forked from OSchip/llvm-project
99 lines
3.7 KiB
LLVM
99 lines
3.7 KiB
LLVM
; Test for the conservative assembly handling mode used by KMSAN.
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; RUN: opt < %s -msan-kernel=1 -msan-check-access-address=0 \
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; RUN: -msan-handle-asm-conservative=0 -S -passes=msan 2>&1 | FileCheck \
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; RUN: "-check-prefix=CHECK" %s
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; RUN: opt < %s -msan-kernel=1 -msan-check-access-address=0 \
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; RUN: -msan-handle-asm-conservative=1 -S -passes=msan 2>&1 | FileCheck \
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; RUN: "-check-prefixes=CHECK,CHECK-CONS" %s
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target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-unknown-linux-gnu"
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; The IR below was generated from the following source:
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; int main() {
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; bool bit;
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; unsigned long value = 2;
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; long nr = 0;
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; unsigned long *addr = &value;
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; asm("btsq %2, %1; setc %0" : "=qm" (bit), "=m" (addr): "Ir" (nr));
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; if (bit)
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; return 0;
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; else
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; return 1;
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; }
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;
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; In the regular instrumentation mode MSan is unable to understand that |bit|
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; is initialized by the asm() call, and therefore reports a false positive on
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; the if-statement.
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; The conservative assembly handling mode initializes every memory location
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; passed by pointer into an asm() call. This prevents false positive reports,
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; but may introduce false negatives.
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;
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; This test makes sure that the conservative mode unpoisons the shadow of |bit|
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; by writing 0 to it.
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define dso_local i32 @main() sanitize_memory {
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entry:
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%retval = alloca i32, align 4
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%bit = alloca i8, align 1
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%value = alloca i64, align 8
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%nr = alloca i64, align 8
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%addr = alloca i64*, align 8
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store i32 0, i32* %retval, align 4
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store i64 2, i64* %value, align 8
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store i64 0, i64* %nr, align 8
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store i64* %value, i64** %addr, align 8
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%0 = load i64, i64* %nr, align 8
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call void asm "btsq $2, $1; setc $0", "=*qm,=*m,Ir,~{dirflag},~{fpsr},~{flags}"(i8* elementtype(i8) %bit, i64** elementtype(i64*) %addr, i64 %0)
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%1 = load i8, i8* %bit, align 1
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%tobool = trunc i8 %1 to i1
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br i1 %tobool, label %if.then, label %if.else
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if.then: ; preds = %entry
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ret i32 0
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if.else: ; preds = %entry
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ret i32 1
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}
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; %nr is first poisoned, then unpoisoned (written to). Need to optimize this in the future.
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; CHECK: [[NRC1:%.*]] = bitcast i64* %nr to i8*
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; CHECK: call void @__msan_poison_alloca(i8* [[NRC1]]{{.*}})
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; CHECK: [[NRC2:%.*]] = bitcast i64* %nr to i8*
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; CHECK: call { i8*, i32* } @__msan_metadata_ptr_for_store_8(i8* [[NRC2]])
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; Hooks for inputs usually go before the assembly statement. But here we have none,
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; because %nr is passed by value. However we check %nr for being initialized.
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; CHECK-CONS: [[NRC3:%.*]] = bitcast i64* %nr to i8*
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; CHECK-CONS: call { i8*, i32* } @__msan_metadata_ptr_for_load_8(i8* [[NRC3]])
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; In the conservative mode, call the store hooks for %bit and %addr:
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; CHECK-CONS: call void @__msan_instrument_asm_store(i8* %bit, i64 1)
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; CHECK-CONS: [[ADDR8S:%.*]] = bitcast i64** %addr to i8*
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; CHECK-CONS: call void @__msan_instrument_asm_store(i8* [[ADDR8S]], i64 8)
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; Landing pad for the %nr check above.
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; CHECK-CONS: call void @__msan_warning
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; CHECK: call void asm "btsq $2, $1; setc $0"
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; Calculating the shadow offset of %bit.
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; CHECKz: [[PTR:%.*]] = ptrtoint {{.*}} %bit to i64
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; CHECKz: [[SH_NUM:%.*]] = xor i64 [[PTR]]
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; CHECKz: [[SHADOW:%.*]] = inttoptr i64 [[SH_NUM]] {{.*}}
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; CHECK: [[META:%.*]] = call {{.*}} @__msan_metadata_ptr_for_load_1(i8* %bit)
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; CHECK: [[SHADOW:%.*]] = extractvalue { i8*, i32* } [[META]], 0
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; Now load the shadow value for the boolean.
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; CHECK: [[MSLD:%.*]] = load {{.*}} [[SHADOW]]
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; CHECK: [[MSPROP:%.*]] = trunc i8 [[MSLD]] to i1
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; Is the shadow poisoned?
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; CHECK: br i1 [[MSPROP]], label %[[IFTRUE:.*]], label {{.*}}
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; If yes, raise a warning.
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; CHECK: [[IFTRUE]]:
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; CHECK: call void @__msan_warning
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