crazy linker: Fix incorrect link map l_addr value.

crazy linker: Fix incorrect link map l_addr value.

Link map's l_addr field should contain the load bias:
- https://android-review.googlesource.com/#/c/46470/2/linker/linker.cpp

It currently contains the load address.  Where the min vaddr of LOAD
segments is zero, the load address and load bias are the same, and the
problem remains hidden.  Android's relocation packer generates a
non-zero min vaddr, and this exposes the problem on arm64 platforms.

The symptom is abort in uw_init_context_1, where uw_frame_state_for
returns _URC_END_OF_STACK rather than (expected) _URC_NO_REASON.
gcc's stack unwinding code does not find correct unwinding information
after an incorrect l_addr has been used to convert from virtual to
physical addresses.  Arm32 does not show the problem because it uses
dl_unwind_find_exidx in place of _Unwind_IteratePhdrCallback.

See also line 196 of:
- https://android.googlesource.com/platform/bionic/+/
      lollipop-mr1-release/linker/linker.cpp

BUG=385553
Committed: https://crrev.com/a0add2c099683dcfc16d3b67c6c1c438c36c2ce7
Cr-Commit-Position: refs/heads/master@{#333040}

[simonb (inactive), 2015-06-05 12:32:08]

simonb@chromium.org changed reviewers:
+ rmcilroy@chromium.org

[rmcilroy, 2015-06-05 12:34:20]

On 2015/06/05 12:32:08, simonb wrote:

Yay! lgtm, thanks!

[simonb (inactive), 2015-06-05 12:54:47]

The CQ bit was checked by simonb@chromium.org

[commit-bot: I haz the power, 2015-06-05 12:54:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1155973005/1

[commit-bot: I haz the power, 2015-06-05 13:23:07]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-05 13:23:52]

Patchset 1 (id:??) landed as
https://crrev.com/a0add2c099683dcfc16d3b67c6c1c438c36c2ce7
Cr-Commit-Position: refs/heads/master@{#333040}