xtensa: add support for TLS
The Xtensa architecture provides a global register called THREADPTR
for the purpose of Thread Local Storage (TLS) support. This allows us
to use a fairly simple implementation, keeping the thread pointer in
the regset and simply saving and restoring it upon entering/exiting
the from user space.
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index a8b0d57..562fac6 100644
--- a/arch/xtensa/kernel/ptrace.c
+++ b/arch/xtensa/kernel/ptrace.c
@@ -66,6 +66,7 @@
__put_user(regs->lcount, &gregset->lcount);
__put_user(regs->windowstart, &gregset->windowstart);
__put_user(regs->windowbase, &gregset->windowbase);
+ __put_user(regs->threadptr, &gregset->threadptr);
for (i = 0; i < XCHAL_NUM_AREGS; i++)
__put_user(regs->areg[i],
@@ -92,6 +93,7 @@
__get_user(regs->lcount, &gregset->lcount);
__get_user(ws, &gregset->windowstart);
__get_user(wb, &gregset->windowbase);
+ __get_user(regs->threadptr, &gregset->threadptr);
regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);