Cygwin: Aarch64: optimize pthread_wrapper register usageHEADmastermain

This patch resolves issues related to unsafe access to deallocated
stack memory in the pthread wrapper for AArch64.

Key changes:
- Removed use of x19 by directly loading the thread function and
  argument using LDP from [WRAPPER_ARG], freeing one register.
- Stored thread function and argument in x20 and x21 before
  VirtualFree to preserve them across calls.
- Used x1 as a temporary register to load the stack base,
  subtract CYGTLS, and update SP.
- Moved the thread argument back into x0 after VirtualFree and
  before calling the thread function.

Earlier, `wrapper_arg` lived on the stack, which was freed via
`VirtualFree`, risking segfaults on later access. Now, the thread
`func` and `arg` are loaded before the stack is freed, stored in
callee-saved registers, and restored to `x0` before calling the
thread function.

Fixes: f4ba145056db ("Aarch64: Add inline assembly pthread wrapper")
Signed-off-by: Thirumalai Nagalingam <thirumalai.nagalingam@multicorewareinc.com>

0 files changed, 0 insertions, 0 deletions