[all-commits] [llvm/llvm-project] 623922: [lldb][AArch64] Save/restore TLS registers around ...

[David Spickett via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6239227172cdc92f3bb72131333f50f83a6439cf
      https://github.com/llvm/llvm-project/commit/6239227172cdc92f3bb72131333f50f83a6439cf
  Author: David Spickett <david.spickett at linaro.org>
  Date:   2023-08-03 (Thu, 03 Aug 2023)

  Changed paths:
    M lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
    M lldb/test/API/linux/aarch64/tls_registers/TestAArch64LinuxTLSRegisters.py
    M lldb/test/API/linux/aarch64/tls_registers/main.c

  Log Message:
  -----------
  [lldb][AArch64] Save/restore TLS registers around expressions

Previously lldb was storing them but not restoring them. Meaning that this function:
```
void expr(uint64_t value) {
  __asm__ volatile("msr tpidr_el0, %0" ::"r"(value));
}
```
When run from lldb:
```
(lldb) expression expr()
```
Would leave tpidr as `value` instead of the original value of the register.

A check for this scenario has been added to TestAArch64LinuxTLSRegisters.py,
which covers tpidr and the SME excluisve tpidr2 register when it's present.

Reviewed By: omjavaid

Differential Revision: https://reviews.llvm.org/D156512