[libunwind][AArch64] Fix libunwind::Registers_arm64::jumpto

Summary:
The AArch64 version of the libunwind function which restores the
CPU state and resumes execution is not interrupt-safe. It restores
the target value of SP before loading the floating-point registers
from the context struct, but that struct is allocated on the stack
which is being deallocated. This means that if an interrupt occurs
during this function, and uses a lot of stack space, it could
overwrite the values about to be loaded into the floating-point
registers.

This patch fixes the issue.

Patch by Oliver Stannard.

Reviewers: phosek, chill

Reviewed By: chill

Subscribers: chill, javed.absar, kristof.beyls, christof, LukeCheeseman, pbarrio, olista01, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D63006

llvm-svn: 363545
1 file changed
tree: 79dbbf6b3f86a160dccfea4a45e19b6882a2b4a2
  1. clang/
  2. clang-tools-extra/
  3. compiler-rt/
  4. debuginfo-tests/
  5. libclc/
  6. libcxx/
  7. libcxxabi/
  8. libunwind/
  9. lld/
  10. lldb/
  11. llgo/
  12. llvm/
  13. openmp/
  14. parallel-libs/
  15. polly/
  16. pstl/
  17. .arcconfig
  18. .clang-format
  19. .clang-tidy
  20. .gitignore
  21. README.md
README.md

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