mirror of
git://git.musl-libc.org/musl
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9ec4283b28
despite documentation that makes it sound a lot different, the only ABI-constraint difference between TLS variants II and I seems to be that variant II stores the initial TLS segment immediately below the thread pointer (i.e. the thread pointer points to the end of it) and variant I stores the initial TLS segment above the thread pointer, requiring the thread descriptor to be stored below. the actual value stored in the thread pointer register also tends to have per-arch random offsets applied to it for silly micro-optimization purposes. with these changes applied, TLS should be basically working on all supported archs except microblaze. I'm still working on getting the necessary information and a working toolchain that can build TLS binaries for microblaze, but in theory, static-linked programs with TLS and dynamic-linked programs where only the main executable uses TLS should already work on microblaze. alignment constraints have not yet been heavily tested, so it's possible that this code does not always align TLS segments correctly on archs that need TLS variant I.
89 lines
2.3 KiB
C
89 lines
2.3 KiB
C
#include <string.h>
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#include <elf.h>
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#define ETC_LDSO_PATH "/etc/ld-musl-mips.path"
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#define IS_COPY(x) ((x)==R_MIPS_COPY)
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#define IS_PLT(x) 1
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static inline void do_single_reloc(
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struct dso *self, unsigned char *base_addr,
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size_t *reloc_addr, int type, size_t addend,
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Sym *sym, size_t sym_size,
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struct symdef def, size_t sym_val)
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{
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switch(type) {
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case R_MIPS_JUMP_SLOT:
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*reloc_addr = sym_val;
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break;
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case R_MIPS_REL32:
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if (sym_val) *reloc_addr += sym_val;
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else *reloc_addr += (size_t)base_addr;
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break;
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case R_MIPS_COPY:
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memcpy(reloc_addr, (void *)sym_val, sym_size);
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break;
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case R_MIPS_TLS_DTPMOD32:
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*reloc_addr = def.dso ? def.dso->tls_id : self->tls_id;
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break;
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case R_MIPS_TLS_DTPREL32:
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*reloc_addr += def.sym->st_value;
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break;
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case R_MIPS_TLS_TPREL32:
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*reloc_addr += def.sym
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? def.sym->st_value + def.dso->tls_offset - 0x7000
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: self->tls_offset - 0x7000;
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break;
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}
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}
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void __reloc_self(int c, size_t *a, size_t *dynv, size_t *got)
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{
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char *base;
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size_t t[20], n;
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for (a+=c+1; *a; a++);
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for (a++; *a; a+=2) if (*a<20) t[*a] = a[1];
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base = (char *)t[AT_BASE];
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if (!base) base = (char *)(t[AT_PHDR] & -4096);
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for (a=dynv; *a; a+=2) if (*a-0x70000000UL<20) t[*a&31] = a[1];
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n = t[DT_MIPS_LOCAL_GOTNO - 0x70000000];
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for (a=got; n; a++, n--) *a += (size_t)base;
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}
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static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride);
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static void do_arch_relocs(struct dso *this, struct dso *head)
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{
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unsigned char *base = this->base;
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size_t *dynv = this->dynv;
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size_t dyn[20] = {0};
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size_t i;
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size_t rel[2], got=0;
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Sym *sym;
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for (i=0; dynv[i]; i+=2) {
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if (dynv[i]-0x70000000UL<20)
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dyn[dynv[i]&31] = dynv[i+1];
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else if (dynv[i] == DT_PLTGOT)
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got = dynv[i+1];
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}
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i = dyn[DT_MIPS_LOCAL_GOTNO-0x70000000];
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if (this->shortname && !strcmp(this->shortname, "libc.so")) {
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got += sizeof(size_t) * i;
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} else {
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for (; i; i--, got+=sizeof(size_t))
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*(size_t *)(base+got) += (size_t)base;
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}
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sym = this->syms + dyn[DT_MIPS_GOTSYM-0x70000000];
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i = dyn[DT_MIPS_SYMTABNO-0x70000000] - dyn[DT_MIPS_GOTSYM-0x70000000];
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for (; i; i--, got+=sizeof(size_t), sym++) {
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rel[0] = got;
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rel[1] = sym-this->syms << 8 | R_MIPS_JUMP_SLOT;
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*(size_t *)(base+got) = 0;
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do_relocs(this, rel, sizeof rel, 2);
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}
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}
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#define NEED_ARCH_RELOCS 1
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#define DYNAMIC_IS_RO 1
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