c0214db51a
For mingw target, if a symbol is not marked DSO local, a `.refptr` is generated for it. This makes CFG check calls use an extra pointer dereference, which adds extra overhead compared to the MSVC version, so mark the CFG guard check funciton pointer DSO local to stop it. This should have no effect on MSVC target. Also adapt the existing cfguard tests to run for mingw targets, so that this change is checked. Reviewed By: rnk Differential Revision: https://reviews.llvm.org/D132331
46 lines
2.2 KiB
LLVM
46 lines
2.2 KiB
LLVM
; RUN: llc < %s -mtriple=x86_64-pc-windows-msvc | FileCheck %s
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; RUN: llc < %s -mtriple=x86_64-w64-windows-gnu | FileCheck %s
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; Control Flow Guard is currently only available on Windows
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declare dllimport i32 @target_func1()
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declare dllimport i32 @target_func2()
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declare dllimport i32 @target_func3()
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@ptrs = dso_local local_unnamed_addr global [2 x void ()*] [void ()* bitcast (i32 ()* @target_func2 to void ()*), void ()* bitcast (i32 ()* @target_func3 to void ()*)], align 16
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; Test address-taken functions from imported DLLs are correctly added to the
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; Guard Address-Taken IAT Entry (.giats) and Guard Function ID (.gfids) sections.
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define i32 @func_cf_giats1() {
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entry:
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; Since it is a dllimport, target_func1 will be represented as "__imp_target_func1" when it is
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; stored in the function pointer. Therefore, the .giats section must contain "__imp_target_func1".
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; Unlike MSVC, we also have "target_func1" in the .gfids section, since this is not a security risk.
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%func_ptr = alloca i32 ()*, align 8
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store i32 ()* @target_func1, i32 ()** %func_ptr, align 8
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%0 = load i32 ()*, i32 ()** %func_ptr, align 8
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%1 = call i32 %0()
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; target_func2 is called directly from a global array, so should only appear in the .gfids section.
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%2 = load i32 ()*, i32 ()** bitcast ([2 x void ()*]* @ptrs to i32 ()**), align 8
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%3 = call i32 %2()
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; target_func3 is called both via a stored function pointer (as with target_func1) and via a gloabl
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; array (as with target_func2), so "target_func3" must appear in .gfids and "__imp_target_func3" in .giats.
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store i32 ()* @target_func3, i32 ()** %func_ptr, align 8
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%4 = load i32 ()*, i32 ()** %func_ptr, align 8
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%5 = call i32 %4()
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%6 = load i32 ()*, i32 ()** bitcast (void ()** getelementptr inbounds ([2 x void ()*], [2 x void ()*]* @ptrs, i64 0, i64 1) to i32 ()**), align 8
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%7 = call i32 %6()
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ret i32 %5
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}
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; CHECK-LABEL: .section .gfids$y,"dr"
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; CHECK-NEXT: .symidx target_func1
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; CHECK-NEXT: .symidx target_func2
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; CHECK-NEXT: .symidx target_func3
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; CHECK-NOT: .symidx
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; CHECK-LABEL: .section .giats$y,"dr"
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; CHECK-NEXT: .symidx __imp_target_func1
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; CHECK-NEXT: .symidx __imp_target_func3
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; CHECK-NOT: .symidx
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!llvm.module.flags = !{!0}
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!0 = !{i32 2, !"cfguard", i32 2}
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