build: Get build-id from linker instead of generating a random one

2021-11-08 09:42:41 +01:00 · 2021-11-08 09:42:41 +01:00 · 0c073fcc44
commit 0c073fcc44
parent 2caf1eaec0
7 changed files with 89 additions and 14 deletions
--- a/stage23/Makefile
+++ b/stage23/Makefile
@ -50,8 +50,6 @@ endif
 COM_OUTPUT = false
 E9_OUTPUT = false

-BUILD_ID := $(shell dd if=/dev/urandom count=8 bs=1 2>/dev/null | od -An -t x4 | sed 's/^ /0x/g;s/ //g')
-
 WERROR = -Werror
 CFLAGS ?= -O3 -g -pipe -Wall -Wextra $(WERROR)

@ -71,7 +69,6 @@ INTERNAL_CFLAGS := \
 	-mno-sse \
 	-mno-sse2 \
 	-MMD \
-	-DBUILD_ID=$(BUILD_ID) \
 	-DLIMINE_VERSION='"$(LIMINE_VERSION)"' \
 	-DLIMINE_COPYRIGHT='"$(LIMINE_COPYRIGHT)"' \
 	-DCOM_OUTPUT=$(COM_OUTPUT) \
@ -141,7 +138,8 @@ INTERNAL_LDFLAGS := \
 ifeq ($(TARGET), bios)
 	INTERNAL_LDFLAGS += \
 		-melf_i386 \
-		-static
+		-static \
+		--build-id=sha1
 endif

 ifeq ($(TARGET), uefi)
@ -246,15 +244,43 @@ $(BUILDDIR)/limine_stage2only.elf: $(OBJ)
 	$(TOOLCHAIN_LD) $^ $(LDFLAGS) $(INTERNAL_LDFLAGS) -Tlinker_stage2only.ld -o $@ || \
 		( echo "This error may mean that stage 2 was trying to use stage 3 symbols before loading stage 3" && \
 		  false )
+	$(TOOLCHAIN_OBJCOPY) -O binary --only-section=.note.gnu.build-id $@ $(BUILDDIR)/build-id.s2.bin
+	cd "$(BUILDDIR)" && \
+		$(TOOLCHAIN_OBJCOPY) -B i8086 -I binary -O $(OBJCOPY_ARCH) build-id.s2.bin build-id.s2.o
+	$(TOOLCHAIN_OBJCOPY) -O binary --only-section=.note.gnu.build-id $@ $(BUILDDIR)/build-id.s3.bin
+	cd "$(BUILDDIR)" && \
+		$(TOOLCHAIN_OBJCOPY) -B i8086 -I binary -O $(OBJCOPY_ARCH) build-id.s3.bin build-id.s3.o
+	$(TOOLCHAIN_LD) $(BUILDDIR)/build-id.s2.o $(BUILDDIR)/build-id.s3.o $^ $(LDFLAGS) $(INTERNAL_LDFLAGS) -Tlinker_stage2only.ld -o $@

 $(BUILDDIR)/limine_nomap.elf: $(OBJ) $(BUILDDIR)/tinf/tinfgzip.o $(BUILDDIR)/tinf/tinflate.o $(BUILDDIR)/font.o $(BUILDDIR)/sys/smp_trampoline.o $(BUILDDIR)/stage2.map.o
 	$(TOOLCHAIN_LD) $^ $(LDFLAGS) $(INTERNAL_LDFLAGS) -Tlinker_nomap.ld -o $@
+	$(TOOLCHAIN_OBJCOPY) -O binary --only-section=.note.gnu.build-id $@ $(BUILDDIR)/build-id.s2.bin
+	cd "$(BUILDDIR)" && \
+		$(TOOLCHAIN_OBJCOPY) -B i8086 -I binary -O $(OBJCOPY_ARCH) build-id.s2.bin build-id.s2.o
+	$(TOOLCHAIN_OBJCOPY) -O binary --only-section=.note.gnu.build-id $@ $(BUILDDIR)/build-id.s3.bin
+	cd "$(BUILDDIR)" && \
+		$(TOOLCHAIN_OBJCOPY) -B i8086 -I binary -O $(OBJCOPY_ARCH) build-id.s3.bin build-id.s3.o
+	$(TOOLCHAIN_LD) $(BUILDDIR)/build-id.s2.o $(BUILDDIR)/build-id.s3.o $^ $(LDFLAGS) $(INTERNAL_LDFLAGS) -Tlinker_nomap.ld -o $@

 $(BUILDDIR)/limine.elf: $(OBJ) $(BUILDDIR)/tinf/tinfgzip.o $(BUILDDIR)/tinf/tinflate.o $(BUILDDIR)/font.o $(BUILDDIR)/sys/smp_trampoline.o $(BUILDDIR)/stage2.map.o $(BUILDDIR)/full.map.o
 	$(TOOLCHAIN_LD) $^ $(LDFLAGS) $(INTERNAL_LDFLAGS) -Tlinker.ld -o $@
+	$(TOOLCHAIN_OBJCOPY) -O binary --only-section=.note.gnu.build-id $@ $(BUILDDIR)/build-id.s2.bin
+	cd "$(BUILDDIR)" && \
+		$(TOOLCHAIN_OBJCOPY) -B i8086 -I binary -O $(OBJCOPY_ARCH) build-id.s2.bin build-id.s2.o
+	$(TOOLCHAIN_OBJCOPY) -O binary --only-section=.note.gnu.build-id $@ $(BUILDDIR)/build-id.s3.bin
+	cd "$(BUILDDIR)" && \
+		$(TOOLCHAIN_OBJCOPY) -B i8086 -I binary -O $(OBJCOPY_ARCH) build-id.s3.bin build-id.s3.o
+	$(TOOLCHAIN_LD) $(BUILDDIR)/build-id.s2.o $(BUILDDIR)/build-id.s3.o $^ $(LDFLAGS) $(INTERNAL_LDFLAGS) -Tlinker.ld -o $@

 $(BUILDDIR)/limine_dbg.elf: $(OBJ) $(BUILDDIR)/tinf/tinfgzip.o $(BUILDDIR)/tinf/tinflate.o $(BUILDDIR)/font.o $(BUILDDIR)/sys/smp_trampoline.o $(BUILDDIR)/stage2.map.o $(BUILDDIR)/full.map.o
 	$(TOOLCHAIN_LD) $^ $(LDFLAGS) $(INTERNAL_LDFLAGS) -Tlinker_dbg.ld -o $@
+	$(TOOLCHAIN_OBJCOPY) -O binary --only-section=.note.gnu.build-id $@ $(BUILDDIR)/build-id.s2.bin
+	cd "$(BUILDDIR)" && \
+		$(TOOLCHAIN_OBJCOPY) -B i8086 -I binary -O $(OBJCOPY_ARCH) build-id.s2.bin build-id.s2.o
+	$(TOOLCHAIN_OBJCOPY) -O binary --only-section=.note.gnu.build-id $@ $(BUILDDIR)/build-id.s3.bin
+	cd "$(BUILDDIR)" && \
+		$(TOOLCHAIN_OBJCOPY) -B i8086 -I binary -O $(OBJCOPY_ARCH) build-id.s3.bin build-id.s3.o
+	$(TOOLCHAIN_LD) $(BUILDDIR)/build-id.s2.o $(BUILDDIR)/build-id.s3.o $^ $(LDFLAGS) $(INTERNAL_LDFLAGS) -Tlinker_dbg.ld -o $@

 endif

--- a/stage23/entry.s2.c
+++ b/stage23/entry.s2.c
@ -21,8 +21,6 @@
 #include <drivers/disk.h>
 #include <sys/idt.h>

-extern uint64_t stage3_build_id;
-
 struct volume *boot_volume;

 #if bios == 1
@ -32,6 +30,8 @@ static bool stage3_found = false;

 extern symbol stage3_addr;
 extern symbol limine_sys_size;
+extern symbol build_id_s2;
+extern symbol build_id_s3;

 static bool stage3_init(struct volume *part) {
    struct file_handle *stage3;
@ -54,7 +54,7 @@ static bool stage3_init(struct volume *part) {

    fclose(stage3);

-    if (BUILD_ID != stage3_build_id) {
+    if (memcmp(build_id_s2 + 16, build_id_s3 + 16, 20) != 0) {
        print("limine.sys build ID mismatch.\n");
        return false;
    }
--- a/stage23/entry.s3.c
+++ b/stage23/entry.s3.c
@ -126,9 +126,6 @@ void uefi_entry(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) {
 #endif

 #if bios == 1
-__attribute__((section(".stage3_build_id")))
-uint64_t stage3_build_id = BUILD_ID;
-
 __attribute__((section(".stage3_entry")))
 #endif
 __attribute__((noreturn))
--- a/stage23/linker.ld
+++ b/stage23/linker.ld
@ -17,6 +17,11 @@ SECTIONS
        *.s2.o(.text*)
    }

+    .stage2.build-id : {
+        build_id_s2 = .;
+        *build-id.s2.o(*)
+    }
+
    .stage2.data : {
        *.s2.o(.data*)
        *.s2.o(.rodata*)
@ -26,10 +31,14 @@ SECTIONS
    .stage3.text : {
        stage3_addr = .;
        *(.stage3_entry*)
-        *(.stage3_build_id*)
        *(.text*)
    }

+    .stage3.build-id : {
+        build_id_s3 = .;
+        *build-id.s3.o(*)
+    }
+
    .stage3.data : {
        *(.data*)
        *(.rodata*)
@ -37,6 +46,10 @@ SECTIONS
        limine_sys_size = . - 0x8000;
    }

+    .note.gnu.build-id : {
+        *(.note.gnu.build-id)
+    }
+
    .bss : {
        bss_begin = .;
        *(COMMON)
--- a/stage23/linker_dbg.ld
+++ b/stage23/linker_dbg.ld
@ -17,6 +17,11 @@ SECTIONS
        *.s2.o(.text*)
    }

+    .stage2.build-id : {
+        build_id_s2 = .;
+        *build-id.s2.o(*)
+    }
+
    .stage2.data : {
        *.s2.o(.data*)
        *.s2.o(.rodata*)
@ -26,10 +31,14 @@ SECTIONS
    .stage3.text : {
        stage3_addr = .;
        *(.stage3_entry*)
-        *(.stage3_build_id*)
        *(.text*)
    }

+    .stage3.build-id : {
+        build_id_s3 = .;
+        *build-id.s3.o(*)
+    }
+
    .stage3.data : {
        *(.data*)
        *(.rodata*)
@ -37,6 +46,10 @@ SECTIONS
        limine_sys_size = . - 0x8000;
    }

+    .note.gnu.build-id : {
+        *(.note.gnu.build-id)
+    }
+
    .bss : {
        bss_begin = .;
        *(COMMON)
--- a/stage23/linker_nomap.ld
+++ b/stage23/linker_nomap.ld
@ -17,6 +17,11 @@ SECTIONS
        *.s2.o(.text*)
    }

+    .stage2.build-id : {
+        build_id_s2 = .;
+        *build-id.s2.o(*)
+    }
+
    .stage2.data : {
        *.s2.o(.data*)
        *.s2.o(.rodata*)
@ -26,10 +31,14 @@ SECTIONS
    .stage3.text : {
        stage3_addr = .;
        *(.stage3_entry*)
-        *(.stage3_build_id*)
        *(.text*)
    }

+    .stage3.build-id : {
+        build_id_s3 = .;
+        *build-id.s3.o(*)
+    }
+
    .stage3.data : {
        *(.data*)
        *(.rodata*)
@ -37,6 +46,10 @@ SECTIONS
        limine_sys_size = . - 0x8000;
    }

+    .note.gnu.build-id : {
+        *(.note.gnu.build-id)
+    }
+
    .bss : {
        bss_begin = .;
        *(COMMON)
--- a/stage23/linker_stage2only.ld
+++ b/stage23/linker_stage2only.ld
@ -17,17 +17,30 @@ SECTIONS
        *.s2.o(.text*)
    }

+    .stage2.build-id : {
+        build_id_s2 = .;
+        *build-id.s2.o(*)
+    }
+
    .stage2.data : {
        *.s2.o(.data*)
        *.s2.o(.rodata*)
        stage2_map = .;
        stage3_addr = .;
-        *(.stage3_build_id*)
        full_map = .;
        limine_sys_size = .;
        getchar_internal = .;
    }

+    .stage3.build-id : {
+        build_id_s3 = .;
+        *build-id.s3.o(*)
+    }
+
+    .note.gnu.build-id : {
+        *(.note.gnu.build-id)
+    }
+
    .bss : {
        bss_begin = .;
        *(COMMON)