[PATCH v3 3/7] ldso: Add ARC support
Vineet Gupta
Vineet.Gupta1 at synopsys.com
Fri Dec 20 14:11:06 UTC 2013
On 12/20/2013 06:59 PM, Bernhard Reutner-Fischer wrote:
> On Fri, Dec 13, 2013 at 02:49:22PM +0530, Vineet Gupta wrote:
>> Signed-off-by: Vineet Gupta <vgupta at synopsys.com>
>> ---
>> ldso/ldso/arc/dl-debug.h | 68 +++++++++++
>> ldso/ldso/arc/dl-startup.h | 89 ++++++++++++++
>> ldso/ldso/arc/dl-syscalls.h | 5 +
>> ldso/ldso/arc/dl-sysdep.h | 150 ++++++++++++++++++++++++
>> ldso/ldso/arc/elfinterp.c | 279 ++++++++++++++++++++++++++++++++++++++++++++
>> ldso/ldso/arc/resolve.S | 57 +++++++++
>> 6 files changed, 648 insertions(+)
>> create mode 100644 ldso/ldso/arc/dl-debug.h
>> create mode 100644 ldso/ldso/arc/dl-startup.h
>> create mode 100644 ldso/ldso/arc/dl-syscalls.h
>> create mode 100644 ldso/ldso/arc/dl-sysdep.h
>> create mode 100644 ldso/ldso/arc/elfinterp.c
>> create mode 100644 ldso/ldso/arc/resolve.S
>>
>> diff --git a/ldso/ldso/arc/dl-debug.h b/ldso/ldso/arc/dl-debug.h
>> new file mode 100644
>> index 000000000000..ff559f27fa31
>> --- /dev/null
>> +++ b/ldso/ldso/arc/dl-debug.h
>> @@ -0,0 +1,68 @@
>> +/*
>> + * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
>> + *
>> + * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
>> + */
>> +static const char *_dl_reltypes_tab[] =
>> +{
>> + "R_ARC_NONE", /* 0 */
>> + "R_ARC_8",
>> + "R_ARC_16",
>> + "R_ARC_24",
>> + "R_ARC_32",
>> + "R_ARC_B26", /* 5 */
>> + "R_ARC_B22_PCREL",
>> + "R_ARC_H30",
>> + "R_ARC_N8",
>> + "R_ARC_N16",
>> + "R_ARC_N24", /* 10 */
>> + "R_ARC_N32",
>> + "R_ARC_SDA",
>> + "R_ARC_SECTOFF",
>> + "R_ARC_S21H_PCREL",
>> + "R_ARC_S21W_PCREL", /* 15 */
>> + "R_ARC_S25H_PCREL",
>> + "R_ARC_S25W_PCREL",
>> + "R_ARC_SDA32",
>> + "R_ARC_SDA_LDST",
>> + "R_ARC_SDA_LDST1", /* 20 */
>> + "R_ARC_SDA_LDST2",
>> + "R_ARC_SDA16_LD",
>> + "R_ARC_SDA16_LD1",
>> + "R_ARC_SDA16_LD2",
>> + "R_ARC_S13_PCREL", /* 25 */
>> + "R_ARC_W",
>> + "R_ARC_32_ME",
>> + "R_ARC_N32_ME",
>> + "R_ARC_SECTOFF_ME",
>> + "R_ARC_SDA32_ME", /* 30 */
>> + "R_ARC_W_ME",
>> + "R_ARC_H30_ME",
>> + "R_ARC_SECTOFF_U8",
>> + "R_ARC_SECTOFF_S9",
>> + "R_AC_SECTOFF_U8", /* 35 */
>> + "R_AC_SECTOFF_U8_1",
>> + "R_AC_SECTOFF_U8_2",
>> + "R_AC_SECTOFF_S9",
>> + "R_AC_SECTOFF_S9_1",
>> + "R_AC_SECTOFF_S9_2", /* 40 */
>> + "R_ARC_SECTOFF_ME_1",
>> + "R_ARC_SECTOFF_ME_2",
>> + "R_ARC_SECTOFF_1",
>> + "R_ARC_SECTOFF_2",
>> + "", /* 45 */
>> + "",
>> + "",
>> + "",
>> + "",
>> + "R_ARC_PC32", /* 50 */
>> + "R_ARC_GOTPC32",
>> + "R_ARC_PLT32",
>> + "R_ARC_COPY",
>> + "R_ARC_GLOB_DAT",
>> + "R_ARC_JMP_SLOT", /* 55 */
>> + "R_ARC_RELATIVE",
>> + "R_ARC_GOTOFF",
>> + "R_ARC_GOTPC",
>> + "R_ARC_GOT32",
>> +};
>> diff --git a/ldso/ldso/arc/dl-startup.h b/ldso/ldso/arc/dl-startup.h
>> new file mode 100644
>> index 000000000000..4a8d5d786b63
>> --- /dev/null
>> +++ b/ldso/ldso/arc/dl-startup.h
>> @@ -0,0 +1,89 @@
>> +/*
>> + * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
>> + *
>> + * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
>> + */
>> +
>> +/*
>> + * vineetg: Refactoring/cleanup of loader entry point
>> + * Removed 6 useless insns
>> + * Joern Improved it even further:
>> + * -better insn scheduling
>> + * -no need for conditional code for _dl_skip_args
>> + * -use of assembler .&2 expressions vs. @gotpc refs (avoids need for GP)
>> + *
>> + * What this code does:
>> + * -ldso starts execution here when kernel returns from execve()
>> + * -calls into generic ldso entry point _dl_start( )
>> + * -optionally adjusts argc for executable if exec passed as cmd
>> + * -calls into app main with address of finaliser
>> + */
>> +__asm__(
>> + ".section .text \n"
>> + ".align 4 \n"
>> + ".global _start \n"
>> + ".hidden _start \n"
>> + ".type _start, at function \n"
>> +
>> + "_start: \n"
>> + " ; ldso entry point, returns app entry point \n"
>> + " bl.d _dl_start \n"
>> + " mov_s r0, sp ; pass ptr to aux vector tbl \n"
>> +
>> + " ; If ldso ran as cmd with executable file nm as arg \n"
>> + " ; as arg, skip the extra args calc by dl_start() \n"
>
> too many "as arg"
Fixed.
>
>> + " ld_s r1, [sp] ; orig argc from aux-vec Tbl \n"
>> +#ifdef STAR_9000535888_FIXED
>
> what is that STAR_9000535888_FIXED thing, can we remove this?
That's SNPS internal bug number for a pending gas issue. This requires a
gcc/binutils fix (@pcl and related relos) which is available in the NPTL branches
of those tools - so not ready for prime time just yet. I will send out an update
at appropriate time.
>
>> + " ld r12, [pcl, _dl_skip_args-.+(.&2)] \n"
>> +#else
>> + " add r12, pcl, _dl_skip_args-.+(.&2) \n"
>> + " ld r12, [r12] \n"
>> +#endif
>> +
>> + " add r2, pcl, _dl_fini-.+(.&2) ; finalizer \n"
>> +
>> + " add2 sp, sp, r12 ; discard argv entries from stack\n"
>> + " sub_s r1, r1, r12 ; adjusted argc, on stack \n"
>> + " st_s r1, [sp] \n"
>> +
>> + " j_s.d [r0] ; app entry point \n"
>> + " mov_s r0, r2 ; ptr to finalizer _dl_fini \n"
>> +
>> + ".size _start,.-_start \n"
>> + ".previous \n"
>> +);
>> +
>> +/*
>> + * Get a pointer to the argv array. On many platforms this can be just
>> + * the address if the first argument, on other platforms we need to
>> + * do something a little more subtle here.
>> + */
>> +#define GET_ARGV(ARGVP, ARGS) ARGVP = ((unsigned long*) ARGS + 1)
>> +
>> +/*
>> + * Dynamic loader bootstrapping:
>> + * Since we don't modify text at runtime, these can only be data relos
>> + * (so safe to assume that they are word aligned).
>> + * And also they HAVE to be RELATIVE relos only
>> + * @RELP is the relo entry being processed
>> + * @REL is the pointer to the address we are relocating.
>> + * @SYMBOL is the symbol involved in the relocation
>> + * @LOAD is the load address.
>> + */
>> +
>> +#define PERFORM_BOOTSTRAP_RELOC(RELP,REL,SYMBOL,LOAD,SYMTAB) \
>> +do { \
>> + int type = ELF32_R_TYPE((RELP)->r_info); \
>> + if (likely(type == R_ARC_RELATIVE)) \
>> + *REL += (unsigned long) LOAD; \
>> + else \
>> + _dl_exit(1); \
>> +}while(0)
>> +
>> +/*
>> + * This will go away once we have DT_RELACOUNT
>> + */
>> +#define ARCH_NEEDS_BOOTSTRAP_RELOCS
>> +
>> +/* we dont need to spit out argc, argv etc for debugging */
>> +#define NO_EARLY_SEND_STDERR 1
>> diff --git a/ldso/ldso/arc/dl-syscalls.h b/ldso/ldso/arc/dl-syscalls.h
>> new file mode 100644
>> index 000000000000..a0b5afc9ec78
>> --- /dev/null
>> +++ b/ldso/ldso/arc/dl-syscalls.h
>> @@ -0,0 +1,5 @@
>> +/*
>> + * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
>> + *
>> + * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
>> + */
>
> I would have added a
> /* stub for arch-specific syscall issues */
> but ok as is.
>
Added as requested.
>> diff --git a/ldso/ldso/arc/dl-sysdep.h b/ldso/ldso/arc/dl-sysdep.h
>> new file mode 100644
>> index 000000000000..dfde3323373b
>> --- /dev/null
>> +++ b/ldso/ldso/arc/dl-sysdep.h
>> @@ -0,0 +1,150 @@
>> +/*
>> + * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
>> + *
>> + * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
>> + */
>> +
>> +#include "elf.h"
>> +
>> +/*
>> + * Define this if the system uses RELOCA.
>> + */
>> +#define ELF_USES_RELOCA
>> +
>> +/*
>> + * Dynamic Linking ABI for ARCompact ISA
>> + *
>> + * PLT
>> + * --------------------------------
>> + * | ld r11, [pcl, off-to-GOT[1] | 0 (20 bytes)
>> + * | | 4
>> + * plt0 | ld r10, [pcl, off-to-GOT[2] | 8
>> + * | | 12
>> + * | j [r10] | 16
>> + * --------------------------------
>> + * | Base address of GOT | 20
>> + * --------------------------------
>> + * | ld r12, [pcl, off-to-GOT[3] | 24 (12 bytes each)
>> + * plt1 | |
>> + * | j_s.d [r12] | 32
>
> plt0 and plt1 lines are still broken, please fix.
Pretty weird - I'm using TS=8 and GVIM seems to show everything correct. Actually
the plt1 is weirder - if I remove the WS after plt1, it becomes unaligned in
editor. Do I need to fixup all TABs in this table to explicit white space. Can you
please do the fixup yourself if I may so ask.
>
>> + * | mov_s r12, pcl | 34
>> + * --------------------------------
>> + * | | 36
>> + * ~ ~
>> + * ~ ~
>> + * | |
>> + * --------------------------------
>> + *
>> + * GOT
>> + * --------------
>> + * | [0] |
>> + * --------------
>> + * | [1] | Module info - setup by ldso
>> + * --------------
>> + * | [2] | resolver entry point
>> + * --------------
>> + * | [3] |
>> + * | ... | Runtime address for function symbols
>> + * | [f] |
>> + * --------------
>> + * | [f+1] |
>> + * | ... | Runtime address for data symbols
>> + * | [last] |
>> + * --------------
>> + */
>> +
>> +/*
>> + * Initialization sequence for a GOT.
>> + * Caller elf_resolve() seeds @GOT_BASE from DT_PLTGOT - which essentially is
>> + * pointer to first PLT entry. The actual GOT base is 5th word in PLT
>> + *
>> + */
>> +#define INIT_GOT(GOT_BASE,MODULE) \
>> +do { \
>> + unsigned long *__plt_base = (unsigned long *)GOT_BASE; \
>> + GOT_BASE = (unsigned long *)(__plt_base[5] + \
>> + (unsigned long)MODULE->loadaddr); \
>> + GOT_BASE[1] = (unsigned long) MODULE; \
>> + GOT_BASE[2] = (unsigned long) _dl_linux_resolve; \
>> +} while(0)
>> +
>> +/* Here we define the magic numbers that this dynamic loader should accept */
>> +#define MAGIC1 EM_ARCOMPACT
>> +#undef MAGIC2
>> +
>> +/* Used for error messages */
>> +#define ELF_TARGET "ARC"
>> +
>> +struct elf_resolve;
>> +extern unsigned long _dl_linux_resolver(struct elf_resolve * tpnt,
>> + unsigned int plt_pc);
>> +
>> +extern unsigned __udivmodsi4(unsigned, unsigned) attribute_hidden;
>> +
>> +#define do_rem(result, n, base) ((result) = \
>> + \
>> + __builtin_constant_p (base) ? (n) % (unsigned) (base) : \
>> + __extension__ ({ \
>> + register unsigned r1 __asm__ ("r1") = (base); \
>> + \
>> + __asm("bl.d @__udivmodsi4` mov r0,%1" \
>
> __asm__
Done !
>
>> + : "=r" (r1) \
>> + : "r" (n), "r" (r1) \
>> + : "r0", "r2", "r3", "r4", "lp_count", "blink", "cc"); \
>> + \
>> + r1; \
>> + }) \
>> +)
>> +
>> +/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
>> + PLT entries should not be allowed to 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_ARC_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
>> + | (((type) == R_ARC_COPY) * ELF_RTYPE_CLASS_COPY))
>> +
>> +/*
>> + * Get the runtime address of GOT[0]
>> + */
>> +static __always_inline Elf32_Addr elf_machine_dynamic(void)
>> +{
>> + Elf32_Addr dyn;
>> +
>> + __asm__("ld %0,[pcl,_DYNAMIC at gotpc]\n\t" : "=r" (dyn));
>> + return dyn;
>> +
>> +/*
>> + * Another way would have been to simply return GP, which due to some
>> + * PIC reference would be automatically setup by gcc in caller
>> + * register Elf32_Addr *got __asm__ ("gp"); return *got;
>> + */
>> +}
>> +
>> +/* Return the run-time load address of the shared object. */
>> +static __always_inline Elf32_Addr elf_machine_load_address(void)
>> +{
>> + /* To find the loadaddr we subtract the runtime addr of any symbol
>> + * say _dl_start from it's build-time addr.
>> + */
>> + Elf32_Addr addr, tmp;
>> + __asm__ (
>> + "ld %1, [pcl, _dl_start at gotpc] ;build addr of _dl_start \n"
>> + "add %0, pcl, _dl_start-.+(.&2) ;runtime addr of _dl_start \n"
>> + "sub %0, %0, %1 ;delta \n"
>> + : "=&r" (addr), "=r"(tmp)
>> + );
>> + return addr;
>> +}
>> +
>> +static __always_inline void
>> +elf_machine_relative (Elf32_Addr 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);
>> + *reloc_addr += load_off;
>> + } while (--relative_count);
>> +}
>> diff --git a/ldso/ldso/arc/elfinterp.c b/ldso/ldso/arc/elfinterp.c
>> new file mode 100644
>> index 000000000000..a3d741b65c4e
>> --- /dev/null
>> +++ b/ldso/ldso/arc/elfinterp.c
>> @@ -0,0 +1,279 @@
>> +/*
>> + * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
>> + *
>> + * Lots of code copied from ../i386/elfinterp.c, so:
>> + * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
>> + * David Engel, Hongjiu Lu and Mitch D'Souza
>> + * Copyright (C) 2001-2002, Erik Andersen
>> + * All rights reserved.
>> + *
>> + * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
>> + */
>> +#include "ldso.h"
>> +
>> +#define ARC_PLT_SIZE 12
>> +
>> +unsigned long
>> +_dl_linux_resolver(struct elf_resolve *tpnt, unsigned int plt_pc)
>> +{
>> + ELF_RELOC *this_reloc, *rel_base;
>> + char *strtab, *symname, *new_addr;
>> + ElfW(Sym) *symtab;
>> + int symtab_index;
>> + unsigned int *got_addr;
>> + unsigned long plt_base;
>> + int plt_idx;
>> +
>> + /* start of .rela.plt */
>> + rel_base = (ELF_RELOC *)(tpnt->dynamic_info[DT_JMPREL]);
>> +
>> + /* starts of .plt (addr of PLT0) */
>> + plt_base = tpnt->dynamic_info[DT_PLTGOT];
>> +
>> + /*
>> + * compute the idx of the yet-unresolved PLT entry in .plt
>> + * Same idx will be used to find the relo entry in .rela.plt
>> + */
>> + plt_idx = (plt_pc - plt_base)/ARC_PLT_SIZE - 2; /* ignoring 2 dummy PLTs */
>> +
>> + this_reloc = rel_base + plt_idx;
>> +
>> + symtab_index = ELF_R_SYM(this_reloc->r_info);
>> + symtab = (ElfW(Sym) *)(intptr_t) (tpnt->dynamic_info[DT_SYMTAB]);
>> + strtab = (char *) (tpnt->dynamic_info[DT_STRTAB]);
>> + symname= strtab + symtab[symtab_index].st_name;
>> +
>> + /* relo-offset to fixup, shd be a .got entry */
>> + got_addr = (unsigned int *)(this_reloc->r_offset + tpnt->loadaddr);
>> +
>> + /* Get the address of the GOT entry */
>> + new_addr = _dl_find_hash(symname, &_dl_loaded_modules->symbol_scope, tpnt,
>> + ELF_RTYPE_CLASS_PLT, NULL);
>> +
>> + if (unlikely(!new_addr)) {
>> + _dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname);
>> + _dl_exit(1);
>> + }
>> +
>> +
>> +#if defined __SUPPORT_LD_DEBUG__
>> + if (_dl_debug_bindings) {
>> + _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
>> + if(_dl_debug_detail)
>> + _dl_dprintf(_dl_debug_file, "\n\tpatched %x ==> %pc @ %pl\n",
>> + *got_addr, new_addr, got_addr);
>> + }
>> +
>> + if (!_dl_debug_nofixups)
>> + *got_addr = (unsigned int)new_addr;
>> +#else
>> + /* Update the .got entry with the runtime address of symbol */
>> + *got_addr = (unsigned int)new_addr;
>> +#endif
>> +
>> + /*
>> + * Return the new addres, where the asm trampoline will jump to
>> + * after re-setting up the orig args
>> + */
>> + return (unsigned long) new_addr;
>> +}
>> +
>> +
>> +static int
>> +_dl_do_reloc(struct elf_resolve *tpnt, struct r_scope_elem *scope,
>> + ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
>> +{
>> + int reloc_type;
>> + int symtab_index;
>> + char *symname;
>> + unsigned long *reloc_addr;
>> + unsigned long symbol_addr;
>> +#if defined __SUPPORT_LD_DEBUG__
>> + unsigned long old_val = 0;
>> +#endif
>> + struct symbol_ref sym_ref;
>> +
>> + reloc_addr = (unsigned long *)(tpnt->loadaddr + rpnt->r_offset);
>> + reloc_type = ELF_R_TYPE(rpnt->r_info);
>> + symtab_index = ELF_R_SYM(rpnt->r_info);
>> + symbol_addr = 0;
>> +
>> + sym_ref.sym = &symtab[symtab_index];
>> + sym_ref.tpnt = NULL;
>> +
>> +#if defined __SUPPORT_LD_DEBUG__
>> + if (reloc_addr)
>> + old_val = *reloc_addr;
>> +#endif
>> +
>> + if (symtab_index) {
>> + symname = strtab + symtab[symtab_index].st_name;
>> + 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 (unlikely(!symbol_addr
>> + && ELF_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK)) {
>> + /* Non-fatal if called from dlopen, hence different ret code */
>> + return 1;
>> + }
>> + } else if (reloc_type == R_ARC_RELATIVE ) {
>> + *reloc_addr += tpnt->loadaddr;
>> + goto log_entry;
>> + }
>> +
>> + switch (reloc_type) {
>> + case R_ARC_32:
>> + *reloc_addr += symbol_addr + rpnt->r_addend;
>> + break;
>> + case R_ARC_PC32:
>> + *reloc_addr += symbol_addr + rpnt->r_addend - (unsigned long) reloc_addr;
>> + break;
>> + case R_ARC_GLOB_DAT:
>> + case R_ARC_JMP_SLOT:
>> + *reloc_addr = symbol_addr;
>> + break;
>> + case R_ARC_COPY:
>> + _dl_memcpy((void *) reloc_addr,(void *) symbol_addr,
>> + symtab[symtab_index].st_size);
>> + break;
>> + default:
>> + return -1;
>> + }
>> +
>> +log_entry:
>> +#if defined __SUPPORT_LD_DEBUG__
>> + if(_dl_debug_detail)
>
> missing space after if
>
>> + _dl_dprintf(_dl_debug_file,"\tpatched: %lx ==> %lx @ %pl: addend %x ",
>> + old_val, *reloc_addr, reloc_addr, rpnt->r_addend);
>> +#endif
>> +
>> + return 0;
>> +}
>> +
>> +static int
>> +_dl_do_lazy_reloc(struct elf_resolve *tpnt, struct r_scope_elem *scope,
>> + ELF_RELOC *rpnt)
>> +{
>> + int reloc_type;
>> + unsigned long *reloc_addr;
>> +#if defined __SUPPORT_LD_DEBUG__
>> + unsigned long old_val;
>> +#endif
>> +
>> + reloc_addr = (unsigned long *)(tpnt->loadaddr + rpnt->r_offset);
>> + reloc_type = ELF_R_TYPE(rpnt->r_info);
>> +
>> +#if defined __SUPPORT_LD_DEBUG__
>> + old_val = *reloc_addr;
>> +#endif
>> +
>> + switch (reloc_type) {
>> + case R_ARC_JMP_SLOT:
>> + *reloc_addr += tpnt->loadaddr;
>> + break;
>> + default:
>> + return -1;
>> + }
>> +
>> +#if defined __SUPPORT_LD_DEBUG__
>> + if(_dl_debug_reloc && _dl_debug_detail)
>> + _dl_dprintf(_dl_debug_file, "\tpatched: %lx ==> %lx @ %pl\n",
>> + old_val, *reloc_addr, reloc_addr);
>> +#endif
>> +
>> + return 0;
>> +}
>> +
>> +#define ___DO_LAZY 1
>> +#define ___DO_NOW 2
>> +
>> +static int _dl_parse(struct elf_resolve *tpnt, struct r_scope_elem *scope,
>> + unsigned long rel_addr, unsigned long rel_size, int type)
>> +{
>> + unsigned int i;
>> + char *strtab;
>> + ElfW(Sym) *symtab;
>> + ELF_RELOC *rpnt;
>> + int symtab_index;
>> + int res = 0;
>> +
>> + /* Now parse the relocation information */
>> + rpnt = (ELF_RELOC *)(intptr_t) (rel_addr);
>> + rel_size = rel_size / sizeof(ELF_RELOC);
>> +
>> + symtab = (ElfW(Sym) *)(intptr_t) (tpnt->dynamic_info[DT_SYMTAB]);
>> + strtab = (char *) (tpnt->dynamic_info[DT_STRTAB]);
>> +
>> + for (i = 0; i < rel_size; i++, rpnt++) {
>> +
>> + symtab_index = ELF_R_SYM(rpnt->r_info);
>> +
>> + debug_sym(symtab,strtab,symtab_index);
>> + debug_reloc(symtab,strtab,rpnt);
>> +
>> + /* constant propagation subsumes the 'if' */
>> + if (type == ___DO_LAZY)
>> + res = _dl_do_lazy_reloc(tpnt, scope, rpnt);
>> + else
>> + res = _dl_do_reloc(tpnt, scope, rpnt, symtab, strtab);
>> +
>> + if (res != 0)
>> + break;
>> + }
>> +
>> + if (unlikely(res != 0)) {
>> + if (res < 0) {
>> + int reloc_type = ELF_R_TYPE(rpnt->r_info);
>> +#if defined __SUPPORT_LD_DEBUG__
>> + _dl_dprintf(2, "can't handle reloc type %s\n ",
>> + _dl_reltypes(reloc_type));
>> +#else
>> + _dl_dprintf(2, "can't handle reloc type %x\n",
>> + reloc_type);
>> +#endif
>> + _dl_exit(-res);
>> + } else {
>> + _dl_dprintf(2, "can't resolve symbol\n");
>> + /* Fall thru to return res */
>> + }
>> + }
>> +
>> + return res;
>> +}
>> +
>> +void
>> +_dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
>> + unsigned long rel_addr,
>> + unsigned long rel_size)
>> +{
>> + /* This func is called for processing .rela.plt of loaded module(s)
>> + * The relo entries handled are JMP_SLOT type for fixing up .got slots
>> + * for external function calls.
>> + * This function doesn't resolve the slots: that is done lazily at
>> + * runtime. The build linker (at least thats what happens for ARC) had
>> + * pre-init the .got slots to point to PLT0. All that is done here is
>> + * to fix them up to point to load value of PLT0 (as opposed to the
>> + * build value).
>> + * On ARC, the loadaddr of dyn exec is zero, thus elfaddr == loadaddr
>> + * Thus there is no point in adding "0" to values and un-necessarily
>> + * stir up the caches and TLB.
>> + * For lsdo processing busybox binary, this skips over 380 relo entries
>> + */
Added fix for a small typo above "lsdo"
Patch inline below - I'll also post it to list.
--------------------------->
>From d7f194a3d2f834ac73fd9711116b266aef31cd45 Mon Sep 17 00:00:00 2001
From: Vineet Gupta <vgupta at synopsys.com>
Date: Fri, 20 Dec 2013 19:35:23 +0530
Subject: [PATCH] ldso: ARC fixlets (fallouts of Bernhard's review)
Signed-off-by: Vineet Gupta <vgupta at synopsys.com>
---
ldso/ldso/arc/dl-startup.h | 2 +-
ldso/ldso/arc/dl-syscalls.h | 2 ++
ldso/ldso/arc/dl-sysdep.h | 2 +-
ldso/ldso/arc/elfinterp.c | 4 ++--
4 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/ldso/ldso/arc/dl-startup.h b/ldso/ldso/arc/dl-startup.h
index 4a8d5d786b63..016155473423 100644
--- a/ldso/ldso/arc/dl-startup.h
+++ b/ldso/ldso/arc/dl-startup.h
@@ -31,7 +31,7 @@ __asm__(
" mov_s r0, sp ; pass ptr to aux vector tbl \n"
" ; If ldso ran as cmd with executable file nm as arg \n"
- " ; as arg, skip the extra args calc by dl_start() \n"
+ " ; skip the extra args calc by dl_start() \n"
" ld_s r1, [sp] ; orig argc from aux-vec Tbl \n"
#ifdef STAR_9000535888_FIXED
" ld r12, [pcl, _dl_skip_args-.+(.&2)] \n"
diff --git a/ldso/ldso/arc/dl-syscalls.h b/ldso/ldso/arc/dl-syscalls.h
index a0b5afc9ec78..a3cbb011b555 100644
--- a/ldso/ldso/arc/dl-syscalls.h
+++ b/ldso/ldso/arc/dl-syscalls.h
@@ -3,3 +3,5 @@
*
* Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
*/
+
+/* stub for arch-specific syscall issues */
diff --git a/ldso/ldso/arc/dl-sysdep.h b/ldso/ldso/arc/dl-sysdep.h
index dfde3323373b..6e2e47c0d29c 100644
--- a/ldso/ldso/arc/dl-sysdep.h
+++ b/ldso/ldso/arc/dl-sysdep.h
@@ -87,7 +87,7 @@ extern unsigned __udivmodsi4(unsigned, unsigned) attribute_hidden;
__extension__ ({ \
register unsigned r1 __asm__ ("r1") = (base); \
\
- __asm("bl.d @__udivmodsi4` mov r0,%1" \
+ __asm__("bl.d @__udivmodsi4` mov r0,%1" \
: "=r" (r1) \
: "r" (n), "r" (r1) \
: "r0", "r2", "r3", "r4", "lp_count", "blink", "cc"); \
diff --git a/ldso/ldso/arc/elfinterp.c b/ldso/ldso/arc/elfinterp.c
index a3d741b65c4e..1d4481c6ff05 100644
--- a/ldso/ldso/arc/elfinterp.c
+++ b/ldso/ldso/arc/elfinterp.c
@@ -148,7 +148,7 @@ _dl_do_reloc(struct elf_resolve *tpnt, struct r_scope_elem *scope,
log_entry:
#if defined __SUPPORT_LD_DEBUG__
- if(_dl_debug_detail)
+ if (_dl_debug_detail)
_dl_dprintf(_dl_debug_file,"\tpatched: %lx ==> %lx @ %pl: addend %x ",
old_val, *reloc_addr, reloc_addr, rpnt->r_addend);
#endif
@@ -263,7 +263,7 @@ _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
* On ARC, the loadaddr of dyn exec is zero, thus elfaddr == loadaddr
* Thus there is no point in adding "0" to values and un-necessarily
* stir up the caches and TLB.
- * For lsdo processing busybox binary, this skips over 380 relo entries
+ * For ldso processing busybox binary, this skips over 380 relo entries
*/
if (rpnt->dyn->loadaddr != 0)
_dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, ___DO_LAZY);
--
1.8.1.2
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