From 3370059668763162340751ac4af4379d1e0cb7aa Mon Sep 17 00:00:00 2001 From: Jason Lowe-Power Date: Sat, 28 Jan 2017 13:37:58 +0530 Subject: [PATCH] x86: Fix implicit stack addressing in 64-bit mode When in 64-bit mode, if the stack is accessed implicitly by an instruction, the alternate address prefix should be ignored if present. This patch adds an extra flag to the ldstop which signifies when the address override should be ignored. Then, for all of the affected instructions, this patch adds two options to the ld and st opcode to use the current stack addressing mode for all addresses and to ignore the AddressSizeFlagBit. Finally, this patch updates the x86 TLB to not truncate the address if it is in 64-bit mode and the IgnoreAddrSizeFlagBit is set. This fixes a problem when calling __libc_start_main with a binary that is linked with a recent version of ld. This version of ld uses the address override prefix (0x67) on the call instruction instead of a nop. Note: This has not been tested in compatibility mode and only the call instruction with the address override prefix has been tested. See [1] page 9 (pdf page 45) For instructions that are affected see [1] page 519 (pdf page 555). [1] http://support.amd.com/TechDocs/24594.pdf Signed-off-by: Sanchayan Maity --- .../general_purpose/control_transfer/call.py | 4 +- .../data_transfer/stack_operations.py | 18 ++-- src/arch/x86/isa/microops/ldstop.isa | 84 +++++++++++++------ 3 files changed, 71 insertions(+), 35 deletions(-) diff --git a/src/arch/x86/isa/insts/general_purpose/control_transfer/call.py b/src/arch/x86/isa/insts/general_purpose/control_transfer/call.py index eaaa18208..18ba93e19 100644 --- a/src/arch/x86/isa/insts/general_purpose/control_transfer/call.py +++ b/src/arch/x86/isa/insts/general_purpose/control_transfer/call.py @@ -45,7 +45,7 @@ def macroop CALL_NEAR_I limm t1, imm rdip t7 # Check target of call - st t7, ss, [0, t0, rsp], "-env.dataSize" + st_stack t7, ss, [0, t0, rsp], "-env.dataSize" subi rsp, rsp, ssz wrip t7, t1 }; @@ -58,7 +58,7 @@ def macroop CALL_NEAR_R rdip t1 # Check target of call - st t1, ss, [0, t0, rsp], "-env.dataSize" + st_stack t1, ss, [0, t0, rsp], "-env.dataSize" subi rsp, rsp, ssz wripi reg, 0 }; diff --git a/src/arch/x86/isa/insts/general_purpose/data_transfer/stack_operations.py b/src/arch/x86/isa/insts/general_purpose/data_transfer/stack_operations.py index be9387ecf..2117a943c 100644 --- a/src/arch/x86/isa/insts/general_purpose/data_transfer/stack_operations.py +++ b/src/arch/x86/isa/insts/general_purpose/data_transfer/stack_operations.py @@ -40,7 +40,7 @@ def macroop POP_R { # Make the default data size of pops 64 bits in 64 bit mode .adjust_env oszIn64Override - ld t1, ss, [1, t0, rsp], dataSize=ssz + ld_stack t1, ss, [1, t0, rsp], dataSize=ssz addi rsp, rsp, ssz, dataSize=asz mov reg, reg, t1 }; @@ -49,7 +49,7 @@ def macroop POP_M { # Make the default data size of pops 64 bits in 64 bit mode .adjust_env oszIn64Override - ld t1, ss, [1, t0, rsp], dataSize=ssz + ld_stack t1, ss, [1, t0, rsp], dataSize=ssz cda seg, sib, disp, dataSize=ssz addi rsp, rsp, ssz, dataSize=asz st t1, seg, sib, disp, dataSize=ssz @@ -70,7 +70,7 @@ def macroop PUSH_R { # Make the default data size of pops 64 bits in 64 bit mode .adjust_env oszIn64Override - st reg, ss, [1, t0, rsp], "-env.stackSize", dataSize=ssz + st_stack reg, ss, [1, t0, rsp], "-env.stackSize", dataSize=ssz subi rsp, rsp, ssz }; @@ -79,7 +79,7 @@ def macroop PUSH_I { .adjust_env oszIn64Override limm t1, imm - st t1, ss, [1, t0, rsp], "-env.stackSize", dataSize=ssz + st_stack t1, ss, [1, t0, rsp], "-env.stackSize", dataSize=ssz subi rsp, rsp, ssz }; @@ -138,7 +138,7 @@ def macroop LEAVE { .adjust_env oszIn64Override mov t1, t1, rbp, dataSize=ssz - ld rbp, ss, [1, t0, t1], dataSize=ssz + ld_stack rbp, ss, [1, t0, t1], dataSize=ssz mov rsp, rsp, t1, dataSize=ssz addi rsp, rsp, ssz, dataSize=ssz }; @@ -156,7 +156,7 @@ def macroop ENTER_I_I { # t1 is now the masked nesting level, and t2 is the amount of storage. # Push rbp. - st rbp, ss, [1, t0, rsp], "-env.dataSize" + st_stack rbp, ss, [1, t0, rsp], "-env.dataSize" subi rsp, rsp, ssz # Save the stack pointer for later @@ -172,8 +172,8 @@ def macroop ENTER_I_I { limm t4, "ULL(-1)", dataSize=8 topOfLoop: - ld t5, ss, [dsz, t4, rbp] - st t5, ss, [1, t0, rsp], "-env.dataSize" + ld_stack t5, ss, [dsz, t4, rbp] + st_stack t5, ss, [1, t0, rsp], "-env.dataSize" subi rsp, rsp, ssz # If we're not done yet, loop @@ -183,7 +183,7 @@ topOfLoop: bottomOfLoop: # Push the old rbp onto the stack - st t6, ss, [1, t0, rsp], "-env.dataSize" + st_stack t6, ss, [1, t0, rsp], "-env.dataSize" subi rsp, rsp, ssz skipLoop: diff --git a/src/arch/x86/isa/microops/ldstop.isa b/src/arch/x86/isa/microops/ldstop.isa index a22bc5fe2..7ba78c8f9 100644 --- a/src/arch/x86/isa/microops/ldstop.isa +++ b/src/arch/x86/isa/microops/ldstop.isa @@ -315,7 +315,8 @@ def template MicroLdStSplitOpConstructor {{ let {{ class LdStOp(X86Microop): def __init__(self, data, segment, addr, disp, - dataSize, addressSize, baseFlags, atCPL0, prefetch, nonSpec): + dataSize, addressSize, baseFlags, atCPL0, prefetch, nonSpec, + implicitStack): self.data = data [self.scale, self.index, self.base] = addr self.disp = disp @@ -331,8 +332,11 @@ let {{ self.instFlags += " | (1ULL << StaticInst::IsDataPrefetch)" if nonSpec: self.instFlags += " | (1ULL << StaticInst::IsNonSpeculative)" - self.memFlags += " | (machInst.legacy.addr ? " + \ - "(AddrSizeFlagBit << FlagShift) : 0)" + # For implicit stack operations, we should use *not* use the + # alternative addressing mode for loads/stores if the prefix is set + if not implicitStack: + self.memFlags += " | (machInst.legacy.addr ? " + \ + "(AddrSizeFlagBit << FlagShift) : 0)" def getAllocator(self, microFlags): allocator = '''new %(class_name)s(machInst, macrocodeBlock, @@ -351,7 +355,8 @@ let {{ class BigLdStOp(X86Microop): def __init__(self, data, segment, addr, disp, - dataSize, addressSize, baseFlags, atCPL0, prefetch, nonSpec): + dataSize, addressSize, baseFlags, atCPL0, prefetch, nonSpec, + implicitStack): self.data = data [self.scale, self.index, self.base] = addr self.disp = disp @@ -367,8 +372,11 @@ let {{ self.instFlags += " | (1ULL << StaticInst::IsDataPrefetch)" if nonSpec: self.instFlags += " | (1ULL << StaticInst::IsNonSpeculative)" - self.memFlags += " | (machInst.legacy.addr ? " + \ - "(AddrSizeFlagBit << FlagShift) : 0)" + # For implicit stack operations, we should use *not* use the + # alternative addressing mode for loads/stores if the prefix is set + if not implicitStack: + self.memFlags += " | (machInst.legacy.addr ? " + \ + "(AddrSizeFlagBit << FlagShift) : 0)" def getAllocator(self, microFlags): allocString = ''' @@ -395,9 +403,11 @@ let {{ class LdStSplitOp(LdStOp): def __init__(self, data, segment, addr, disp, - dataSize, addressSize, baseFlags, atCPL0, prefetch, nonSpec): + dataSize, addressSize, baseFlags, atCPL0, prefetch, nonSpec, + implicitStack): super(LdStSplitOp, self).__init__(0, segment, addr, disp, - dataSize, addressSize, baseFlags, atCPL0, prefetch, nonSpec) + dataSize, addressSize, baseFlags, atCPL0, prefetch, nonSpec, + implicitStack) (self.dataLow, self.dataHi) = data def getAllocator(self, microFlags): @@ -435,7 +445,8 @@ let {{ calculateEA = 'EA = SegBase + ' + segmentEAExpr def defineMicroLoadOp(mnemonic, code, bigCode='', - mem_flags="0", big=True, nonSpec=False): + mem_flags="0", big=True, nonSpec=False, + implicitStack=False): global header_output global decoder_output global exec_output @@ -460,17 +471,26 @@ let {{ exec_output += MicroLoadInitiateAcc.subst(iop) exec_output += MicroLoadCompleteAcc.subst(iop) + if implicitStack: + # For instructions that implicitly access the stack, the address + # size is the same as the stack segment pointer size, not the + # address size if specified by the instruction prefix + addressSize = "env.stackSize" + else: + addressSize = "env.addressSize" + base = LdStOp if big: base = BigLdStOp class LoadOp(base): def __init__(self, data, segment, addr, disp = 0, dataSize="env.dataSize", - addressSize="env.addressSize", - atCPL0=False, prefetch=False, nonSpec=nonSpec): + addressSize=addressSize, + atCPL0=False, prefetch=False, nonSpec=nonSpec, + implicitStack=implicitStack): super(LoadOp, self).__init__(data, segment, addr, disp, dataSize, addressSize, mem_flags, - atCPL0, prefetch, nonSpec) + atCPL0, prefetch, nonSpec, implicitStack) self.className = Name self.mnemonic = name @@ -478,6 +498,10 @@ let {{ defineMicroLoadOp('Ld', 'Data = merge(Data, Mem, dataSize);', 'Data = Mem & mask(dataSize * 8);') + # Load micro-op used in macro-ops that implicitly access the stack + defineMicroLoadOp('Ld_stack', 'Data = merge(Data, Mem, dataSize);', + 'Data = Mem & mask(dataSize * 8);', + implicitStack=True) defineMicroLoadOp('Ldst', 'Data = merge(Data, Mem, dataSize);', 'Data = Mem & mask(dataSize * 8);', '(StoreCheck << FlagShift)') @@ -544,10 +568,11 @@ let {{ def __init__(self, data, segment, addr, disp = 0, dataSize="env.dataSize", addressSize="env.addressSize", - atCPL0=False, prefetch=False, nonSpec=nonSpec): + atCPL0=False, prefetch=False, nonSpec=nonSpec, + implicitStack=False): super(LoadOp, self).__init__(data, segment, addr, disp, dataSize, addressSize, mem_flags, - atCPL0, prefetch, nonSpec) + atCPL0, prefetch, nonSpec, implicitStack) self.className = Name self.mnemonic = name @@ -574,7 +599,8 @@ let {{ '(StoreCheck << FlagShift) | Request::LOCKED_RMW', nonSpec=True) - def defineMicroStoreOp(mnemonic, code, completeCode="", mem_flags="0"): + def defineMicroStoreOp(mnemonic, code, completeCode="", mem_flags="0", + implicitStack=False): global header_output global decoder_output global exec_output @@ -594,20 +620,31 @@ let {{ exec_output += MicroStoreInitiateAcc.subst(iop) exec_output += MicroStoreCompleteAcc.subst(iop) + if implicitStack: + # For instructions that implicitly access the stack, the address + # size is the same as the stack segment pointer size, not the + # address size if specified by the instruction prefix + addressSize = "env.stackSize" + else: + addressSize = "env.addressSize" + class StoreOp(LdStOp): def __init__(self, data, segment, addr, disp = 0, dataSize="env.dataSize", - addressSize="env.addressSize", - atCPL0=False, nonSpec=False): + addressSize=addressSize, + atCPL0=False, nonSpec=False, implicitStack=implicitStack): super(StoreOp, self).__init__(data, segment, addr, disp, dataSize, addressSize, mem_flags, atCPL0, False, - nonSpec) + nonSpec, implicitStack) self.className = Name self.mnemonic = name microopClasses[name] = StoreOp defineMicroStoreOp('St', 'Mem = pick(Data, 2, dataSize);') + # Store micro-op used in macro-ops that implicitly access the stack + defineMicroStoreOp('St_stack', 'Mem = pick(Data, 2, dataSize);', + implicitStack=True) defineMicroStoreOp('Stul', 'Mem = pick(Data, 2, dataSize);', mem_flags="Request::LOCKED_RMW") @@ -655,10 +692,10 @@ let {{ def __init__(self, data, segment, addr, disp = 0, dataSize="env.dataSize", addressSize="env.addressSize", - atCPL0=False, nonSpec=False): + atCPL0=False, nonSpec=False, implicitStack=False): super(StoreOp, self).__init__(data, segment, addr, disp, dataSize, addressSize, mem_flags, atCPL0, False, - nonSpec) + nonSpec, implicitStack) self.className = Name self.mnemonic = name @@ -694,7 +731,7 @@ let {{ def __init__(self, data, segment, addr, disp = 0, dataSize="env.dataSize", addressSize="env.addressSize"): super(LeaOp, self).__init__(data, segment, addr, disp, - dataSize, addressSize, "0", False, False, False) + dataSize, addressSize, "0", False, False, False, False) self.className = "Lea" self.mnemonic = "lea" @@ -715,7 +752,7 @@ let {{ addressSize="env.addressSize"): super(TiaOp, self).__init__("InstRegIndex(NUM_INTREGS)", segment, addr, disp, dataSize, addressSize, "0", False, False, - False) + False, False) self.className = "Tia" self.mnemonic = "tia" @@ -727,10 +764,9 @@ let {{ addressSize="env.addressSize", atCPL0=False): super(CdaOp, self).__init__("InstRegIndex(NUM_INTREGS)", segment, addr, disp, dataSize, addressSize, "Request::NO_ACCESS", - atCPL0, False, False) + atCPL0, False, False, False) self.className = "Cda" self.mnemonic = "cda" microopClasses["cda"] = CdaOp }}; -