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llvm-project/llvm/test/CodeGen/X86/stack_guard_remat.ll

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[stack protector] Fix a potential security bug in stack protector where the address of the stack guard was being spilled to the stack. Previously the address of the stack guard would get spilled to the stack if it was impossible to keep it in a register. This patch introduces a new target independent node and pseudo instruction which gets expanded post-RA to a sequence of instructions that load the stack guard value. Register allocator can now just remat the value when it can't keep it in a register. <rdar://problem/12475629> llvm-svn: 213967
2014-07-26 03:31:34 +08:00
; RUN: llc < %s -mtriple=x86_64-apple-darwin -no-integrated-as | FileCheck %s -check-prefix=CHECK
;CHECK: foo2
;CHECK: movq ___stack_chk_guard@GOTPCREL(%rip), [[R0:%[a-z0-9]+]]
;CHECK: movq ([[R0]]), {{%[a-z0-9]+}}
; Function Attrs: nounwind ssp uwtable
define i32 @test_stack_guard_remat() #0 {
entry:
%a1 = alloca [256 x i32], align 16
%0 = bitcast [256 x i32]* %a1 to i8*
call void @llvm.lifetime.start(i64 1024, i8* %0)
[opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction One of several parallel first steps to remove the target type of pointers, replacing them with a single opaque pointer type. This adds an explicit type parameter to the gep instruction so that when the first parameter becomes an opaque pointer type, the type to gep through is still available to the instructions. * This doesn't modify gep operators, only instructions (operators will be handled separately) * Textual IR changes only. Bitcode (including upgrade) and changing the in-memory representation will be in separate changes. * geps of vectors are transformed as: getelementptr <4 x float*> %x, ... ->getelementptr float, <4 x float*> %x, ... Then, once the opaque pointer type is introduced, this will ultimately look like: getelementptr float, <4 x ptr> %x with the unambiguous interpretation that it is a vector of pointers to float. * address spaces remain on the pointer, not the type: getelementptr float addrspace(1)* %x ->getelementptr float, float addrspace(1)* %x Then, eventually: getelementptr float, ptr addrspace(1) %x Importantly, the massive amount of test case churn has been automated by same crappy python code. I had to manually update a few test cases that wouldn't fit the script's model (r228970,r229196,r229197,r229198). The python script just massages stdin and writes the result to stdout, I then wrapped that in a shell script to handle replacing files, then using the usual find+xargs to migrate all the files. update.py: import fileinput import sys import re ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))") normrep = re.compile( r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))") def conv(match, line): if not match: return line line = match.groups()[0] if len(match.groups()[5]) == 0: line += match.groups()[2] line += match.groups()[3] line += ", " line += match.groups()[1] line += "\n" return line for line in sys.stdin: if line.find("getelementptr ") == line.find("getelementptr inbounds"): if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("): line = conv(re.match(ibrep, line), line) elif line.find("getelementptr ") != line.find("getelementptr ("): line = conv(re.match(normrep, line), line) sys.stdout.write(line) apply.sh: for name in "$@" do python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name" rm -f "$name.tmp" done The actual commands: From llvm/src: find test/ -name *.ll | xargs ./apply.sh From llvm/src/tools/clang: find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}" From llvm/src/tools/polly: find test/ -name *.ll | xargs ./apply.sh After that, check-all (with llvm, clang, clang-tools-extra, lld, compiler-rt, and polly all checked out). The extra 'rm' in the apply.sh script is due to a few files in clang's test suite using interesting unicode stuff that my python script was throwing exceptions on. None of those files needed to be migrated, so it seemed sufficient to ignore those cases. Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7636 llvm-svn: 230786
2015-02-28 03:29:02 +08:00
%arraydecay = getelementptr inbounds [256 x i32], [256 x i32]* %a1, i64 0, i64 0
[stack protector] Fix a potential security bug in stack protector where the address of the stack guard was being spilled to the stack. Previously the address of the stack guard would get spilled to the stack if it was impossible to keep it in a register. This patch introduces a new target independent node and pseudo instruction which gets expanded post-RA to a sequence of instructions that load the stack guard value. Register allocator can now just remat the value when it can't keep it in a register. <rdar://problem/12475629> llvm-svn: 213967
2014-07-26 03:31:34 +08:00
call void @foo3(i32* %arraydecay)
call void asm sideeffect "foo2", "~{r12},~{r13},~{r14},~{r15},~{ebx},~{esi},~{edi},~{dirflag},~{fpsr},~{flags}"()
call void @llvm.lifetime.end(i64 1024, i8* %0)
ret i32 0
}
; Function Attrs: nounwind
declare void @llvm.lifetime.start(i64, i8* nocapture)
declare void @foo3(i32*)
; Function Attrs: nounwind
declare void @llvm.lifetime.end(i64, i8* nocapture)
attributes #0 = { nounwind ssp uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }