From 0ec49dab6794166d67fae4764ce7fdea42ea6103 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 29 Aug 2018 12:48:42 -0400 Subject: [PATCH] fix async thread cancellation on powerpc64 entering the local entry point for __cancel from __cp_cancel is valid if __cp_cancel was reached from __syscall_cp, since both are in libc and share the same TOC pointer, but it is not valid if __cp_cancel was reached when cancel_handler rewrote the program counter for asynchronous cancellation of code outside libc. to ensure __cancel is entered with a valid TOC pointer, recompute the correct value in a PC-relative manner before jumping. --- src/thread/powerpc64/syscall_cp.s | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/thread/powerpc64/syscall_cp.s b/src/thread/powerpc64/syscall_cp.s index d420dbde..ef50ed00 100644 --- a/src/thread/powerpc64/syscall_cp.s +++ b/src/thread/powerpc64/syscall_cp.s @@ -34,4 +34,11 @@ __cp_end: blr __cp_cancel: + mflr 0 + bl 1f + .long .TOC.-. +1: mflr 3 + lwa 2, 0(3) + add 2, 2, 3 + mtlr 0 b __cancel