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Commit 499a351e authored by Oskar Viljasaar's avatar Oskar Viljasaar
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Import openwrt pending patch 305-mips_module_reloc

parent 6448bf4f
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......@@ -94,8 +94,18 @@ all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlinuz
cflags-y += -G 0 -mno-abicalls -fno-pic -pipe -mno-branch-likely
cflags-y += -msoft-float
LDFLAGS_vmlinux += -G 0 -static -n -nostdlib
ifdef CONFIG_64BIT
KBUILD_AFLAGS_MODULE += -mlong-calls
KBUILD_CFLAGS_MODULE += -mlong-calls
else
ifdef CONFIG_DYNAMIC_FTRACE
KBUILD_AFLAGS_MODULE += -mlong-calls
KBUILD_CFLAGS_MODULE += -mlong-calls
else
KBUILD_AFLAGS_MODULE += -mno-long-calls
KBUILD_CFLAGS_MODULE += -mno-long-calls
endif
endif
ifeq ($(CONFIG_RELOCATABLE),y)
LDFLAGS_vmlinux += --emit-relocs
......
......@@ -12,6 +12,11 @@ struct mod_arch_specific {
const struct exception_table_entry *dbe_start;
const struct exception_table_entry *dbe_end;
struct mips_hi16 *r_mips_hi16_list;
void *phys_plt_tbl;
void *virt_plt_tbl;
unsigned int phys_plt_offset;
unsigned int virt_plt_offset;
};
typedef uint8_t Elf64_Byte; /* Type for a 8-bit quantity. */
......
......@@ -44,14 +44,221 @@ struct mips_hi16 {
static LIST_HEAD(dbe_list);
static DEFINE_SPINLOCK(dbe_lock);
#ifdef MODULE_START
/*
* Get the potential max trampolines size required of the init and
* non-init sections. Only used if we cannot find enough contiguous
* physically mapped memory to put the module into.
*/
static unsigned int
get_plt_size(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
const char *secstrings, unsigned int symindex, bool is_init)
{
unsigned long ret = 0;
unsigned int i, j;
Elf_Sym *syms;
/* Everything marked ALLOC (this includes the exported symbols) */
for (i = 1; i < hdr->e_shnum; ++i) {
unsigned int info = sechdrs[i].sh_info;
if (sechdrs[i].sh_type != SHT_REL
&& sechdrs[i].sh_type != SHT_RELA)
continue;
/* Not a valid relocation section? */
if (info >= hdr->e_shnum)
continue;
/* Don't bother with non-allocated sections */
if (!(sechdrs[info].sh_flags & SHF_ALLOC))
continue;
/* If it's called *.init*, and we're not init, we're
not interested */
if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
!= is_init)
continue;
syms = (Elf_Sym *) sechdrs[symindex].sh_addr;
if (sechdrs[i].sh_type == SHT_REL) {
Elf_Mips_Rel *rel = (void *) sechdrs[i].sh_addr;
unsigned int size = sechdrs[i].sh_size / sizeof(*rel);
for (j = 0; j < size; ++j) {
Elf_Sym *sym;
if (ELF_MIPS_R_TYPE(rel[j]) != R_MIPS_26)
continue;
sym = syms + ELF_MIPS_R_SYM(rel[j]);
if (!is_init && sym->st_shndx != SHN_UNDEF)
continue;
ret += 4 * sizeof(int);
}
} else {
Elf_Mips_Rela *rela = (void *) sechdrs[i].sh_addr;
unsigned int size = sechdrs[i].sh_size / sizeof(*rela);
for (j = 0; j < size; ++j) {
Elf_Sym *sym;
if (ELF_MIPS_R_TYPE(rela[j]) != R_MIPS_26)
continue;
sym = syms + ELF_MIPS_R_SYM(rela[j]);
if (!is_init && sym->st_shndx != SHN_UNDEF)
continue;
ret += 4 * sizeof(int);
}
}
}
return ret;
}
#ifndef MODULE_START
static void *alloc_phys(unsigned long size)
{
unsigned order;
struct page *page;
struct page *p;
size = PAGE_ALIGN(size);
order = get_order(size);
page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN |
__GFP_THISNODE, order);
if (!page)
return NULL;
split_page(page, order);
/* mark all pages except for the last one */
for (p = page; p + 1 < page + (size >> PAGE_SHIFT); ++p)
set_bit(PG_owner_priv_1, &p->flags);
for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
__free_page(p);
return page_address(page);
}
#endif
static void free_phys(void *ptr)
{
struct page *page;
bool free;
page = virt_to_page(ptr);
do {
free = test_and_clear_bit(PG_owner_priv_1, &page->flags);
__free_page(page);
page++;
} while (free);
}
void *module_alloc(unsigned long size)
{
#ifdef MODULE_START
return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
__builtin_return_address(0));
#else
void *ptr;
if (size == 0)
return NULL;
ptr = alloc_phys(size);
/* If we failed to allocate physically contiguous memory,
* fall back to regular vmalloc. The module loader code will
* create jump tables to handle long jumps */
if (!ptr)
return vmalloc(size);
return ptr;
#endif
}
static inline bool is_phys_addr(void *ptr)
{
#ifdef CONFIG_64BIT
return (KSEGX((unsigned long)ptr) == CKSEG0);
#else
return (KSEGX(ptr) == KSEG0);
#endif
}
/* Free memory returned from module_alloc */
void module_memfree(void *module_region)
{
if (is_phys_addr(module_region))
free_phys(module_region);
else
vfree(module_region);
}
static void *__module_alloc(int size, bool phys)
{
void *ptr;
if (phys)
ptr = kmalloc(size, GFP_KERNEL);
else
ptr = vmalloc(size);
return ptr;
}
static void __module_free(void *ptr)
{
if (is_phys_addr(ptr))
kfree(ptr);
else
vfree(ptr);
}
int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
char *secstrings, struct module *mod)
{
unsigned int symindex = 0;
unsigned int core_size, init_size;
int i;
mod->arch.phys_plt_offset = 0;
mod->arch.virt_plt_offset = 0;
mod->arch.phys_plt_tbl = NULL;
mod->arch.virt_plt_tbl = NULL;
if (IS_ENABLED(CONFIG_64BIT))
return 0;
for (i = 1; i < hdr->e_shnum; i++)
if (sechdrs[i].sh_type == SHT_SYMTAB)
symindex = i;
core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
if ((core_size + init_size) == 0)
return 0;
mod->arch.phys_plt_tbl = __module_alloc(core_size + init_size, 1);
if (!mod->arch.phys_plt_tbl)
return -ENOMEM;
mod->arch.virt_plt_tbl = __module_alloc(core_size + init_size, 0);
if (!mod->arch.virt_plt_tbl) {
__module_free(mod->arch.phys_plt_tbl);
mod->arch.phys_plt_tbl = NULL;
return -ENOMEM;
}
return 0;
}
static int apply_r_mips_none(struct module *me, u32 *location,
u32 base, Elf_Addr v, bool rela)
......@@ -67,9 +274,40 @@ static int apply_r_mips_32(struct module *me, u32 *location,
return 0;
}
static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
void *start, Elf_Addr v)
{
unsigned *tramp = start + *plt_offset;
*plt_offset += 4 * sizeof(int);
/* adjust carry for addiu */
if (v & 0x00008000)
v += 0x10000;
tramp[0] = 0x3c190000 | (v >> 16); /* lui t9, hi16 */
tramp[1] = 0x27390000 | (v & 0xffff); /* addiu t9, t9, lo16 */
tramp[2] = 0x03200008; /* jr t9 */
tramp[3] = 0x00000000; /* nop */
return (Elf_Addr) tramp;
}
static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
{
if (is_phys_addr(location))
return add_plt_entry_to(&me->arch.phys_plt_offset,
me->arch.phys_plt_tbl, v);
else
return add_plt_entry_to(&me->arch.virt_plt_offset,
me->arch.virt_plt_tbl, v);
}
static int apply_r_mips_26(struct module *me, u32 *location,
u32 base, Elf_Addr v, bool rela)
{
u32 ofs = base & 0x03ffffff;
if (v % 4) {
pr_err("module %s: dangerous R_MIPS_26 relocation\n",
me->name);
......@@ -77,13 +315,17 @@ static int apply_r_mips_26(struct module *me, u32 *location,
}
if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
pr_err("module %s: relocation overflow\n",
me->name);
return -ENOEXEC;
v = add_plt_entry(me, location, v + (ofs << 2));
if (!v) {
pr_err("module %s: relocation overflow\n",
me->name);
return -ENOEXEC;
}
ofs = 0;
}
*location = (*location & ~0x03ffffff) |
((base + (v >> 2)) & 0x03ffffff);
((ofs + (v >> 2)) & 0x03ffffff);
return 0;
}
......@@ -459,9 +701,36 @@ int module_finalize(const Elf_Ehdr *hdr,
list_add(&me->arch.dbe_list, &dbe_list);
spin_unlock_irq(&dbe_lock);
}
/* Get rid of the fixup trampoline if we're running the module
* from physically mapped address space */
if (me->arch.phys_plt_offset == 0) {
__module_free(me->arch.phys_plt_tbl);
me->arch.phys_plt_tbl = NULL;
}
if (me->arch.virt_plt_offset == 0) {
__module_free(me->arch.virt_plt_tbl);
me->arch.virt_plt_tbl = NULL;
}
return 0;
}
void module_arch_freeing_init(struct module *mod)
{
if (mod->state == MODULE_STATE_LIVE)
return;
if (mod->arch.phys_plt_tbl) {
__module_free(mod->arch.phys_plt_tbl);
mod->arch.phys_plt_tbl = NULL;
}
if (mod->arch.virt_plt_tbl) {
__module_free(mod->arch.virt_plt_tbl);
mod->arch.virt_plt_tbl = NULL;
}
}
void module_arch_cleanup(struct module *mod)
{
spin_lock_irq(&dbe_lock);
......
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