3 files changed, 42 insertions, 43 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index ddef482f1334..6a803a0b75df 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -616,24 +616,25 @@ static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
 static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
                             struct pid *pid, struct task_struct *task)
 {
-        long nr;
-        unsigned long args[6], sp, pc;
+        struct syscall_info info;
+        u64 *args = &info.data.args[0];
         int res;
 
         res = lock_trace(task);
         if (res)
                 return res;
 
-        if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
+        if (task_current_syscall(task, &info))
                 seq_puts(m, "running\n");
-        else if (nr < 0)
-                seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
+        else if (info.data.nr < 0)
+                seq_printf(m, "%d 0x%llx 0x%llx\n",
+                           info.data.nr, info.sp, info.data.instruction_pointer);
         else
                 seq_printf(m,
-                       "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
-                       nr,
+                       "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
+                       info.data.nr,
                        args[0], args[1], args[2], args[3], args[4], args[5],
-                       sp, pc);
+                       info.sp, info.data.instruction_pointer);
         unlock_trace(task);
 
         return 0;
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index edb9b040c94c..d5084ebd9f03 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -9,6 +9,13 @@
 #include <linux/bug.h>                  /* For BUG_ON.  */
 #include <linux/pid_namespace.h>        /* For task_active_pid_ns.  */
 #include <uapi/linux/ptrace.h>
+#include <linux/seccomp.h>
+
+/* Add sp to seccomp_data, as seccomp is user API, we don't want to modify it */
+struct syscall_info {
+        __u64                   sp;
+        struct seccomp_data     data;
+};
 
 extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
                             void *buf, int len, unsigned int gup_flags);
@@ -407,9 +414,7 @@ static inline void user_single_step_report(struct pt_regs *regs)
 #define current_user_stack_pointer() user_stack_pointer(current_pt_regs())
 #endif
 
-extern int task_current_syscall(struct task_struct *target, long *callno,
-                                unsigned long args[6], unsigned int maxargs,
-                                unsigned long *sp, unsigned long *pc);
+extern int task_current_syscall(struct task_struct *target, struct syscall_info *info);
 
 extern void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact);
 #endif
diff --git a/lib/syscall.c b/lib/syscall.c
index 1a7077f20eae..e8467e17b9a2 100644
--- a/lib/syscall.c
+++ b/lib/syscall.c
@@ -5,16 +5,14 @@
 #include <linux/export.h>
 #include <asm/syscall.h>
 
-static int collect_syscall(struct task_struct *target, long *callno,
-                           unsigned long args[6], unsigned int maxargs,
-                           unsigned long *sp, unsigned long *pc)
+static int collect_syscall(struct task_struct *target, struct syscall_info *info)
 {
         struct pt_regs *regs;
 
         if (!try_get_task_stack(target)) {
                 /* Task has no stack, so the task isn't in a syscall. */
-                *sp = *pc = 0;
-                *callno = -1;
+                memset(info, 0, sizeof(*info));
+                info->data.nr = -1;
                 return 0;
         }
 
@@ -24,12 +22,13 @@ static int collect_syscall(struct task_struct *target, long *callno,
                 return -EAGAIN;
         }
 
-        *sp = user_stack_pointer(regs);
-        *pc = instruction_pointer(regs);
+        info->sp = user_stack_pointer(regs);
+        info->data.instruction_pointer = instruction_pointer(regs);
 
-        *callno = syscall_get_nr(target, regs);
-        if (*callno != -1L && maxargs > 0)
-                syscall_get_arguments(target, regs, 0, maxargs, args);
+        info->data.nr = syscall_get_nr(target, regs);
+        if (info->data.nr != -1L)
+                syscall_get_arguments(target, regs, 0, 6,
+                                      (unsigned long *)&info->data.args[0]);
 
         put_task_stack(target);
         return 0;
@@ -38,41 +37,35 @@ static int collect_syscall(struct task_struct *target, long *callno,
 /**
  * task_current_syscall - Discover what a blocked task is doing.
  * @target:             thread to examine
- * @callno:             filled with system call number or -1
- * @args:               filled with @maxargs system call arguments
- * @maxargs:            number of elements in @args to fill
- * @sp:                 filled with user stack pointer
- * @pc:                 filled with user PC
+ * @info:               structure with the following fields:
+ *                       .sp        - filled with user stack pointer
+ *                       .data.nr   - filled with system call number or -1
+ *                       .data.args - filled with @maxargs system call arguments
+ *                       .data.instruction_pointer - filled with user PC
  *
- * If @target is blocked in a system call, returns zero with *@callno
- * set to the the call's number and @args filled in with its arguments.
- * Registers not used for system call arguments may not be available and
- * it is not kosher to use &struct user_regset calls while the system
+ * If @target is blocked in a system call, returns zero with @info.data.nr
+ * set to the the call's number and @info.data.args filled in with its
+ * arguments. Registers not used for system call arguments may not be available
+ * and it is not kosher to use &struct user_regset calls while the system
  * call is still in progress.  Note we may get this result if @target
  * has finished its system call but not yet returned to user mode, such
  * as when it's stopped for signal handling or syscall exit tracing.
  *
  * If @target is blocked in the kernel during a fault or exception,
- * returns zero with *@callno set to -1 and does not fill in @args.
- * If so, it's now safe to examine @target using &struct user_regset
- * get() calls as long as we're sure @target won't return to user mode.
+ * returns zero with *@info.data.nr set to -1 and does not fill in
+ * @info.data.args. If so, it's now safe to examine @target using
+ * &struct user_regset get() calls as long as we're sure @target won't return
+ * to user mode.
  *
  * Returns -%EAGAIN if @target does not remain blocked.
- *
- * Returns -%EINVAL if @maxargs is too large (maximum is six).
  */
-int task_current_syscall(struct task_struct *target, long *callno,
-                         unsigned long args[6], unsigned int maxargs,
-                         unsigned long *sp, unsigned long *pc)
+int task_current_syscall(struct task_struct *target, struct syscall_info *info)
 {
         long state;
         unsigned long ncsw;
 
-        if (unlikely(maxargs > 6))
-                return -EINVAL;
-
         if (target == current)
-                return collect_syscall(target, callno, args, maxargs, sp, pc);
+                return collect_syscall(target, info);
 
         state = target->state;
         if (unlikely(!state))
@@ -80,7 +73,7 @@ int task_current_syscall(struct task_struct *target, long *callno,
 
         ncsw = wait_task_inactive(target, state);
         if (unlikely(!ncsw) ||
-            unlikely(collect_syscall(target, callno, args, maxargs, sp, pc)) ||
+            unlikely(collect_syscall(target, info)) ||
             unlikely(wait_task_inactive(target, state) != ncsw))
                 return -EAGAIN;