From 789f4154db2297525163c4e389d37d2dc93c460b Mon Sep 17 00:00:00 2001 From: Simon Atanasyan Date: Sat, 12 Jan 2019 11:12:08 +0000 Subject: [PATCH] [ORC][MIPS] Fill delay-slot after `jr` instruction MIPS `jr` instruction uses a delay-slot. To escape execution of arbitrary instruction we should either fill the delay-slot by `nop` instruction or swap `jr` instruction and logically preceding instruction. This fix implements the second method to generate a bit more effective code. llvm-svn: 351001 --- llvm/lib/ExecutionEngine/Orc/OrcABISupport.cpp | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/llvm/lib/ExecutionEngine/Orc/OrcABISupport.cpp b/llvm/lib/ExecutionEngine/Orc/OrcABISupport.cpp index 3f513e4..aa40555 100644 --- a/llvm/lib/ExecutionEngine/Orc/OrcABISupport.cpp +++ b/llvm/lib/ExecutionEngine/Orc/OrcABISupport.cpp @@ -610,13 +610,13 @@ void OrcMips32_Base::writeResolverCode(uint8_t *ResolverMem, 0x8fa40008, // 0xe8: lw $a0,8($sp) 0x27bd0068, // 0xec: addiu $sp,$sp,104 0x0300f825, // 0xf0: move $ra, $t8 - 0x00000000, // 0xf4: move $t9, $v0/v1 - 0x03200008 // 0xf8: jr $t9 + 0x03200008, // 0xf4: jr $t9 + 0x00000000, // 0xf8: move $t9, $v0/v1 }; const unsigned ReentryFnAddrOffset = 0x7c; // JIT re-entry fn addr lui const unsigned CallbackMgrAddrOffset = 0x6c; // Callback manager addr lui - const unsigned Offsett = 0xf4; + const unsigned Offsett = 0xf8; memcpy(ResolverMem, ResolverCode, sizeof(ResolverCode)); @@ -810,8 +810,8 @@ void OrcMips64::writeResolverCode(uint8_t *ResolverMem, JITReentryFn ReentryFn, 0xdfa30008, // 0x10c: ld v1, 8(sp) 0x67bd00d0, // 0x110: daddiu $sp,$sp,208 0x0300f825, // 0x114: move $ra, $t8 - 0x0040c825, // 0x118: move $t9, $v0 - 0x03200008 // 0x11c: jr $t9 + 0x03200008, // 0x118: jr $t9 + 0x0040c825, // 0x11c: move $t9, $v0 }; const unsigned ReentryFnAddrOffset = 0x8c; // JIT re-entry fn addr lui -- 2.7.4