Commit graph

12 commits

Author SHA1 Message Date
Steven Moreland
8401230be6 bionic: max_android_page_size to 16384
The maximum page size Android supports
now is 16384, and Art only supports 16kB,
so we can save a bit of space.

Bug: 332556665
Test: N/A
Change-Id: I23df607bcc5cf9e96d7b6a66169413cd1a883f7e
2024-05-22 18:29:04 +00:00
Kalesh Singh
461c64db9e bionic: libdl_cfi: Remove PAGE_SIZE usage
Use max_page_size() for build time variable alignments instead
of PAGE_SIZE.

In the 4k targets there is no functional difference since
max_page_size() == page_size() == 4096.

On a 16kb device max_page_size() == 65536 and page_size() == 16384.
However, aligning up does not incur any memory regressions
since the .bss/.data sections are still be backed in PAGE_SIZE'ed
chunks. See: go/16k-page-aligned-variables

Bug: 296275298
Test: mma
Change-Id: Ic944235d8a5742a51a8fb0f2a0b75e532f404110
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
2023-08-24 23:36:33 -07:00
Peter Collingbourne
191ecdc49b Fix a few bionic test failures caused by hwasan global instrumentation.
The call to the load hook needs to be moved before the call to link_image()
because the latter calls ifunc resolvers which might access global
variables. This fixes a bunch of ifunc tests.

The dlfcn.segment_gap test is currently failing. One problem is that the name
of the .bss.end_of_gap section changes as a result of global instrumentation.
Add some wildcards in so that we match both names. The other problem seems
to be the same as b/139089152.

It turns out that we need to untag pointers in a few more places. Since we have
quite a few of these now it seems worth creating a function for it.

Test: bionic-unit-tests
Change-Id: I44e2b0904faacdda7cc0c5e844ffc09de01dea2d
2019-08-15 09:21:34 -07:00
Peter Collingbourne
45f0a3b642 Clear pointer tags as required for HWASAN for globals.
A future version of HWASAN will set pointer tags when taking the address of
a global. This means that we need to untag pointers in a couple of cases
where potential global pointers are passed to an interface that expects
untagged pointers:

- The WriteProtected class, whose only instances are globals, passes its
  own address to mprotect. However, our device kernels do not currently
  untag pointers passed to mprotect (the proposed upstream kernel patches
  do, however, untag these pointers), so once HWASAN starts tagging global
  pointers, this will start failing.
- The shadow_load function loads from a shadow that corresponds to the
  address space bounds of loaded binaries. Since these address space
  bounds are untagged, the pointer needs to be untagged to match.

Test: boots
Change-Id: I3f11ce6eb7261752e5ff6d039d04dd45516b236f
2019-07-16 13:38:38 -07:00
Evgenii Stepanov
ded4524cb0 [cfi] Fix __cfi_check address calculation.
The current code is incorrect when the target address is 18 bit aligned.

Test: stops random (and extremely rare) crashes in media.extractor
Bug: 63400743
Bug: 65590288

Change-Id: I65b45ff0c4b57a7ff08d3f5b3d80f41167d3c0f8
2017-09-15 14:15:54 -07:00
Evgenii Stepanov
97c16f8dca [cfi] Export __cfi_shadow_size.
__cfi_shadow_size returns the size of the CFI shadow mapping, or 0 if
CFI is not (yet) used in this process. This can be used to adjust
RLIMIT_AS setting.

Test: device bionic tests
Bug: 64293803
Change-Id: Icd7164f96aa7115b3585c21c0f68529cd2f07c11
2017-08-03 14:04:15 -07:00
Evgenii Stepanov
68ecec1965 Fix CFI initialization crash on x86.
Third try.

Bug: 34752378
Test: bionic tests
Change-Id: I247c127489a8ee38404e104f28d916a704e35f36
2017-02-02 14:44:46 -08:00
Evgenii Stepanov
beb3eb1790 Revert "Fix CFI initialization crash on x86."
Breaks aosp-master/sdk.

This reverts commit 4ccd4317f9.
2017-01-31 17:10:03 -08:00
Evgenii Stepanov
4ccd4317f9 Fix CFI initialization crash on x86.
Second try.

Bug: 34752378
Test: bionic tests
Change-Id: I0a7453154671918b2e6e72f0bb9074c29ceb0f34
2017-01-31 13:44:55 -08:00
Alex Cheung
6fcd7a7d28 Revert "Fix CFI initialization crash on x86."
This reverts commit be46d3871c.

Reverting due to broken build:

https://android-build.googleplex.com/builds/branch-dashboard/aosp-master?build_id=3687823

Change-Id: I30968398edd9a094fce878839ba0a002ed487a77
2017-01-31 04:19:50 +00:00
Evgenii Stepanov
be46d3871c Fix CFI initialization crash on x86.
Bug: 34752378
Test: bionic tests
Change-Id: If8e33f76a1a2d83356d818fed506ea624f579860
2017-01-30 14:29:48 -08:00
Evgenii Stepanov
0a3637d3eb Runtime support for CFI
Control Flow Integrity support in bionic.

General design:
http://clang.llvm.org/docs/ControlFlowIntegrityDesign.html#shared-library-support

This CL implements subsections "CFI Shadow" and "CFI_SlowPath" in the above document.

Bug: 22033465
Test: bionic device tests
Change-Id: I14dfea630de468eb5620e7f55f92b1397ba06217
2017-01-18 13:13:52 -08:00