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llvm-project/llvm/test/Instrumentation/AddressSanitizer/stack_dynamic_alloca.ll

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[ASan] Change fake stack and local variables handling. This commit changes the way we get fake stack from ASan runtime (to find use-after-return errors) and the way we represent local variables: - __asan_stack_malloc function now returns pointer to newly allocated fake stack frame, or NULL if frame cannot be allocated. It doesn't take pointer to real stack as an input argument, it is calculated inside the runtime. - __asan_stack_free function doesn't take pointer to real stack as an input argument. Now this function is never called if fake stack frame wasn't allocated. - __asan_init version is bumped to reflect changes in the ABI. - new flag "-asan-stack-dynamic-alloca" allows to store all the function local variables in a dynamic alloca, instead of the static one. It reduces the stack space usage in use-after-return mode (dynamic alloca will not be called if the local variables are stored in a fake stack), and improves the debug info quality for local variables (they will not be described relatively to %rbp/%rsp, which are assumed to be clobbered by function calls). This flag is turned off by default for now, but I plan to turn it on after more testing. llvm-svn: 224062
2014-12-12 05:53:03 +08:00
; RUN: opt < %s -asan -asan-module -asan-stack-dynamic-alloca \
; RUN: -asan-use-after-return -S | FileCheck %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
define void @Func1() sanitize_address {
entry:
; CHECK-LABEL: Func1
; CHECK: entry:
[opaque pointer type] Add textual IR support for explicit type parameter to load instruction Essentially the same as the GEP change in r230786. A similar migration script can be used to update test cases, though a few more test case improvements/changes were required this time around: (r229269-r229278) import fileinput import sys import re pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)") for line in sys.stdin: sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line)) Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7649 llvm-svn: 230794
2015-02-28 05:17:42 +08:00
; CHECK: load i32, i32* @__asan_option_detect_stack_use_after_return
[ASan] Change fake stack and local variables handling. This commit changes the way we get fake stack from ASan runtime (to find use-after-return errors) and the way we represent local variables: - __asan_stack_malloc function now returns pointer to newly allocated fake stack frame, or NULL if frame cannot be allocated. It doesn't take pointer to real stack as an input argument, it is calculated inside the runtime. - __asan_stack_free function doesn't take pointer to real stack as an input argument. Now this function is never called if fake stack frame wasn't allocated. - __asan_init version is bumped to reflect changes in the ABI. - new flag "-asan-stack-dynamic-alloca" allows to store all the function local variables in a dynamic alloca, instead of the static one. It reduces the stack space usage in use-after-return mode (dynamic alloca will not be called if the local variables are stored in a fake stack), and improves the debug info quality for local variables (they will not be described relatively to %rbp/%rsp, which are assumed to be clobbered by function calls). This flag is turned off by default for now, but I plan to turn it on after more testing. llvm-svn: 224062
2014-12-12 05:53:03 +08:00
; CHECK: <label>:[[UAR_ENABLED_BB:[0-9]+]]
; CHECK: [[FAKE_STACK_RT:%[0-9]+]] = call i64 @__asan_stack_malloc_
; CHECK: <label>:[[FAKE_STACK_BB:[0-9]+]]
; CHECK: [[FAKE_STACK:%[0-9]+]] = phi i64 [ 0, %entry ], [ [[FAKE_STACK_RT]], %[[UAR_ENABLED_BB]] ]
; CHECK: icmp eq i64 [[FAKE_STACK]], 0
; CHECK: <label>:[[NO_FAKE_STACK_BB:[0-9]+]]
; CHECK: %MyAlloca = alloca i8, i64
; CHECK: [[ALLOCA:%[0-9]+]] = ptrtoint i8* %MyAlloca
; CHECK: phi i64 [ [[FAKE_STACK]], %[[FAKE_STACK_BB]] ], [ [[ALLOCA]], %[[NO_FAKE_STACK_BB]] ]
; CHECK: ret void
%XXX = alloca [20 x i8], align 1
[asan] Skip promotable allocas to improve performance at -O0 Currently, the ASan executables built with -O0 are unnecessarily slow. The main reason is that ASan instrumentation pass inserts redundant checks around promotable allocas. These allocas do not get instrumented under -O1 because they get converted to virtual registered by mem2reg. With this patch, ASan instrumentation pass will only instrument non promotable allocas, giving us a speedup of 39% on a collection of benchmarks with -O0. (There is no measurable speedup at -O1.) llvm-svn: 230724
2015-02-27 11:12:36 +08:00
%arr.ptr = bitcast [20 x i8]* %XXX to i8*
store volatile i8 0, i8* %arr.ptr
[ASan] Change fake stack and local variables handling. This commit changes the way we get fake stack from ASan runtime (to find use-after-return errors) and the way we represent local variables: - __asan_stack_malloc function now returns pointer to newly allocated fake stack frame, or NULL if frame cannot be allocated. It doesn't take pointer to real stack as an input argument, it is calculated inside the runtime. - __asan_stack_free function doesn't take pointer to real stack as an input argument. Now this function is never called if fake stack frame wasn't allocated. - __asan_init version is bumped to reflect changes in the ABI. - new flag "-asan-stack-dynamic-alloca" allows to store all the function local variables in a dynamic alloca, instead of the static one. It reduces the stack space usage in use-after-return mode (dynamic alloca will not be called if the local variables are stored in a fake stack), and improves the debug info quality for local variables (they will not be described relatively to %rbp/%rsp, which are assumed to be clobbered by function calls). This flag is turned off by default for now, but I plan to turn it on after more testing. llvm-svn: 224062
2014-12-12 05:53:03 +08:00
ret void
}
; Test that dynamic alloca is not used for functions with inline assembly.
define void @Func2() sanitize_address {
entry:
; CHECK-LABEL: Func2
; CHECK: alloca [96 x i8]
; CHECK: ret void
%XXX = alloca [20 x i8], align 1
[asan] Skip promotable allocas to improve performance at -O0 Currently, the ASan executables built with -O0 are unnecessarily slow. The main reason is that ASan instrumentation pass inserts redundant checks around promotable allocas. These allocas do not get instrumented under -O1 because they get converted to virtual registered by mem2reg. With this patch, ASan instrumentation pass will only instrument non promotable allocas, giving us a speedup of 39% on a collection of benchmarks with -O0. (There is no measurable speedup at -O1.) llvm-svn: 230724
2015-02-27 11:12:36 +08:00
%arr.ptr = bitcast [20 x i8]* %XXX to i8*
store volatile i8 0, i8* %arr.ptr
[ASan] Change fake stack and local variables handling. This commit changes the way we get fake stack from ASan runtime (to find use-after-return errors) and the way we represent local variables: - __asan_stack_malloc function now returns pointer to newly allocated fake stack frame, or NULL if frame cannot be allocated. It doesn't take pointer to real stack as an input argument, it is calculated inside the runtime. - __asan_stack_free function doesn't take pointer to real stack as an input argument. Now this function is never called if fake stack frame wasn't allocated. - __asan_init version is bumped to reflect changes in the ABI. - new flag "-asan-stack-dynamic-alloca" allows to store all the function local variables in a dynamic alloca, instead of the static one. It reduces the stack space usage in use-after-return mode (dynamic alloca will not be called if the local variables are stored in a fake stack), and improves the debug info quality for local variables (they will not be described relatively to %rbp/%rsp, which are assumed to be clobbered by function calls). This flag is turned off by default for now, but I plan to turn it on after more testing. llvm-svn: 224062
2014-12-12 05:53:03 +08:00
call void asm sideeffect "mov %%rbx, %%rcx", "~{dirflag},~{fpsr},~{flags}"() nounwind
ret void
}
[ASan] Disable dynamic alloca and UAR detection in presence of returns_twice calls. Summary: returns_twice (most importantly, setjmp) functions are optimization-hostile: if local variable is promoted to register, and is changed between setjmp() and longjmp() calls, this update will be undone. This is the reason why "man setjmp" advises to mark all these locals as "volatile". This can not be enough for ASan, though: when it replaces static alloca with dynamic one, optionally called if UAR mode is enabled, it adds a whole lot of SSA values, and computations of local variable addresses, that can involve virtual registers, and cause unexpected behavior, when these registers are restored from buffer saved in setjmp. To fix this, just disable dynamic alloca and UAR tricks whenever we see a returns_twice call in the function. Reviewers: rnk Subscribers: llvm-commits, kcc Differential Revision: http://reviews.llvm.org/D11495 llvm-svn: 243561
2015-07-30 03:36:08 +08:00
; Test that dynamic alloca is not used when setjmp is present.
%struct.__jmp_buf_tag = type { [8 x i64], i32, %struct.__sigset_t }
%struct.__sigset_t = type { [16 x i64] }
@_ZL3buf = internal global [1 x %struct.__jmp_buf_tag] zeroinitializer, align 16
define void @Func3() uwtable sanitize_address {
; CHECK-LABEL: define void @Func3
; CHECK-NOT: __asan_option_detect_stack_use_after_return
; CHECK-NOT: __asan_stack_malloc
; CHECK: call void @__asan_handle_no_return
; CHECK: call void @longjmp
; CHECK: ret void
entry:
%a = alloca i32, align 4
%call = call i32 @_setjmp(%struct.__jmp_buf_tag* getelementptr inbounds ([1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* @_ZL3buf, i32 0, i32 0)) nounwind returns_twice
%cmp = icmp eq i32 0, %call
br i1 %cmp, label %if.then, label %if.end
if.then: ; preds = %entry
call void @longjmp(%struct.__jmp_buf_tag* getelementptr inbounds ([1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* @_ZL3buf, i32 0, i32 0), i32 1) noreturn nounwind
unreachable
if.end: ; preds = %entry
call void @_Z10escape_ptrPi(i32* %a)
ret void
}
declare i32 @_setjmp(%struct.__jmp_buf_tag*) nounwind returns_twice
declare void @longjmp(%struct.__jmp_buf_tag*, i32) noreturn nounwind
declare void @_Z10escape_ptrPi(i32*)