[llvm] [RISCV] Fix assertion failure when using -fstack-clash-protection (PR #135248)

via llvm-commits llvm-commits at lists.llvm.org
Thu Apr 10 13:16:49 PDT 2025


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-risc-v

Author: Paul Kirth (ilovepi)

<details>
<summary>Changes</summary>

We can't assume MBBI is still pointing at MBB if we've already expanded
a probe. We need to re-query the MBB from MBBI. Fixes #<!-- -->135206

Co-authored-by: Craig Topper <craig.topper@<!-- -->sifive.com>

---
Full diff: https://github.com/llvm/llvm-project/pull/135248.diff


2 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVFrameLowering.cpp (+5-3) 
- (added) llvm/test/CodeGen/RISCV/pr135206.ll (+118) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
index c7b2b781422d1..a83119957d95e 100644
--- a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
@@ -2270,11 +2270,13 @@ TargetStackID::Value RISCVFrameLowering::getStackIDForScalableVectors() const {
 }
 
 // Synthesize the probe loop.
-static void emitStackProbeInline(MachineFunction &MF, MachineBasicBlock &MBB,
-                                 MachineBasicBlock::iterator MBBI, DebugLoc DL,
+static void emitStackProbeInline(MachineBasicBlock::iterator MBBI, DebugLoc DL,
                                  Register TargetReg, bool IsRVV) {
   assert(TargetReg != RISCV::X2 && "New top of stack cannot already be in SP");
 
+  MachineBasicBlock &MBB = *MBBI->getParent();
+  MachineFunction &MF = *MBB.getParent();
+
   auto &Subtarget = MF.getSubtarget<RISCVSubtarget>();
   const RISCVInstrInfo *TII = Subtarget.getInstrInfo();
   bool IsRV64 = Subtarget.is64Bit();
@@ -2363,7 +2365,7 @@ void RISCVFrameLowering::inlineStackProbe(MachineFunction &MF,
       MachineBasicBlock::iterator MBBI = MI->getIterator();
       DebugLoc DL = MBB.findDebugLoc(MBBI);
       Register TargetReg = MI->getOperand(1).getReg();
-      emitStackProbeInline(MF, MBB, MBBI, DL, TargetReg,
+      emitStackProbeInline(MBBI, DL, TargetReg,
                            (MI->getOpcode() == RISCV::PROBED_STACKALLOC_RVV));
       MBBI->eraseFromParent();
     }
diff --git a/llvm/test/CodeGen/RISCV/pr135206.ll b/llvm/test/CodeGen/RISCV/pr135206.ll
new file mode 100644
index 0000000000000..c7988cbc685fa
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/pr135206.ll
@@ -0,0 +1,118 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+
+; RUN: llc < %s -o - | FileCheck %s
+
+target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
+target triple = "riscv64-unknown-fuchsia"
+
+%"struct.fuchsia_sysmem::wire::BufferCollectionConstraints" = type { %"struct.fuchsia_sysmem::wire::BufferUsage", i32, i32, i32, i32, i32, i8, %"struct.fuchsia_sysmem::wire::BufferMemoryConstraints", i32, [4 x i8], %"struct.fidl::Array.94" }
+%"struct.fuchsia_sysmem::wire::BufferUsage" = type { i32, i32, i32, i32, i32 }
+%"struct.fuchsia_sysmem::wire::BufferMemoryConstraints" = type { i32, i32, i8, i8, i8, i8, i8, i32, %"struct.fidl::Array" }
+%"struct.fidl::Array" = type { [32 x i64] }
+%"struct.fidl::Array.94" = type { [32 x %"struct.fuchsia_sysmem::wire::ImageFormatConstraints"] }
+%"struct.fuchsia_sysmem::wire::ImageFormatConstraints" = type <{ %"struct.fuchsia_sysmem::wire::PixelFormat", i32, %"struct.fidl::Array.95", i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [4 x i8] }>
+%"struct.fuchsia_sysmem::wire::PixelFormat" = type { i32, i8, %"struct.fuchsia_sysmem::wire::FormatModifier" }
+%"struct.fuchsia_sysmem::wire::FormatModifier" = type { i64 }
+%"struct.fidl::Array.95" = type { [32 x %"struct.fuchsia_sysmem::wire::ColorSpace"] }
+%"struct.fuchsia_sysmem::wire::ColorSpace" = type { i32 }
+
+; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
+declare void @llvm.memset.p0.i64(ptr writeonly captures(none), i8, i64, i1 immarg) #0
+
+define fastcc i1 @_ZN12_GLOBAL__N_121AttachTokenSucceedsV1EbbN3fit13function_implILm16ELb0EFvRN14fuchsia_sysmem4wire27BufferCollectionConstraintsEENSt3__29allocatorISt4byteEEEESB_SB_NS1_ILm16ELb0EFvRNS3_21BufferCollectionInfo2EESA_EEj() #1 {
+; CHECK-LABEL: _ZN12_GLOBAL__N_121AttachTokenSucceedsV1EbbN3fit13function_implILm16ELb0EFvRN14fuchsia_sysmem4wire27BufferCollectionConstraintsEENSt3__29allocatorISt4byteEEEESB_SB_NS1_ILm16ELb0EFvRNS3_21BufferCollectionInfo2EESA_EEj:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    addi sp, sp, -2032
+; CHECK-NEXT:    .cfi_def_cfa_offset 2032
+; CHECK-NEXT:    sd ra, 2024(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    sd s0, 2016(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    sd s1, 2008(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    sd s2, 2000(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    sd s3, 1992(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_offset ra, -8
+; CHECK-NEXT:    .cfi_offset s0, -16
+; CHECK-NEXT:    .cfi_offset s1, -24
+; CHECK-NEXT:    .cfi_offset s2, -32
+; CHECK-NEXT:    .cfi_offset s3, -40
+; CHECK-NEXT:    lui a0, 5
+; CHECK-NEXT:    sub t1, sp, a0
+; CHECK-NEXT:    .cfi_def_cfa t1, 20480
+; CHECK-NEXT:    lui t2, 1
+; CHECK-NEXT:  .LBB0_1: # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    sub sp, sp, t2
+; CHECK-NEXT:    sd zero, 0(sp)
+; CHECK-NEXT:    bne sp, t1, .LBB0_1
+; CHECK-NEXT:  # %bb.2:
+; CHECK-NEXT:    .cfi_def_cfa_register sp
+; CHECK-NEXT:    addi sp, sp, -848
+; CHECK-NEXT:    .cfi_def_cfa_offset 21328
+; CHECK-NEXT:    csrr t1, vlenb
+; CHECK-NEXT:    .cfi_def_cfa t1, -8
+; CHECK-NEXT:    lui t2, 1
+; CHECK-NEXT:  .LBB0_3: # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    sub sp, sp, t2
+; CHECK-NEXT:    sd zero, 0(sp)
+; CHECK-NEXT:    sub t1, t1, t2
+; CHECK-NEXT:    bge t1, t2, .LBB0_3
+; CHECK-NEXT:  # %bb.4:
+; CHECK-NEXT:    .cfi_def_cfa_register sp
+; CHECK-NEXT:    sub sp, sp, t1
+; CHECK-NEXT:    .cfi_escape 0x0f, 0x0f, 0x72, 0x00, 0x11, 0xc0, 0xb6, 0x01, 0x22, 0x11, 0x01, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # sp + 23360 + 1 * vlenb
+; CHECK-NEXT:    li s0, 0
+; CHECK-NEXT:    li a0, 170
+; CHECK-NEXT:    li s1, 32
+; CHECK-NEXT:    lui a1, %hi(.LCPI0_0)
+; CHECK-NEXT:    vsetivli zero, 16, e8, m1, ta, ma
+; CHECK-NEXT:    vmv.v.x v8, a0
+; CHECK-NEXT:    lui a0, 6
+; CHECK-NEXT:    addiw a0, a0, -1264
+; CHECK-NEXT:    add a0, sp, a0
+; CHECK-NEXT:    vs1r.v v8, (a0) # vscale x 8-byte Folded Spill
+; CHECK-NEXT:    ld s2, %lo(.LCPI0_0)(a1)
+; CHECK-NEXT:    vse8.v v8, (s1)
+; CHECK-NEXT:    li s3, 16
+; CHECK-NEXT:    vse8.v v8, (s3)
+; CHECK-NEXT:    vse8.v v8, (zero)
+; CHECK-NEXT:    sd s2, 48(zero)
+; CHECK-NEXT:    jalr s0
+; CHECK-NEXT:    lui a0, 6
+; CHECK-NEXT:    addiw a0, a0, -1264
+; CHECK-NEXT:    add a0, sp, a0
+; CHECK-NEXT:    vl1r.v v8, (a0) # vscale x 8-byte Folded Reload
+; CHECK-NEXT:    vsetivli zero, 16, e8, m1, ta, ma
+; CHECK-NEXT:    vse8.v v8, (zero)
+; CHECK-NEXT:    vse8.v v8, (s3)
+; CHECK-NEXT:    vse8.v v8, (s1)
+; CHECK-NEXT:    sd s2, 48(zero)
+; CHECK-NEXT:    li a0, 0
+; CHECK-NEXT:    csrr a1, vlenb
+; CHECK-NEXT:    add sp, sp, a1
+; CHECK-NEXT:    .cfi_def_cfa sp, 2032
+; CHECK-NEXT:    lui a1, 5
+; CHECK-NEXT:    addiw a1, a1, 848
+; CHECK-NEXT:    add sp, sp, a1
+; CHECK-NEXT:    .cfi_def_cfa_offset 2032
+; CHECK-NEXT:    ld ra, 2024(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    ld s0, 2016(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    ld s1, 2008(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    ld s2, 2000(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    ld s3, 1992(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    .cfi_restore ra
+; CHECK-NEXT:    .cfi_restore s0
+; CHECK-NEXT:    .cfi_restore s1
+; CHECK-NEXT:    .cfi_restore s2
+; CHECK-NEXT:    .cfi_restore s3
+; CHECK-NEXT:    addi sp, sp, 2032
+; CHECK-NEXT:    .cfi_def_cfa_offset 0
+; CHECK-NEXT:    ret
+  %1 = alloca %"struct.fuchsia_sysmem::wire::BufferCollectionConstraints", align 8
+  %2 = alloca %"struct.fuchsia_sysmem::wire::BufferCollectionConstraints", align 8
+  %3 = alloca %"struct.fuchsia_sysmem::wire::BufferCollectionConstraints", align 8
+  call void @llvm.memset.p0.i64(ptr null, i8 -86, i64 56, i1 false)
+  %4 = call ptr null()
+  call void @llvm.memset.p0.i64(ptr null, i8 -86, i64 56, i1 false)
+  ret i1 false
+}
+
+attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: write) }
+attributes #1 = { "probe-stack"="inline-asm" "target-features"="+v" }

``````````

</details>


https://github.com/llvm/llvm-project/pull/135248


More information about the llvm-commits mailing list