| ... | ... | @@ -539,6 +539,26 @@ const Section = struct { |
| 539 | 539 | } |
| 540 | 540 | } |
| 541 | 541 | |
| 542 | fn ensureAligned(shndx: Index, elf: *Elf, min_align: std.mem.Alignment) Error!void { |
| 543 | switch (elf.shdrPtr(shndx)) { |
| 544 | inline else => |shdr| { |
| 545 | if (elf.targetLoad(&shdr.addralign) >= min_align.toByteUnits()) { |
| 546 | return; // already aligned |
| 547 | } |
| 548 | elf.targetStore(&shdr.addralign, @intCast(min_align.toByteUnits())); |
| 549 | }, |
| 550 | } |
| 551 | const ni = shndx.get(elf).ni; |
| 552 | if (min_align.compare(.gt, ni.alignment(&elf.mf))) { |
| 553 | try ni.realign(&elf.mf, elf.base.comp.gpa, min_align, .{}); |
| 554 | } |
| 555 | switch (elf.getNode(ni.parent(&elf.mf))) { |
| 556 | .elf => {}, |
| 557 | .segment => |phndx| try elf.ensureSegmentAligned(phndx, min_align), |
| 558 | else => unreachable, |
| 559 | } |
| 560 | } |
| 561 | |
| 542 | 562 | /// Asserts that `rela_shndx` is a `SHT_RELA` section and ensures that its node has enough |
| 543 | 563 | /// unused space to hold `n` additional `ElfN.Rela` entries. |
| 544 | 564 | fn relaEnsureAdditionalCapacity(rela_shndx: Index, elf: *Elf, n: usize) Error!void { |
| ... | ... | @@ -3455,6 +3475,16 @@ fn initHeaders( |
| 3455 | 3475 | .@"64" => .@"8", |
| 3456 | 3476 | }; |
| 3457 | 3477 | |
| 3478 | // Minimum alignment for an arbitrarily-chosen set of "large" nodes in the file (e.g. common |
| 3479 | // sections), to allow `MappedFile` to perform operations more efficiently. The downside to |
| 3480 | // using `elf.mf.flags.block_size` is that it causes outputs to be potentially unreproducible |
| 3481 | // across host filesystems, so in the future we may want to set this to `.@"1"` when using a |
| 3482 | // build mode that requires reproducibility. |
| 3483 | // |
| 3484 | // It can be handy to temporarily set this to `.@"1"` when working on the linker, because it |
| 3485 | // prevents alignment bugs from being hidden by your filesystem's block alignment. |
| 3486 | const node_block_align: std.mem.Alignment = elf.mf.flags.block_size; |
| 3487 | |
| 3458 | 3488 | const plt: PltInfo = .fromMachine(machine); |
| 3459 | 3489 | |
| 3460 | 3490 | const shnum: u32 = shnum: { |
| ... | ... | @@ -3577,7 +3607,7 @@ fn initHeaders( |
| 3577 | 3607 | |
| 3578 | 3608 | elf.nodes.appendAssumeCapacity(.archive_header); |
| 3579 | 3609 | elf.ni.elf = try elf.mf.addLastChildNode(gpa, elf.ni.archive, .{ |
| 3580 | | .alignment = elf.mf.flags.block_size.max(.@"2"), |
| 3610 | .alignment = node_block_align.max(.@"2"), |
| 3581 | 3611 | .next_moved = true, |
| 3582 | 3612 | .bubbles_moved = false, |
| 3583 | 3613 | .enable_next_moved = true, |
| ... | ... | @@ -3648,36 +3678,16 @@ fn initHeaders( |
| 3648 | 3678 | |
| 3649 | 3679 | elf.ni.shdr = try elf.mf.addLastChildNode(gpa, elf.ni.elf, .{ |
| 3650 | 3680 | .size = 1 * entsize.sh, // as above, only the null shdr initially |
| 3651 | | .alignment = elf.mf.flags.block_size, |
| 3681 | .alignment = addr_align.max(node_block_align), |
| 3652 | 3682 | .moved = true, |
| 3653 | 3683 | .resized = true, |
| 3654 | 3684 | }); |
| 3655 | 3685 | elf.nodes.appendAssumeCapacity(.shdr); |
| 3656 | 3686 | |
| 3657 | | const page_align: std.mem.Alignment = .fromByteUnits(switch (machine) { |
| 3658 | | .AARCH64 => 0x10000, |
| 3659 | | .LOONGARCH => 0x4000, |
| 3660 | | .PPC64 => 0x10000, |
| 3661 | | .RISCV => 0x1000, |
| 3662 | | .SPARCV9 => 0x100000, |
| 3663 | | .X86_64 => 0x1000, |
| 3664 | | |
| 3665 | | //.@"68K" => 0x2000, |
| 3666 | | //.AMDGPU => 0x10000, |
| 3667 | | //.ARC_COMPACT2 => 0x2000, |
| 3668 | | //.AVR => 0x1, |
| 3669 | | //.BPF => 0x100000, |
| 3670 | | //.MIPS => 0x10000, |
| 3671 | | //.MSP430 => 0x4, |
| 3672 | | //.PPC => 0x10000, |
| 3673 | | //.QDSP6 => 0x10000, |
| 3674 | | //.SPARC => 0x10000, |
| 3675 | | //.SPARC32PLUS => 0x10000, |
| 3676 | | }); |
| 3677 | | |
| 3678 | | var ph_vaddr: u32 = if (@"type" != .REL) ph_vaddr: { |
| 3687 | if (@"type" != .REL) { |
| 3679 | 3688 | elf.ni.rodata = try elf.mf.addLastChildNode(gpa, elf.ni.elf, .{ |
| 3680 | | .alignment = elf.mf.flags.block_size, |
| 3689 | // Must be at least `addr_align` for `elf.ni.phdr` to be placed inside this node |
| 3690 | .alignment = node_block_align.max(addr_align), |
| 3681 | 3691 | .moved = true, |
| 3682 | 3692 | .bubbles_moved = false, |
| 3683 | 3693 | }); |
| ... | ... | @@ -3686,7 +3696,7 @@ fn initHeaders( |
| 3686 | 3696 | |
| 3687 | 3697 | elf.ni.phdr = try elf.mf.addOnlyChildNode(gpa, elf.ni.rodata, .{ |
| 3688 | 3698 | .size = @as(u64, phnum) * entsize.ph, |
| 3689 | | .alignment = addr_align, |
| 3699 | .alignment = addr_align, // keep in sync with `elf.ni.rodata` alignment above |
| 3690 | 3700 | .moved = true, |
| 3691 | 3701 | .resized = true, |
| 3692 | 3702 | .bubbles_moved = false, |
| ... | ... | @@ -3695,7 +3705,7 @@ fn initHeaders( |
| 3695 | 3705 | elf.phdrs.items[phndx.phdr] = elf.ni.phdr; |
| 3696 | 3706 | |
| 3697 | 3707 | elf.ni.text = try elf.mf.addLastChildNode(gpa, elf.ni.elf, .{ |
| 3698 | | .alignment = elf.mf.flags.block_size, |
| 3708 | .alignment = node_block_align, |
| 3699 | 3709 | .moved = true, |
| 3700 | 3710 | .bubbles_moved = false, |
| 3701 | 3711 | }); |
| ... | ... | @@ -3703,7 +3713,8 @@ fn initHeaders( |
| 3703 | 3713 | elf.phdrs.items[phndx.text] = elf.ni.text; |
| 3704 | 3714 | |
| 3705 | 3715 | elf.ni.data = try elf.mf.addLastChildNode(gpa, elf.ni.elf, .{ |
| 3706 | | .alignment = elf.mf.flags.block_size, |
| 3716 | // Must be at least `addr_align` for `elf.ni.data_rel_ro` to be placed inside this node |
| 3717 | .alignment = node_block_align.max(addr_align), |
| 3707 | 3718 | .moved = true, |
| 3708 | 3719 | .bubbles_moved = false, |
| 3709 | 3720 | }); |
| ... | ... | @@ -3711,36 +3722,66 @@ fn initHeaders( |
| 3711 | 3722 | elf.phdrs.items[phndx.data] = elf.ni.data; |
| 3712 | 3723 | |
| 3713 | 3724 | elf.ni.data_rel_ro = try elf.mf.addOnlyChildNode(gpa, elf.ni.data, .{ |
| 3714 | | .alignment = elf.mf.flags.block_size, |
| 3725 | // Must be at least `addr_align` for the `PT_DYNAMIC` node to be placed inside this one |
| 3726 | // later (if `have_dynamic_section`). Keep in sync with `elf.ni.data` alignment above. |
| 3727 | .alignment = node_block_align.max(addr_align), |
| 3715 | 3728 | .moved = true, |
| 3716 | 3729 | .bubbles_moved = false, |
| 3717 | 3730 | }); |
| 3718 | 3731 | elf.nodes.appendAssumeCapacity(.{ .segment = phndx.relro }); |
| 3719 | 3732 | elf.phdrs.items[phndx.relro] = elf.ni.data_rel_ro; |
| 3720 | 3733 | |
| 3721 | | elf.phdrs.items[phndx.gnu_stack] = .none; |
| 3734 | if (comp.config.any_non_single_threaded) { |
| 3735 | elf.ni.tls = try elf.mf.addLastChildNode(gpa, elf.ni.rodata, .{ |
| 3736 | .alignment = node_block_align, |
| 3737 | .moved = true, |
| 3738 | .bubbles_moved = false, |
| 3739 | }); |
| 3740 | elf.nodes.appendAssumeCapacity(.{ .segment = phndx.tls }); |
| 3741 | elf.phdrs.items[phndx.tls] = elf.ni.tls; |
| 3742 | } |
| 3722 | 3743 | |
| 3723 | | break :ph_vaddr switch (elf.ehdrType()) { |
| 3724 | | .REL, .DYN => 0, |
| 3725 | | .EXEC => switch (machine) { |
| 3726 | | .AARCH64, |
| 3727 | | => 0x200000, |
| 3728 | | .LOONGARCH => 0x10000, |
| 3729 | | .PPC64 => 0x10000000, |
| 3730 | | .RISCV => 0x10000, |
| 3731 | | .SPARCV9 => 0x100000, |
| 3732 | | .X86_64 => 0x200000, |
| 3733 | | }, |
| 3734 | | }; |
| 3735 | | } else undefined; |
| 3744 | elf.phdrs.items[phndx.gnu_stack] = .none; |
| 3745 | } |
| 3736 | 3746 | switch (class) { |
| 3737 | 3747 | .NONE, _ => unreachable, |
| 3738 | 3748 | inline else => |ct_class| { |
| 3739 | 3749 | const ElfN = ct_class.ElfN(); |
| 3740 | 3750 | const target_endian = elf.targetEndian(); |
| 3741 | 3751 | |
| 3742 | | if (@"type" != .REL) { |
| 3752 | populate_phdrs: { |
| 3753 | // Initially we will give every `PT_LOAD` segment this address. When we re-allocate |
| 3754 | // segments in the virtual address space in `flushMoved` and `flushResized`, we will |
| 3755 | // move some segments to higher addresses to prevent overlap. This address therefore |
| 3756 | // becomes the image's "base address"; i.e. the first `PT_LOAD` segment will start |
| 3757 | // at this address. The base address could eventually end up higher than this due to |
| 3758 | // how we re-allocate the address space, but never lower. |
| 3759 | const base_vaddr: u64 = switch (@"type") { |
| 3760 | .REL => break :populate_phdrs, |
| 3761 | .DYN => 0, |
| 3762 | .EXEC => switch (machine) { |
| 3763 | .AARCH64 => 0x200000, |
| 3764 | .LOONGARCH => 0x10000, |
| 3765 | .PPC64 => 0x10000000, |
| 3766 | .RISCV => 0x10000, |
| 3767 | .SPARCV9 => 0x100000, |
| 3768 | .X86_64 => 0x200000, |
| 3769 | }, |
| 3770 | }; |
| 3771 | |
| 3772 | // All `PT_LOAD` segments are given this `.@"align"`. However, to avoid bloating the |
| 3773 | // binary, their *nodes* are not aligned to this boundary---ELF only requires that |
| 3774 | // ecah segment's address equals its file offset modulo this alignment, not that its |
| 3775 | // file offset is actually aligned to this boundary. This property is maintained by |
| 3776 | // the segment virtual address space allocation logic. |
| 3777 | const page_align = elf.targetPageAlign(); |
| 3778 | |
| 3779 | // We will populate elements in this slice (by index). The `PT_LOAD` segments are |
| 3780 | // actually `PT_NULL` for now, because we initialize `filesz` and `memsz` to zero. |
| 3781 | // Any which end up non-empty will have their size populated (and their type set to |
| 3782 | // `PT_LOAD`) by the segment virtual address space allocation logic. |
| 3743 | 3783 | const phdr: []ElfN.Phdr = @ptrCast(@alignCast(elf.ni.phdr.slice(&elf.mf))); |
| 3784 | |
| 3744 | 3785 | const ph_phdr = &phdr[phndx.phdr]; |
| 3745 | 3786 | ph_phdr.* = .{ |
| 3746 | 3787 | .type = .PHDR, |
| ... | ... | @@ -3752,7 +3793,6 @@ fn initHeaders( |
| 3752 | 3793 | .flags = .{ .R = true }, |
| 3753 | 3794 | .@"align" = @intCast(elf.ni.phdr.alignment(&elf.mf).toByteUnits()), |
| 3754 | 3795 | }; |
| 3755 | | if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Phdr, ph_phdr); |
| 3756 | 3796 | |
| 3757 | 3797 | if (maybe_interp) |_| { |
| 3758 | 3798 | const ph_interp = &phdr[phndx.interp]; |
| ... | ... | @@ -3766,53 +3806,43 @@ fn initHeaders( |
| 3766 | 3806 | .flags = .{ .R = true }, |
| 3767 | 3807 | .@"align" = 1, |
| 3768 | 3808 | }; |
| 3769 | | if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Phdr, ph_interp); |
| 3770 | 3809 | } |
| 3771 | 3810 | |
| 3772 | | _, const rodata_size = elf.ni.rodata.location(&elf.mf).resolve(&elf.mf); |
| 3773 | 3811 | const ph_rodata = &phdr[phndx.rodata]; |
| 3774 | 3812 | ph_rodata.* = .{ |
| 3775 | | .type = if (rodata_size == 0) .NULL else .LOAD, |
| 3813 | .type = .NULL, |
| 3776 | 3814 | .offset = 0, |
| 3777 | | .vaddr = ph_vaddr, |
| 3778 | | .paddr = ph_vaddr, |
| 3779 | | .filesz = @intCast(rodata_size), |
| 3780 | | .memsz = @intCast(rodata_size), |
| 3815 | .vaddr = @intCast(base_vaddr), |
| 3816 | .paddr = @intCast(base_vaddr), |
| 3817 | .filesz = 0, |
| 3818 | .memsz = 0, |
| 3781 | 3819 | .flags = .{ .R = true }, |
| 3782 | | .@"align" = @intCast(elf.ni.rodata.alignment(&elf.mf).max(page_align).toByteUnits()), |
| 3820 | .@"align" = @intCast(page_align.toByteUnits()), |
| 3783 | 3821 | }; |
| 3784 | | if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Phdr, ph_rodata); |
| 3785 | | ph_vaddr += @intCast(rodata_size); |
| 3786 | 3822 | |
| 3787 | | _, const text_size = elf.ni.text.location(&elf.mf).resolve(&elf.mf); |
| 3788 | 3823 | const ph_text = &phdr[phndx.text]; |
| 3789 | 3824 | ph_text.* = .{ |
| 3790 | | .type = if (text_size == 0) .NULL else .LOAD, |
| 3825 | .type = .NULL, |
| 3791 | 3826 | .offset = 0, |
| 3792 | | .vaddr = ph_vaddr, |
| 3793 | | .paddr = ph_vaddr, |
| 3794 | | .filesz = @intCast(text_size), |
| 3795 | | .memsz = @intCast(text_size), |
| 3827 | .vaddr = @intCast(base_vaddr), |
| 3828 | .paddr = @intCast(base_vaddr), |
| 3829 | .filesz = 0, |
| 3830 | .memsz = 0, |
| 3796 | 3831 | .flags = .{ .R = true, .X = true }, |
| 3797 | | .@"align" = @intCast(elf.ni.text.alignment(&elf.mf).max(page_align).toByteUnits()), |
| 3832 | .@"align" = @intCast(page_align.toByteUnits()), |
| 3798 | 3833 | }; |
| 3799 | | if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Phdr, ph_text); |
| 3800 | | ph_vaddr += @intCast(text_size); |
| 3801 | 3834 | |
| 3802 | | _, const data_size = elf.ni.data.location(&elf.mf).resolve(&elf.mf); |
| 3803 | 3835 | const ph_data = &phdr[phndx.data]; |
| 3804 | 3836 | ph_data.* = .{ |
| 3805 | | .type = if (data_size == 0) .NULL else .LOAD, |
| 3837 | .type = .NULL, |
| 3806 | 3838 | .offset = 0, |
| 3807 | | .vaddr = ph_vaddr, |
| 3808 | | .paddr = ph_vaddr, |
| 3809 | | .filesz = @intCast(data_size), |
| 3810 | | .memsz = @intCast(data_size), |
| 3839 | .vaddr = @intCast(base_vaddr), |
| 3840 | .paddr = @intCast(base_vaddr), |
| 3841 | .filesz = 0, |
| 3842 | .memsz = 0, |
| 3811 | 3843 | .flags = .{ .R = true, .W = true }, |
| 3812 | | .@"align" = @intCast(elf.ni.data.alignment(&elf.mf).max(page_align).toByteUnits()), |
| 3844 | .@"align" = @intCast(page_align.toByteUnits()), |
| 3813 | 3845 | }; |
| 3814 | | if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Phdr, ph_data); |
| 3815 | | ph_vaddr += @intCast(data_size); |
| 3816 | 3846 | |
| 3817 | 3847 | if (comp.config.any_non_single_threaded) { |
| 3818 | 3848 | const ph_tls = &phdr[phndx.tls]; |
| ... | ... | @@ -3824,9 +3854,8 @@ fn initHeaders( |
| 3824 | 3854 | .filesz = 0, |
| 3825 | 3855 | .memsz = 0, |
| 3826 | 3856 | .flags = .{ .R = true }, |
| 3827 | | .@"align" = @intCast(elf.mf.flags.block_size.toByteUnits()), |
| 3857 | .@"align" = @intCast(elf.ni.tls.alignment(&elf.mf).toByteUnits()), |
| 3828 | 3858 | }; |
| 3829 | | if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Phdr, ph_tls); |
| 3830 | 3859 | } |
| 3831 | 3860 | |
| 3832 | 3861 | if (have_dynamic_section) { |
| ... | ... | @@ -3841,7 +3870,6 @@ fn initHeaders( |
| 3841 | 3870 | .flags = .{ .R = true, .W = true }, |
| 3842 | 3871 | .@"align" = @intCast(addr_align.toByteUnits()), |
| 3843 | 3872 | }; |
| 3844 | | if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Phdr, ph_dynamic); |
| 3845 | 3873 | } |
| 3846 | 3874 | |
| 3847 | 3875 | const ph_relro = &phdr[phndx.relro]; |
| ... | ... | @@ -3853,9 +3881,8 @@ fn initHeaders( |
| 3853 | 3881 | .filesz = 0, |
| 3854 | 3882 | .memsz = 0, |
| 3855 | 3883 | .flags = .{ .R = true }, |
| 3856 | | .@"align" = @intCast(elf.mf.flags.block_size.toByteUnits()), |
| 3884 | .@"align" = @intCast(elf.ni.data_rel_ro.alignment(&elf.mf).toByteUnits()), |
| 3857 | 3885 | }; |
| 3858 | | if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Phdr, ph_relro); |
| 3859 | 3886 | |
| 3860 | 3887 | const ph_gnu_stack = &phdr[phndx.gnu_stack]; |
| 3861 | 3888 | ph_gnu_stack.* = .{ |
| ... | ... | @@ -3868,7 +3895,10 @@ fn initHeaders( |
| 3868 | 3895 | .flags = .{ .R = true, .W = true }, |
| 3869 | 3896 | .@"align" = 1, |
| 3870 | 3897 | }; |
| 3871 | | if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Phdr, ph_gnu_stack); |
| 3898 | |
| 3899 | if (target_endian != std.lang.Endian.native) { |
| 3900 | std.mem.byteSwapAllElements(ElfN.Phdr, phdr); |
| 3901 | } |
| 3872 | 3902 | } |
| 3873 | 3903 | |
| 3874 | 3904 | const sh_undef: *ElfN.Shdr = @ptrCast(@alignCast(elf.ni.shdr.slice(&elf.mf))); |
| ... | ... | @@ -3896,7 +3926,7 @@ fn initHeaders( |
| 3896 | 3926 | .size = @sizeOf(ElfN.Sym) * 1, |
| 3897 | 3927 | .addralign = addr_align, |
| 3898 | 3928 | .entsize = @sizeOf(ElfN.Sym), |
| 3899 | | .node_align = elf.mf.flags.block_size, |
| 3929 | .node_align = node_block_align, |
| 3900 | 3930 | .info = 1, // index of first non-local symbol |
| 3901 | 3931 | })); |
| 3902 | 3932 | const symtab_null = @field(elf.symPtr(.null), @tagName(ct_class)); |
| ... | ... | @@ -3918,7 +3948,7 @@ fn initHeaders( |
| 3918 | 3948 | .type = .STRTAB, |
| 3919 | 3949 | .size = 1, |
| 3920 | 3950 | .entsize = 1, |
| 3921 | | .node_align = elf.mf.flags.block_size, |
| 3951 | .node_align = node_block_align, |
| 3922 | 3952 | })); |
| 3923 | 3953 | Section.Index.get(.shstrtab, elf).ni.slice(&elf.mf)[0] = 0; |
| 3924 | 3954 | |
| ... | ... | @@ -3930,7 +3960,7 @@ fn initHeaders( |
| 3930 | 3960 | .type = .STRTAB, |
| 3931 | 3961 | .size = 1, |
| 3932 | 3962 | .entsize = 1, |
| 3933 | | .node_align = elf.mf.flags.block_size, |
| 3963 | .node_align = node_block_align, |
| 3934 | 3964 | })); |
| 3935 | 3965 | Section.Index.get(.strtab, elf).ni.slice(&elf.mf)[0] = 0; |
| 3936 | 3966 | switch (elf.shdrPtr(.symtab)) { |
| ... | ... | @@ -3940,22 +3970,22 @@ fn initHeaders( |
| 3940 | 3970 | assert(.rodata == try elf.addSection(elf.ni.rodata, .{ |
| 3941 | 3971 | .name = ".rodata", |
| 3942 | 3972 | .flags = .{ .ALLOC = true }, |
| 3943 | | .addralign = elf.mf.flags.block_size, |
| 3973 | .node_align = node_block_align, |
| 3944 | 3974 | })); |
| 3945 | 3975 | assert(.text == try elf.addSection(elf.ni.text, .{ |
| 3946 | 3976 | .name = ".text", |
| 3947 | 3977 | .flags = .{ .ALLOC = true, .EXECINSTR = true }, |
| 3948 | | .addralign = elf.mf.flags.block_size, |
| 3978 | .node_align = node_block_align, |
| 3949 | 3979 | })); |
| 3950 | 3980 | assert(.data == try elf.addSection(elf.ni.data, .{ |
| 3951 | 3981 | .name = ".data", |
| 3952 | 3982 | .flags = .{ .WRITE = true, .ALLOC = true }, |
| 3953 | | .addralign = elf.mf.flags.block_size, |
| 3983 | .node_align = node_block_align, |
| 3954 | 3984 | })); |
| 3955 | 3985 | assert(.data_rel_ro == try elf.addSection(elf.ni.data_rel_ro, .{ |
| 3956 | 3986 | .name = ".data.rel.ro", |
| 3957 | 3987 | .flags = .{ .WRITE = true, .ALLOC = true }, |
| 3958 | | .addralign = elf.mf.flags.block_size, |
| 3988 | .node_align = node_block_align, |
| 3959 | 3989 | })); |
| 3960 | 3990 | if (@"type" != .REL) { |
| 3961 | 3991 | elf.shndx.got = try elf.addSection(elf.ni.data_rel_ro, .{ |
| ... | ... | @@ -3992,13 +4022,13 @@ fn initHeaders( |
| 3992 | 4022 | }, |
| 3993 | 4023 | .size = plt.entry_size * plt.header_entries, |
| 3994 | 4024 | .addralign = plt.@"align", |
| 3995 | | .node_align = elf.mf.flags.block_size, |
| 4025 | .node_align = node_block_align, |
| 3996 | 4026 | }); |
| 3997 | 4027 | if (plt.plt_sec != null) elf.shndx.plt_sec = try elf.addSection(elf.ni.text, .{ |
| 3998 | 4028 | .name = ".plt.sec", |
| 3999 | 4029 | .flags = .{ .ALLOC = true, .EXECINSTR = true }, |
| 4000 | 4030 | .addralign = plt.@"align", |
| 4001 | | .node_align = elf.mf.flags.block_size, |
| 4031 | .node_align = node_block_align, |
| 4002 | 4032 | }); |
| 4003 | 4033 | if (maybe_interp) |interp| { |
| 4004 | 4034 | const interp_ni = try elf.mf.addLastChildNode(gpa, elf.ni.rodata, .{ |
| ... | ... | @@ -4021,6 +4051,7 @@ fn initHeaders( |
| 4021 | 4051 | sec_interp[interp.len] = 0; |
| 4022 | 4052 | } |
| 4023 | 4053 | if (have_dynamic_section) { |
| 4054 | assert(elf.ni.data_rel_ro.alignment(&elf.mf).compare(.gte, addr_align)); |
| 4024 | 4055 | const dynamic_ni = try elf.mf.addLastChildNode(gpa, elf.ni.data_rel_ro, .{ |
| 4025 | 4056 | .alignment = addr_align, |
| 4026 | 4057 | .moved = true, |
| ... | ... | @@ -4035,7 +4066,7 @@ fn initHeaders( |
| 4035 | 4066 | .flags = .{ .ALLOC = true }, |
| 4036 | 4067 | .size = 1, |
| 4037 | 4068 | .entsize = 1, |
| 4038 | | .node_align = elf.mf.flags.block_size, |
| 4069 | .node_align = node_block_align, |
| 4039 | 4070 | }); |
| 4040 | 4071 | dynstr_shndx.get(elf).ni.slice(&elf.mf)[0] = 0; |
| 4041 | 4072 | elf.shndx.dynstr = dynstr_shndx; |
| ... | ... | @@ -4053,7 +4084,7 @@ fn initHeaders( |
| 4053 | 4084 | .info = 1, |
| 4054 | 4085 | .addralign = addr_align, |
| 4055 | 4086 | .entsize = @sizeOf(Sym), |
| 4056 | | .node_align = elf.mf.flags.block_size, |
| 4087 | .node_align = node_block_align, |
| 4057 | 4088 | }); |
| 4058 | 4089 | const dynsym_null = @field(elf.dynsymPtr(0), @tagName(ct_class)); |
| 4059 | 4090 | dynsym_null.* = .{ |
| ... | ... | @@ -4081,7 +4112,7 @@ fn initHeaders( |
| 4081 | 4112 | .link = elf.shndx.dynsym.toSection().?, |
| 4082 | 4113 | .addralign = addr_align, |
| 4083 | 4114 | .entsize = rela_size, |
| 4084 | | .node_align = elf.mf.flags.block_size, |
| 4115 | .node_align = node_block_align, |
| 4085 | 4116 | }); |
| 4086 | 4117 | elf.shndx.rela_plt = try elf.addSection(elf.ni.rodata, .{ |
| 4087 | 4118 | .name = ".rela.plt", |
| ... | ... | @@ -4091,7 +4122,7 @@ fn initHeaders( |
| 4091 | 4122 | .info = (if (plt.got_plt != null) elf.shndx.got_plt else elf.shndx.plt).toSection().?, |
| 4092 | 4123 | .addralign = addr_align, |
| 4093 | 4124 | .entsize = rela_size, |
| 4094 | | .node_align = elf.mf.flags.block_size, |
| 4125 | .node_align = node_block_align, |
| 4095 | 4126 | }); |
| 4096 | 4127 | elf.shndx.dynamic = try elf.addSection(dynamic_ni, .{ |
| 4097 | 4128 | .name = ".dynamic", |
| ... | ... | @@ -4198,15 +4229,6 @@ fn initHeaders( |
| 4198 | 4229 | .SPARCV9 => {}, |
| 4199 | 4230 | } |
| 4200 | 4231 | } |
| 4201 | | if (comp.config.any_non_single_threaded) { |
| 4202 | | elf.ni.tls = try elf.mf.addLastChildNode(gpa, elf.ni.rodata, .{ |
| 4203 | | .alignment = elf.mf.flags.block_size, |
| 4204 | | .moved = true, |
| 4205 | | .bubbles_moved = false, |
| 4206 | | }); |
| 4207 | | elf.nodes.appendAssumeCapacity(.{ .segment = phndx.tls }); |
| 4208 | | elf.phdrs.items[phndx.tls] = elf.ni.tls; |
| 4209 | | } |
| 4210 | 4232 | |
| 4211 | 4233 | // Populate reserved GOT words. |
| 4212 | 4234 | switch (machine) { |
| ... | ... | @@ -4382,7 +4404,7 @@ fn initHeaders( |
| 4382 | 4404 | if (comp.config.any_non_single_threaded) elf.shndx.tdata = try elf.addSection(elf.ni.tls, .{ |
| 4383 | 4405 | .name = ".tdata", |
| 4384 | 4406 | .flags = .{ .WRITE = true, .ALLOC = true, .TLS = true }, |
| 4385 | | .addralign = elf.mf.flags.block_size, |
| 4407 | .node_align = node_block_align, |
| 4386 | 4408 | }); |
| 4387 | 4409 | |
| 4388 | 4410 | assert(elf.nodes.len == expected_nodes_len); |
| ... | ... | @@ -4648,6 +4670,28 @@ fn ehdrType(elf: *const Elf) EhdrType { |
| 4648 | 4670 | fn targetPtrSize(elf: *const Elf) u8 { |
| 4649 | 4671 | return elf.identClass().size(); |
| 4650 | 4672 | } |
| 4673 | fn targetPageAlign(elf: *const Elf) std.mem.Alignment { |
| 4674 | return .fromByteUnits(switch (elf.ehdrMachine()) { |
| 4675 | .AARCH64 => 0x10000, |
| 4676 | .LOONGARCH => 0x4000, |
| 4677 | .PPC64 => 0x10000, |
| 4678 | .RISCV => 0x1000, |
| 4679 | .SPARCV9 => 0x100000, |
| 4680 | .X86_64 => 0x1000, |
| 4681 | |
| 4682 | //.@"68K" => 0x2000, |
| 4683 | //.AMDGPU => 0x10000, |
| 4684 | //.ARC_COMPACT2 => 0x2000, |
| 4685 | //.AVR => 0x1, |
| 4686 | //.BPF => 0x100000, |
| 4687 | //.MIPS => 0x10000, |
| 4688 | //.MSP430 => 0x4, |
| 4689 | //.PPC => 0x10000, |
| 4690 | //.QDSP6 => 0x10000, |
| 4691 | //.SPARC => 0x10000, |
| 4692 | //.SPARC32PLUS => 0x10000, |
| 4693 | }); |
| 4694 | } |
| 4651 | 4695 | fn targetEndian(elf: *const Elf) std.lang.Endian { |
| 4652 | 4696 | const ident_data: std.elf.DATA = @fromBackingInt(elf.ni.elf.sliceConst(&elf.mf)[std.elf.EI.DATA]); |
| 4653 | 4697 | return ident_data.endian(); |
| ... | ... | @@ -4790,7 +4834,9 @@ fn shdrPtr(elf: *Elf, shndx: Section.Index) ShdrPtr { |
| 4790 | 4834 | switch (elf.identClass()) { |
| 4791 | 4835 | .NONE, _ => unreachable, |
| 4792 | 4836 | inline else => |class| { |
| 4793 | | const shdr_slice: []class.ElfN().Shdr = @ptrCast(@alignCast(raw_slice)); |
| 4837 | const shdr_slice: []class.ElfN().Shdr = @ptrCast(@alignCast( |
| 4838 | raw_slice[0 .. elf.shdrs.items.len * @sizeOf(class.ElfN().Shdr)], |
| 4839 | )); |
| 4794 | 4840 | const shdr_ptr = &shdr_slice[@backingInt(shndx)]; |
| 4795 | 4841 | return @unionInit(ShdrPtr, @tagName(class), shdr_ptr); |
| 4796 | 4842 | }, |
| ... | ... | @@ -4845,7 +4891,6 @@ fn navType(elf: *const Elf, nav_resolved: InternPool.Nav.Resolved) std.elf.STT { |
| 4845 | 4891 | fn mapInputSection(elf: *Elf, opts: struct { |
| 4846 | 4892 | name: []const u8, |
| 4847 | 4893 | flags: std.elf.SHF, |
| 4848 | | addralign: std.elf.Xword, |
| 4849 | 4894 | entsize: std.elf.Xword, |
| 4850 | 4895 | }) (Error || error{ |
| 4851 | 4896 | UnsupportedSectionFlags, |
| ... | ... | @@ -4917,16 +4962,12 @@ fn mapInputSection(elf: *Elf, opts: struct { |
| 4917 | 4962 | flags.COMPRESSED = false; |
| 4918 | 4963 | break :flags flags; |
| 4919 | 4964 | }, |
| 4920 | | .node_align = .fromByteUnits(std.math.ceilPowerOfTwoAssert( |
| 4921 | | usize, |
| 4922 | | @intCast(@max(opts.addralign, 1)), |
| 4923 | | )), |
| 4924 | 4965 | .entsize = std.math.lossyCast(u32, opts.entsize), |
| 4925 | 4966 | }); |
| 4926 | 4967 | }; |
| 4927 | | // Validate that the input is compatible with this section... |
| 4928 | 4968 | switch (elf.shdrPtr(existing_shndx)) { |
| 4929 | 4969 | inline else => |shdr| { |
| 4970 | // Validate that the input is compatible with this section |
| 4930 | 4971 | const cur_flags = elf.targetLoad(&shdr.flags).shf; |
| 4931 | 4972 | if (cur_flags.EXECINSTR != opts.flags.EXECINSTR or |
| 4932 | 4973 | cur_flags.WRITE != opts.flags.WRITE or |
| ... | ... | @@ -4939,20 +4980,8 @@ fn mapInputSection(elf: *Elf, opts: struct { |
| 4939 | 4980 | .NULL, .PROGBITS => {}, |
| 4940 | 4981 | else => return error.SectionTypeConflict, |
| 4941 | 4982 | } |
| 4942 | | }, |
| 4943 | | } |
| 4944 | | // ...then realign the section's node if necessary... |
| 4945 | | if (opts.addralign > existing_shndx.get(elf).ni.alignment(&elf.mf).toByteUnits()) { |
| 4946 | | const new_alignment: std.mem.Alignment = .fromByteUnits( |
| 4947 | | std.math.ceilPowerOfTwoAssert(usize, @intCast(opts.addralign)), |
| 4948 | | ); |
| 4949 | | try existing_shndx.get(elf).ni.realign(&elf.mf, gpa, new_alignment, .{}); |
| 4950 | | } |
| 4951 | | // ...and update the shdr as needed. |
| 4952 | | switch (elf.shdrPtr(existing_shndx)) { |
| 4953 | | inline else => |shdr| { |
| 4954 | | // Combine the section flags. |
| 4955 | | const cur_flags = elf.targetLoad(&shdr.flags).shf; |
| 4983 | |
| 4984 | // All okay, combine the section flags |
| 4956 | 4985 | elf.targetStore(&shdr.flags, .{ .shf = .{ |
| 4957 | 4986 | .EXECINSTR = cur_flags.EXECINSTR, |
| 4958 | 4987 | .WRITE = cur_flags.WRITE, |
| ... | ... | @@ -4961,11 +4990,6 @@ fn mapInputSection(elf: *Elf, opts: struct { |
| 4961 | 4990 | .STRINGS = cur_flags.STRINGS and opts.flags.STRINGS, |
| 4962 | 4991 | .MERGE = cur_flags.MERGE and opts.flags.MERGE, |
| 4963 | 4992 | } }); |
| 4964 | | // Increase addralign to the maximum of the current value and the new value---the node |
| 4965 | | // alignment was already increased above. |
| 4966 | | if (opts.addralign > elf.targetLoad(&shdr.addralign)) { |
| 4967 | | elf.targetStore(&shdr.addralign, @intCast(opts.addralign)); |
| 4968 | | } |
| 4969 | 4993 | }, |
| 4970 | 4994 | } |
| 4971 | 4995 | return existing_shndx; |
| ... | ... | @@ -4993,7 +5017,6 @@ fn navMapIndex(elf: *Elf, zcu: *Zcu, nav_index: InternPool.Nav.Index) Error!Node |
| 4993 | 5017 | .TLS = elf.base.comp.config.any_non_single_threaded and |
| 4994 | 5018 | nav.resolved.?.@"threadlocal", |
| 4995 | 5019 | }, |
| 4996 | | .addralign = 1, |
| 4997 | 5020 | .entsize = 0, |
| 4998 | 5021 | })) |shndx| { |
| 4999 | 5022 | break :section shndx; |
| ... | ... | @@ -5039,6 +5062,7 @@ fn navMapIndex(elf: *Elf, zcu: *Zcu, nav_index: InternPool.Nav.Index) Error!Node |
| 5039 | 5062 | else => |a| a, |
| 5040 | 5063 | }, |
| 5041 | 5064 | }; |
| 5065 | try shndx.ensureAligned(elf, alignment.toStdMem()); |
| 5042 | 5066 | const node = try elf.mf.addLastChildNode(gpa, shndx.get(elf).ni, .{ |
| 5043 | 5067 | .alignment = alignment.toStdMem(), |
| 5044 | 5068 | }); |
| ... | ... | @@ -5082,6 +5106,7 @@ fn uavMapIndex( |
| 5082 | 5106 | const umi: Node.UavMapIndex = @fromBackingInt(@intCast(uav_gop.index)); |
| 5083 | 5107 | if (!uav_gop.found_existing) { |
| 5084 | 5108 | const shndx: Section.Index = .data_rel_ro; // TODO: it would be better to use `.rodata` if the UAV value doesn't have relocs |
| 5109 | try shndx.ensureAligned(elf, resolved_align.toStdMem()); |
| 5085 | 5110 | const node = try elf.mf.addLastChildNode(gpa, shndx.get(elf).ni, .{ |
| 5086 | 5111 | .moved = true, // see assert at end of `genUav` |
| 5087 | 5112 | .alignment = resolved_align.toStdMem(), |
| ... | ... | @@ -5108,6 +5133,8 @@ fn uavMapIndex( |
| 5108 | 5133 | elf.pending_uavs.appendAssumeCapacity(umi); |
| 5109 | 5134 | } else { |
| 5110 | 5135 | const node = uav_gop.value_ptr.lsi.index().ptr(elf).node; |
| 5136 | const shndx = elf.getNode(node.parent(&elf.mf)).section; |
| 5137 | try shndx.ensureAligned(elf, resolved_align.toStdMem()); |
| 5111 | 5138 | if (resolved_align.toStdMem().order(node.alignment(&elf.mf)).compare(.gt)) { |
| 5112 | 5139 | try node.realign(&elf.mf, gpa, resolved_align.toStdMem(), .{}); |
| 5113 | 5140 | } |
| ... | ... | @@ -5408,7 +5435,6 @@ fn loadObject( |
| 5408 | 5435 | const shndx = elf.mapInputSection(.{ |
| 5409 | 5436 | .name = name, |
| 5410 | 5437 | .flags = section.shdr.flags.shf, |
| 5411 | | .addralign = section.shdr.addralign, |
| 5412 | 5438 | .entsize = section.shdr.entsize, |
| 5413 | 5439 | }) catch |err| switch (err) { |
| 5414 | 5440 | error.StripSection => continue, |
| ... | ... | @@ -5507,12 +5533,13 @@ fn loadObject( |
| 5507 | 5533 | .node_fixed = true, |
| 5508 | 5534 | }, |
| 5509 | 5535 | }; |
| 5536 | const need_align: std.mem.Alignment = .fromByteUnits( |
| 5537 | std.math.ceilPowerOfTwoAssert(usize, @intCast(@max(section.shdr.addralign, 1))), |
| 5538 | ); |
| 5539 | try opts.shndx.ensureAligned(elf, need_align); |
| 5510 | 5540 | const ni = try elf.mf.addLastChildNode(gpa, opts.shndx.get(elf).ni, .{ |
| 5511 | 5541 | .size = section.shdr.size, |
| 5512 | | .alignment = .fromByteUnits(std.math.ceilPowerOfTwoAssert( |
| 5513 | | usize, |
| 5514 | | @intCast(@max(section.shdr.addralign, 1)), |
| 5515 | | )), |
| 5542 | .alignment = need_align, |
| 5516 | 5543 | .moved = true, // see assert at end of `flushInputSection` |
| 5517 | 5544 | .fixed = opts.node_fixed, |
| 5518 | 5545 | }); |
| ... | ... | @@ -5882,6 +5909,7 @@ fn loadDso(elf: *Elf, path: std.Build.Cache.Path, fr: *Io.File.Reader) (LoadPars |
| 5882 | 5909 | if (elf.copied_globals.get(name)) |copied_global| { |
| 5883 | 5910 | // We have a copy relocation for this global, but the amount of space we |
| 5884 | 5911 | // reserved for it could be too small or underaligned! |
| 5912 | try Section.Index.data.ensureAligned(elf, gop.value_ptr.alignment); |
| 5885 | 5913 | try copied_global.node.resize(&elf.mf, gpa, gop.value_ptr.size); |
| 5886 | 5914 | try copied_global.node.realign(&elf.mf, gpa, gop.value_ptr.alignment, .{}); |
| 5887 | 5915 | const global_ptr = elf.globalByName(name).?; |
| ... | ... | @@ -6264,7 +6292,8 @@ fn addSection(elf: *Elf, segment_ni: MappedFile.Node.Index, opts: struct { |
| 6264 | 6292 | else => {}, |
| 6265 | 6293 | } |
| 6266 | 6294 | if (opts.flags.ALLOC and elf.ehdrType() != .REL) { |
| 6267 | | assert(elf.getNode(segment_ni) == .segment); |
| 6295 | const phndx = elf.getNode(segment_ni).segment; |
| 6296 | try elf.ensureSegmentAligned(phndx, opts.addralign); |
| 6268 | 6297 | } |
| 6269 | 6298 | const gpa = elf.base.comp.gpa; |
| 6270 | 6299 | try elf.nodes.ensureUnusedCapacity(gpa, 1); |
| ... | ... | @@ -7145,6 +7174,8 @@ fn maybeAddCopyRelocation(elf: *Elf, global_name: String(.strtab)) Error!bool { |
| 7145 | 7174 | if (gop.found_existing) return true; |
| 7146 | 7175 | errdefer assert(elf.copied_globals.pop().?.key == global_name); |
| 7147 | 7176 | |
| 7177 | try Section.Index.data.ensureAligned(elf, dso_global.alignment); |
| 7178 | |
| 7148 | 7179 | try elf.nodes.ensureUnusedCapacity(gpa, 1); |
| 7149 | 7180 | const node = try elf.mf.addLastChildNode(gpa, Section.Index.data.get(elf).ni, .{ |
| 7150 | 7181 | .size = dso_global.size, |
| ... | ... | @@ -7777,17 +7808,22 @@ fn flushMoved(elf: *Elf, ni: MappedFile.Node.Index) std.mem.Allocator.Error!void |
| 7777 | 7808 | const ph = &phdr[phndx]; |
| 7778 | 7809 | switch (elf.targetLoad(&ph.type)) { |
| 7779 | 7810 | else => unreachable, |
| 7780 | | .NULL, .LOAD => return, |
| 7811 | |
| 7812 | .NULL, .LOAD => { |
| 7813 | try elf.allocateSegmentLoadAddress(phndx); |
| 7814 | }, |
| 7781 | 7815 | |
| 7782 | 7816 | .DYNAMIC, |
| 7783 | 7817 | .INTERP, |
| 7784 | 7818 | .PHDR, |
| 7785 | 7819 | .TLS, |
| 7786 | 7820 | .GNU_RELRO, |
| 7787 | | => {}, |
| 7821 | => { |
| 7822 | const new_vaddr = elf.computeNodeVAddr(ni); |
| 7823 | elf.targetStore(&ph.vaddr, @intCast(new_vaddr)); |
| 7824 | elf.targetStore(&ph.paddr, @intCast(new_vaddr)); |
| 7825 | }, |
| 7788 | 7826 | } |
| 7789 | | elf.targetStore(&ph.vaddr, @intCast(elf.computeNodeVAddr(ni))); |
| 7790 | | ph.paddr = ph.vaddr; |
| 7791 | 7827 | }, |
| 7792 | 7828 | } |
| 7793 | 7829 | }, |
| ... | ... | @@ -7928,6 +7964,114 @@ fn flushMoved(elf: *Elf, ni: MappedFile.Node.Index) std.mem.Allocator.Error!void |
| 7928 | 7964 | try ni.childrenMoved(elf.base.comp.gpa, &elf.mf); |
| 7929 | 7965 | } |
| 7930 | 7966 | |
| 7967 | /// Given the index of a `PT_LOAD`/`PT_NULL` segment, assumes that the phdr's `offset` and `filesz` |
| 7968 | /// have been updated as needed by the caller, and updates the `@"align"`, `vaddr`, `paddr`, and |
| 7969 | /// `memsz` fields of the segment, in order to place it at a valid virtual address. |
| 7970 | /// |
| 7971 | /// TODO: this function is currently a source of non-determinism in the linker, because handling the |
| 7972 | /// moving or resizing of a segment could reorder them and thereby affect how we handle *future* |
| 7973 | /// changes to segments. |
| 7974 | fn allocateSegmentLoadAddress(elf: *Elf, orig_phndx: u32) std.mem.Allocator.Error!void { |
| 7975 | const segment_ni = elf.phdrs.items[orig_phndx]; |
| 7976 | assert(elf.getNode(segment_ni).segment == orig_phndx); |
| 7977 | const page_align = elf.targetPageAlign(); |
| 7978 | const node_align = segment_ni.alignment(&elf.mf); |
| 7979 | const ph_align = page_align.max(node_align); |
| 7980 | switch (elf.phdrSlice()) { |
| 7981 | inline else => |phdr| { |
| 7982 | const offset = elf.targetLoad(&phdr[orig_phndx].offset); |
| 7983 | const size = elf.targetLoad(&phdr[orig_phndx].filesz); |
| 7984 | |
| 7985 | if (size == 0) { |
| 7986 | assert(elf.targetLoad(&phdr[orig_phndx].type) == .NULL); |
| 7987 | } else { |
| 7988 | assert(elf.targetLoad(&phdr[orig_phndx].type) == .LOAD); |
| 7989 | } |
| 7990 | |
| 7991 | elf.targetStore(&phdr[orig_phndx].memsz, size); |
| 7992 | elf.targetStore(&phdr[orig_phndx].@"align", @intCast(ph_align.toByteUnits())); |
| 7993 | |
| 7994 | const orig_vaddr = elf.targetLoad(&phdr[orig_phndx].vaddr); |
| 7995 | assert(elf.targetLoad(&phdr[orig_phndx].paddr) == orig_vaddr); |
| 7996 | |
| 7997 | var vaddr: u64 = orig_vaddr; |
| 7998 | |
| 7999 | // First, we will shift the virtual address as needed in order to maintain the required |
| 8000 | // property that vaddr is congruent to offset modulo the phdr alignment. |
| 8001 | { |
| 8002 | // Compute the candidate address by undoing the current offset and then re-offsetting |
| 8003 | vaddr = std.mem.alignBackward(u64, vaddr, ph_align.toByteUnits()) + offset % ph_align.toByteUnits(); |
| 8004 | // If `node_align` is greater than `page_align`, the address we just set might be in |
| 8005 | // the previous segment. The first page we "own" is the one in which the old vaddr |
| 8006 | // resides, so check against that. |
| 8007 | const first_good_vaddr = std.mem.alignBackward(u64, orig_vaddr, page_align.toByteUnits()); |
| 8008 | if (vaddr < first_good_vaddr) { |
| 8009 | // Yep, we crossed into the previous segment's pages, so correct for that by |
| 8010 | // offsetting our address by another `ph_align`. |
| 8011 | vaddr += ph_align.toByteUnits(); |
| 8012 | assert(vaddr >= first_good_vaddr); |
| 8013 | } |
| 8014 | } |
| 8015 | |
| 8016 | // If our size has changed, or if the address shift above caused our "end" address to |
| 8017 | // cross a page boundary, then we might be overlapping with the next segment's pages. In |
| 8018 | // that case, we will jump past that segment and give ourselves a new address after it. |
| 8019 | // We'll need to repeat this for every loadable phdr after us, until we're no longer |
| 8020 | // overlapping anything. |
| 8021 | var phndx = orig_phndx; |
| 8022 | for (phdr[orig_phndx + 1 ..], orig_phndx + 1..) |*next_ph, next_phndx| { |
| 8023 | switch (elf.targetLoad(&next_ph.type)) { |
| 8024 | .NULL, .LOAD => {}, |
| 8025 | else => { |
| 8026 | // All loadable segments have contiguous indices, so this indicates we have |
| 8027 | // become the last loadable segment, meaning we definitely don't overlap any |
| 8028 | // other loadable segment. |
| 8029 | break; |
| 8030 | }, |
| 8031 | } |
| 8032 | |
| 8033 | const next_vaddr = elf.targetLoad(&next_ph.vaddr); |
| 8034 | // Find the first virtual address which the next phdr "owns" by aligning its vaddr |
| 8035 | // backwards to the start of the page. |
| 8036 | const next_page_vaddr = std.mem.alignBackward(u64, next_vaddr, page_align.toByteUnits()); |
| 8037 | |
| 8038 | // If we're at the same vaddr we started at, then all we're worried about is the |
| 8039 | // segment fitting here. However, if we've already changed our virtual address, then |
| 8040 | // we might as well try to reserve a bit *more* virtual address space while we're at |
| 8041 | // it, because changing virtual address is quite disruptive (we need to re-flush a |
| 8042 | // lot of stuff!) and giving ourselves more space will make it less likely to happen |
| 8043 | // again. |
| 8044 | const target_size = if (vaddr == orig_vaddr) size else size * 4; |
| 8045 | if (vaddr + target_size <= next_page_vaddr) { |
| 8046 | break; // hooray, we fit here! |
| 8047 | } |
| 8048 | |
| 8049 | // We don't fit here, so shift ourselves forward (i.e. swap with `next_phndx`). But |
| 8050 | // first we need to adjust `vaddr` to come after it. |
| 8051 | const next_size = elf.targetLoad(&next_ph.memsz); |
| 8052 | // Instead of putting ourselves right after `next_ph`, we'll go a bit later in the |
| 8053 | // address space so that `next_ph` has address space to grow into (like above). |
| 8054 | vaddr = ph_align.forward(next_vaddr + next_size * 4) + offset % ph_align.toByteUnits(); |
| 8055 | |
| 8056 | // Now just swap the phdrs and update our `phndx`. |
| 8057 | std.mem.swap(@TypeOf(next_ph.*), &phdr[phndx], next_ph); |
| 8058 | const next_ni = elf.phdrs.items[next_phndx]; |
| 8059 | elf.phdrs.items[phndx] = next_ni; |
| 8060 | elf.nodes.items(.data)[@backingInt(next_ni)] = .{ .segment = phndx }; |
| 8061 | elf.phdrs.items[next_phndx] = segment_ni; |
| 8062 | elf.nodes.items(.data)[@backingInt(segment_ni)] = .{ .segment = @intCast(next_phndx) }; |
| 8063 | phndx = @intCast(next_phndx); |
| 8064 | } |
| 8065 | |
| 8066 | if (vaddr != orig_vaddr) { |
| 8067 | elf.targetStore(&phdr[phndx].vaddr, @intCast(vaddr)); |
| 8068 | elf.targetStore(&phdr[phndx].paddr, @intCast(vaddr)); |
| 8069 | try segment_ni.childrenMoved(elf.base.comp.gpa, &elf.mf); |
| 8070 | } |
| 8071 | }, |
| 8072 | } |
| 8073 | } |
| 8074 | |
| 7931 | 8075 | fn flushResized(elf: *Elf, ni: MappedFile.Node.Index) std.mem.Allocator.Error!void { |
| 7932 | 8076 | const trace = tracy.trace(@src()); |
| 7933 | 8077 | defer trace.end(); |
| ... | ... | @@ -7955,68 +8099,40 @@ fn flushResized(elf: *Elf, ni: MappedFile.Node.Index) std.mem.Allocator.Error!vo |
| 7955 | 8099 | assert(elf.phdrs.items[phndx] == ni); |
| 7956 | 8100 | const ph = &phdr[phndx]; |
| 7957 | 8101 | elf.targetStore(&ph.filesz, @intCast(size)); |
| 7958 | | if (size > elf.targetLoad(&ph.memsz)) { |
| 7959 | | switch (elf.targetLoad(&ph.type)) { |
| 7960 | | else => unreachable, |
| 7961 | | .NULL => if (size > 0) elf.targetStore(&ph.type, .LOAD), |
| 7962 | | .LOAD => if (size == 0) elf.targetStore(&ph.type, .NULL), |
| 7963 | | .DYNAMIC, .INTERP, .PHDR, std.elf.PT.GNU_RELRO => { |
| 7964 | | elf.targetStore(&ph.memsz, @intCast(size)); |
| 7965 | | return; |
| 7966 | | }, |
| 7967 | | .TLS => { |
| 7968 | | elf.targetStore(&ph.memsz, @intCast(size)); |
| 7969 | | // TPOFF relocations care about the size of the TLS segment. Re-apply |
| 7970 | | // those, and also update any GOT entries from GOTTPOFF relocations. |
| 7971 | | for (elf.tls_size_symbol_relocs.keys()) |reloc| { |
| 7972 | | reloc.get(elf).apply(elf); |
| 7973 | | } |
| 7974 | | for (elf.got.keys(), 0..) |got_key, got_index| { |
| 7975 | | switch (got_key) { |
| 7976 | | .reserved, |
| 7977 | | .symbol, |
| 7978 | | .tlsld0, |
| 7979 | | .tlsld1, |
| 7980 | | .tlsgd0, |
| 7981 | | .tlsgd1, |
| 7982 | | => { |
| 7983 | | @branchHint(.likely); |
| 7984 | | continue; |
| 7985 | | }, |
| 8102 | switch (elf.targetLoad(&ph.type)) { |
| 8103 | else => unreachable, |
| 8104 | .NULL, .LOAD => { |
| 8105 | elf.targetStore(&ph.type, if (size > 0) .LOAD else .NULL); |
| 8106 | try elf.allocateSegmentLoadAddress(phndx); |
| 8107 | }, |
| 8108 | .DYNAMIC, .INTERP, .PHDR, std.elf.PT.GNU_RELRO => { |
| 8109 | elf.targetStore(&ph.memsz, @intCast(size)); |
| 8110 | }, |
| 8111 | .TLS => { |
| 8112 | elf.targetStore(&ph.memsz, @intCast(size)); |
| 8113 | // TPOFF relocations care about the size of the TLS segment. Re-apply |
| 8114 | // those, and also update any GOT entries from GOTTPOFF relocations. |
| 8115 | for (elf.tls_size_symbol_relocs.keys()) |reloc| { |
| 8116 | reloc.get(elf).apply(elf); |
| 8117 | } |
| 8118 | for (elf.got.keys(), 0..) |got_key, got_index| { |
| 8119 | switch (got_key) { |
| 8120 | .reserved, |
| 8121 | .symbol, |
| 8122 | .tlsld0, |
| 8123 | .tlsld1, |
| 8124 | .tlsgd0, |
| 8125 | .tlsgd1, |
| 8126 | => { |
| 8127 | @branchHint(.likely); |
| 8128 | continue; |
| 8129 | }, |
| 7986 | 8130 | |
| 7987 | | .tpoff => elf.updateGotEntry(got_index), |
| 7988 | | } |
| 8131 | .tpoff => elf.updateGotEntry(got_index), |
| 7989 | 8132 | } |
| 7990 | | return ni.childrenMoved(elf.base.comp.gpa, &elf.mf); |
| 7991 | | }, |
| 7992 | | } |
| 7993 | | const memsz = ni.alignment(&elf.mf).forward(@intCast(size * 4)); |
| 7994 | | elf.targetStore(&ph.memsz, @intCast(memsz)); |
| 7995 | | var vaddr = elf.targetLoad(&ph.vaddr); |
| 7996 | | var new_phndx = phndx; |
| 7997 | | for (phdr[phndx + 1 ..], phndx + 1..) |*next_ph, next_phndx| { |
| 7998 | | switch (elf.targetLoad(&next_ph.type)) { |
| 7999 | | else => unreachable, |
| 8000 | | .NULL, .LOAD => {}, |
| 8001 | | .DYNAMIC, .INTERP, .PHDR, .TLS, .GNU_RELRO, .GNU_STACK => break, |
| 8002 | 8133 | } |
| 8003 | | const next_vaddr = elf.targetLoad(&next_ph.vaddr); |
| 8004 | | if (vaddr + memsz <= next_vaddr) break; |
| 8005 | | vaddr = next_vaddr + elf.targetLoad(&next_ph.memsz); |
| 8006 | | std.mem.swap(@TypeOf(ph.*), &phdr[new_phndx], next_ph); |
| 8007 | | const next_ni = elf.phdrs.items[next_phndx]; |
| 8008 | | elf.phdrs.items[new_phndx] = next_ni; |
| 8009 | | elf.nodes.items(.data)[@backingInt(next_ni)] = .{ .segment = new_phndx }; |
| 8010 | | new_phndx = @intCast(next_phndx); |
| 8011 | | } |
| 8012 | | if (new_phndx != phndx) { |
| 8013 | | const new_ph = &phdr[new_phndx]; |
| 8014 | | elf.targetStore(&new_ph.vaddr, vaddr); |
| 8015 | | new_ph.paddr = new_ph.vaddr; |
| 8016 | | elf.phdrs.items[new_phndx] = ni; |
| 8017 | | elf.nodes.items(.data)[@backingInt(ni)] = .{ .segment = new_phndx }; |
| 8018 | 8134 | try ni.childrenMoved(elf.base.comp.gpa, &elf.mf); |
| 8019 | | } |
| 8135 | }, |
| 8020 | 8136 | } |
| 8021 | 8137 | }, |
| 8022 | 8138 | }, |
| ... | ... | @@ -8693,6 +8809,46 @@ pub fn printNode( |
| 8693 | 8809 | } |
| 8694 | 8810 | } |
| 8695 | 8811 | |
| 8812 | fn ensureSegmentAligned(elf: *Elf, start_phndx: u32, min_align: std.mem.Alignment) Error!void { |
| 8813 | const gpa = elf.base.comp.gpa; |
| 8814 | // We need to loop through parent nodes because segments may be nested (e.g. a PT_TLS segment |
| 8815 | // inside a PT_LOAD segment). |
| 8816 | var phndx = start_phndx; |
| 8817 | while (true) { |
| 8818 | // Align the actual node |
| 8819 | const seg_ni = elf.phdrs.items[phndx]; |
| 8820 | if (min_align.compare(.gt, seg_ni.alignment(&elf.mf))) { |
| 8821 | try seg_ni.realign(&elf.mf, gpa, min_align, .{}); |
| 8822 | } |
| 8823 | // Update the phdr `@"align"` field if necessary |
| 8824 | switch (elf.phdrSlice()) { |
| 8825 | inline else => |phdr| switch (elf.targetLoad(&phdr[phndx].type)) { |
| 8826 | .NULL, .LOAD => { |
| 8827 | // The `@"align"` field is managed by `allocateSegmentLoadAddress`. |
| 8828 | // |
| 8829 | // It's very likely that the node was moved and/or resized when we realigned it |
| 8830 | // just above, but it is possible that it was not moved *but* still has an |
| 8831 | // unaligned virtual address. In that case, we need to ensure the segment's |
| 8832 | // virtual address range will be recomputed. |
| 8833 | if (!min_align.check(elf.targetLoad(&phdr[phndx].vaddr))) { |
| 8834 | try seg_ni.moved(gpa, &elf.mf); |
| 8835 | } |
| 8836 | }, |
| 8837 | else => elf.targetStore(&phdr[phndx].@"align", @intCast(@max( |
| 8838 | elf.targetLoad(&phdr[phndx].@"align"), |
| 8839 | min_align.toByteUnits(), |
| 8840 | ))), |
| 8841 | }, |
| 8842 | } |
| 8843 | // Continue on to the parent segment, if any |
| 8844 | switch (elf.getNode(seg_ni.parent(&elf.mf))) { |
| 8845 | .segment => |parent_phndx| phndx = parent_phndx, |
| 8846 | .elf => return, |
| 8847 | else => unreachable, |
| 8848 | } |
| 8849 | } |
| 8850 | } |
| 8851 | |
| 8696 | 8852 | /// Must be called deterministically after any call to `MappedFile.Node.Index.resize` |
| 8697 | 8853 | /// (of `elf.ni.elf` or one of its children) before any possible calls to `idle`. |
| 8698 | 8854 | fn ensureElfNodeSize(elf: *Elf) MappedFile.Error!void { |
Matthew Lugg <mlugg@mlugg.co.uk> 2026-08-13 21:08:02+01:00
Commit is signed but in an unrecognized format.
src