review generic tls support

*-link.c: remove stupid loops
tccelf.c: ...also
tccgen.c: create .tdata/.tbss sections only when needed

arm-link.c

@@ -434,29 +434,12 @@ ST_FUNC void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
             return;
         case R_ARM_TLS_LE32:
             {
-                ElfW(Sym) *sym;
-                Section *sec;
                 int32_t x;
-                addr_t tls_start = 0, tls_end = 0, tls_align = 1;
+                if (s1->tls_end) {
-                int i;
+                    x = val - s1->tls_start + 8;
-
-                sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
-                sec = s1->sections[sym->st_shndx];
-
-                for (i = 1; i < s1->nb_sections; i++) {
-                    Section *s = s1->sections[i];
-                    if (s->sh_flags & SHF_TLS && s->sh_size) {
-                        if (!tls_start || s->sh_addr < tls_start)
-                            tls_start = s->sh_addr;
-                        if (s->sh_addr + s->sh_size > tls_end)
-                            tls_end = s->sh_addr + s->sh_size;
-                        if (s->sh_addralign > tls_align)
-                            tls_align = s->sh_addralign;
-                    }
-                }
-                if (tls_end > tls_start) {
-                    x = val - tls_start + 8;
                 } else {
+                    ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
+                    Section *sec = s1->sections[sym->st_shndx];
                     x = val - sec->sh_addr - sec->data_offset + 8;
                 }
                 add32le(ptr, x);

arm64-link.c

@@ -371,17 +371,8 @@ ST_FUNC void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
             return;
         case R_AARCH64_TLSLE_ADD_TPREL_HI12:
         case R_AARCH64_TLSLE_ADD_TPREL_LO12: {
-            addr_t tls_start = 0;
-            int i;
-            for (i = 1; i < s1->nb_sections; i++) {
-                Section *s = s1->sections[i];
-                if (s->sh_flags & SHF_TLS && s->sh_size) {
-                    if (!tls_start || s->sh_addr < tls_start)
-                        tls_start = s->sh_addr;
-                }
-            }
             /* glibc arm64: tp points to tcbhead_t (DTV), TLS data starts after it */
-            int64_t tp_offset = val - tls_start + 16;
+            int64_t tp_offset = val - s1->tls_start + 16;
             int64_t imm;
             if (type == R_AARCH64_TLSLE_ADD_TPREL_HI12)
                 imm = (tp_offset >> 12) & 0xfff;

i386-link.c

@@ -318,31 +318,12 @@ ST_FUNC void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
             return;
         case R_386_TLS_LE:
             {
-                ElfW(Sym) *sym;
-                Section *sec;
                 int32_t x;
-                addr_t tls_start = 0, tls_end = 0, tls_align = 1;
+                if (s1->tls_end) {
-                int i;
+                    x = val - s1->tls_end;
-
-                sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
-                sec = s1->sections[sym->st_shndx];
-
-                for (i = 1; i < s1->nb_sections; i++) {
-                    Section *s = s1->sections[i];
-                    if (s->sh_flags & SHF_TLS && s->sh_size) {
-                        if (!tls_start || s->sh_addr < tls_start)
-                            tls_start = s->sh_addr;
-                        if (s->sh_addr + s->sh_size > tls_end)
-                            tls_end = s->sh_addr + s->sh_size;
-                        if (s->sh_addralign > tls_align)
-                            tls_align = s->sh_addralign;
-                    }
-                }
-                if (tls_end > tls_start) {
-                    addr_t tls_size = tls_end - tls_start;
-                    addr_t aligned_size = (tls_size + tls_align - 1) & ~(tls_align - 1);
-                    x = val - (tls_start + aligned_size);
                 } else {
+                    ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
+                    Section *sec = s1->sections[sym->st_shndx];
                     x = val - sec->sh_addr - sec->data_offset;
                 }
                 add32le(ptr, x);

riscv64-link.c

@@ -407,17 +407,7 @@ ST_FUNC void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
 
     case R_RISCV_TPREL_HI20:
     case R_RISCV_TPREL_LO12_I: {
-        addr_t tls_start = 0;
+        int64_t tp_offset = val - s1->tls_start;
-        int64_t tp_offset;
-        int i;
-        for (i = 1; i < s1->nb_sections; i++) {
-            Section *s = s1->sections[i];
-            if (s->sh_flags & SHF_TLS && s->sh_size) {
-                if (!tls_start || s->sh_addr < tls_start)
-                    tls_start = s->sh_addr;
-            }
-        }
-        tp_offset = val - tls_start;
         if (type == R_RISCV_TPREL_HI20) {
             off64 = (int64_t)(tp_offset + 0x800) >> 12;
             if ((off64 + ((uint64_t)1 << 20)) >> 21)

tcc.h

@@ -889,7 +889,6 @@ struct TCCState {
 
     /* predefined sections */
     Section *text_section, *data_section, *rodata_section, *bss_section;
-    Section *tdata_section, *tbss_section;
     Section *common_section;
     Section *cur_text_section; /* current section where function code is generated */
 #ifdef CONFIG_TCC_BCHECK
@@ -930,6 +929,8 @@ struct TCCState {
     ElfW_Rel *qrel;
     #define qrel s1->qrel
 
+    addr_t tls_start, tls_end;
+
 #ifdef TCC_TARGET_RISCV64
     struct pcrel_hi { addr_t addr, val; } **pcrel_hi_entries;
     int nb_pcrel_hi_entries;
@@ -1979,8 +1980,6 @@ static inline void post_sem(TCCSem *p) {
 #define data_section        TCC_STATE_VAR(data_section)
 #define rodata_section      TCC_STATE_VAR(rodata_section)
 #define bss_section         TCC_STATE_VAR(bss_section)
-#define tdata_section       TCC_STATE_VAR(tdata_section)
-#define tbss_section        TCC_STATE_VAR(tbss_section)
 #define common_section      TCC_STATE_VAR(common_section)
 #define cur_text_section    TCC_STATE_VAR(cur_text_section)
 #define bounds_section      TCC_STATE_VAR(bounds_section)

tccelf.c

@@ -70,8 +70,6 @@ ST_FUNC void tccelf_new(TCCState *s)
     /* create ro data section (make ro after relocation done with GNU_RELRO) */
     rodata_section = new_section(s, rdata, SHT_PROGBITS, shf_RELRO);
     bss_section = new_section(s, ".bss", SHT_NOBITS, SHF_ALLOC | SHF_WRITE);
-    tdata_section = new_section(s, ".tdata", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE | SHF_TLS);
-    tbss_section = new_section(s, ".tbss", SHT_NOBITS, SHF_ALLOC | SHF_WRITE | SHF_TLS);
     common_section = new_section(s, ".common", SHT_NOBITS, SHF_PRIVATE);
     common_section->sh_num = SHN_COMMON;
 
@@ -2198,12 +2196,11 @@ struct dyn_inf {
     ElfW(Phdr) *phdr;
     int phnum;
     int shnum;
+    int tls;
+    int relro;
     Section *interp;
     Section *note;
     Section *gnu_hash;
-
-    /* read only segment mapping for GNU_RELRO */
-    Section _roinf, *roinf;
 };
 
 /* Decide the layout of sections loaded in memory. This must be done before
@@ -2226,7 +2223,7 @@ static int sort_sections(TCCState *s1, int *sec_order, struct dyn_inf *d)
             if (s->sh_flags & SHF_WRITE)
                 j = 0x200;
             if (s->sh_flags & SHF_TLS)
-                j += 0x200;
+                j = 0x300;
         } else {
             j = 0x700;
         }
@@ -2287,6 +2284,9 @@ static int sort_sections(TCCState *s1, int *sec_order, struct dyn_inf *d)
     sec_order[0] = 0;
     d->shnum = 1;
 
+#define SHFX_NEWPH (1 << 4)
+#define SHFX_RELRO (1 << 5)
+
     /* count PT_LOAD headers needed */
     n = f0 = 0;
     for (i = 1; i < nb_sections; i++) {
@@ -2297,18 +2297,21 @@ static int sort_sections(TCCState *s1, int *sec_order, struct dyn_inf *d)
             ++d->shnum;
         if (k < 0x700) {
             f = s->sh_flags & (SHF_ALLOC|SHF_WRITE|SHF_EXECINSTR);
-#if TARGETOS_NetBSD
+#if TARGETOS_NetBSD || TARGETOS_FreeBSD
 	    /* NetBSD only supports 2 PT_LOAD sections.
 	       See: https://blog.netbsd.org/tnf/entry/the_first_report_on_lld */
 	    if ((f & SHF_WRITE) == 0)
                 f |= SHF_EXECINSTR;
 #else
             if ((k & 0xfff0) == 0x240) /* RELRO sections */
-                f |= 1<<4;
+                d->relro = 1, f |= SHFX_RELRO;
 #endif
             /* start new header when flags changed or relro, but avoid zero memsz */
             if (f != f0 && s->sh_size)
-                f0 = f, ++n, f |= 1<<8;
+                f0 = f, ++n, f |= SHFX_NEWPH;
+
+            if ((s->sh_flags & SHF_TLS) && s->sh_size)
+                d->tls = 1, f |= SHF_TLS;
         }
         sec_cls[i] = f;
         //printf("ph %d sec %02d : %3X %3X  %8.2X  %04X  %s\n", (f>0) * n, i, f, k, s->sh_type, (int)s->sh_size, s->name);
@@ -2331,13 +2334,24 @@ static ElfW(Phdr) *fill_phdr(ElfW(Phdr) *ph, int type, Section *s)
     return ph;
 }
 
+static ElfW(Phdr) *update_phdr(ElfW(Phdr) *ph, int type, Section *s, addr_t addr, int file_offset)
+{
+    if (ph->p_type == 0) {
+        fill_phdr(ph, type, s);
+        ph->p_flags |= PF_W;
+    }
+    ph->p_filesz = file_offset - ph->p_offset;
+    ph->p_memsz = addr - ph->p_vaddr;
+    return ph;
+}
+
 /* Assign sections to segments and decide how are sections laid out when loaded
    in memory. This function also fills corresponding program headers. */
 static int layout_sections(TCCState *s1, int *sec_order, struct dyn_inf *d)
 {
     Section *s;
     addr_t addr, tmp, align, s_align, base;
-    ElfW(Phdr) *ph = NULL;
+    ElfW(Phdr) *ph = NULL, *ph2;
     int i, f, n, phnum, phfill;
     int file_offset;
 
@@ -2347,26 +2361,16 @@ static int layout_sections(TCCState *s1, int *sec_order, struct dyn_inf *d)
     if (d->interp)
         phfill = 2;
     phnum += phfill;
+    if (d->tls)
+        d->tls = phnum, ++phnum;
+    if (d->relro)
+        d->relro = phnum, ++phnum;
     if (d->note)
         ++phnum;
     if (d->dynamic)
         ++phnum;
     if (eh_frame_hdr_section)
         ++phnum;
-    if (d->roinf)
-        ++phnum;
-    {
-        int has_tls = 0;
-        for (i = 1; i < s1->nb_sections; i++) {
-            s = s1->sections[i];
-            if (s->sh_flags & SHF_TLS) {
-                has_tls = 1;
-                break;
-            }
-        }
-        if (has_tls)
-            ++phnum;
-    }
     d->phnum = phnum;
     d->phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
 
@@ -2415,7 +2419,7 @@ static int layout_sections(TCCState *s1, int *sec_order, struct dyn_inf *d)
             continue;
         }
 
-        if ((f & 1<<8) && n) {
+        if ((f & SHFX_NEWPH) && n) {
             /* different rwx section flags */
             if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
                 /* if in the middle of a page, w e duplicate the page in
@@ -2433,51 +2437,53 @@ static int layout_sections(TCCState *s1, int *sec_order, struct dyn_inf *d)
         s->sh_offset = file_offset;
         s->sh_addr = addr;
 
-        if (f & 1<<8) {
+        addr += s->sh_size;
+        if (s->sh_type != SHT_NOBITS)
+            file_offset += s->sh_size;
+
+        if (f & SHFX_NEWPH) {
             /* set new program header */
             ph = &d->phdr[phfill + n];
-            ph->p_type = PT_LOAD;
+            fill_phdr(ph, PT_LOAD, s);
             ph->p_align = s_align;
-            ph->p_flags = PF_R;
             if (f & SHF_WRITE)
                 ph->p_flags |= PF_W;
             if (f & SHF_EXECINSTR)
                 ph->p_flags |= PF_X;
-
-            ph->p_offset = file_offset;
-            ph->p_vaddr = addr;
             if (n == 0) {
 		/* Make the first PT_LOAD segment include the program
 		   headers itself (and the ELF header as well), it'll
 		   come out with same memory use but will make various
 		   tools like binutils strip work better.  */
 		ph->p_offset = 0;
-		ph->p_vaddr = base;
+                ph->p_paddr = ph->p_vaddr = base;
             }
-            ph->p_paddr = ph->p_vaddr;
             ++n;
         }
 
-        if (f & 1<<4) {
+        if (ph)
-            Section *roinf = &d->_roinf;
+            update_phdr(ph, 0, 0, addr, file_offset);
-            if (roinf->sh_size == 0) {
+
-                roinf->sh_offset = s->sh_offset;
+        if (f & SHFX_RELRO) {
-                roinf->sh_addr = s->sh_addr;
+            ph2 = update_phdr(&d->phdr[d->relro], PT_GNU_RELRO, s, addr, file_offset);
-                roinf->sh_addralign = 1;
+            ph2->p_align = 1;
-	    }
-            roinf->sh_size = (addr - roinf->sh_addr) + s->sh_size;
         }
 
-        addr += s->sh_size;
+        if (f & SHF_TLS) {
-        if (s->sh_type != SHT_NOBITS)
+            ph2 = update_phdr(&d->phdr[d->tls], PT_TLS, s, addr, file_offset);
-            file_offset += s->sh_size;
+            if (s->sh_addralign > ph2->p_align)
-
+                ph2->p_align = s->sh_addralign;
-        if (ph) {
-            ph->p_filesz = file_offset - ph->p_offset;
-            ph->p_memsz = addr - ph->p_vaddr;
         }
     }
 
+    if (d->tls) {
+        ++ph;
+        /* for xxx-link.c:relocate() */
+        s1->tls_start = ph->p_vaddr;
+        s1->tls_end = s1->tls_start + ph->p_memsz + (-ph->p_memsz & (ph->p_align - 1));
+    }
+    if (d->relro)
+        ++ph;
     /* Fill other headers */
     if (d->note)
         fill_phdr(++ph, PT_NOTE, d->note);
@@ -2485,36 +2491,6 @@ static int layout_sections(TCCState *s1, int *sec_order, struct dyn_inf *d)
         fill_phdr(++ph, PT_DYNAMIC, d->dynamic)->p_flags |= PF_W;
     if (eh_frame_hdr_section)
         fill_phdr(++ph, PT_GNU_EH_FRAME, eh_frame_hdr_section);
-    if (d->roinf)
-        fill_phdr(++ph, PT_GNU_RELRO, d->roinf)->p_flags |= PF_W;
-    {
-        /* Create PT_TLS segment covering all TLS sections */
-        Section *tls_start_sec = NULL;
-        addr_t tls_start = 0, tls_end = 0;
-        for (i = 1; i < s1->nb_sections; i++) {
-            s = s1->sections[i];
-            if (s->sh_flags & SHF_TLS && s->sh_size) {
-                if (!tls_start_sec) {
-                    tls_start_sec = s;
-                    tls_start = s->sh_addr;
-                    tls_end = s->sh_addr + s->sh_size;
-                } else {
-                    if (s->sh_addr < tls_start)
-                        tls_start = s->sh_addr;
-                    if (s->sh_addr + s->sh_size > tls_end)
-                        tls_end = s->sh_addr + s->sh_size;
-                }
-            }
-        }
-        if (tls_start_sec) {
-            ph = fill_phdr(++ph, PT_TLS, tls_start_sec);
-            ph->p_vaddr = tls_start;
-            ph->p_paddr = tls_start;
-            ph->p_filesz = tls_end - tls_start;
-            ph->p_memsz = ph->p_filesz;
-            ph->p_align = tls_start_sec->sh_addralign;
-        }
-    }
     if (d->interp)
         fill_phdr(&d->phdr[1], PT_INTERP, d->interp);
     if (phfill) {
@@ -2823,7 +2799,7 @@ static void reorder_sections(TCCState *s1, int *sec_order)
 
     backmap = tcc_malloc(s1->nb_sections * sizeof(backmap[0]));
     for (i = 0, nnew = 0, snew = NULL; i < s1->nb_sections; i++) {
-	k = sec_order[i];
+	k = sec_order ? sec_order[i] : i;
 	s = s1->sections[k];
 	if (!i || s->sh_name) {
 	    backmap[k] = nnew;
@@ -2986,7 +2962,6 @@ static int elf_output_file(TCCState *s1, const char *filename)
     ret = -1;
     interp = dynstr = dynamic = NULL;
     sec_order = NULL;
-    dyninf.roinf = &dyninf._roinf;
 
 #ifdef TCC_TARGET_ARM
     create_arm_attribute_section (s1);
@@ -3008,10 +2983,6 @@ static int elf_output_file(TCCState *s1, const char *filename)
     dyninf.note = create_bsd_note_section (s1, ".note.tag", "FreeBSD");
 #endif
 
-#if TARGETOS_FreeBSD || TARGETOS_NetBSD
-    dyninf.roinf = NULL;
-#endif
-
         /* if linking, also link in runtime libraries (libc, libgcc, etc.) */
         tcc_add_runtime(s1);
 	resolve_common_syms(s1);

tccgen.c

@@ -8400,10 +8400,9 @@ static void decl_initializer_alloc(CType *type, AttributeDef *ad, int r,
             while ((tp->t & (VT_BTYPE|VT_ARRAY)) == (VT_PTR|VT_ARRAY))
                 tp = &tp->ref->type;
             if (type->t & VT_TLS) {
-                if (has_init)
+                sec = find_section(tcc_state, has_init ? ".tdata" : ".tbss");
-                    sec = tdata_section;
+                sec->sh_flags = SHF_ALLOC | SHF_WRITE | SHF_TLS;
-                else
+                sec->sh_type = has_init ? SHT_PROGBITS : SHT_NOBITS;
-                    sec = tbss_section;
             } else if (tp->t & VT_CONSTANT) {
 		sec = rodata_section;
             } else if (has_init) {

tests/tests2/Makefile

@@ -57,8 +57,8 @@ endif
 ifeq ($(CONFIG_OSX),yes)
  SKIP += 144_tls.test # TLS runtime not supported on Mach-O
 endif
-ifeq (,$(filter i386 x86_64 riscv64 arm64,$(ARCH)))
+ifeq (-$(ARCH)-,-arm-)
- SKIP += 144_tls.test # TLS only implemented on these architectures so far
+ SKIP += 144_tls.test # doesn't work currently
 endif
 ifneq (-$(ARCH)-,-arm64-)
  SKIP += 138_arm64_encoding.test

x86_64-link.c

@@ -368,70 +368,29 @@ ST_FUNC void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
                     tcc_error_noabort("unexpected R_X86_64_TLSLD pattern");
             }
             break;
+
         case R_X86_64_DTPOFF32:
         case R_X86_64_TPOFF32:
-            {
-                ElfW(Sym) *sym;
-                Section *sec;
-                int32_t x;
-                addr_t tls_start = 0, tls_end = 0, tls_align = 1;
-                int i;
-
-                sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
-                sec = s1->sections[sym->st_shndx];
-
-                for (i = 1; i < s1->nb_sections; i++) {
-                    Section *s = s1->sections[i];
-                    if (s->sh_flags & SHF_TLS && s->sh_size) {
-                        if (!tls_start || s->sh_addr < tls_start)
-                            tls_start = s->sh_addr;
-                        if (s->sh_addr + s->sh_size > tls_end)
-                            tls_end = s->sh_addr + s->sh_size;
-                        if (s->sh_addralign > tls_align)
-                            tls_align = s->sh_addralign;
-                    }
-                }
-                if (tls_end > tls_start) {
-                    addr_t tls_size = tls_end - tls_start;
-                    addr_t aligned_size = (tls_size + tls_align - 1) & ~(tls_align - 1);
-                    x = val - (tls_start + aligned_size);
-                } else {
-                    x = val - sec->sh_addr - sec->data_offset;
-                }
-                add32le(ptr, x);
-            }
-            break;
         case R_X86_64_DTPOFF64:
         case R_X86_64_TPOFF64:
             {
-                ElfW(Sym) *sym;
-                Section *sec;
                 int32_t x;
-                addr_t tls_start = 0, tls_end = 0, tls_align = 1;
+                if (s1->tls_end) {
-                int i;
+                    x = val - s1->tls_end;
-
-                sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
-                sec = s1->sections[sym->st_shndx];
-
-                for (i = 1; i < s1->nb_sections; i++) {
-                    Section *s = s1->sections[i];
-                    if (s->sh_flags & SHF_TLS && s->sh_size) {
-                        if (!tls_start || s->sh_addr < tls_start)
-                            tls_start = s->sh_addr;
-                        if (s->sh_addr + s->sh_size > tls_end)
-                            tls_end = s->sh_addr + s->sh_size;
-                        if (s->sh_addralign > tls_align)
-                            tls_align = s->sh_addralign;
-                    }
-                }
-                if (tls_end > tls_start) {
-                    addr_t tls_size = tls_end - tls_start;
-                    addr_t aligned_size = (tls_size + tls_align - 1) & ~(tls_align - 1);
-                    x = val - (tls_start + aligned_size);
                 } else {
+                    ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
+                    Section *sec = s1->sections[sym->st_shndx];
                     x = val - sec->sh_addr - sec->data_offset;
                 }
-                add64le(ptr, x);
+                switch (type) {
+                case R_X86_64_DTPOFF64:
+                case R_X86_64_TPOFF64:
+                    add64le(ptr, x);
+                    break;
+                default:
+                    add32le(ptr, x);
+                    break;
+                }
             }
             break;
         case R_X86_64_NONE: