From fc7a0c4878dac2d721ec18cafe1b6bcff7faa771 Mon Sep 17 00:00:00 2001 From: Alex Rønne Petersen Date: Sat, 15 Feb 2025 02:44:58 +0100 Subject: Sema: Fix fnptr alignment safety checks to account for potential ISA tag. As seen on e.g. Arm/Thumb and MIPS (MIPS16/microMIPS). Fixes #22888. --- src/Sema.zig | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) (limited to 'src/Sema.zig') diff --git a/src/Sema.zig b/src/Sema.zig index cbfeef6339..7e3ab51a29 100644 --- a/src/Sema.zig +++ b/src/Sema.zig @@ -23099,8 +23099,14 @@ fn zirPtrFromInt(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError! } if (ptr_align.compare(.gt, .@"1")) { const align_bytes_minus_1 = ptr_align.toByteUnits().? - 1; - const align_minus_1 = Air.internedToRef((try sema.splat(operand_ty, try pt.intValue(Type.usize, align_bytes_minus_1))).toIntern()); - const remainder = try block.addBinOp(.bit_and, operand_coerced, align_minus_1); + const align_mask = Air.internedToRef((try sema.splat(operand_ty, try pt.intValue( + Type.usize, + if (elem_ty.fnPtrMaskOrNull(zcu)) |mask| + align_bytes_minus_1 & mask + else + align_bytes_minus_1, + ))).toIntern()); + const remainder = try block.addBinOp(.bit_and, operand_coerced, align_mask); const is_aligned = if (is_vector) all_aligned: { const splat_zero_usize = Air.internedToRef((try sema.splat(operand_ty, .zero_usize)).toIntern()); const is_aligned = try block.addCmpVector(remainder, splat_zero_usize, .eq); @@ -23129,8 +23135,14 @@ fn zirPtrFromInt(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError! } if (ptr_align.compare(.gt, .@"1")) { const align_bytes_minus_1 = ptr_align.toByteUnits().? - 1; - const align_minus_1 = Air.internedToRef((try pt.intValue(Type.usize, align_bytes_minus_1)).toIntern()); - const remainder = try block.addBinOp(.bit_and, elem_coerced, align_minus_1); + const align_mask = Air.internedToRef((try pt.intValue( + Type.usize, + if (elem_ty.fnPtrMaskOrNull(zcu)) |mask| + align_bytes_minus_1 & mask + else + align_bytes_minus_1, + )).toIntern()); + const remainder = try block.addBinOp(.bit_and, elem_coerced, align_mask); const is_aligned = try block.addBinOp(.cmp_eq, remainder, .zero_usize); try sema.addSafetyCheck(block, src, is_aligned, .incorrect_alignment); } @@ -23710,13 +23722,19 @@ fn ptrCastFull( try Type.fromInterned(dest_info.child).hasRuntimeBitsSema(pt)) { const align_bytes_minus_1 = dest_align.toByteUnits().? - 1; - const align_minus_1 = Air.internedToRef((try pt.intValue(Type.usize, align_bytes_minus_1)).toIntern()); + const align_mask = Air.internedToRef((try pt.intValue( + Type.usize, + if (Type.fromInterned(dest_info.child).fnPtrMaskOrNull(zcu)) |mask| + align_bytes_minus_1 & mask + else + align_bytes_minus_1, + )).toIntern()); const actual_ptr = if (src_info.flags.size == .slice) try sema.analyzeSlicePtr(block, src, ptr, operand_ty) else ptr; const ptr_int = try block.addBitCast(.usize, actual_ptr); - const remainder = try block.addBinOp(.bit_and, ptr_int, align_minus_1); + const remainder = try block.addBinOp(.bit_and, ptr_int, align_mask); const is_aligned = try block.addBinOp(.cmp_eq, remainder, .zero_usize); const ok = if (src_info.flags.size == .slice and dest_info.flags.size == .slice) ok: { const len = try sema.analyzeSliceLen(block, operand_src, ptr); -- cgit v1.2.3