From 056f9d818eaf1dbe9e9d63b64b109fd9b608fa36 Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Fri, 24 Aug 2018 23:11:59 +0000 Subject: rewrite __aeabi_read_tp in asm __aeabi_read_tp used to call c code, but that was incorrect as the arm runtime abi specifies special pcs for this function: it is only allowed to clobber r0, ip, lr and cpsr. maintainer's note: the old code explicitly saved and restored all general-purpose registers which are call-clobbered in the normal calling convention, so it's unlikely that any real-world compilers produced code that could break. however theoretically they could have chosen to use floating point registers, in which case the caller's values of those registers would be clobbered. --- src/thread/arm/__aeabi_read_tp.s | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'src/thread/arm/__aeabi_read_tp.s') diff --git a/src/thread/arm/__aeabi_read_tp.s b/src/thread/arm/__aeabi_read_tp.s index 9d0cd311..2585620c 100644 --- a/src/thread/arm/__aeabi_read_tp.s +++ b/src/thread/arm/__aeabi_read_tp.s @@ -2,7 +2,9 @@ .global __aeabi_read_tp .type __aeabi_read_tp,%function __aeabi_read_tp: - push {r1,r2,r3,lr} - bl __aeabi_read_tp_c - pop {r1,r2,r3,lr} - bx lr + ldr r0,1f + add r0,r0,pc + ldr r0,[r0] +2: bx r0 + .align 2 +1: .word __a_gettp_ptr - 2b -- cgit v1.2.1