Consistently include BTI markers in every assembly file

Trying to migrate Chromium to the "link all the asm files together"
strategy broke the aarch64 Android build because some of the ifdef'd out
assembly files were missing the .note.gnu.property section for BTI. If
we add support for IBT, that'll be another one.

To fix this, introduce <openssl/asm_base.h>, which must be included at
the start of every assembly file (before the target ifdefs). This does a
couple things:

- It emits BTI and noexecstack markers into every assembly file, even
  those that ifdef themselves out.

- It resolves the MSan -> OPENSSL_NO_ASM logic, so we only need to do it
  once.

- It defines the same OPENSSL_X86_64, etc., defines we set elsewhere, so
  we can ensure they're consistent.

This required carving files up a bit. <openssl/base.h> has a lot of
things, such that trying to guard everything in it on __ASSEMBLER__
would be tedious. Instead, I moved the target defines to a new
<openssl/target.h>. Then <openssl/asm_base.h> is the new header that
pulls in all those things.

Bug: 542
Change-Id: I1682b4d929adea72908655fa1bb15765a6b3473b
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/60765
Reviewed-by: Bob Beck <bbe@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
13 files changed
tree: 9c85e8a04ecb74085ad7b1c191f1933489a520eb
  1. .github/
  2. cmake/
  3. crypto/
  4. decrepit/
  5. fuzz/
  6. include/
  7. pki/
  8. rust/
  9. ssl/
  10. third_party/
  11. tool/
  12. util/
  13. .clang-format
  14. .gitignore
  15. API-CONVENTIONS.md
  16. BREAKING-CHANGES.md
  17. BUILDING.md
  18. CMakeLists.txt
  19. codereview.settings
  20. CONTRIBUTING.md
  21. FUZZING.md
  22. go.mod
  23. go.sum
  24. INCORPORATING.md
  25. LICENSE
  26. PORTING.md
  27. README.md
  28. SANDBOXING.md
  29. sources.cmake
  30. STYLE.md
README.md

BoringSSL

BoringSSL is a fork of OpenSSL that is designed to meet Google's needs.

Although BoringSSL is an open source project, it is not intended for general use, as OpenSSL is. We don't recommend that third parties depend upon it. Doing so is likely to be frustrating because there are no guarantees of API or ABI stability.

Programs ship their own copies of BoringSSL when they use it and we update everything as needed when deciding to make API changes. This allows us to mostly avoid compromises in the name of compatibility. It works for us, but it may not work for you.

BoringSSL arose because Google used OpenSSL for many years in various ways and, over time, built up a large number of patches that were maintained while tracking upstream OpenSSL. As Google's product portfolio became more complex, more copies of OpenSSL sprung up and the effort involved in maintaining all these patches in multiple places was growing steadily.

Currently BoringSSL is the SSL library in Chrome/Chromium, Android (but it's not part of the NDK) and a number of other apps/programs.

Project links:

There are other files in this directory which might be helpful: