIF_SYSCALL_EMU)
+		ret = report_syscall_entry(regs);
+		if (ret || (flags & _TIF_SYSCALL_EMU))
 			return NO_SYSCALL;
 	}
 
@@ -2423,7 +2444,7 @@ void syscall_trace_exit(struct pt_regs *regs)
 		trace_sys_exit(regs, syscall_get_return_value(current, regs));
 
 	if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP))
-		report_syscall(regs, PTRACE_SYSCALL_EXIT);
+		report_syscall_exit(regs);
 
 	rseq_syscall(regs);
 }

arch/xtensa/include/asm/syscall.h

@@ -61,7 +61,6 @@ static inline void syscall_set_return_value(struct task_struct *task,
 	regs->areg[2] = (long) error ? error : val;
 }
 
-#define SYSCALL_MAX_ARGS 6
 #define XTENSA_SYSCALL_ARGUMENT_REGS {6, 3, 4, 5, 8, 9}
 
 static inline void syscall_get_arguments(struct task_struct *task,