__libc_setup_tls

🧵 Summary:
you could find the entire code here As the function name suggests, __libc_setup_tls initializes the Thread-Local Storage (TLS) for the main thread by:

• Searching for the TLS segment in the binary (via .tdata and .tbss) and extracting size/alignment info

• Allocating memory for the initial TLS block (including the TCB and alignment)

• Setting up global TLS metadata like _dl_tls_static_size, _dl_tls_static_align, and initializing the static DTV

note :

dl_tls_static_align is base on the TCB_ALIGNMENT but could be change if the tls has a bigger alignment

the function use only brk for allocation to avoid using malloc because of errno who is a tls var