mirror of
https://github.com/ziglang/zig.git
synced 2025-12-06 06:13:07 +00:00
Elf2: incrementally update object relocs
This commit is contained in:
Jacob Young
parent
b1d46339b5
commit
02a241f472
@ -164,7 +164,26 @@ pub const Node = union(enum) {
|
||||
}
|
||||
};
|
||||
|
||||
pub const Section = struct { si: Symbol.Index, rela_si: Symbol.Index };
|
||||
pub const Section = struct {
|
||||
si: Symbol.Index,
|
||||
rela_si: Symbol.Index,
|
||||
rela_free: RelIndex,
|
||||
|
||||
pub const RelIndex = enum(u32) {
|
||||
none,
|
||||
_,
|
||||
|
||||
pub fn wrap(i: ?u32) RelIndex {
|
||||
return @enumFromInt((i orelse return .none) + 1);
|
||||
}
|
||||
pub fn unwrap(ri: RelIndex) ?u32 {
|
||||
return switch (ri) {
|
||||
.none => null,
|
||||
else => @intFromEnum(ri) - 1,
|
||||
};
|
||||
}
|
||||
};
|
||||
};
|
||||
|
||||
pub const StringTable = struct {
|
||||
map: std.HashMapUnmanaged(u32, void, StringTable.Context, std.hash_map.default_max_load_percentage),
|
||||
@ -462,7 +481,7 @@ pub const Reloc = extern struct {
|
||||
next: Reloc.Index,
|
||||
loc: Symbol.Index,
|
||||
target: Symbol.Index,
|
||||
rel_index: u32,
|
||||
index: Section.RelIndex,
|
||||
offset: u64,
|
||||
addend: i64,
|
||||
|
||||
@ -472,6 +491,16 @@ pub const Reloc = extern struct {
|
||||
RISCV: std.elf.R_RISCV,
|
||||
PPC64: std.elf.R_PPC64,
|
||||
|
||||
pub fn none(elf: *Elf) Reloc.Type {
|
||||
return switch (elf.ehdrField(.machine)) {
|
||||
else => unreachable,
|
||||
.AARCH64 => .{ .AARCH64 = .NONE },
|
||||
.PPC64 => .{ .PPC64 = .NONE },
|
||||
.RISCV => .{ .RISCV = .NONE },
|
||||
.X86_64 => .{ .X86_64 = .NONE },
|
||||
};
|
||||
}
|
||||
|
||||
pub fn absAddr(elf: *Elf) Reloc.Type {
|
||||
return switch (elf.ehdrField(.machine)) {
|
||||
else => unreachable,
|
||||
@ -481,12 +510,35 @@ pub const Reloc = extern struct {
|
||||
.X86_64 => .{ .X86_64 = .@"64" },
|
||||
};
|
||||
}
|
||||
|
||||
pub fn sizeAddr(elf: *Elf) Reloc.Type {
|
||||
return switch (elf.ehdrField(.machine)) {
|
||||
else => unreachable,
|
||||
.X86_64 => .{ .X86_64 = .SIZE64 },
|
||||
};
|
||||
}
|
||||
|
||||
pub fn wrap(int: u32, elf: *Elf) Reloc.Type {
|
||||
return switch (elf.ehdrField(.machine)) {
|
||||
else => unreachable,
|
||||
inline .AARCH64,
|
||||
.PPC64,
|
||||
.RISCV,
|
||||
.X86_64,
|
||||
=> |machine| @unionInit(Reloc.Type, @tagName(machine), @enumFromInt(int)),
|
||||
};
|
||||
}
|
||||
|
||||
pub fn unwrap(rt: Reloc.Type, elf: *Elf) u32 {
|
||||
return switch (elf.ehdrField(.machine)) {
|
||||
else => unreachable,
|
||||
inline .AARCH64,
|
||||
.PPC64,
|
||||
.RISCV,
|
||||
.X86_64,
|
||||
=> |machine| @intFromEnum(@field(rt, @tagName(machine))),
|
||||
};
|
||||
}
|
||||
};
|
||||
|
||||
pub const Index = enum(u32) {
|
||||
@ -590,6 +642,33 @@ pub const Reloc = extern struct {
|
||||
.none => {},
|
||||
else => |next| next.get(elf).prev = reloc.prev,
|
||||
}
|
||||
switch (elf.ehdrField(.type)) {
|
||||
.NONE, .CORE, _ => unreachable,
|
||||
.REL => {
|
||||
const sh = reloc.loc.shndx(elf).get(elf);
|
||||
switch (elf.shdrPtr(sh.rela_si.shndx(elf))) {
|
||||
inline else => |shdr, class| {
|
||||
const Rela = class.ElfN().Rela;
|
||||
const ent_size = elf.targetLoad(&shdr.entsize);
|
||||
const start = ent_size * reloc.index.unwrap().?;
|
||||
const rela_slice = sh.rela_si.node(elf).slice(&elf.mf);
|
||||
const rela: *Rela = @ptrCast(@alignCast(
|
||||
rela_slice[@intCast(start)..][0..@intCast(ent_size)],
|
||||
));
|
||||
rela.* = .{
|
||||
.offset = @intFromEnum(sh.rela_free),
|
||||
.info = .{
|
||||
.type = @intCast(Reloc.Type.none(elf).unwrap(elf)),
|
||||
.sym = 0,
|
||||
},
|
||||
.addend = 0,
|
||||
};
|
||||
},
|
||||
}
|
||||
sh.rela_free = reloc.index;
|
||||
},
|
||||
.EXEC, .DYN => assert(reloc.index == .none),
|
||||
}
|
||||
reloc.* = undefined;
|
||||
}
|
||||
|
||||
@ -1036,7 +1115,7 @@ fn initHeaders(
|
||||
.entsize = 0,
|
||||
};
|
||||
if (target_endian != native_endian) std.mem.byteSwapAllFields(ElfN.Shdr, sh_undef);
|
||||
elf.shdrs.appendAssumeCapacity(.{ .si = .null, .rela_si = .null });
|
||||
elf.shdrs.appendAssumeCapacity(.{ .si = .null, .rela_si = .null, .rela_free = .none });
|
||||
|
||||
try elf.symtab.ensureTotalCapacity(gpa, 1);
|
||||
elf.symtab.addOneAssumeCapacity().* = .{
|
||||
@ -1880,18 +1959,7 @@ fn loadObject(
|
||||
rel.offset - loc_sec.shdr.addr,
|
||||
target_si,
|
||||
rel.addend,
|
||||
switch (elf.ehdrField(.machine)) {
|
||||
else => unreachable,
|
||||
inline .AARCH64,
|
||||
.PPC64,
|
||||
.RISCV,
|
||||
.X86_64,
|
||||
=> |machine| @unionInit(
|
||||
Reloc.Type,
|
||||
@tagName(machine),
|
||||
@enumFromInt(rel.info.type),
|
||||
),
|
||||
},
|
||||
.wrap(rel.info.type, elf),
|
||||
);
|
||||
}
|
||||
},
|
||||
@ -2156,7 +2224,7 @@ fn addSection(elf: *Elf, segment_ni: MappedFile.Node.Index, opts: struct {
|
||||
});
|
||||
const si = elf.addSymbolAssumeCapacity();
|
||||
elf.nodes.appendAssumeCapacity(.{ .section = si });
|
||||
elf.shdrs.appendAssumeCapacity(.{ .si = si, .rela_si = .null });
|
||||
elf.shdrs.appendAssumeCapacity(.{ .si = si, .rela_si = .null, .rela_free = .none });
|
||||
si.get(elf).ni = ni;
|
||||
const addr = elf.computeNodeVAddr(ni);
|
||||
const offset = ni.fileLocation(&elf.mf, false).offset;
|
||||
@ -2275,39 +2343,44 @@ pub fn addRelocAssumeCapacity(
|
||||
.next = target.target_relocs,
|
||||
.loc = loc_si,
|
||||
.target = target_si,
|
||||
.rel_index = switch (elf.ehdrField(.type)) {
|
||||
.index = index: switch (elf.ehdrField(.type)) {
|
||||
.NONE, .CORE, _ => unreachable,
|
||||
.REL => rel_index: {
|
||||
const rela_si = loc_si.shndx(elf).get(elf).rela_si;
|
||||
switch (elf.shdrPtr(rela_si.shndx(elf))) {
|
||||
.REL => {
|
||||
const sh = loc_si.shndx(elf).get(elf);
|
||||
switch (elf.shdrPtr(sh.rela_si.shndx(elf))) {
|
||||
inline else => |shdr, class| {
|
||||
const Rela = class.ElfN().Rela;
|
||||
const old_size = elf.targetLoad(&shdr.size);
|
||||
const ent_size = elf.targetLoad(&shdr.entsize);
|
||||
const rela_slice = sh.rela_si.node(elf).slice(&elf.mf);
|
||||
const index: u32 = if (sh.rela_free.unwrap()) |index| alloc_index: {
|
||||
const rela: *Rela = @ptrCast(@alignCast(
|
||||
rela_slice[@intCast(ent_size * index)..][0..@intCast(ent_size)],
|
||||
));
|
||||
sh.rela_free = @enumFromInt(rela.offset);
|
||||
break :alloc_index index;
|
||||
} else alloc_index: {
|
||||
const old_size = elf.targetLoad(&shdr.size);
|
||||
const new_size = old_size + ent_size;
|
||||
elf.targetStore(&shdr.size, @intCast(new_size));
|
||||
break :alloc_index @intCast(@divExact(old_size, ent_size));
|
||||
};
|
||||
const rela: *Rela = @ptrCast(@alignCast(
|
||||
rela_si.node(elf).slice(&elf.mf)[@intCast(old_size)..@intCast(new_size)],
|
||||
rela_slice[@intCast(ent_size * index)..][0..@intCast(ent_size)],
|
||||
));
|
||||
rela.* = .{
|
||||
.offset = @intCast(offset),
|
||||
.info = .{
|
||||
.type = switch (elf.ehdrField(.machine)) {
|
||||
else => |machine| @panic(@tagName(machine)),
|
||||
inline .X86_64, .AARCH64, .RISCV, .PPC64 => |machine| @intCast(
|
||||
@intFromEnum(@field(@"type", @tagName(machine))),
|
||||
),
|
||||
},
|
||||
.type = @intCast(@"type".unwrap(elf)),
|
||||
.sym = @intCast(@intFromEnum(target_si)),
|
||||
},
|
||||
.addend = @intCast(addend),
|
||||
};
|
||||
if (elf.targetEndian() != native_endian) std.mem.byteSwapAllFields(Rela, rela);
|
||||
break :rel_index @intCast(@divExact(old_size, ent_size));
|
||||
break :index .wrap(index);
|
||||
},
|
||||
}
|
||||
},
|
||||
.EXEC, .DYN => 0,
|
||||
.EXEC, .DYN => .none,
|
||||
},
|
||||
.offset = offset,
|
||||
.addend = addend,
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user