3d049bce98
Add support for match-all tags and GOT-free runtime calls, which
are both required for the kernel to be able to support outlined
checks. This requires extending the access info to let the backend
know when to enable these features. To make the code easier to maintain
introduce an enum with the bit field positions for the access info.
Allow outlined checks to be enabled with -mllvm
-hwasan-inline-all-checks=0. Kernels that contain runtime support for
outlined checks may pass this flag. Kernels lacking runtime support
will continue to link because they do not pass the flag. Old versions
of LLVM will ignore the flag and continue to use inline checks.
With a separate kernel patch [1] I measured the code size of defconfig
+ tag-based KASAN, as well as boot time (i.e. time to init launch)
on a DragonBoard 845c with an Android arm64 GKI kernel. The results
are below:
code size boot time
before 92824064 6.18s
after 38822400 6.65s
[1] https://linux-review.googlesource.com/id/I1a30036c70ab3c3ee78d75ed9b87ef7cdc3fdb76
Depends on D90425
Differential Revision: https://reviews.llvm.org/D90426
48 lines
2.1 KiB
LLVM
48 lines
2.1 KiB
LLVM
; Test KHWASan instrumentation.
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;
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; RUN: opt < %s -hwasan -hwasan-kernel=1 -hwasan-recover=1 -S | FileCheck %s --allow-empty --check-prefixes=INIT
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; RUN: opt < %s -hwasan -hwasan-kernel=1 -hwasan-recover=1 -S | FileCheck %s --check-prefixes=CHECK,NOOFFSET,MATCH-ALL
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; RUN: opt < %s -hwasan -hwasan-kernel=1 -hwasan-recover=1 -hwasan-mapping-offset=12345678 -S | FileCheck %s --check-prefixes=CHECK,OFFSET,MATCH-ALL
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; RUN: opt < %s -hwasan -hwasan-kernel=1 -hwasan-recover=1 -hwasan-match-all-tag=-1 -S | FileCheck %s --check-prefixes=CHECK,NOOFFSET,NO-MATCH-ALL
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; RUN: opt < %s -hwasan -hwasan-kernel=1 -hwasan-recover=1 -hwasan-inline-all-checks=0 -hwasan-mapping-offset=12345678 -S | FileCheck %s --check-prefixes=OUTLINE
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target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
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target triple = "aarch64--linux-android"
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define i8 @test_load(i8* %a) sanitize_hwaddress {
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; CHECK-LABEL: @test_load(
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; OFFSET: %[[SHADOW:[^ ]*]] = call i8* asm "", "=r,0"(i8* inttoptr (i64 12345678 to i8*))
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; CHECK: %[[A:[^ ]*]] = ptrtoint i8* %a to i64
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; CHECK: %[[B:[^ ]*]] = lshr i64 %[[A]], 56
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; CHECK: %[[PTRTAG:[^ ]*]] = trunc i64 %[[B]] to i8
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; CHECK: %[[C:[^ ]*]] = or i64 %[[A]], -72057594037927936
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; CHECK: %[[D:[^ ]*]] = lshr i64 %[[C]], 4
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; NOOFFSET: %[[E:[^ ]*]] = inttoptr i64 %[[D]] to i8*
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; OFFSET: %[[E:[^ ]*]] = getelementptr i8, i8* %[[SHADOW]], i64 %[[D]]
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; CHECK: %[[MEMTAG:[^ ]*]] = load i8, i8* %[[E]]
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; CHECK: %[[F:[^ ]*]] = icmp ne i8 %[[PTRTAG]], %[[MEMTAG]]
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; MATCH-ALL: %[[G:[^ ]*]] = icmp ne i8 %[[PTRTAG]], -1
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; MATCH-ALL: %[[H:[^ ]*]] = and i1 %[[F]], %[[G]]
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; MATCH-ALL: br i1 %[[H]], label {{.*}}, label {{.*}}, !prof {{.*}}
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; NO-MATCH-ALL: br i1 %[[F]], label {{.*}}, label {{.*}}, !prof {{.*}}
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; CHECK: call void asm sideeffect "brk #2336", "{x0}"(i64 %[[A]])
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; CHECK: br label
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; CHECK: %[[G:[^ ]*]] = load i8, i8* %a, align 4
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; CHECK: ret i8 %[[G]]
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; OUTLINE: %[[SHADOW:[^ ]*]] = call i8* asm "", "=r,0"(i8* inttoptr (i64 12345678 to i8*))
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; OUTLINE: call void @llvm.hwasan.check.memaccess(i8* %[[SHADOW]], i8* %a, i32 67043360)
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entry:
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%b = load i8, i8* %a, align 4
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ret i8 %b
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}
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; INIT-NOT: call void @__hwasan_init
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