hc
2024-12-19 9370bb92b2d16684ee45cf24e879c93c509162da
kernel/lib/syscall.c
....@@ -5,16 +5,15 @@
55 #include <linux/export.h>
66 #include <asm/syscall.h>
77
8
-static int collect_syscall(struct task_struct *target, long *callno,
9
- unsigned long args[6], unsigned int maxargs,
10
- unsigned long *sp, unsigned long *pc)
8
+static int collect_syscall(struct task_struct *target, struct syscall_info *info)
119 {
10
+ unsigned long args[6] = { };
1211 struct pt_regs *regs;
1312
1413 if (!try_get_task_stack(target)) {
1514 /* Task has no stack, so the task isn't in a syscall. */
16
- *sp = *pc = 0;
17
- *callno = -1;
15
+ memset(info, 0, sizeof(*info));
16
+ info->data.nr = -1;
1817 return 0;
1918 }
2019
....@@ -24,12 +23,19 @@
2423 return -EAGAIN;
2524 }
2625
27
- *sp = user_stack_pointer(regs);
28
- *pc = instruction_pointer(regs);
26
+ info->sp = user_stack_pointer(regs);
27
+ info->data.instruction_pointer = instruction_pointer(regs);
2928
30
- *callno = syscall_get_nr(target, regs);
31
- if (*callno != -1L && maxargs > 0)
32
- syscall_get_arguments(target, regs, 0, maxargs, args);
29
+ info->data.nr = syscall_get_nr(target, regs);
30
+ if (info->data.nr != -1L)
31
+ syscall_get_arguments(target, regs, args);
32
+
33
+ info->data.args[0] = args[0];
34
+ info->data.args[1] = args[1];
35
+ info->data.args[2] = args[2];
36
+ info->data.args[3] = args[3];
37
+ info->data.args[4] = args[4];
38
+ info->data.args[5] = args[5];
3339
3440 put_task_stack(target);
3541 return 0;
....@@ -38,41 +44,35 @@
3844 /**
3945 * task_current_syscall - Discover what a blocked task is doing.
4046 * @target: thread to examine
41
- * @callno: filled with system call number or -1
42
- * @args: filled with @maxargs system call arguments
43
- * @maxargs: number of elements in @args to fill
44
- * @sp: filled with user stack pointer
45
- * @pc: filled with user PC
47
+ * @info: structure with the following fields:
48
+ * .sp - filled with user stack pointer
49
+ * .data.nr - filled with system call number or -1
50
+ * .data.args - filled with @maxargs system call arguments
51
+ * .data.instruction_pointer - filled with user PC
4652 *
47
- * If @target is blocked in a system call, returns zero with *@callno
48
- * set to the the call's number and @args filled in with its arguments.
49
- * Registers not used for system call arguments may not be available and
50
- * it is not kosher to use &struct user_regset calls while the system
53
+ * If @target is blocked in a system call, returns zero with @info.data.nr
54
+ * set to the call's number and @info.data.args filled in with its
55
+ * arguments. Registers not used for system call arguments may not be available
56
+ * and it is not kosher to use &struct user_regset calls while the system
5157 * call is still in progress. Note we may get this result if @target
5258 * has finished its system call but not yet returned to user mode, such
5359 * as when it's stopped for signal handling or syscall exit tracing.
5460 *
5561 * If @target is blocked in the kernel during a fault or exception,
56
- * returns zero with *@callno set to -1 and does not fill in @args.
57
- * If so, it's now safe to examine @target using &struct user_regset
58
- * get() calls as long as we're sure @target won't return to user mode.
62
+ * returns zero with *@info.data.nr set to -1 and does not fill in
63
+ * @info.data.args. If so, it's now safe to examine @target using
64
+ * &struct user_regset get() calls as long as we're sure @target won't return
65
+ * to user mode.
5966 *
6067 * Returns -%EAGAIN if @target does not remain blocked.
61
- *
62
- * Returns -%EINVAL if @maxargs is too large (maximum is six).
6368 */
64
-int task_current_syscall(struct task_struct *target, long *callno,
65
- unsigned long args[6], unsigned int maxargs,
66
- unsigned long *sp, unsigned long *pc)
69
+int task_current_syscall(struct task_struct *target, struct syscall_info *info)
6770 {
6871 long state;
6972 unsigned long ncsw;
7073
71
- if (unlikely(maxargs > 6))
72
- return -EINVAL;
73
-
7474 if (target == current)
75
- return collect_syscall(target, callno, args, maxargs, sp, pc);
75
+ return collect_syscall(target, info);
7676
7777 state = target->state;
7878 if (unlikely(!state))
....@@ -80,7 +80,7 @@
8080
8181 ncsw = wait_task_inactive(target, state);
8282 if (unlikely(!ncsw) ||
83
- unlikely(collect_syscall(target, callno, args, maxargs, sp, pc)) ||
83
+ unlikely(collect_syscall(target, info)) ||
8484 unlikely(wait_task_inactive(target, state) != ncsw))
8585 return -EAGAIN;
8686