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fa1ddc4f0e6829a28be436efe89dd4c0c9018dcc [patch]

bf28b1d077f7cd1e4da6e29fef47e0ec8e6aec80

499683d565c47c000a74b8f637d9697f80d86845

fa1ddc4f0e6829a28be436efe89dd4c0c9018dcc.tar.gz

For debugging purposes, the boot loader is now able to load an additional symbol table into memory and hand it over to the kernel.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@7695 a95241bf-73f2-0310-859d-f6bbb57e9c96

Diff

 headers/private/kernel/boot/elf.h |   4 ++++
 src/kernel/boot/loader/elf.cpp    | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 114 insertions(+), 2 deletions(-)

diff --git a/headers/private/kernel/boot/elf.h b/headers/private/kernel/boot/elf.h
index 8d83020..f3b80cc 100644
--- a/headers/private/kernel/boot/elf.h
+++ b/headers/private/kernel/boot/elf.h
@@ -18,6 +18,10 @@
	addr_range	dynamic_section;
	struct Elf32_Ehdr elf_header;

	struct Elf32_Sym *debug_symbols;
	const char	*debug_string_table;
	uint32		num_debug_symbols, debug_string_table_size;

	image_id	id;
		// the ID field will be filled out in the kernel
};
diff --git a/src/kernel/boot/loader/elf.cpp b/src/kernel/boot/loader/elf.cpp
index 3d1fc3f..ce9605f 100644
--- a/src/kernel/boot/loader/elf.cpp
+++ b/src/kernel/boot/loader/elf.cpp
@@ -37,6 +37,106 @@
}


static status_t
load_elf_symbol_table(int fd, preloaded_image *image)
{
	struct Elf32_Ehdr &elfHeader = image->elf_header;
	Elf32_Sym *symbolTable = NULL;
	Elf32_Shdr *stringHeader = NULL;
	uint32 numSymbols = 0;
	char *stringTable;
	status_t status;

	// get section headers

	ssize_t size = elfHeader.e_shnum * elfHeader.e_shentsize;
	Elf32_Shdr *sectionHeaders = (struct Elf32_Shdr *)malloc(size);
	if (sectionHeaders == NULL) {
		dprintf("error allocating space for section headers\n");
		return B_NO_MEMORY;
	}

	ssize_t length = read_pos(fd, elfHeader.e_shoff, sectionHeaders, size);
	if (length < size) {
		TRACE(("error reading in program headers\n"));
		status = B_ERROR;
		goto error1;
	}
	
	// find symbol table in section headers
	
	for (int32 i = 0; i < elfHeader.e_shnum; i++) {
		if (sectionHeaders[i].sh_type == SHT_SYMTAB) {
			stringHeader = &sectionHeaders[sectionHeaders[i].sh_link];

			if (stringHeader->sh_type != SHT_STRTAB) {
				TRACE(("doesn't link to string table\n"));
				status = B_BAD_DATA;
				goto error1;
			}

			// read in symbol table
			symbolTable = (Elf32_Sym *)kernel_args_malloc(size = sectionHeaders[i].sh_size);
			if (symbolTable == NULL) {
				status = B_NO_MEMORY;
				goto error1;
			}

			length = read_pos(fd, sectionHeaders[i].sh_offset, symbolTable, size);
			if (length < size) {
				TRACE(("error reading in symbol table\n"));
				status = B_ERROR;
				goto error1;
			}

			numSymbols = size / sizeof(Elf32_Sym);
			break;
		}
	}

	if (symbolTable == NULL) {
		TRACE(("no symbol table\n"));
		status = B_BAD_VALUE;
		goto error1;
	}

	// read in string table

	stringTable = (char *)kernel_args_malloc(size = stringHeader->sh_size);
	if (stringTable == NULL) {
		status = B_NO_MEMORY;
		goto error2;
	}

	length = read_pos(fd, stringHeader->sh_offset, stringTable, size);
	if (length < size) {
		TRACE(("error reading in string table\n"));
		status = B_ERROR;
		goto error3;
	}

	TRACE(("loaded debug %ld symbols\n", numSymbols));

	// insert tables into image
	image->debug_symbols = symbolTable;
	image->num_debug_symbols = numSymbols;
	image->debug_string_table = stringTable;
	image->debug_string_table_size = size;

	free(sectionHeaders);
	return B_OK;

error3:
	kernel_args_free(stringTable);
error2:
	kernel_args_free(symbolTable);
error1:
	free(sectionHeaders);

	return status;
}


status_t
elf_load_image(int fd, preloaded_image *image)
{
@@ -74,7 +174,7 @@
	image->data_region.size = 0;
	image->text_region.size = 0;

	for (int i = 0; i < elfHeader.e_phnum; i++) {
	for (int32 i = 0; i < elfHeader.e_phnum; i++) {
		switch (programHeaders[i].p_type) {
			case PT_LOAD:
				break;
@@ -141,7 +241,7 @@
		else
			continue;

		TRACE(("load segment %d...\n", i));
		TRACE(("load segment %d (%ld bytes)...\n", i, programHeaders[i].p_filesz));

		length = read_pos(fd, programHeaders[i].p_offset,
			(void *)(region->start + (programHeaders[i].p_vaddr % B_PAGE_SIZE)),
@@ -155,6 +255,14 @@

	// modify the dynamic section by the delta of the regions
	image->dynamic_section.start += image->text_region.delta;

	image->num_debug_symbols = 0;
	image->debug_symbols = NULL;
	image->debug_string_table = NULL;

	// ToDo: this should be enabled by kernel settings!
	if (1)
		load_elf_symbol_table(fd, image);

	free(programHeaders);