ld: implement support for exposing ld functions to loaded executables

sys/ld/self.c

@@ -0,0 +1,44 @@
+#include "elf.h"
+
+#include <magenta/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define LD_NAME              "ld64.so"
+#define LD_IMAGE_BASE_OFFSET 1024
+
+extern char _DYNAMIC[];
+extern char _ld_image_base[];
+extern char _ld_image_limit[];
+
+struct elf_image *get_self(void)
+{
+	struct elf_image *self = malloc(sizeof *self);
+	memset(self, 0x0, sizeof *self);
+
+	snprintf(
+		self->e_leaf.l_name,
+		sizeof self->e_leaf.l_name,
+		"%s",
+		LD_NAME);
+	kern_config_get(
+		KERN_CFG_PAGE_SIZE,
+		&self->e_page_size,
+		sizeof self->e_page_size);
+
+	self->e_base = (virt_addr_t)_ld_image_base - LD_IMAGE_BASE_OFFSET;
+	self->e_length = (virt_addr_t)_ld_image_limit - self->e_base;
+	if (self->e_length & (self->e_page_size - 1)) {
+		self->e_length &= ~(self->e_page_size - 1);
+		self->e_length += self->e_page_size;
+	}
+
+	self->e_dynamic.p_type = PT_DYNAMIC;
+	self->e_dynamic.p_align = 8;
+	self->e_dynamic.p_memsz = self->e_dynamic.p_filesz = (size_t)-1;
+	self->e_dynamic.p_vaddr = (virt_addr_t)_DYNAMIC - self->e_base;
+
+	elf_image_parse_dynamic(self);
+
+	return self;
+}