14ce567fa2
Add `zeroext` attribute for below callbacks' first parameter (8bit shadow variable arguments) to conform to many platforms' ABI calling convention and some compiler behavior. - __dfsan_load_callback - __dfsan_store_callback - __dfsan_cmp_callback - __dfsan_conditional_callback - __dfsan_conditional_callback_origin - __dfsan_reaches_function_callback - __dfsan_reaches_function_callback_origin The type of these callbacks' first parameter is u8 (see the definition of `dfsan_label`). First, many platforms' ABI requires unsigned integer data types (except unsigned int) are zero-extended when stored in general-purpose register. Second, the problem is that compiler optimization may assume the arguments are zero-extended and, if not, misbehave, e.g. it uses an `i8` argument to index into a jump table. If the argument has non-zero high bits, the output executable may crash at run-time. So we need to add the `zeroext` attribute when declaring and calling them. Reviewed By: browneee, MaskRay Differential Revision: https://reviews.llvm.org/D140689
30 lines
809 B
LLVM
30 lines
809 B
LLVM
; RUN: opt < %s -passes=dfsan -dfsan-reaches-function-callbacks=1 -S | FileCheck %s
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target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-pc-linux-gnu"
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declare i32 @f()
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define void @load(i32) {
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; CHECK-LABEL: define void @load.dfsan
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; CHECK: call{{.*}}@__dfsan_reaches_function_callback
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%i = alloca i32
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store i32 %0, ptr %i
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ret void
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}
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define void @store(ptr) {
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; CHECK-LABEL: define void @store.dfsan
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; CHECK: call{{.*}}@__dfsan_reaches_function_callback
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%load = load i32, ptr %0
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ret void
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}
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define void @call() {
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; CHECK-LABEL: define void @call.dfsan
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; CHECK: call{{.*}}@__dfsan_reaches_function_callback
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%ret = call i32 @f()
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ret void
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}
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; CHECK-LABEL: @__dfsan_reaches_function_callback(i8 zeroext, ptr, i32, ptr)
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