From 9f26ebded188ed78c3571a4ca1477dd6351bc647 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sun, 24 May 2015 23:03:47 -0400 Subject: [PATCH] fix stack alignment code in mips crt_arch.h the instruction used to align the stack, "and $sp, $sp, -8", does not actually exist; it's expanded to 2 instructions using the 'at' (assembler temporary) register, and thus cannot be used in a branch delay slot. since alignment mod 16 commutes with subtracting 8, simply swapping these two operations fixes the problem. crt1.o was not affected because it's still being generated from a dedicated asm source file. dlstart.lo was not affected because the stack pointer it receives is already aligned by the kernel. but Scrt1.o was affected in cases where the dynamic linker gave it a misaligned stack pointer. --- arch/mips/crt_arch.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/mips/crt_arch.h b/arch/mips/crt_arch.h index 058de5c3..21e139b9 100644 --- a/arch/mips/crt_arch.h +++ b/arch/mips/crt_arch.h @@ -22,8 +22,8 @@ __asm__( " addu $5, $5, $gp \n" " lw $25, 4($ra) \n" " addu $25, $25, $gp \n" -" subu $sp, $sp, 16 \n" +" and $sp, $sp, -8 \n" " jalr $25 \n" -" and $sp, $sp, -8 \n" +" subu $sp, $sp, 16 \n" ".set pop \n" ); -- 2.25.1