musl/arch/mips/reloc.h
Szabolcs Nagy b20760c023 support configurable page size on mips, powerpc and microblaze
PAGE_SIZE was hardcoded to 4096, which is historically what most
systems use, but on several archs it is a kernel config parameter,
user space can only know it at execution time from the aux vector.

PAGE_SIZE and PAGESIZE are not defined on archs where page size is
a runtime parameter, applications should use sysconf(_SC_PAGE_SIZE)
to query it. Internally libc code defines PAGE_SIZE to libc.page_size,
which is set to aux[AT_PAGESZ] in __init_libc and early in __dynlink
as well. (Note that libc.page_size can be accessed without GOT, ie.
before relocations are done)

Some fpathconf settings are hardcoded to 4096, these should be actually
queried from the filesystem using statfs.
2013-09-15 02:00:32 +00:00

96 lines
2.4 KiB
C

#include <string.h>
#include <elf.h>
#include <endian.h>
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define ENDIAN_SUFFIX "el"
#else
#define ENDIAN_SUFFIX ""
#endif
#define LDSO_ARCH "mips" ENDIAN_SUFFIX
#define IS_COPY(x) ((x)==R_MIPS_COPY)
#define IS_PLT(x) 1
static inline void do_single_reloc(
struct dso *self, unsigned char *base_addr,
size_t *reloc_addr, int type, size_t addend,
Sym *sym, size_t sym_size,
struct symdef def, size_t sym_val)
{
switch(type) {
case R_MIPS_JUMP_SLOT:
*reloc_addr = sym_val;
break;
case R_MIPS_REL32:
if (sym_val) *reloc_addr += sym_val;
else *reloc_addr += (size_t)base_addr;
break;
case R_MIPS_COPY:
memcpy(reloc_addr, (void *)sym_val, sym_size);
break;
case R_MIPS_TLS_DTPMOD32:
*reloc_addr = def.dso ? def.dso->tls_id : self->tls_id;
break;
case R_MIPS_TLS_DTPREL32:
*reloc_addr += def.sym->st_value;
break;
case R_MIPS_TLS_TPREL32:
*reloc_addr += def.sym
? def.sym->st_value + def.dso->tls_offset - 0x7000
: self->tls_offset - 0x7000;
break;
}
}
void __reloc_self(int c, size_t *a, size_t *dynv, size_t *got)
{
char *base;
size_t t[20], n;
for (a+=c+1; *a; a++);
for (a++; *a; a+=2) if (*a<20) t[*a] = a[1];
base = (char *)t[AT_BASE];
if (!base) base = (char *)(t[AT_PHDR] & -t[AT_PAGESZ]);
for (a=dynv; *a; a+=2) if (*a-0x70000000UL<20) t[*a&31] = a[1];
n = t[DT_MIPS_LOCAL_GOTNO - 0x70000000];
for (a=got; n; a++, n--) *a += (size_t)base;
}
static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride);
static void do_arch_relocs(struct dso *this, struct dso *head)
{
unsigned char *base = this->base;
size_t *dynv = this->dynv;
size_t dyn[20] = {0};
size_t i;
size_t rel[2], got=0;
Sym *sym;
for (i=0; dynv[i]; i+=2) {
if (dynv[i]-0x70000000UL<20)
dyn[dynv[i]&31] = dynv[i+1];
else if (dynv[i] == DT_PLTGOT)
got = dynv[i+1];
}
i = dyn[DT_MIPS_LOCAL_GOTNO-0x70000000];
if (this->shortname && !strcmp(this->shortname, "libc.so")) {
got += sizeof(size_t) * i;
} else {
for (; i; i--, got+=sizeof(size_t))
*(size_t *)(base+got) += (size_t)base;
}
sym = this->syms + dyn[DT_MIPS_GOTSYM-0x70000000];
i = dyn[DT_MIPS_SYMTABNO-0x70000000] - dyn[DT_MIPS_GOTSYM-0x70000000];
for (; i; i--, got+=sizeof(size_t), sym++) {
rel[0] = got;
rel[1] = sym-this->syms << 8 | R_MIPS_JUMP_SLOT;
*(size_t *)(base+got) = 0;
do_relocs(this, rel, sizeof rel, 2);
}
}
#define NEED_ARCH_RELOCS 1
#define DYNAMIC_IS_RO 1