maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/clang/test/CodeGen/ubsan-pointer-overflow.m

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

28 lines
915 B
Mathematica
Raw Normal View History

[ubsan] Add a check for pointer overflow UB Check pointer arithmetic for overflow. For some more background on this check, see: https://wdtz.org/catching-pointer-overflow-bugs.html https://reviews.llvm.org/D20322 Patch by Will Dietz and John Regehr! This version of the patch is different from the original in a few ways: - It introduces the EmitCheckedInBoundsGEP utility which inserts checks when the pointer overflow check is enabled. - It does some constant-folding to reduce instrumentation overhead. - It does not check some GEPs in CGExprCXX. I'm not sure that inserting checks here, or in CGClass, would catch many bugs. Possible future directions for this check: - Introduce CGF.EmitCheckedStructGEP, to detect overflows when accessing structures. Testing: Apart from the added lit test, I ran check-llvm and check-clang with a stage2, ubsan-instrumented clang. Will and John have also done extensive testing on numerous open source projects. Differential Revision: https://reviews.llvm.org/D33305 llvm-svn: 304459
2017-06-02 03:22:18 +08:00
// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -w -emit-llvm -o - %s -fsanitize=pointer-overflow | FileCheck %s
// CHECK-LABEL: define void @variable_len_array_arith
void variable_len_array_arith(int n, int k) {
int vla[n];
int (*p)[n] = &vla;
// CHECK: getelementptr inbounds i32, i32* {{.*}}, i64 [[INC:%.*]]
// CHECK: @llvm.smul.with.overflow.i64(i64 4, i64 [[INC]]), !nosanitize
[ubsan] Detect invalid unsigned pointer index expression (clang) Adding an unsigned offset to a base pointer has undefined behavior if the result of the expression would precede the base. An example from @regehr: int foo(char *p, unsigned offset) { return p + offset >= p; // This may be optimized to '1'. } foo(p, -1); // UB. This patch extends the pointer overflow check in ubsan to detect invalid unsigned pointer index expressions. It changes the instrumentation to only permit non-negative offsets in pointer index expressions when all of the GEP indices are unsigned. Testing: check-llvm, check-clang run on a stage2, ubsan-instrumented build. Differential Revision: https://reviews.llvm.org/D33910 llvm-svn: 305216
2017-06-13 02:42:51 +08:00
// CHECK-NOT: select
[ubsan] Add a check for pointer overflow UB Check pointer arithmetic for overflow. For some more background on this check, see: https://wdtz.org/catching-pointer-overflow-bugs.html https://reviews.llvm.org/D20322 Patch by Will Dietz and John Regehr! This version of the patch is different from the original in a few ways: - It introduces the EmitCheckedInBoundsGEP utility which inserts checks when the pointer overflow check is enabled. - It does some constant-folding to reduce instrumentation overhead. - It does not check some GEPs in CGExprCXX. I'm not sure that inserting checks here, or in CGClass, would catch many bugs. Possible future directions for this check: - Introduce CGF.EmitCheckedStructGEP, to detect overflows when accessing structures. Testing: Apart from the added lit test, I ran check-llvm and check-clang with a stage2, ubsan-instrumented clang. Will and John have also done extensive testing on numerous open source projects. Differential Revision: https://reviews.llvm.org/D33305 llvm-svn: 304459
2017-06-02 03:22:18 +08:00
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
++p;
// CHECK: getelementptr inbounds i32, i32* {{.*}}, i64 [[IDXPROM:%.*]]
// CHECK: @llvm.smul.with.overflow.i64(i64 4, i64 [[IDXPROM]]), !nosanitize
[ubsan] Detect invalid unsigned pointer index expression (clang) Adding an unsigned offset to a base pointer has undefined behavior if the result of the expression would precede the base. An example from @regehr: int foo(char *p, unsigned offset) { return p + offset >= p; // This may be optimized to '1'. } foo(p, -1); // UB. This patch extends the pointer overflow check in ubsan to detect invalid unsigned pointer index expressions. It changes the instrumentation to only permit non-negative offsets in pointer index expressions when all of the GEP indices are unsigned. Testing: check-llvm, check-clang run on a stage2, ubsan-instrumented build. Differential Revision: https://reviews.llvm.org/D33910 llvm-svn: 305216
2017-06-13 02:42:51 +08:00
// CHECK: select
[ubsan] Add a check for pointer overflow UB Check pointer arithmetic for overflow. For some more background on this check, see: https://wdtz.org/catching-pointer-overflow-bugs.html https://reviews.llvm.org/D20322 Patch by Will Dietz and John Regehr! This version of the patch is different from the original in a few ways: - It introduces the EmitCheckedInBoundsGEP utility which inserts checks when the pointer overflow check is enabled. - It does some constant-folding to reduce instrumentation overhead. - It does not check some GEPs in CGExprCXX. I'm not sure that inserting checks here, or in CGClass, would catch many bugs. Possible future directions for this check: - Introduce CGF.EmitCheckedStructGEP, to detect overflows when accessing structures. Testing: Apart from the added lit test, I ran check-llvm and check-clang with a stage2, ubsan-instrumented clang. Will and John have also done extensive testing on numerous open source projects. Differential Revision: https://reviews.llvm.org/D33305 llvm-svn: 304459
2017-06-02 03:22:18 +08:00
// CHECK: call void @__ubsan_handle_pointer_overflow{{.*}}
p + k;
}
// CHECK-LABEL: define void @objc_id
void objc_id(id *p) {
// CHECK: add i64 {{.*}}, 8, !nosanitize
[ubsan] Detect invalid unsigned pointer index expression (clang) Adding an unsigned offset to a base pointer has undefined behavior if the result of the expression would precede the base. An example from @regehr: int foo(char *p, unsigned offset) { return p + offset >= p; // This may be optimized to '1'. } foo(p, -1); // UB. This patch extends the pointer overflow check in ubsan to detect invalid unsigned pointer index expressions. It changes the instrumentation to only permit non-negative offsets in pointer index expressions when all of the GEP indices are unsigned. Testing: check-llvm, check-clang run on a stage2, ubsan-instrumented build. Differential Revision: https://reviews.llvm.org/D33910 llvm-svn: 305216
2017-06-13 02:42:51 +08:00
// CHECK-NOT: select
[ubsan] Add a check for pointer overflow UB Check pointer arithmetic for overflow. For some more background on this check, see: https://wdtz.org/catching-pointer-overflow-bugs.html https://reviews.llvm.org/D20322 Patch by Will Dietz and John Regehr! This version of the patch is different from the original in a few ways: - It introduces the EmitCheckedInBoundsGEP utility which inserts checks when the pointer overflow check is enabled. - It does some constant-folding to reduce instrumentation overhead. - It does not check some GEPs in CGExprCXX. I'm not sure that inserting checks here, or in CGClass, would catch many bugs. Possible future directions for this check: - Introduce CGF.EmitCheckedStructGEP, to detect overflows when accessing structures. Testing: Apart from the added lit test, I ran check-llvm and check-clang with a stage2, ubsan-instrumented clang. Will and John have also done extensive testing on numerous open source projects. Differential Revision: https://reviews.llvm.org/D33305 llvm-svn: 304459
2017-06-02 03:22:18 +08:00
// CHECK: @__ubsan_handle_pointer_overflow{{.*}}
p++;
}