kjarna runtime

1 files changed, 65 insertions, 7 deletions

diff --git a/kjarna_runtime/dynamic_x86_64.c b/kjarna_runtime/dynamic_x86_64.c
index e49f13d..3d85582 100644
--- a/kjarna_runtime/dynamic_x86_64.c
+++ b/kjarna_runtime/dynamic_x86_64.c
@@ -59,23 +59,81 @@ void kc_dynamic_init(char *base, Elf64_Dyn *dyn)
 		dso_info.pltgot[2] = (uintptr_t)_rtld_link;
 	}
 
-	kc_reloc(dso_info.base, dso_info.reladyn.entries, dso_info.reladyn.size, dso_info.reladyn.entsize);
-	kc_reloc(dso_info.base, dso_info.jmprel.entries, dso_info.jmprel.size, dso_info.jmprel.entsize);
+	kc_dynamic_reloc(base, &dso_info.jmprel);
+	kc_dynamic_reloc(base, &dso_info.reladyn);
 }
 
 void *kc_dynamic_link(struct elf64_dso_info *dso, int index)
 {
+	struct kjarna_interface *ftab = entry_params->interface;
+
 	int symindex = ELF64_R_SYM(dso->jmprel.entries[index].r_info);
 	int strindex = dso->dynsym.entries[symindex].st_name;
 	const char *name = &dso->dynsym.strings[strindex];
-	uintptr_t *fixup = (uintptr_t *)dso->base + dso->jmprel.entries[index].r_offset;
+	uintptr_t *fixup = (uintptr_t *)(dso->base + dso->jmprel.entries[index].r_offset);
 
-	if (strcmp(name, "write") == 0)
+	// TODO: generate a symbol table for kjarna interface
+	// TODO: implement symbol lookup (maybe hashed too)
+	if (strcmp(name, "open") == 0)
+	{
+		*fixup = (uintptr_t)*ftab->open;
+	}
+	else if (strcmp(name, "close") == 0)
+	{
+		*fixup = (uintptr_t)*ftab->close;
+	}
+	else if (strcmp(name, "read") == 0)
+	{
+		*fixup = (uintptr_t)*ftab->read;
+	}
+	else if (strcmp(name, "write") == 0)
+	{
+		*fixup = (uintptr_t)*ftab->write;
+	}
+	else if (strcmp(name, "lseek") == 0)
 	{
-		*fixup = (uintptr_t)*entry_params->interface->write;
-		return fixup;
+		*fixup = (uintptr_t)*ftab->lseek;
 	}
+	else if (strcmp(name, "mmap") == 0)
+	{
+		*fixup = (uintptr_t)*ftab->mmap;
+	}
+	else if (strcmp(name, "munmap") == 0)
+	{
+		*fixup = (uintptr_t)*ftab->munmap;
+	}
+	else
+	{
+		return nullptr;
+	}
+
+	return fixup;
+}
+
+static void do_rela(char *base, Elf64_Rela *rela)
+{
+	uintptr_t *fixup = (uintptr_t *)(base + rela->r_offset);
+
+    switch (ELF64_R_TYPE(rela->r_info))
+    {
+        case R_X86_64_JUMP_SLOT:
+            *fixup += (uintptr_t)base;
+            break;
+        case R_X86_64_RELATIVE:
+            *fixup = (uintptr_t)(rela->r_addend + base);
+            break;
+        default:
+            break;
+    }
+}
+
+void kc_dynamic_reloc(char *base, struct elf64_relatab *rela)
+{
+    // perform the actual relocation
 
-	return nullptr;
+    for (size_t i = 0; rela->entries && (i < rela->size); i += rela->entsize)
+    {
+        do_rela(base, &rela->entries[i]);
+    }
 }