Without MMU, we cannot mark memory regions as read-only.

* ldso/ldso/dl-elf.c (_dl_protect_relro): Do nothing if __ARCH_USE_MMU__ is defined.

Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/ldso/ldso/dl-elf.c b/ldso/ldso/dl-elf.c index d264e6a..1768b5b 100644 --- a/ldso/ldso/dl-elf.c +++ b/ldso/ldso/dl-elf.c @@ -117,6 +117,7 @@ int _dl_unmap_cache(void) void _dl_protect_relro (struct elf_resolve *l) { +#ifdef __ARCH_USE_MMU__ ElfW(Addr) base = (ElfW(Addr)) DL_RELOC_ADDR(l->loadaddr, l->relro_addr); ElfW(Addr) start = (base & PAGE_ALIGN); ElfW(Addr) end = ((base + l->relro_size) & PAGE_ALIGN); @@ -126,6 +127,7 @@ _dl_protect_relro (struct elf_resolve *l) _dl_dprintf(2, "%s: cannot apply additional memory protection after relocation", l->libname); _dl_exit(0); } +#endif }

/* This function's behavior must exactly match that

Add FDPIC dynamic relocations support, similar to what other FDPIC targets do.

Lazy binding is implemented in a folllow-up patch.

Disable the SEND* macros because they involve relocations to access constant strings that are unsupported by the existing arm version.

Define DL_START, START, ARCH_NEEDS_BOOTSTRAP_RELOCS, DL_CHECK_LIB_TYPE similarly to what other FDPIC targets do.

Define raise() because _dl_find_hash references __aeabi_uidivmod, which uses __aeabi_idiv0 which in turn references raise.

* include/elf.h (R_ARM_FUNCDESC): Define. (R_ARM_FUNCDESC_VALUE): Define. * ldso/include/dl-string.h (SEND_STDERR, SEND_ADDRESS_STDERR) (SEND_NUMBER_STDERR): Define empty for __FDPIC__. * ldso/ldso/arm/dl-inlines.h: New file. * ldso/ldso/arm/dl-startup.h (PERFORM_BOOTSTRAP_RELOC): Fix type of load_addr. Fix handling of R_ARM_RELATIVE, add support for R_ARM_FUNCDESC_VALUE. (DL_START, START): Define for __FDPIC__. (raise): Define. * ldso/ldso/arm/dl-sysdep.h (ARCH_NEEDS_BOOTSTRAP_RELOCS): Define. (DL_CHECK_LIB_TYPE): Define. (elf_machine_type_class): Take into account FDPIC related relocations. (elf_machine_load_address): Support __FDPIC__. (elf_machine_relative): Likewise. * ldso/ldso/arm/elfinterp.c (_dl_linux_resolver): Dummy support for __FDPIC__, implemented in a later patch. (_dl_do_reloc): Fix reloc_adr computation for __FDPIC__, fix handling of local symbols. Fix handling of R_ARM_RELATIVE, add support for R_ARM_FUNCDESC_VALUE, R_ARM_FUNCDESC. * ldso/ldso/arm/resolve.S: Make _dl_linux_resolve hidden. * ldso/ldso/fdpic/dl-inlines.h (htab_delete): Declare. * libc/sysdeps/linux/arm/bits/elf-fdpic.h: New file, similar to bfin's. * libc/sysdeps/linux/arm/crtreloc.c: Likewise. * libc/sysdeps/linux/arm/find_exidx.c (__dl_addr_in_loadaddr) Define. (find_exidx_callback): Support __FDPIC__.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/include/elf.h b/include/elf.h index 2db85c5..6280a56 100644 --- a/include/elf.h +++ b/include/elf.h @@ -2696,6 +2696,8 @@ typedef Elf32_Addr Elf32_Conflict; #define R_ARM_TLS_LDO12 109 #define R_ARM_TLS_LE12 110 #define R_ARM_TLS_IE12GP 111 +#define R_ARM_FUNCDESC 163 +#define R_ARM_FUNCDESC_VALUE 164 #define R_ARM_RXPC25 249 #define R_ARM_RSBREL32 250 #define R_ARM_THM_RPC22 251 diff --git a/ldso/include/dl-string.h b/ldso/include/dl-string.h index fc1d1fc..bf69971 100644 --- a/ldso/include/dl-string.h +++ b/ldso/include/dl-string.h @@ -256,7 +256,8 @@ static __always_inline char * _dl_simple_ltoahex(char *local, unsigned long i)

/* On some (wierd) arches, none of this stuff works at all, so * disable the whole lot... */ -#if defined(__mips__) +/* The same applies for ARM FDPIC at least for the moment. */ +#if defined(__mips__) || (__FDPIC__)

# define SEND_STDERR(X) # define SEND_ADDRESS_STDERR(X, add_a_newline) diff --git a/ldso/ldso/arm/dl-inlines.h b/ldso/ldso/arm/dl-inlines.h new file mode 100644 index 0000000..8fdf6eb --- /dev/null +++ b/ldso/ldso/arm/dl-inlines.h @@ -0,0 +1 @@ +#include "../fdpic/dl-inlines.h" diff --git a/ldso/ldso/arm/dl-startup.h b/ldso/ldso/arm/dl-startup.h index 371dc22..d15264f 100644 --- a/ldso/ldso/arm/dl-startup.h +++ b/ldso/ldso/arm/dl-startup.h @@ -131,7 +131,7 @@ __asm__( /* Handle relocation of the symbols in the dynamic loader. */ static __always_inline void PERFORM_BOOTSTRAP_RELOC(ELF_RELOC *rpnt, unsigned long *reloc_addr, - unsigned long symbol_addr, unsigned long load_addr, Elf32_Sym *symtab) + unsigned long symbol_addr, DL_LOADADDR_TYPE load_addr, Elf32_Sym *symtab) { switch (ELF_R_TYPE(rpnt->r_info)) { case R_ARM_NONE: @@ -176,12 +176,53 @@ void PERFORM_BOOTSTRAP_RELOC(ELF_RELOC *rpnt, unsigned long *reloc_addr, *reloc_addr = symbol_addr; break; case R_ARM_RELATIVE: - *reloc_addr += load_addr; + *reloc_addr = DL_RELOC_ADDR(load_addr, *reloc_addr); break; case R_ARM_COPY: break; + case R_ARM_FUNCDESC_VALUE: + { + struct funcdesc_value *dst = (struct funcdesc_value *) reloc_addr; + + dst->entry_point += symbol_addr; + dst->got_value = load_addr.got_value; + } + break; default: SEND_STDERR("Unsupported relocation type\n"); _dl_exit(1); } } + +#ifdef __FDPIC__ +#undef DL_START +#define DL_START(X) \ +static void __attribute__ ((used)) \ +_dl_start (Elf32_Addr dl_boot_got_pointer, \ + struct elf32_fdpic_loadmap *dl_boot_progmap, \ + struct elf32_fdpic_loadmap *dl_boot_ldsomap, \ + Elf32_Dyn *dl_boot_ldso_dyn_pointer, \ + struct funcdesc_value *dl_main_funcdesc, \ + X) + +/* + * Transfer control to the user's application, once the dynamic loader + * is done. We return the address of the function's entry point to + * _dl_boot, see boot1_arch.h. + */ +#define START() do { \ + struct elf_resolve *exec_mod = _dl_loaded_modules; \ + dl_main_funcdesc->entry_point = _dl_elf_main; \ + while (exec_mod->libtype != elf_executable) \ + exec_mod = exec_mod->next; \ + dl_main_funcdesc->got_value = exec_mod->loadaddr.got_value; \ + return; \ +} while (0) + +/* We use __aeabi_idiv0 in _dl_find_hash, so we need to have the raise + symbol. */ +int raise(int sig) +{ + _dl_exit(1); +} +#endif /* __FDPIC__ */ diff --git a/ldso/ldso/arm/dl-sysdep.h b/ldso/ldso/arm/dl-sysdep.h index a47a552..2bb0023 100644 --- a/ldso/ldso/arm/dl-sysdep.h +++ b/ldso/ldso/arm/dl-sysdep.h @@ -10,6 +10,19 @@ /* Define this if the system uses RELOCA. */ #undef ELF_USES_RELOCA #include <elf.h> + +#ifdef __FDPIC__ +/* Need bootstrap relocations */ +#define ARCH_NEEDS_BOOTSTRAP_RELOCS + +#define DL_CHECK_LIB_TYPE(epnt, piclib, _dl_progname, libname) \ +do \ +{ \ + (piclib) = 2; \ +} \ +while (0) +#endif /* __FDPIC__ */ + /* Initialization sequence for the GOT. */ #define INIT_GOT(GOT_BASE,MODULE) \ { \ @@ -62,11 +75,17 @@ unsigned long _dl_linux_resolver(struct elf_resolve * tpnt, int reloc_entry); define the value.

ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one - of the main executable's symbols, as for a COPY reloc. */ -#define elf_machine_type_class(type) \ - ((((type) == R_ARM_JUMP_SLOT || (type) == R_ARM_TLS_DTPMOD32 \ + of the main executable's symbols, as for a COPY reloc. + + Avoid R_ARM_ABS32 to go through the PLT so that R_ARM_TARGET1 + translated to R_ARM_ABS32 doesn't use the PLT: otherwise, this + breaks init_array because functions are referenced through the + PLT. */ +#define elf_machine_type_class(type) \ + ((((type) == R_ARM_JUMP_SLOT || (type) == R_ARM_TLS_DTPMOD32 \ + || (type) == R_ARM_FUNCDESC_VALUE || (type) == R_ARM_FUNCDESC || (type) == R_ARM_ABS32 \ || (type) == R_ARM_TLS_DTPOFF32 || (type) == R_ARM_TLS_TPOFF32) \ - * ELF_RTYPE_CLASS_PLT) \ + * ELF_RTYPE_CLASS_PLT) \ | (((type) == R_ARM_COPY) * ELF_RTYPE_CLASS_COPY))

/* Return the link-time address of _DYNAMIC. Conveniently, this is the @@ -106,10 +125,22 @@ elf_machine_dynamic (void)

extern char __dl_start[] __asm__("_dl_start");

+/* We must force strings used early in the bootstrap into the data + segment. */ +#undef SEND_EARLY_STDERR +#define SEND_EARLY_STDERR(S) \ + do { /* FIXME: implement */; } while (0) + +#undef INIT_GOT +#include "../fdpic/dl-sysdep.h" + /* Return the run-time load address of the shared object. */ static __always_inline Elf32_Addr __attribute__ ((unused)) elf_machine_load_address (void) { +#if defined(__FDPIC__) + return 0; +#else Elf32_Addr got_addr = (Elf32_Addr) &__dl_start; Elf32_Addr pcrel_addr; #if defined __OPTIMIZE__ && !defined __thumb__ @@ -128,19 +159,29 @@ elf_machine_load_address (void) : "=r" (pcrel_addr), "=r" (tmp)); #endif return pcrel_addr - got_addr; +#endif }

static __always_inline void -elf_machine_relative (Elf32_Addr load_off, const Elf32_Addr rel_addr, +elf_machine_relative (DL_LOADADDR_TYPE load_off, const Elf32_Addr rel_addr, Elf32_Word relative_count) { - Elf32_Rel * rpnt = (void *) rel_addr; - --rpnt; - do { - Elf32_Addr *const reloc_addr = (void *) (load_off + (++rpnt)->r_offset); +#if defined(__FDPIC__) + Elf32_Rel *rpnt = (void *) rel_addr; + + do { + unsigned long *reloc_addr = (unsigned long *) DL_RELOC_ADDR(load_off, rpnt->r_offset);

- *reloc_addr += load_off; - } while (--relative_count); + *reloc_addr = DL_RELOC_ADDR(load_off, *reloc_addr); + rpnt++; +#else + Elf32_Rel * rpnt = (void *) rel_addr; + --rpnt; + do { + Elf32_Addr *const reloc_addr = (void *) (load_off + (++rpnt)->r_offset); + *reloc_addr += load_off; +#endif + } while(--relative_count); } #endif /* !_ARCH_DL_SYSDEP */

diff --git a/ldso/ldso/arm/elfinterp.c b/ldso/ldso/arm/elfinterp.c index 96809a9..1435c2c 100644 --- a/ldso/ldso/arm/elfinterp.c +++ b/ldso/ldso/arm/elfinterp.c @@ -36,6 +36,11 @@ extern int _dl_linux_resolve(void);

unsigned long _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry) { +#if __FDPIC__ + /* FIXME: implement. */ + while(1) ; + return 0; +#else ELF_RELOC *this_reloc; char *strtab; char *symname; @@ -88,6 +93,7 @@ unsigned long _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry) #endif

return new_addr; +#endif }

static int @@ -181,7 +187,7 @@ _dl_do_reloc (struct elf_resolve *tpnt,struct r_scope_elem *scope, struct elf_resolve *def_mod = 0; int goof = 0;

- reloc_addr = (unsigned long *) (tpnt->loadaddr + (unsigned long) rpnt->r_offset); + reloc_addr = (unsigned long *) DL_RELOC_ADDR(tpnt->loadaddr, rpnt->r_offset);

reloc_type = ELF_R_TYPE(rpnt->r_info); symtab_index = ELF_R_SYM(rpnt->r_info); @@ -191,25 +197,30 @@ _dl_do_reloc (struct elf_resolve *tpnt,struct r_scope_elem *scope, symname = strtab + symtab[symtab_index].st_name;

if (symtab_index) { - symbol_addr = (unsigned long)_dl_find_hash(symname, scope, tpnt, - elf_machine_type_class(reloc_type), &sym_ref); - - /* - * We want to allow undefined references to weak symbols - this might - * have been intentional. We should not be linking local symbols - * here, so all bases should be covered. - */ - if (!symbol_addr && (ELF_ST_TYPE(symtab[symtab_index].st_info) != STT_TLS) - && (ELF_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK)) { - /* This may be non-fatal if called from dlopen. */ - return 1; - - } - if (_dl_trace_prelink) { - _dl_debug_lookup (symname, tpnt, &symtab[symtab_index], - &sym_ref, elf_machine_type_class(reloc_type)); + if (ELF_ST_BIND (symtab[symtab_index].st_info) == STB_LOCAL) { + symbol_addr = (unsigned long) DL_RELOC_ADDR(tpnt->loadaddr, symtab[symtab_index].st_value); + def_mod = tpnt; + } else { + symbol_addr = (unsigned long)_dl_find_hash(symname, scope, tpnt, + elf_machine_type_class(reloc_type), &sym_ref); + + /* + * We want to allow undefined references to weak symbols - this might + * have been intentional. We should not be linking local symbols + * here, so all bases should be covered. + */ + if (!symbol_addr && (ELF_ST_TYPE(symtab[symtab_index].st_info) != STT_TLS) + && (ELF_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK)) { + /* This may be non-fatal if called from dlopen. */ + return 1; + + } + if (_dl_trace_prelink) { + _dl_debug_lookup (symname, tpnt, &symtab[symtab_index], + &sym_ref, elf_machine_type_class(reloc_type)); + } + def_mod = sym_ref.tpnt; } - def_mod = sym_ref.tpnt; } else { /* * Relocs against STN_UNDEF are usually treated as using a @@ -267,12 +278,40 @@ _dl_do_reloc (struct elf_resolve *tpnt,struct r_scope_elem *scope, *reloc_addr = symbol_addr; break; case R_ARM_RELATIVE: - *reloc_addr += (unsigned long) tpnt->loadaddr; + *reloc_addr = DL_RELOC_ADDR(tpnt->loadaddr, *reloc_addr); break; case R_ARM_COPY: _dl_memcpy((void *) reloc_addr, (void *) symbol_addr, symtab[symtab_index].st_size); break; + case R_ARM_FUNCDESC_VALUE: + { + struct funcdesc_value funcval; + struct funcdesc_value *dst = (struct funcdesc_value *) reloc_addr; + + funcval.entry_point = (void*)symbol_addr; + /* Add offset to section address for local symbols. */ + if (ELF_ST_BIND(symtab[symtab_index].st_info) == STB_LOCAL) + funcval.entry_point += *reloc_addr; + funcval.got_value = def_mod->loadaddr.got_value; + *dst = funcval; + } + break; + case R_ARM_FUNCDESC: + { + unsigned long reloc_value = *reloc_addr; + + if (symbol_addr) + reloc_value = (unsigned long) _dl_funcdesc_for(symbol_addr + reloc_value, sym_ref.tpnt->loadaddr.got_value); + else + /* Relocation against an + undefined weak symbol: + set funcdesc to zero. */ + reloc_value = 0; + + *reloc_addr = reloc_value; + } + break; #if defined USE_TLS && USE_TLS case R_ARM_TLS_DTPMOD32: *reloc_addr = def_mod->l_tls_modid; @@ -330,7 +369,6 @@ _dl_do_lazy_reloc (struct elf_resolve *tpnt, struct r_scope_elem *scope,

#endif return 0; - }

void _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt, @@ -345,3 +383,6 @@ int _dl_parse_relocation_information(struct dyn_elf *rpnt, return _dl_parse(rpnt->dyn, scope, rel_addr, rel_size, _dl_do_reloc); }

+#ifndef IS_IN_libdl +# include "../../libc/sysdeps/linux/arm/crtreloc.c" +#endif diff --git a/ldso/ldso/arm/resolve.S b/ldso/ldso/arm/resolve.S index 7e0058e..2a51643 100644 --- a/ldso/ldso/arm/resolve.S +++ b/ldso/ldso/arm/resolve.S @@ -102,6 +102,7 @@ .align 4 @ 16 byte boundary and there are 32 bytes below (arm case) #if 1 /*(!defined(__thumb__) || defined __THUMB_INTERWORK__) || defined(__thumb2__)*/ .arm + .hidden _dl_linux_resolve .globl _dl_linux_resolve .type _dl_linux_resolve,%function .align 4; diff --git a/ldso/ldso/fdpic/dl-inlines.h b/ldso/ldso/fdpic/dl-inlines.h index f590875..89e7a9a 100644 --- a/ldso/ldso/fdpic/dl-inlines.h +++ b/ldso/ldso/fdpic/dl-inlines.h @@ -7,6 +7,8 @@

#include <inline-hashtab.h>

+static __always_inline void htab_delete(struct funcdesc_ht *htab); + /* Initialize a DL_LOADADDR_TYPE given a got pointer and a complete load map. */ static __always_inline void __dl_init_loadaddr_map(struct elf32_fdpic_loadaddr *loadaddr, Elf32_Addr dl_boot_got_pointer, diff --git a/libc/sysdeps/linux/arm/bits/elf-fdpic.h b/libc/sysdeps/linux/arm/bits/elf-fdpic.h new file mode 100644 index 0000000..3d6db54 --- /dev/null +++ b/libc/sysdeps/linux/arm/bits/elf-fdpic.h @@ -0,0 +1,114 @@ +/* Copyright 2003, 2004 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Lesser General Public License as +published by the Free Software Foundation; either version 2.1 of the +License, or (at your option) any later version. + +In addition to the permissions in the GNU Lesser General Public +License, the Free Software Foundation gives you unlimited +permission to link the compiled version of this file with other +programs, and to distribute those programs without any restriction +coming from the use of this file. (The GNU Lesser General Public +License restrictions do apply in other respects; for example, they +cover modification of the file, and distribution when not linked +into another program.) + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Lesser General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, see http://www.gnu.org/licenses/. */ + +#ifndef _BITS_ELF_FDPIC_H +#define _BITS_ELF_FDPIC_H + +/* These data structures are described in the FDPIC ABI extension. + The kernel passes a process a memory map, such that for every LOAD + segment there is an elf32_fdpic_loadseg entry. A pointer to an + elf32_fdpic_loadmap is passed in r7 at start-up, and a pointer to + an additional such map is passed in r8 for the interpreter, when + there is one. */ + +#include <elf.h> + +/* This data structure represents a PT_LOAD segment. */ +struct elf32_fdpic_loadseg +{ + /* Core address to which the segment is mapped. */ + Elf32_Addr addr; + /* VMA recorded in the program header. */ + Elf32_Addr p_vaddr; + /* Size of this segment in memory. */ + Elf32_Word p_memsz; +}; + +struct elf32_fdpic_loadmap { + /* Protocol version number, must be zero. */ + Elf32_Half version; + /* Number of segments in this map. */ + Elf32_Half nsegs; + /* The actual memory map. */ + struct elf32_fdpic_loadseg segs[/*nsegs*/]; +}; + +struct elf32_fdpic_loadaddr { + struct elf32_fdpic_loadmap *map; + void *got_value; +}; + +/* Map a pointer's VMA to its corresponding address according to the + load map. */ +static __always_inline void * +__reloc_pointer (void *p, + const struct elf32_fdpic_loadmap *map) +{ + int c; + +#if 0 + if (map->version != 0) + /* Crash. */ + ((void(*)())0)(); +#endif + + /* No special provision is made for NULL. We don't want NULL + addresses to go through relocation, so they shouldn't be in + .rofixup sections, and, if they're present in dynamic + relocations, they shall be mapped to the NULL address without + undergoing relocations. */ + + for (c = 0; + /* Take advantage of the fact that the loadmap is ordered by + virtual addresses. In general there will only be 2 entries, + so it's not profitable to do a binary search. */ + c < map->nsegs && p >= (void*)map->segs[c].p_vaddr; + c++) + { + /* This should be computed as part of the pointer comparison + above, but we want to use the carry in the comparison, so we + can't convert it to an integer type beforehand. */ + unsigned long offset = p - (void*)map->segs[c].p_vaddr; + /* We only check for one-past-the-end for the last segment, + assumed to be the data segment, because other cases are + ambiguous in the absence of padding between segments, and + rofixup already serves as padding between text and data. + Unfortunately, unless we special-case the last segment, we + fail to relocate the _end symbol. */ + if (offset < map->segs[c].p_memsz + || (offset == map->segs[c].p_memsz && c + 1 == map->nsegs)) + return (char*)map->segs[c].addr + offset; + } + + /* We might want to crash instead. */ + return (void*)-1; +} + +# define __RELOC_POINTER(ptr, loadaddr) \ + (__reloc_pointer ((void*)(ptr), \ + (loadaddr).map)) + +#endif /* _BITS_ELF_FDPIC_H */ diff --git a/libc/sysdeps/linux/arm/crtreloc.c b/libc/sysdeps/linux/arm/crtreloc.c new file mode 100644 index 0000000..560b416 --- /dev/null +++ b/libc/sysdeps/linux/arm/crtreloc.c @@ -0,0 +1,144 @@ +/* Copyright (C) 2003, 2004 Free Software Foundation, Inc. + written by Alexandre Oliva aoliva@redhat.com +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Lesser General Public License as +published by the Free Software Foundation; either version 2.1 of the +License, or (at your option) any later version. + +In addition to the permissions in the GNU Lesser General Public +License, the Free Software Foundation gives you unlimited +permission to link the compiled version of this file with other +programs, and to distribute those programs without any restriction +coming from the use of this file. (The GNU Lesser General Public +License restrictions do apply in other respects; for example, they +cover modification of the file, and distribution when not linked +into another program.) + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Lesser General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, see http://www.gnu.org/licenses/. */ + +#ifdef __FDPIC__ + +#include <sys/types.h> +#include <link.h> + +/* This file is to be compiled into crt object files, to enable + executables to easily self-relocate. */ + +union word { + char c[4]; + void *v; +}; + +/* Compute the runtime address of pointer in the range [p,e), and then + map the pointer pointed by it. */ +static __always_inline void *** +reloc_range_indirect (void ***p, void ***e, + const struct elf32_fdpic_loadmap *map) +{ + while (p < e) + { + if (*p != (void **)-1) + { + void *ptr = __reloc_pointer (*p, map); + if (ptr != (void *)-1) + { + void *pt; + if ((long)ptr & 3) + { + unsigned char *c = ptr; + int i; + unsigned long v = 0; + for (i = 0; i < 4; i++) + v |= c[i] << 8 * i; + pt = (void *)v; + } + else + pt = *(void**)ptr; + pt = __reloc_pointer (pt, map); + if ((long)ptr & 3) + { + unsigned char *c = ptr; + int i; + unsigned long v = (unsigned long)pt; + for (i = 0; i < 4; i++, v >>= 8) + c[i] = v; + } + else + *(void**)ptr = pt; + } + } + p++; + } + return p; +} + +/* Call __reloc_range_indirect for the given range except for the last + entry, whose contents are only relocated. It's expected to hold + the GOT value. */ +attribute_hidden void* +__self_reloc (const struct elf32_fdpic_loadmap *map, + void ***p, void ***e) +{ + p = reloc_range_indirect (p, e-1, map); + + if (p >= e) + return (void*)-1; + + return __reloc_pointer (*p, map); +} + +#if 0 +/* These are other functions that might be useful, but that we don't + need. */ + +/* Remap pointers in [p,e). */ +static __always_inline void** +reloc_range (void **p, void **e, + const struct elf32_fdpic_loadmap *map) +{ + while (p < e) + { + *p = __reloc_pointer (*p, map); + p++; + } + return p; +} + +/* Remap p, adjust e by the same offset, then map the pointers in the + range determined by them. */ +void attribute_hidden +__reloc_range (const struct elf32_fdpic_loadmap *map, + void **p, void **e) +{ + void **old = p; + + p = __reloc_pointer (p, map); + e += p - old; + reloc_range (p, e, map); +} + +/* Remap p, adjust e by the same offset, then map pointers referenced + by the (unadjusted) pointers in the range. Return the relocated + value of the last pointer in the range. */ +void* attribute_hidden +__reloc_range_indirect (const struct elf32_fdpic_loadmap *map, + void ***p, void ***e) +{ + void ***old = p; + + p = __reloc_pointer (p, map); + e += p - old; + return reloc_range_indirect (p, e, map); +} +#endif + +#endif /* __FDPIC__ */ diff --git a/libc/sysdeps/linux/arm/find_exidx.c b/libc/sysdeps/linux/arm/find_exidx.c index 679d90c..cd4d442 100644 --- a/libc/sysdeps/linux/arm/find_exidx.c +++ b/libc/sysdeps/linux/arm/find_exidx.c @@ -18,6 +18,23 @@ #include <link.h> #include <unwind.h>

+#if __FDPIC__ +#include <bits/elf-fdpic.h> +static __always_inline int +__dl_addr_in_loadaddr(void *p, struct elf32_fdpic_loadaddr loadaddr) +{ + struct elf32_fdpic_loadmap *map = loadaddr.map; + int c; + + for (c = 0; c < map->nsegs; c++) + if ((void *)map->segs[c].addr <= p && + (char *)p < (char *)map->segs[c].addr + map->segs[c].p_memsz) + return 1; + + return 0; +} +#endif + struct unw_eh_callback_data { _Unwind_Ptr pc; @@ -32,6 +49,26 @@ struct unw_eh_callback_data static int find_exidx_callback (struct dl_phdr_info * info, size_t size, void * ptr) { +#if __FDPIC__ + struct unw_eh_callback_data * data; + const ElfW(Phdr) *phdr; + int i; + int match = 0; + + data = (struct unw_eh_callback_data *) ptr; + if (__dl_addr_in_loadaddr((void *) data->pc, info->dlpi_addr)) { + match = 1; + phdr = info->dlpi_phdr; + for (i = info->dlpi_phnum; i > 0; i--, phdr++) { + if (phdr->p_type == PT_ARM_EXIDX) { + data->exidx_start = (_Unwind_Ptr) __RELOC_POINTER(phdr->p_vaddr, info->dlpi_addr); + data->exidx_len = phdr->p_memsz; + } + } + } + + return match; +#else struct unw_eh_callback_data * data; const ElfW(Phdr) *phdr; int i; @@ -59,6 +96,7 @@ find_exidx_callback (struct dl_phdr_info * info, size_t size, void * ptr) }

return match; +#endif }

* ldso/ldso/ldso.c (_start): Fix definition for __FDPIC__.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/ldso/ldso/ldso.c b/ldso/ldso/ldso.c index 17818b5..c625757 100644 --- a/ldso/ldso/ldso.c +++ b/ldso/ldso/ldso.c @@ -109,7 +109,13 @@ static unsigned char *_dl_mmap_zero = NULL; /* Also used by _dl_malloc */ static struct elf_resolve **init_fini_list; static struct elf_resolve **scope_elem_list; static unsigned int nlist; /* # items in init_fini_list */ +#ifdef __FDPIC__ +/* We need to take the address of _start instead of its FUNCDESC: + declare it as void* to control the relocation emitted. */ +extern void *_start; +#else extern void _start(void); +#endif

#ifdef __UCLIBC_HAS_SSP__ # include <dl-osinfo.h>

In ARM_EABI mode, the pread64 syscall parameters are aligned on 64-bits. This syscall is used in rtld when processing FDPIC relocations.

* ldso/include/dl-syscall.h (__syscall_pread): Fix definition. (__dl_pread): Fix syscall invocation. * ldso/ldso/fdpic/dl-sysdep.h (__DL_PREAD): Handle __NR_pread64.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/ldso/include/dl-syscall.h b/ldso/include/dl-syscall.h index 5ba8c87..9d80c6a 100644 --- a/ldso/include/dl-syscall.h +++ b/ldso/include/dl-syscall.h @@ -159,14 +159,25 @@ static __always_inline _syscall4(int, _dl_readlink, int, id, const char *, path,

#ifdef __NR_pread64 #define __NR___syscall_pread __NR_pread64 +#ifdef __UCLIBC_SYSCALL_ALIGN_64BIT__ +static __always_inline _syscall6(ssize_t, __syscall_pread, int, fd, void *, buf, size_t, dummy, + size_t, count, off_t, offset_hi, off_t, offset_lo) + +static __always_inline ssize_t +_dl_pread(int fd, void *buf, size_t count, off_t offset) +{ + return __syscall_pread(fd, buf, count, 0, __LONG_LONG_PAIR((offset >> 32), (offset & 0xffffffff))); +} +#else static __always_inline _syscall5(ssize_t, __syscall_pread, int, fd, void *, buf, size_t, count, off_t, offset_hi, off_t, offset_lo)

static __always_inline ssize_t _dl_pread(int fd, void *buf, size_t count, off_t offset) { - return __syscall_pread(fd, buf, count, offset, offset >> 31); + return __syscall_pread(fd, buf, count, __LONG_LONG_PAIR(offset >> 31, offset)); } +#endif #elif defined __NR_pread #define __NR___syscall_pread __NR_pread static __always_inline _syscall5(ssize_t, __syscall_pread, int, fd, void *, buf, diff --git a/ldso/ldso/fdpic/dl-sysdep.h b/ldso/ldso/fdpic/dl-sysdep.h index 546811a..6ab303b 100644 --- a/ldso/ldso/fdpic/dl-sysdep.h +++ b/ldso/ldso/fdpic/dl-sysdep.h @@ -96,7 +96,7 @@ struct funcdesc_ht; elfinterp.c. */ #define DL_SKIP_BOOTSTRAP_RELOC(SYMTAB, INDEX, STRTAB) 0

-#ifdef __NR_pread +#if defined(__NR_pread) || defined(__NR_pread64) #define _DL_PREAD(FD, BUF, SIZE, OFFSET) \ (_dl_pread((FD), (BUF), (SIZE), (OFFSET))) #endif

* libc/misc/internals/__uClibc_main.c (funcdesc_value): New. (fdpic_init_array_jump): New. (__uClibc_fini): Support __FDPIC__. (__uClibc_main): Likewise.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/libc/misc/internals/__uClibc_main.c b/libc/misc/internals/__uClibc_main.c index d80565e..d8286f2 100644 --- a/libc/misc/internals/__uClibc_main.c +++ b/libc/misc/internals/__uClibc_main.c @@ -48,6 +48,39 @@ int _pe_secure = 0; libc_hidden_data_def(_pe_secure)

+#if !defined(SHARED) && defined(__FDPIC__) +struct funcdesc_value +{ + void *entry_point; + void *got_value; +} __attribute__((__aligned__(8))); + + +/* Prevent compiler optimization that removes GOT assignment. + + Due to optimization passes (block split and move), in the rare case + where use r9 is the single instruction in a block we can have the + following behaviour: + - this block is marked as a forward block since use is not + considered as an active instruction after reload pass. + + - In this case a jump in this block can be moved to the start of the + next one and so remove use in this flow of instructions which can + lead to a removal of r9 restoration after a call. */ +#define _dl_stabilize_funcdesc(val) \ + ({ __asm__ ("" : "+m" (*(val))); (val); }) + +static void fdpic_init_array_jump(void *addr) +{ + struct funcdesc_value *fm = (struct funcdesc_value *) fdpic_init_array_jump; + struct funcdesc_value fd = {addr, fm->got_value}; + + void (*pf)(void) = (void*) _dl_stabilize_funcdesc(&fd); + + (*pf)(); +} +#endif + #ifndef SHARED void *__libc_stack_end = NULL;

@@ -307,7 +340,11 @@ void __uClibc_fini(void) # elif !defined (__UCLIBC_FORMAT_SHARED_FLAT__) size_t i = __fini_array_end - __fini_array_start; while (i-- > 0) +#if !defined(SHARED) && defined(__FDPIC__) + fdpic_init_array_jump(__fini_array_start[i]); +#else (*__fini_array_start [i]) (); +#endif # endif if (__app_fini != NULL) (__app_fini)(); @@ -436,7 +473,11 @@ void __uClibc_main(int (*main)(int, char **, char **), int argc, const size_t size = __preinit_array_end - __preinit_array_start; size_t i; for (i = 0; i < size; i++) +#if !defined(SHARED) && defined(__FDPIC__) + fdpic_init_array_jump(__preinit_array_start[i]); +#else (*__preinit_array_start [i]) (); +#endif } # endif /* Run all the application's ctors now. */ @@ -452,7 +493,11 @@ void __uClibc_main(int (*main)(int, char **, char **), int argc, const size_t size = __init_array_end - __init_array_start; size_t i; for (i = 0; i < size; i++) +#if !defined(SHARED) && defined(__FDPIC__) + fdpic_init_array_jump(__init_array_start[i]); +#else (*__init_array_start [i]) (); +#endif } # endif #endif

Otherwise we have link errors because of unresolved refs in libgcc.a:

ld: /lib/gcc/arm-none-uclinuxfdpiceabi/9.0.0/libgcc.a(pr-support.o): in function `_Unwind_GetDataRelBase': /libgcc/config/arm/pr-support.c:378: undefined reference to `abort' ld: /lib/gcc/arm-none-uclinuxfdpiceabi/9.0.0/libgcc.a(unwind-arm.o): in function `unwind_phase2_forced': /libgcc/unwind-arm-common.inc:511: undefined reference to `memcpy'

* ldso/ldso/Makefile.in (CFLAGS-rtld): Always use -fno-unwind-tables -fno-asynchronous-unwind-tables on arm

Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/ldso/ldso/Makefile.in b/ldso/ldso/Makefile.in index acb1a5b..4f2a184 100644 --- a/ldso/ldso/Makefile.in +++ b/ldso/ldso/Makefile.in @@ -14,12 +14,10 @@ ifneq ($(TARGET_ARCH),arc) CFLAGS-rtld += -fno-omit-frame-pointer endif

-ifeq ($(DODEBUG),y) ifeq ($(TARGET_ARCH),arm) # This stuff will not work with -funwind-tables / -fasynchronous-unwind-tables CFLAGS-rtld += -fno-unwind-tables -fno-asynchronous-unwind-tables endif -endif

CFLAGS-rtld += -I$(top_srcdir)ldso/ldso/$(TARGET_ARCH) -I$(top_srcdir)ldso/include -I$(top_srcdir)ldso/ldso CFLAGS-rtld += -DUCLIBC_RUNTIME_PREFIX="$(RUNTIME_PREFIX)" -DUCLIBC_LDSO="$(UCLIBC_LDSO)"

* extra/Configs/Config.in: enable UCLIBC_HAS_THREADS_NATIVE on TARGET_arm.

Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in index 7443903..f96511f 100644 --- a/extra/Configs/Config.in +++ b/extra/Configs/Config.in @@ -541,7 +541,7 @@ config UCLIBC_HAS_THREADS_NATIVE !TARGET_h8300 && \ !TARGET_hppa && \ !TARGET_ia64 && \ - ARCH_USE_MMU + (ARCH_USE_MMU || TARGET_arm) help If you want to compile uClibc with NPTL support, then answer Y.

Make _dl_initial_error_catch_tsd hidden, such that we do not need a FUNCDESC relocation when initializing _dl_error_catch_tsd.

* ldso/ldso/dl-tls.c (_dl_initial_error_catch_tsd): Declare hidden.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/ldso/ldso/dl-tls.c b/ldso/ldso/dl-tls.c index 2d21242..80da815 100644 --- a/ldso/ldso/dl-tls.c +++ b/ldso/ldso/dl-tls.c @@ -957,6 +957,7 @@ _dl_add_to_slotinfo (struct link_map *l) /* Taken from glibc/elf/rtld.c */ static bool tls_init_tp_called;

+rtld_hidden_proto(_dl_initial_error_catch_tsd) /* _dl_error_catch_tsd points to this for the single-threaded case. It's reset by the thread library for multithreaded programs. */ void ** __attribute__ ((const))

They do not work on MMU-less systems.

For atfork, implement a hidden function that always returns EPERM.

* libpthread/nptl/sysdeps/unix/sysv/linux/fork.c: Disable if __ARCH_USE_MMU__ is not defined. * libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c (__libc_pthread_init): Handle __ARCH_USE_MMU__. * libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c: Likewise. * libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c: Likewise.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/fork.c b/libpthread/nptl/sysdeps/unix/sysv/linux/fork.c index 9b96152..429fb90 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/fork.c +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/fork.c @@ -28,6 +28,7 @@ #include <atomic.h> #include <errno.h>

+#ifdef __ARCH_USE_MMU__ unsigned long int *__fork_generation_pointer;

@@ -206,3 +207,5 @@ fork (void) return pid; } libc_hidden_def(fork) + +#endif /* __ARCH_USE_MMU__ */ diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c b/libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c index 0df9951..0cdbcfe 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c @@ -40,10 +40,14 @@ __libc_pthread_init ( void (*reclaim) (void)) { /* Remember the pointer to the generation counter in libpthread. */ +#ifdef __ARCH_USE_MMU__ __fork_generation_pointer = ptr; +#endif

/* Called by a child after fork. */ +#ifdef __ARCH_USE_MMU__ __register_atfork (NULL, NULL, reclaim, NULL); +#endif

#ifndef TLS_MULTIPLE_THREADS_IN_TCB return &__libc_multiple_threads; diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c b/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c index b745f9d..55835e5 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c @@ -24,6 +24,7 @@ #include <tls.h>

+#ifdef __ARCH_USE_MMU__ /* Lock to protect allocation and deallocation of fork handlers. */ int __fork_lock = LLL_LOCK_INITIALIZER;

@@ -118,6 +119,18 @@ __linkin_atfork (struct fork_handler *newp) while (catomic_compare_and_exchange_bool_acq (&__fork_handlers, newp, newp->next) != 0); } +#else +int +__register_atfork ( + void (*prepare) (void), + void (*parent) (void), + void (*child) (void), + void *dso_handle) +{ + return EPERM; +} +libc_hidden_def (__register_atfork) +#endif

#if 0 libc_freeres_fn (free_mem) @@ -145,4 +158,3 @@ libc_freeres_fn (free_mem) } } #endif - diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c b/libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c index 69e2621..e958e71 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c @@ -22,7 +22,7 @@ #include <atomic.h> #include <tls.h>

- +#ifdef __ARCH_USE_MMU__ void __unregister_atfork ( void *dso_handle) @@ -120,3 +120,11 @@ __unregister_atfork ( deleted = deleted->next; } } +#else +void +__unregister_atfork ( + void *dso_handle) +{ + /* Nothing to do. */ +} +#endif

phdr->p_vaddr of TLS segment is not a valid value for FDPIC so we can either translate phdr->p_vaddr using loadmap (not easy here) or use a new linker script defined symbol, whih this patch does.

* libpthread/nptl/sysdeps/generic/libc-tls.c (__tdata_start): Declare. (__libc_setup_tls): Support __FDPIC__.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/libpthread/nptl/sysdeps/generic/libc-tls.c b/libpthread/nptl/sysdeps/generic/libc-tls.c index 58e77ff..725f3df 100644 --- a/libpthread/nptl/sysdeps/generic/libc-tls.c +++ b/libpthread/nptl/sysdeps/generic/libc-tls.c @@ -36,6 +36,11 @@ extern ElfW(Phdr) *_dl_phdr; extern size_t _dl_phnum;

+#ifdef __FDPIC__ +/* phdr->p_vaddr is not valid in FDPIC mode. To find tdata start we + use the linker script defined symbol __tdata_start. */ +extern int __tdata_start; +#endif

static dtv_t static_dtv[2 + TLS_SLOTINFO_SURPLUS];

@@ -130,7 +135,11 @@ __libc_setup_tls (size_t tcbsize, size_t tcbalign) /* Remember the values we need. */ memsz = phdr->p_memsz; filesz = phdr->p_filesz; +#ifdef __FDPIC__ + initimage = (void *) &__tdata_start; +#else initimage = (void *) phdr->p_vaddr; +#endif align = phdr->p_align; if (phdr->p_align > max_align) max_align = phdr->p_align;

* libpthread/nptl/Makefile.in (libpthread-routines-): Remove pthread_mutex_getprioceiling.c and pthread_mutex_setprioceiling.c.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/libpthread/nptl/Makefile.in b/libpthread/nptl/Makefile.in index a2f30ac..bd220ba 100644 --- a/libpthread/nptl/Makefile.in +++ b/libpthread/nptl/Makefile.in @@ -18,7 +18,6 @@ libpthread-shared-only-routines-y = version.c libpthread-static-only-routines-y = pthread_atfork.c libpthread-routines- += $(notdir $(wildcard $(libpthread_DIR)/gen_*.c)) # dummy generated files libpthread-routines- += allocatestack.c # dummy included by pthread_create.c -libpthread-routines- += pthread_mutex_getprioceiling.c pthread_mutex_setprioceiling.c # XXX: delete those or use them! libpthread-routines-$(UCLIBC_SUSV4_LEGACY) += pthread_getconcurrency.c \ pthread_setconcurrency.c libpthread_CSRC = $(filter-out $(libpthread-routines-) \

busybox init checks it has pid 1, but getpid() returns another value when building busybox statically. This is because the corresponding area is not cleared when allocated (it is allocated with MAP_UNINITIALIZED, whose behavior depends on the Linux kernel's CONFIG_MMAP_ALLOW_UNINITIALIZED).

This patch fixes the problem by explicitly clearing the memory area.

* libpthread/nptl/sysdeps/generic/libc-tls.c (__libc_tls_setup): Clear tlsblock.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/libpthread/nptl/sysdeps/generic/libc-tls.c b/libpthread/nptl/sysdeps/generic/libc-tls.c index 725f3df..5f89c91 100644 --- a/libpthread/nptl/sysdeps/generic/libc-tls.c +++ b/libpthread/nptl/sysdeps/generic/libc-tls.c @@ -162,6 +162,7 @@ __libc_setup_tls (size_t tcbsize, size_t tcbalign) tcb_offset = roundup (tcbsize, align ?: 1); tlsblock = sbrk (tcb_offset + memsz + max_align + TLS_PRE_TCB_SIZE + GL(dl_tls_static_size)); + memset(tlsblock, '\0', tcb_offset + memsz + max_align + TLS_PRE_TCB_SIZE + GL(dl_tls_static_size)); tlsblock += TLS_PRE_TCB_SIZE; # else /* In case a model with a different layout for the TCB and DTV

In case __nptl_nthreads is not defined in the final binary then avoid dereferencing the address since it's null. Anyway this means there is no other thread and so we must exit.

* libc/misc/internals/__uClibc_main.c (__uClibc_main): Handle case where &__nptl_nthreads is null.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/libc/misc/internals/__uClibc_main.c b/libc/misc/internals/__uClibc_main.c index d8286f2..849bca8 100644 --- a/libc/misc/internals/__uClibc_main.c +++ b/libc/misc/internals/__uClibc_main.c @@ -544,7 +544,7 @@ void __uClibc_main(int (*main)(int, char **, char **), int argc, result = 0; unsigned int *const ptr = &__nptl_nthreads;

- if (! atomic_decrement_and_test (ptr)) + if (ptr && ! atomic_decrement_and_test (ptr)) /* Not much left to do but to exit the thread, not the process. */ __exit_thread_inline (0); }

* libm/s_isnan.c: Add isnan weak alias.

Signed-off-by: Mickaël Guêné mickael.guene@st.com Signed-off-by: Christophe Lyon christophe.lyon@st.com

diff --git a/libm/s_isnan.c b/libm/s_isnan.c index 1bc49cb..1aabb74 100644 --- a/libm/s_isnan.c +++ b/libm/s_isnan.c @@ -26,4 +26,5 @@ int __isnan(double x) hx = 0x7ff00000 - hx; return (int)(((u_int32_t)hx)>>31); } +weak_alias(__isnan, isnan) libm_hidden_def(__isnan)