Created attachment 7656 [details]
statfs test program

It seems there is a mismatch between the struct statfs used by libc and that used by the arm64 kernel.  The call to statfs() writes 120 bytes, but struct statfs is only 88 bytes.  The attached test program shows this.

I experienced seg faults due to stack corruption when calling statfs() with an automatic struct statfs variable.
 
Building for arm64.
libuClibc-1.0.30

Using master at revision 751df64eb344eee6a583755de09d3d506ac2fe33.

The output of statfs-test program:

sizeof statfs: 88
sizeof packed: 138
  1: 94 94
  2: 19 19
  3: 2  2
  4: 1  1
  5: 0  0
  6: 0  0
  7: 0  0
  8: 0  0
  9: 0  0
 10: 10 10
 11: 0  0
 12: 0  0
 13: 0  0
 14: 0  0
 15: 0  0
 16: 0  0
 17: 72 72
 18: a5 a5
 19: 7  7
 20: 0  0
 21: 0  0
 22: 0  0
 23: 0  0
 24: 0  0
 25: 83 83
 26: 80 80
 27: 7  7
 28: 0  0
 29: 0  0
 30: 0  0
 31: 0  0
 32: 0  0
 33: 83 83
 34: 80 80
 35: 7  7
 36: 0  0
 37: 0  0
 38: 0  0
 39: 0  0
 40: 0  0
 41: 72 72
 42: a5 a5
 43: 7  7
 44: 0  0
 45: 0  0
 46: 0  0
 47: 0  0
 48: 0  0
 49: d9 d9
 50: a0 a0
 51: 7  7
 52: 0  0
 53: 0  0
 54: 0  0
 55: 0  0
 56: 0  0
 57: 0  0
 58: 0  0
 59: 0  0
 60: 0  0
 61: 0  0
 62: 0  0
 63: 0  0
 64: 0  0
 65: ff ff
 66: 0  0
 67: 0  0
 68: 0  0
 69: 0  0
 70: 0  0
 71: 0  0
 72: 0  0
 73: 0  0
 74: 10 10
 75: 0  0
 76: 0  0
 77: 0  0
 78: 0  0
 79: 0  0
 80: 0  0
 81: 20 20
 82: 0  0
 83: 0  0
 84: 0  0
 85: 0  0
 86: 0  0
 87: 0  0
 88: 0  0
 89: 0  0
 90: 0  0
 91: 0  0
 92: 0  0
 93: 0  0
 94: 0  0
 95: 0  0
 96: 0  0
 97: 0  0
 98: 0  0
 99: 0  0
100: 0  0
101: 0  0
102: 0  0
103: 0  0
104: 0  0
105: 0  0
106: 0  0
107: 0  0
108: 0  0
109: 0  0
110: 0  0
111: 0  0
112: 0  0
113: 0  0
114: 0  0
115: 0  0
116: 0  0
117: 0  0
118: 0  0
119: 0  0
120: 0  0
121: ff cc
122: ff cc
123: ff cc
124: ff cc
125: ff cc
126: ff cc
127: ff cc
128: ff cc
129: ff cc
130: ff cc
131: ff cc
132: ff cc
133: ff cc
134: ff cc
135: ff cc
136: ff cc
137: ff cc
138: ff cc