authorgravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2023-09-27 19:41:59+02:00
committergravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2023-09-27 19:41:59+02:00
log8b7255c22a9dcdd9396bbd1f7c212a5c2be71dd0
tree1701fc448ca07573e888fc7ee8521302db02bda2
parent111349f83c456200c131c222d06cdf83fa62ac54

elf: hint allocateSegment where to put the segment at

1 files changed, 25 insertions(+), 8 deletions(-)

src/link/Elf.zig+25-8
...@@ -413,6 +413,7 @@ fn findFreeSpace(self: *Elf, object_size: u64, min_alignment: u64) u64 {...@@ -413,6 +413,7 @@ fn findFreeSpace(self: *Elf, object_size: u64, min_alignment: u64) u64 {
413const AllocateSegmentOpts = struct {413const AllocateSegmentOpts = struct {
414 size: u64,414 size: u64,
415 alignment: u64,415 alignment: u64,
416 addr: ?u64 = null,
416 flags: u32 = elf.PF_R,417 flags: u32 = elf.PF_R,
417};418};
418419
...@@ -423,8 +424,8 @@ pub fn allocateSegment(self: *Elf, opts: AllocateSegmentOpts) error{OutOfMemory}...@@ -423,8 +424,8 @@ pub fn allocateSegment(self: *Elf, opts: AllocateSegmentOpts) error{OutOfMemory}
423 // Memory is always allocated in sequence.424 // Memory is always allocated in sequence.
424 // TODO is this correct? Or should we implement something similar to `findFreeSpace`?425 // TODO is this correct? Or should we implement something similar to `findFreeSpace`?
425 // How would that impact HCS?426 // How would that impact HCS?
426 const addr = blk: {427 const addr = opts.addr orelse blk: {
427 assert(self.phdr_table_load_index != null);428 assert(index >= 1);
428 const phdr = &self.phdrs.items[index - 1];429 const phdr = &self.phdrs.items[index - 1];
429 const increased_size = padToIdeal(phdr.p_vaddr + phdr.p_memsz);430 const increased_size = padToIdeal(phdr.p_vaddr + phdr.p_memsz);
430 break :blk mem.alignForward(u64, increased_size, opts.alignment);431 break :blk mem.alignForward(u64, increased_size, opts.alignment);
...@@ -532,6 +533,7 @@ pub fn populateMissingMetadata(self: *Elf) !void {...@@ -532,6 +533,7 @@ pub fn populateMissingMetadata(self: *Elf) !void {
532 .p64 => false,533 .p64 => false,
533 };534 };
534 const ptr_size: u8 = self.ptrWidthBytes();535 const ptr_size: u8 = self.ptrWidthBytes();
536 const is_linux = self.base.options.target.os.tag == .linux;
535 const image_base = self.calcImageBase();537 const image_base = self.calcImageBase();
536538
537 if (self.phdr_table_index == null) {539 if (self.phdr_table_index == null) {
...@@ -570,6 +572,7 @@ pub fn populateMissingMetadata(self: *Elf) !void {...@@ -570,6 +572,7 @@ pub fn populateMissingMetadata(self: *Elf) !void {
570572
571 if (self.phdr_load_re_index == null) {573 if (self.phdr_load_re_index == null) {
572 self.phdr_load_re_index = try self.allocateSegment(.{574 self.phdr_load_re_index = try self.allocateSegment(.{
575 .addr = self.defaultEntryAddress(),
573 .size = self.base.options.program_code_size_hint,576 .size = self.base.options.program_code_size_hint,
574 .alignment = self.page_size,577 .alignment = self.page_size,
575 .flags = elf.PF_X | elf.PF_R | elf.PF_W,578 .flags = elf.PF_X | elf.PF_R | elf.PF_W,
...@@ -578,10 +581,12 @@ pub fn populateMissingMetadata(self: *Elf) !void {...@@ -578,10 +581,12 @@ pub fn populateMissingMetadata(self: *Elf) !void {
578 }581 }
579582
580 if (self.phdr_got_index == null) {583 if (self.phdr_got_index == null) {
584 const addr: u64 = if (ptr_size >= 4) 0x4000000 else 0x8000;
581 // We really only need ptr alignment but since we are using PROGBITS, linux requires585 // We really only need ptr alignment but since we are using PROGBITS, linux requires
582 // page align.586 // page align.
583 const alignment = if (self.base.options.target.os.tag == .linux) self.page_size else @as(u16, ptr_size);587 const alignment = if (is_linux) self.page_size else @as(u16, ptr_size);
584 self.phdr_got_index = try self.allocateSegment(.{588 self.phdr_got_index = try self.allocateSegment(.{
589 .addr = addr,
585 .size = @as(u64, ptr_size) * self.base.options.symbol_count_hint,590 .size = @as(u64, ptr_size) * self.base.options.symbol_count_hint,
586 .alignment = alignment,591 .alignment = alignment,
587 .flags = elf.PF_R | elf.PF_W,592 .flags = elf.PF_R | elf.PF_W,
...@@ -589,9 +594,10 @@ pub fn populateMissingMetadata(self: *Elf) !void {...@@ -589,9 +594,10 @@ pub fn populateMissingMetadata(self: *Elf) !void {
589 }594 }
590595
591 if (self.phdr_load_ro_index == null) {596 if (self.phdr_load_ro_index == null) {
592 // Same reason as for GOT597 const addr: u64 = if (ptr_size >= 4) 0xc000000 else 0xa000;
593 const alignment = if (self.base.options.target.os.tag == .linux) self.page_size else @as(u16, ptr_size);598 const alignment = if (is_linux) self.page_size else @as(u16, ptr_size);
594 self.phdr_load_ro_index = try self.allocateSegment(.{599 self.phdr_load_ro_index = try self.allocateSegment(.{
600 .addr = addr,
595 .size = 1024,601 .size = 1024,
596 .alignment = alignment,602 .alignment = alignment,
597 .flags = elf.PF_R | elf.PF_W,603 .flags = elf.PF_R | elf.PF_W,
...@@ -599,9 +605,10 @@ pub fn populateMissingMetadata(self: *Elf) !void {...@@ -599,9 +605,10 @@ pub fn populateMissingMetadata(self: *Elf) !void {
599 }605 }
600606
601 if (self.phdr_load_rw_index == null) {607 if (self.phdr_load_rw_index == null) {
602 // Same reason as for GOT608 const addr: u64 = if (ptr_size >= 4) 0x10000000 else 0xc000;
603 const alignment = if (self.base.options.target.os.tag == .linux) self.page_size else @as(u16, ptr_size);609 const alignment = if (is_linux) self.page_size else @as(u16, ptr_size);
604 self.phdr_load_rw_index = try self.allocateSegment(.{610 self.phdr_load_rw_index = try self.allocateSegment(.{
611 .addr = addr,
605 .size = 1024,612 .size = 1024,
606 .alignment = alignment,613 .alignment = alignment,
607 .flags = elf.PF_R | elf.PF_W,614 .flags = elf.PF_R | elf.PF_W,
...@@ -609,8 +616,10 @@ pub fn populateMissingMetadata(self: *Elf) !void {...@@ -609,8 +616,10 @@ pub fn populateMissingMetadata(self: *Elf) !void {
609 }616 }
610617
611 if (self.phdr_load_zerofill_index == null) {618 if (self.phdr_load_zerofill_index == null) {
612 const alignment = if (self.base.options.target.os.tag == .linux) self.page_size else @as(u16, ptr_size);619 const addr: u64 = if (ptr_size >= 4) 0x14000000 else 0xf000;
620 const alignment = if (is_linux) self.page_size else @as(u16, ptr_size);
613 self.phdr_load_zerofill_index = try self.allocateSegment(.{621 self.phdr_load_zerofill_index = try self.allocateSegment(.{
622 .addr = addr,
614 .size = 0,623 .size = 0,
615 .alignment = alignment,624 .alignment = alignment,
616 .flags = elf.PF_R | elf.PF_W,625 .flags = elf.PF_R | elf.PF_W,
...@@ -3801,6 +3810,14 @@ pub fn calcImageBase(self: Elf) u64 {...@@ -3801,6 +3810,14 @@ pub fn calcImageBase(self: Elf) u64 {
3801 };3810 };
3802}3811}
38033812
3813pub fn defaultEntryAddress(self: Elf) u64 {
3814 if (self.entry_addr) |addr| return addr;
3815 return switch (self.base.options.target.cpu.arch) {
3816 .spu_2 => 0,
3817 else => default_entry_addr,
3818 };
3819}
3820
3804pub fn isDynLib(self: Elf) bool {3821pub fn isDynLib(self: Elf) bool {
3805 return self.base.options.output_mode == .Lib and self.base.options.link_mode == .Dynamic;3822 return self.base.options.output_mode == .Lib and self.base.options.link_mode == .Dynamic;
3806}3823}