ARM: invalidate proc info after non-dwarf unw_step()
After successfully stepping the cursor on ARM, the proc info is
invalidated only in dwarf_step(). Invalidate the proc info also when
stepping with the non-dwarf based methods. This fixes
unw_get_proc_info() returning stale data.
The core dump unwinder can be used for demonstrating the bug. When
unwinding based only on DWARF data, the proc info is correct:
$ UNW_ARM_UNWIND_METHOD=1 ./test-coredump-unwind core `cat backing_files` 2>/dev/null
ip=0x000086d8 proc=000086d4-000086dc handler=0x00000000 lsda=0x00000000
ip=0x000086ef proc=000086dc-000086f2 handler=0x00000000 lsda=0x00000000
ip=0x000086e7 proc=000086dc-000086f2 handler=0x00000000 lsda=0x00000000
ip=0x00008597 proc=00008584-0000859a handler=0x00000000 lsda=0x00000000
ip=0x76e3ac3b proc=76e3aba0-76e3acec handler=0x00000000 lsda=0x00000000
When unwinding based only on the exidx method, we see the proc info
lagging behind:
$ UNW_ARM_UNWIND_METHOD=4 ./test-coredump-unwind core `cat backing_files` 2>/dev/null
ip=0x000086d8 proc=000086d4-000086db handler=0x00000000 lsda=0x00000000
ip=0x000086ef proc=000086d4-000086db handler=0x00000000 lsda=0x00000000
ip=0x000086e7 proc=000086dc-000086f3 handler=0x00000000 lsda=0x00000000
ip=0x00008597 proc=000086dc-000086f3 handler=0x00000000 lsda=0x00000000
ip=0x76e3ac3b proc=00008584-0000859b handler=0x00000000 lsda=0x00000000
ip=0x000085c3 proc=76e3aba0-76e3ae4b handler=0x00000000 lsda=0x00000000
Finally, with this patch applied, we get the desired proc info also with
the exidx unwinder:
$ UNW_ARM_UNWIND_METHOD=4 ./test-coredump-unwind core `cat backing_files` 2>/dev/null
ip=0x000086d8 proc=000086d4-000086db handler=0x00000000 lsda=0x00000000
ip=0x000086ef proc=000086dc-000086f3 handler=0x00000000 lsda=0x00000000
ip=0x000086e7 proc=000086dc-000086f3 handler=0x00000000 lsda=0x00000000
ip=0x00008597 proc=00008584-0000859b handler=0x00000000 lsda=0x00000000
ip=0x76e3ac3b proc=76e3aba0-76e3ae4b handler=0x00000000 lsda=0x00000000
ip=0x000085c3 proc=0000859c-00008613 handler=0x00000000 lsda=0x00000000
1 file changed