xref: /openbmc/qemu/tests/tcg/aarch64/system/semiheap.c (revision 7a5951f6)
1 /*
2  * Semihosting System HEAPINFO Test
3  *
4  * Copyright (c) 2021 Linaro Ltd
5  *
6  * SPDX-License-Identifier: GPL-2.0-or-later
7  */
8 
9 #include <stdint.h>
10 #include <stddef.h>
11 #include <minilib.h>
12 
13 #define SYS_HEAPINFO    0x16
14 
15 uintptr_t __semi_call(uintptr_t type, uintptr_t arg0)
16 {
17     register uintptr_t t asm("x0") = type;
18     register uintptr_t a0 asm("x1") = arg0;
19     asm("hlt 0xf000"
20         : "=r" (t)
21         : "r" (t), "r" (a0)
22         : "memory" );
23 
24     return t;
25 }
26 
27 int main(int argc, char *argv[argc])
28 {
29     struct {
30         void *heap_base;
31         void *heap_limit;
32         void *stack_base;
33         void *stack_limit;
34     } info = { };
35     void *ptr_to_info = (void *) &info;
36     uint32_t *ptr_to_heap;
37     int i;
38 
39     ml_printf("Semihosting Heap Info Test\n");
40 
41     __semi_call(SYS_HEAPINFO, (uintptr_t) &ptr_to_info);
42 
43     if (info.heap_base == NULL || info.heap_limit == NULL) {
44         ml_printf("null heap: %p -> %p\n", info.heap_base, info.heap_limit);
45         return -1;
46     }
47 
48     /* Error if heap base is above limit */
49     if ((uintptr_t) info.heap_base >= (uintptr_t) info.heap_limit) {
50         ml_printf("heap base %p >= heap_limit %p\n",
51                info.heap_base, info.heap_limit);
52         return -2;
53     }
54 
55     if (info.stack_base == NULL) {
56         ml_printf("null stack: %p -> %p\n", info.stack_base, info.stack_limit);
57         return -3;
58     }
59 
60     /*
61      * boot.S put our stack somewhere inside the data segment of the
62      * ELF file, and we know that SYS_HEAPINFO won't pick a range
63      * that overlaps with part of a loaded ELF file. So the info
64      * struct (on the stack) should not be inside the reported heap.
65      */
66     if (ptr_to_info > info.heap_base && ptr_to_info < info.heap_limit) {
67         ml_printf("info appears to be inside the heap: %p in %p:%p\n",
68                ptr_to_info, info.heap_base, info.heap_limit);
69         return -4;
70     }
71 
72     ml_printf("heap: %p -> %p\n", info.heap_base, info.heap_limit);
73     ml_printf("stack: %p <- %p\n", info.stack_limit, info.stack_base);
74 
75     /* finally can we read/write the heap */
76     ptr_to_heap = info.heap_base;
77     for (i = 0; i < 512; i++) {
78         *ptr_to_heap++ = i;
79     }
80     ptr_to_heap = info.heap_base;
81     for (i = 0; i < 512; i++) {
82         uint32_t tmp = *ptr_to_heap;
83         if (tmp != i) {
84             ml_printf("unexpected value in heap: %d @ %p", tmp, ptr_to_heap);
85             return -5;
86         }
87         ptr_to_heap++;
88     }
89     ml_printf("r/w to heap upto %p\n", ptr_to_heap);
90 
91     ml_printf("Passed HeapInfo checks\n");
92     return 0;
93 }
94