Add "memtag" sanitizer that detects and mitigates stack memory issues
using armv8.5 Memory Tagging Extension.
It is similar in principle to HWASan, which is a software implementation
of the same idea, but there are enough differencies to warrant a new
sanitizer type IMHO. It is also expected to have very different
performance properties.
The new sanitizer does not have a runtime library (it may grow one
later, along with a "debugging" mode). Similar to SafeStack and
StackProtector, the instrumentation pass (in a follow up change) will be
inserted in all cases, but will only affect functions marked with the
new sanitize_memtag attribute.
Reviewers: pcc, hctim, vitalybuka, ostannard
Subscribers: srhines, mehdi_amini, javed.absar, kristof.beyls, hiraditya, cryptoad, steven_wu, dexonsmith, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D64169
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366123
91177308-0d34-0410-b5e6-
96231b3b80d8
* code 56: ``nocf_check``
* code 57: ``optforfuzzing``
* code 58: ``shadowcallstack``
+* code 64: ``sanitize_memtag``
.. note::
The ``allocsize`` attribute has a special encoding for its arguments. Its two
This attribute indicates that HWAddressSanitizer checks
(dynamic address safety analysis based on tagged pointers) are enabled for
this function.
+``sanitize_memtag``
+ This attribute indicates that MemTagSanitizer checks
+ (dynamic address safety analysis based on Armv8 MTE) are enabled for
+ this function.
``speculative_load_hardening``
This attribute indicates that
`Speculative Load Hardening <https://llvm.org/docs/SpeculativeLoadHardening.html>`_
ATTR_KIND_IMMARG = 60,
ATTR_KIND_WILLRETURN = 61,
ATTR_KIND_NOFREE = 62,
- ATTR_KIND_NOSYNC = 63
+ ATTR_KIND_NOSYNC = 63,
+ ATTR_KIND_SANITIZE_MEMTAG = 64,
};
enum ComdatSelectionKindCodes {
/// HWAddressSanitizer is on.
def SanitizeHWAddress : EnumAttr<"sanitize_hwaddress">;
+/// MemTagSanitizer is on.
+def SanitizeMemTag : EnumAttr<"sanitize_memtag">;
+
/// Speculative Load Hardening is enabled.
///
/// Note that this uses the default compatibility (always compatible during
def : CompatRule<"isEqual<SanitizeThreadAttr>">;
def : CompatRule<"isEqual<SanitizeMemoryAttr>">;
def : CompatRule<"isEqual<SanitizeHWAddressAttr>">;
+def : CompatRule<"isEqual<SanitizeMemTagAttr>">;
def : CompatRule<"isEqual<SafeStackAttr>">;
def : CompatRule<"isEqual<ShadowCallStackAttr>">;
KEYWORD(shadowcallstack);
KEYWORD(sanitize_address);
KEYWORD(sanitize_hwaddress);
+ KEYWORD(sanitize_memtag);
KEYWORD(sanitize_thread);
KEYWORD(sanitize_memory);
KEYWORD(speculative_load_hardening);
B.addAttribute(Attribute::SanitizeAddress); break;
case lltok::kw_sanitize_hwaddress:
B.addAttribute(Attribute::SanitizeHWAddress); break;
+ case lltok::kw_sanitize_memtag:
+ B.addAttribute(Attribute::SanitizeMemTag); break;
case lltok::kw_sanitize_thread:
B.addAttribute(Attribute::SanitizeThread); break;
case lltok::kw_sanitize_memory:
case lltok::kw_returns_twice:
case lltok::kw_sanitize_address:
case lltok::kw_sanitize_hwaddress:
+ case lltok::kw_sanitize_memtag:
case lltok::kw_sanitize_memory:
case lltok::kw_sanitize_thread:
case lltok::kw_speculative_load_hardening:
case lltok::kw_returns_twice:
case lltok::kw_sanitize_address:
case lltok::kw_sanitize_hwaddress:
+ case lltok::kw_sanitize_memtag:
case lltok::kw_sanitize_memory:
case lltok::kw_sanitize_thread:
case lltok::kw_speculative_load_hardening:
kw_argmemonly,
kw_sanitize_address,
kw_sanitize_hwaddress,
+ kw_sanitize_memtag,
kw_builtin,
kw_byval,
kw_inalloca,
case Attribute::AllocSize:
llvm_unreachable("allocsize not supported in raw format");
break;
+ case Attribute::SanitizeMemTag:
+ llvm_unreachable("sanitize_memtag attribute not supported in raw format");
+ break;
}
llvm_unreachable("Unsupported attribute type");
}
for (Attribute::AttrKind I = Attribute::None; I != Attribute::EndAttrKinds;
I = Attribute::AttrKind(I + 1)) {
- if (I == Attribute::Dereferenceable ||
+ if (I == Attribute::SanitizeMemTag ||
+ I == Attribute::Dereferenceable ||
I == Attribute::DereferenceableOrNull ||
I == Attribute::ArgMemOnly ||
I == Attribute::AllocSize ||
return Attribute::ZExt;
case bitc::ATTR_KIND_IMMARG:
return Attribute::ImmArg;
+ case bitc::ATTR_KIND_SANITIZE_MEMTAG:
+ return Attribute::SanitizeMemTag;
}
}
return bitc::ATTR_KIND_Z_EXT;
case Attribute::ImmArg:
return bitc::ATTR_KIND_IMMARG;
+ case Attribute::SanitizeMemTag:
+ return bitc::ATTR_KIND_SANITIZE_MEMTAG;
case Attribute::EndAttrKinds:
llvm_unreachable("Can not encode end-attribute kinds marker.");
case Attribute::None:
return "sanitize_address";
if (hasAttribute(Attribute::SanitizeHWAddress))
return "sanitize_hwaddress";
+ if (hasAttribute(Attribute::SanitizeMemTag))
+ return "sanitize_memtag";
if (hasAttribute(Attribute::AlwaysInline))
return "alwaysinline";
if (hasAttribute(Attribute::ArgMemOnly))
case Attribute::ReturnsTwice:
case Attribute::SanitizeAddress:
case Attribute::SanitizeHWAddress:
+ case Attribute::SanitizeMemTag:
case Attribute::SanitizeThread:
case Attribute::SanitizeMemory:
case Attribute::MinSize:
.Case("sanitize_hwaddress", Attribute::SanitizeHWAddress)
.Case("sanitize_memory", Attribute::SanitizeMemory)
.Case("sanitize_thread", Attribute::SanitizeThread)
+ .Case("sanitize_memtag", Attribute::SanitizeMemTag)
.Case("speculative_load_hardening", Attribute::SpeculativeLoadHardening)
.Case("ssp", Attribute::StackProtect)
.Case("sspreq", Attribute::StackProtectReq)
case Attribute::SanitizeMemory:
case Attribute::SanitizeThread:
case Attribute::SanitizeHWAddress:
+ case Attribute::SanitizeMemTag:
case Attribute::SpeculativeLoadHardening:
case Attribute::StackProtect:
case Attribute::StackProtectReq:
; CHECK: define void @f34()
{
call void @nobuiltin() nobuiltin
-; CHECK: call void @nobuiltin() #39
+; CHECK: call void @nobuiltin() #40
ret void;
}
ret void
}
+; CHECK: define void @f63() #39
+define void @f63() sanitize_memtag
+{
+ ret void;
+}
+
; CHECK: attributes #0 = { noreturn }
; CHECK: attributes #1 = { nounwind }
; CHECK: attributes #2 = { readnone }
; CHECK: attributes #36 = { willreturn }
; CHECK: attributes #37 = { nofree }
; CHECK: attributes #38 = { nosync }
-; CHECK: attributes #39 = { nobuiltin }
+; CHECK: attributes #39 = { sanitize_memtag }
+; CHECK: attributes #40 = { nobuiltin }
ret i32 %i
}
+define i32 @sanitize_memtag_callee(i32 %i) sanitize_memtag {
+ ret i32 %i
+}
+
define i32 @safestack_callee(i32 %i) safestack {
ret i32 %i
}
ret i32 %i
}
+define i32 @alwaysinline_sanitize_memtag_callee(i32 %i) alwaysinline sanitize_memtag {
+ ret i32 %i
+}
+
define i32 @alwaysinline_safestack_callee(i32 %i) alwaysinline safestack {
ret i32 %i
}
; CHECK-NEXT: ret i32
}
+define i32 @test_no_sanitize_memtag(i32 %arg) {
+ %x1 = call i32 @noattr_callee(i32 %arg)
+ %x2 = call i32 @sanitize_memtag_callee(i32 %x1)
+ %x3 = call i32 @alwaysinline_callee(i32 %x2)
+ %x4 = call i32 @alwaysinline_sanitize_memtag_callee(i32 %x3)
+ ret i32 %x4
+; CHECK-LABEL: @test_no_sanitize_memtag(
+; CHECK-NEXT: @sanitize_memtag_callee
+; CHECK-NEXT: ret i32
+}
+
; Check that:
; * noattr callee is not inlined into sanitize_(address|memory|thread) caller,
; CHECK-NEXT: ret i32
}
+define i32 @test_sanitize_memtag(i32 %arg) sanitize_memtag {
+ %x1 = call i32 @noattr_callee(i32 %arg)
+ %x2 = call i32 @sanitize_memtag_callee(i32 %x1)
+ %x3 = call i32 @alwaysinline_callee(i32 %x2)
+ %x4 = call i32 @alwaysinline_sanitize_memtag_callee(i32 %x3)
+ ret i32 %x4
+; CHECK-LABEL: @test_sanitize_memtag(
+; CHECK-NEXT: @noattr_callee
+; CHECK-NEXT: ret i32
+}
+
define i32 @test_safestack(i32 %arg) safestack {
%x1 = call i32 @noattr_callee(i32 %arg)
%x2 = call i32 @safestack_callee(i32 %x1)
"inaccessiblemem_or_argmemonly" "inlinehint" "jumptable" "minsize" "naked" "nobuiltin"
"noduplicate" "noimplicitfloat" "noinline" "nonlazybind" "noredzone" "noreturn"
"norecurse" "nounwind" "optnone" "optsize" "readnone" "readonly" "returns_twice"
- "speculatable" "ssp" "sspreq" "sspstrong" "safestack" "sanitize_address" "sanitize_hwaddress"
+ "speculatable" "ssp" "sspreq" "sspstrong" "safestack" "sanitize_address" "sanitize_hwaddress" "sanitize_memtag"
"sanitize_thread" "sanitize_memory" "strictfp" "uwtable" "writeonly" "immarg") 'symbols) . font-lock-constant-face)
;; Variables
'("%[-a-zA-Z$._][-a-zA-Z$._0-9]*" . font-lock-variable-name-face)