Revert "[IR] add fn attr for no_stack_protector; prevent inlining on mismatch"

This reverts commit b7926ce6d7.

Going with a simpler approach.
This commit is contained in:
Nick Desaulniers 2020-11-17 17:17:44 -08:00
parent dd6087cac0
commit f4c6080ab8
30 changed files with 17 additions and 293 deletions

View File

@ -3938,10 +3938,6 @@ option.
int bar(int y); // bar can be built with the stack protector.
A callee that has a stack protector will not be inlined into a
``__attribute__((no_stack_protector))`` caller, and vice-versa, even if the
callee is marked ``__attribute__((always_inline))``.
}];
}

View File

@ -1642,14 +1642,14 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
if (!hasUnwindExceptions(LangOpts))
B.addAttribute(llvm::Attribute::NoUnwind);
if (D && D->hasAttr<NoStackProtectorAttr>())
B.addAttribute(llvm::Attribute::NoStackProtect);
else if (LangOpts.getStackProtector() == LangOptions::SSPOn)
B.addAttribute(llvm::Attribute::StackProtect);
else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
B.addAttribute(llvm::Attribute::StackProtectStrong);
else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
B.addAttribute(llvm::Attribute::StackProtectReq);
if (!D || !D->hasAttr<NoStackProtectorAttr>()) {
if (LangOpts.getStackProtector() == LangOptions::SSPOn)
B.addAttribute(llvm::Attribute::StackProtect);
else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
B.addAttribute(llvm::Attribute::StackProtectStrong);
else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
B.addAttribute(llvm::Attribute::StackProtectReq);
}
if (!D) {
// If we don't have a declaration to control inlining, the function isn't

View File

@ -36,7 +36,7 @@ void test2(const char *msg) {
// SSPREQ: attributes #[[A]] = {{.*}} sspreq
// SAFESTACK-NOSSP: attributes #[[A]] = {{.*}} safestack
// SAFESTACK-NOSSP-NOT: attributes #[[A]] = {{.*}} ssp
// SAFESTACK-NOSSP-NOT: ssp
// SAFESTACK-SSP: attributes #[[A]] = {{.*}} safestack ssp{{ }}
// SAFESTACK-SSPSTRONG: attributes #[[A]] = {{.*}} safestack sspstrong
@ -47,11 +47,6 @@ void test2(const char *msg) {
// SSPSTRONG-NOT: attributes #[[B]] = {{.*}} sspstrong
// SSPREQ-NOT: attributes #[[B]] = {{.*}} sspreq
// NOSSP: attributes #[[B]] = {{.*}} nossp
// SSP: attributes #[[B]] = {{.*}} nossp
// SSPSTRONG: attributes #[[B]] = {{.*}} nossp
// SSPREQ: attributes #[[B]] = {{.*}} nossp
// SAFESTACK-SSP: attributes #[[B]] = {{.*}} safestack
// SAFESTACK-SSP-NOT: attributes #[[B]] = {{.*}} safestack ssp{{ }}
// SAFESTACK-SSPSTRONG: attributes #[[B]] = {{.*}} safestack

View File

@ -1,34 +0,0 @@
// RUN: %clang_cc1 -stack-protector 2 -Rpass-missed=inline -O2 -verify %s -emit-llvm-only
void side_effect(void);
void foo(void) {
side_effect();
}
// expected-remark@+3 {{foo will not be inlined into bar: stack protected callee but caller requested no stack protector}}
__attribute__((no_stack_protector))
void bar(void) {
foo();
}
// expected-remark@+2 {{bar will not be inlined into baz: stack protected caller but callee requested no stack protector}}
void baz(void) {
bar();
}
void ssp_callee(void);
// No issue; matching stack protections.
void ssp_caller(void) {
ssp_callee();
}
__attribute__((no_stack_protector))
void nossp_callee(void);
// No issue; matching stack protections.
__attribute__((no_stack_protector))
void nossp_caller(void) {
nossp_callee();
}

View File

@ -78,7 +78,6 @@ func TestAttributes(t *testing.T) {
"returns_twice",
"signext",
"safestack",
"nossp",
"ssp",
"sspreq",
"sspstrong",

View File

@ -122,7 +122,6 @@ module Attribute = struct
| Noinline
| Alwaysinline
| Optsize
| Nossp
| Ssp
| Sspreq
| Alignment of int

View File

@ -1070,7 +1070,6 @@ The integer codes are mapped to well-known attributes as follows.
* code 68: ``noundef``
* code 69: ``byref``
* code 70: ``mustprogress``
* code 71: ``nossp``
.. note::
The ``allocsize`` attribute has a special encoding for its arguments. Its two

View File

@ -1825,22 +1825,6 @@ example:
undefined behavior, the undefined behavior may be observed even
if the call site is dead code.
``nossp``
This attribute indicates the function should not emit a stack smashing
protector. This is useful for code that intentionally manipulates the stack
canary, such as operating system kernel code that must save/restore such
canary values on context switch.
If a function with the ``nossp`` attribute calls a callee function that has
a stack protector function attribute, such as ``ssp``, ``sspreq``, or
``sspstrong`` (or vice-versa), then the callee will not be inline
substituted into the caller. Even when the callee is ``alwaysinline``, the
above holds.
Such inlining might break assumptions in the function that was built
without stack protection. This permits the functions that would have stack
protection to retain their stack protector.
``ssp``
This attribute indicates that the function should emit a stack
smashing protector. It is in the form of a "canary" --- a random value

View File

@ -652,7 +652,6 @@ enum AttributeKindCodes {
ATTR_KIND_NOUNDEF = 68,
ATTR_KIND_BYREF = 69,
ATTR_KIND_MUSTPROGRESS = 70,
ATTR_KIND_NO_STACK_PROTECT = 71,
};
enum ComdatSelectionKindCodes {

View File

@ -191,9 +191,6 @@ def StackAlignment : IntAttr<"alignstack">;
/// Function can be speculated.
def Speculatable : EnumAttr<"speculatable">;
/// Stack protection explicitly disabled.
def NoStackProtect : EnumAttr<"nossp">;
/// Stack protection.
def StackProtect : EnumAttr<"ssp">;

View File

@ -679,7 +679,6 @@ lltok::Kind LLLexer::LexIdentifier() {
KEYWORD(signext);
KEYWORD(speculatable);
KEYWORD(sret);
KEYWORD(nossp);
KEYWORD(ssp);
KEYWORD(sspreq);
KEYWORD(sspstrong);

View File

@ -1377,9 +1377,6 @@ bool LLParser::parseFnAttributeValuePairs(AttrBuilder &B,
case lltok::kw_returns_twice:
B.addAttribute(Attribute::ReturnsTwice); break;
case lltok::kw_speculatable: B.addAttribute(Attribute::Speculatable); break;
case lltok::kw_nossp:
B.addAttribute(Attribute::NoStackProtect);
break;
case lltok::kw_ssp: B.addAttribute(Attribute::StackProtect); break;
case lltok::kw_sspreq: B.addAttribute(Attribute::StackProtectReq); break;
case lltok::kw_sspstrong:
@ -1791,7 +1788,6 @@ bool LLParser::parseOptionalParamAttrs(AttrBuilder &B) {
case lltok::kw_sanitize_memory:
case lltok::kw_sanitize_thread:
case lltok::kw_speculative_load_hardening:
case lltok::kw_nossp:
case lltok::kw_ssp:
case lltok::kw_sspreq:
case lltok::kw_sspstrong:
@ -1900,7 +1896,6 @@ bool LLParser::parseOptionalReturnAttrs(AttrBuilder &B) {
case lltok::kw_sanitize_memory:
case lltok::kw_sanitize_thread:
case lltok::kw_speculative_load_hardening:
case lltok::kw_nossp:
case lltok::kw_ssp:
case lltok::kw_sspreq:
case lltok::kw_sspstrong:

View File

@ -224,7 +224,6 @@ enum Kind {
kw_returns_twice,
kw_signext,
kw_speculatable,
kw_nossp,
kw_ssp,
kw_sspreq,
kw_sspstrong,

View File

@ -700,8 +700,6 @@ static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
return bitc::ATTR_KIND_SPECULATABLE;
case Attribute::StackAlignment:
return bitc::ATTR_KIND_STACK_ALIGNMENT;
case Attribute::NoStackProtect:
return bitc::ATTR_KIND_NO_STACK_PROTECT;
case Attribute::StackProtect:
return bitc::ATTR_KIND_STACK_PROTECT;
case Attribute::StackProtectReq:

View File

@ -270,15 +270,13 @@ static const CallInst *findStackProtectorIntrinsic(Function &F) {
/// regardless of size, functions with any buffer regardless of type and size,
/// functions with aggregates that contain any buffer regardless of type and
/// size, and functions that contain stack-based variables that have had their
/// address taken. The heuristic will be disregarded for functions explicitly
/// marked nossp.
/// address taken.
bool StackProtector::RequiresStackProtector() {
bool Strong = false;
bool NeedsProtector = false;
HasPrologue = findStackProtectorIntrinsic(*F);
if (F->hasFnAttribute(Attribute::SafeStack) ||
F->hasFnAttribute(Attribute::NoStackProtect))
if (F->hasFnAttribute(Attribute::SafeStack))
return false;
// We are constructing the OptimizationRemarkEmitter on the fly rather than

View File

@ -425,8 +425,6 @@ std::string Attribute::getAsString(bool InAttrGrp) const {
return "speculative_load_hardening";
if (hasAttribute(Attribute::Speculatable))
return "speculatable";
if (hasAttribute(Attribute::NoStackProtect))
return "nossp";
if (hasAttribute(Attribute::StackProtect))
return "ssp";
if (hasAttribute(Attribute::StackProtectReq))
@ -1941,17 +1939,9 @@ static void setOR(Function &Caller, const Function &Callee) {
/// If the inlined function had a higher stack protection level than the
/// calling function, then bump up the caller's stack protection level.
static void adjustCallerSSPLevel(Function &Caller, const Function &Callee) {
assert(!(Callee.hasFnAttribute(Attribute::NoStackProtect) &&
(Caller.hasFnAttribute(Attribute::StackProtect) ||
Caller.hasFnAttribute(Attribute::StackProtectStrong) ||
Caller.hasFnAttribute(Attribute::StackProtectReq))) &&
"stack protected caller but callee requested no stack protector");
assert(!(Caller.hasFnAttribute(Attribute::NoStackProtect) &&
(Callee.hasFnAttribute(Attribute::StackProtect) ||
Callee.hasFnAttribute(Attribute::StackProtectStrong) ||
Callee.hasFnAttribute(Attribute::StackProtectReq))) &&
"stack protected callee but caller requested no stack protector");
// If upgrading the SSP attribute, clear out the old SSP Attributes first.
// Having multiple SSP attributes doesn't actually hurt, but it adds useless
// clutter to the IR.
AttrBuilder OldSSPAttr;
OldSSPAttr.addAttribute(Attribute::StackProtect)
.addAttribute(Attribute::StackProtectStrong)

View File

@ -1602,7 +1602,6 @@ static bool isFuncOnlyAttr(Attribute::AttrKind Kind) {
case Attribute::NoInline:
case Attribute::AlwaysInline:
case Attribute::OptimizeForSize:
case Attribute::NoStackProtect:
case Attribute::StackProtect:
case Attribute::StackProtectReq:
case Attribute::StackProtectStrong:
@ -1998,19 +1997,6 @@ void Verifier::verifyFunctionAttrs(FunctionType *FT, AttributeList Attrs,
CheckFailed(
"\"patchable-function-entry\" takes an unsigned integer: " + S, V);
}
{
unsigned N = 0;
if (Attrs.hasFnAttribute(Attribute::NoStackProtect))
++N;
if (Attrs.hasFnAttribute(Attribute::StackProtect))
++N;
if (Attrs.hasFnAttribute(Attribute::StackProtectReq))
++N;
if (Attrs.hasFnAttribute(Attribute::StackProtectStrong))
++N;
Assert(N < 2,
"nossp, ssp, sspreq, sspstrong fn attrs are mutually exclusive", V);
}
}
void Verifier::verifyFunctionMetadata(

View File

@ -68,7 +68,6 @@ static Attribute::AttrKind parseAttrKind(StringRef Kind) {
.Case("sanitize_thread", Attribute::SanitizeThread)
.Case("sanitize_memtag", Attribute::SanitizeMemTag)
.Case("speculative_load_hardening", Attribute::SpeculativeLoadHardening)
.Case("nossp", Attribute::NoStackProtect)
.Case("ssp", Attribute::StackProtect)
.Case("sspreq", Attribute::StackProtectReq)
.Case("sspstrong", Attribute::StackProtectStrong)

View File

@ -965,7 +965,6 @@ Function *CodeExtractor::constructFunction(const ValueSet &inputs,
case Attribute::SanitizeHWAddress:
case Attribute::SanitizeMemTag:
case Attribute::SpeculativeLoadHardening:
case Attribute::NoStackProtect:
case Attribute::StackProtect:
case Attribute::StackProtectReq:
case Attribute::StackProtectStrong:

View File

@ -1667,22 +1667,6 @@ llvm::InlineResult llvm::InlineFunction(CallBase &CB, InlineFunctionInfo &IFI,
return InlineResult::failure("incompatible GC");
}
// Inlining a function that explicitly should not have a stack protector may
// break the code if inlined into a function that does have a stack
// protector.
if (LLVM_UNLIKELY(Caller->hasFnAttribute(Attribute::NoStackProtect)))
if (CalledFunc->hasFnAttribute(Attribute::StackProtect) ||
CalledFunc->hasFnAttribute(Attribute::StackProtectStrong) ||
CalledFunc->hasFnAttribute(Attribute::StackProtectReq))
return InlineResult::failure(
"stack protected callee but caller requested no stack protector");
if (LLVM_UNLIKELY(CalledFunc->hasFnAttribute(Attribute::NoStackProtect)))
if (Caller->hasFnAttribute(Attribute::StackProtect) ||
Caller->hasFnAttribute(Attribute::StackProtectStrong) ||
Caller->hasFnAttribute(Attribute::StackProtectReq))
return InlineResult::failure(
"stack protected caller but callee requested no stack protector");
// Get the personality function from the callee if it contains a landing pad.
Constant *CalledPersonality =
CalledFunc->hasPersonalityFn()

View File

@ -1,5 +1,5 @@
; RUN: llc -mtriple=x86_64-pc-linux-gnu -start-before=stack-protector -stop-after=stack-protector -o - < %s | FileCheck %s
; Bugs 42238/43308/47479: Test some additional situations not caught previously.
; Bugs 42238/43308: Test some additional situations not caught previously.
define void @store_captures() #0 {
; CHECK-LABEL: @store_captures(
@ -162,31 +162,4 @@ entry:
declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg)
; Test that the same function does not get a canary if nossp fn attr is set.
declare dso_local void @foo(i8*)
define dso_local void @bar_sspstrong(i64 %0) #0 {
; CHECK-LABEL: @bar_sspstrong
; CHECK-NEXT: %StackGuardSlot = alloca i8*
%2 = alloca i64, align 8
store i64 %0, i64* %2, align 8
%3 = load i64, i64* %2, align 8
%4 = alloca i8, i64 %3, align 16
call void @foo(i8* %4)
ret void
}
define dso_local void @bar_nossp(i64 %0) #1 {
; CHECK-LABEL: @bar_nossp
; CHECK-NEXT: %2 = alloca i64
%2 = alloca i64, align 8
store i64 %0, i64* %2, align 8
%3 = load i64, i64* %2, align 8
%4 = alloca i8, i64 %3, align 16
call void @foo(i8* %4)
ret void
}
attributes #0 = { sspstrong }
attributes #1 = { nossp }

View File

@ -73,10 +73,10 @@ entry:
attributes #0 = {
inlinehint minsize noduplicate noimplicitfloat norecurse noredzone nounwind
nonlazybind optsize safestack sanitize_address sanitize_hwaddress sanitize_memory
sanitize_thread sspstrong strictfp uwtable "foo"="bar"
sanitize_thread ssp sspreq sspstrong strictfp uwtable "foo"="bar"
"patchable-function"="prologue-short-redirect" "probe-stack"="_foo_guard" "stack-probe-size"="4096" }
; CHECK: attributes [[FN_ATTRS]] = { inlinehint minsize noduplicate noimplicitfloat norecurse noredzone nounwind nonlazybind optsize safestack sanitize_address sanitize_hwaddress sanitize_memory sanitize_thread sspstrong strictfp uwtable "foo"="bar" "patchable-function"="prologue-short-redirect" "probe-stack"="_foo_guard" "stack-probe-size"="4096" }
; CHECK: attributes [[FN_ATTRS]] = { inlinehint minsize noduplicate noimplicitfloat norecurse noredzone nounwind nonlazybind optsize safestack sanitize_address sanitize_hwaddress sanitize_memory sanitize_thread ssp sspreq sspstrong strictfp uwtable "foo"="bar" "patchable-function"="prologue-short-redirect" "probe-stack"="_foo_guard" "stack-probe-size"="4096" }
; attributes to drop
attributes #1 = {

View File

@ -1,64 +0,0 @@
; RUN: opt -inline -o - -S %s | FileCheck %s
; RUN: opt -passes='cgscc(inline)' %s -S | FileCheck %s
; RUN: opt -always-inline -o - -S %s | FileCheck %s
declare dso_local void @foo(i8*)
define dso_local void @ssp(i64 %0) #0 {
%2 = alloca i64, align 8
store i64 %0, i64* %2, align 8
%3 = load i64, i64* %2, align 8
%4 = alloca i8, i64 %3, align 16
call void @foo(i8* %4)
ret void
}
define dso_local void @ssp_alwaysinline(i64 %0) #1 {
%2 = alloca i64, align 8
store i64 %0, i64* %2, align 8
%3 = load i64, i64* %2, align 8
%4 = alloca i8, i64 %3, align 16
call void @foo(i8* %4)
ret void
}
define dso_local void @nossp() #2 {
; Check that the calls to @ssp and @ssp_alwaysinline are not inlined into
; @nossp, since @nossp does not want a stack protector.
; CHECK-LABEL: @nossp
; CHECK-NEXT: call void @ssp
; CHECK-NEXT: call void @ssp_alwaysinline
call void @ssp(i64 1024)
call void @ssp_alwaysinline(i64 1024)
ret void
}
define dso_local void @nossp_alwaysinline() #3 {
call void @ssp(i64 1024)
call void @ssp_alwaysinline(i64 1024)
ret void
}
define dso_local void @nossp_caller() #2 {
; Permit nossp callee to be inlined into nossp caller.
; CHECK-LABEL: @nossp_caller
; CHECK-NEXT: call void @ssp
; CHECK-NEXT: call void @ssp_alwaysinline
; CHECK-NOT: call void @nossp_alwaysinline
call void @nossp_alwaysinline()
ret void
}
define dso_local void @ssp2() #0 {
; Check the call to @nossp is not inlined, since @nossp should not have a stack
; protector.
; CHECK-LABEL: @ssp2
; CHECK-NEXT: call void @nossp
call void @nossp()
ret void
}
attributes #0 = { sspstrong }
attributes #1 = { sspstrong alwaysinline }
attributes #2 = { nossp }
attributes #3 = { nossp alwaysinline}

View File

@ -1,10 +1,6 @@
; RUN: opt -inline %s -S | FileCheck %s
; RUN: opt -passes='cgscc(inline)' %s -S | FileCheck %s
; Ensure SSP attributes are propagated correctly when inlining.
; This test case covers callers that are unspecified in their level of stack
; protection. See also llvm/test/Transforms/Inline/inline_nossp.ll
; which tests callers with ``nossp`` function attribute which is stack
; protection explicitly disabled.
@.str = private unnamed_addr constant [11 x i8] c"fun_nossp\0A\00", align 1
@.str1 = private unnamed_addr constant [9 x i8] c"fun_ssp\0A\00", align 1

View File

@ -1,58 +0,0 @@
; RUN: not opt -verify -o - %s 2>&1 | FileCheck %s
define void @test_1 () #1 { ret void }
define void @test_2 () #2 { ret void }
define void @test_3 () #3 { ret void }
define void @test_4 () #4 { ret void }
define void @test_5 () #5 { ret void }
define void @test_6 () #6 { ret void }
define void @test_7 () #7 { ret void }
define void @test_8 () #8 { ret void }
define void @test_9 () #9 { ret void }
define void @test_10 () #10 { ret void }
define void @test_11 () #10 { ret void }
define void @test_12 () #10 { ret void }
define void @test_13 () #10 { ret void }
define void @test_14 () #10 { ret void }
attributes #0 = { nossp }
attributes #1 = { ssp }
attributes #2 = { sspreq }
attributes #3 = { sspstrong }
attributes #4 = { nossp ssp }
attributes #5 = { nossp sspreq }
attributes #6 = { nossp sspstrong }
attributes #7 = { ssp sspreq }
attributes #8 = { ssp sspstrong }
attributes #9 = { sspreq sspstrong }
attributes #10 = { nossp ssp sspreq }
attributes #11 = { nossp ssp sspstrong }
attributes #12 = { nossp sspreq sspstrong }
attributes #13 = { ssp sspreq sspstrong }
attributes #14 = { nossp ssp sspreq sspstrong }
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_4
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_5
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_6
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_7
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_8
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_9
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_10
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_11
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_12
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_13
; CHECK: fn attrs are mutually exclusive
; CHECK-NEXT: void ()* @test_14

View File

@ -26,7 +26,7 @@
"inaccessiblemem_or_argmemonly" "inlinehint" "jumptable" "minsize" "mustprogress" "naked" "nobuiltin"
"noduplicate" "nofree" "noimplicitfloat" "noinline" "nonlazybind" "noredzone" "noreturn"
"norecurse" "noundef" "nounwind" "optnone" "optsize" "readnone" "readonly" "returns_twice"
"speculatable" "nossp" "ssp" "sspreq" "sspstrong" "safestack" "sanitize_address" "sanitize_hwaddress" "sanitize_memtag"
"speculatable" "ssp" "sspreq" "sspstrong" "safestack" "sanitize_address" "sanitize_hwaddress" "sanitize_memtag"
"sanitize_thread" "sanitize_memory" "strictfp" "uwtable" "willreturn" "writeonly" "immarg") 'symbols) . font-lock-constant-face)
;; Variables
'("%[-a-zA-Z$._][-a-zA-Z$._0-9]*" . font-lock-variable-name-face)

View File

@ -93,7 +93,6 @@
<item> optsize </item>
<item> readnone </item>
<item> readonly </item>
<item> nossp </item>
<item> ssp </item>
<item> sspreq </item>
<item> sspstrong </item>

View File

@ -168,7 +168,6 @@ FuncAttr ::= noreturn
| noinline
| alwaysinline
| optsize
| nossp
| ssp
| sspreq
| returns_twice

View File

@ -148,7 +148,6 @@ syn keyword llvmKeyword
\ spir_func
\ spir_kernel
\ sret
\ nossp
\ ssp
\ sspreq
\ sspstrong

View File

@ -245,7 +245,6 @@ patterns:
\\bspir_func\\b|\
\\bspir_kernel\\b|\
\\bsret\\b|\
\\bnossp\\b|\
\\bssp\\b|\
\\bsspreq\\b|\
\\bsspstrong\\b|\