我故意撞车调查。源代码:
int* crashPointer = nullptr;
*crashPointer = 7;
生成的程序集:
11feb8: e3005007 movw r5, #7
11febc: e3006000 movw r6, #0 <--- r6 is #0
11fec0: e50b0014 str r0, [fp, #-20] ; 0xffffffec
11fec4: e50b1018 str r1, [fp, #-24] ; 0xffffffe8
11fec8: e51b0014 ldr r0, [fp, #-20] ; 0xffffffec
int* crashPointer = nullptr;
11fecc: e50b601c str r6, [fp, #-28] ; 0xffffffe4 <--- Stores #0 to [fp, #-28] from r6
*crashPointer = 7;
11fed0: e51b101c ldr r1, [fp, #-28] ; 0xffffffe4 <--- Loads #0 from [fp, #-28] to r1
11fed4: e5815000 str r5, [r1] <--- This should crash since it's trying to dereference r1 which is #0
11fed4
signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0
r0 ea408800 r1 00000000 r2 00000006 r3 ea6ccfa0
r4 ea6d1b2a r5 00000007 r6 00000000 r7 ea3ff904
r8 00000001 r9 e8b22ec0 sl ea6b5be9 fp ea3ff5c0
ip ea6d1af8 sp ea3ff550 lr ea6d09aa pc ea696ed4 cpsr 600f0010
...
ea577000-ea6d7000 r-xp 00000000 fe:01 1556782 libSomeLib.so
结论:
ea696ed4-ea577000=11fed4
总而言之:没有必要在崩溃转储中向PC值添加偏移量(至少对于Android armv7)。