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author | Eric Andersen <andersen@codepoet.org> | 2004-06-12 08:38:39 +0000 |
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committer | Eric Andersen <andersen@codepoet.org> | 2004-06-12 08:38:39 +0000 |
commit | 018f4ef5f8b9c7fb3e0fa3574bfd2c17f24b4253 (patch) | |
tree | 867d2f0fba3a98909872dc2e6abe8a0da8bb2c10 /ldso/ldso/sparc/elfinterp.c | |
parent | 2ca977faefda1b8c807291e3ee4a817d919b44de (diff) |
Jakub Bogusz from pld-linux dot org writes:
Hello,
I managed to get ldso (and thus shared linking to uClibc) to work on
sparc (actually sparc64 kernel with 32-bit userspace), at least on
simple "hello world" program (more complex ones not tested).
Some notes on attached patch (against 0.9.26, would require some work
to apply on current CVS - but I tested 0.9.26, not CVS):
- ELF magic cannot be examined by _dl_strncmp so early, probably because of
string constant, like on ppc/mips/sh
(note that early SEND_STDERR still crashes when trying to do _dl_strlen
- I suppose that string constants require relocation; but adding
load_addr didn't help, just ELF header was displayed instead of crash)
- mmap() is syscall6 like on ppc/mips/sh, not old i386 mmap()
- for generic sparc (i.e. not sparcv8/sparcv9) gcc produces .udiv/.urem
calls for unsigned integer / and % operators - so these operations
must be avoided. I copied do_rem definition from arm header.
But / and % are used also in _dl_simple_ltoa() and
_dl_simple_ltoahex(); in ltoahex gcc optimizes it to shifts (but
I think it's safer to use shifts explicitly, not rely on
optimization...).
I changed % in ltoa to do_rem, but as there was no do_div definition,
I changed all "%d" specifiers to "%x" to avoid crashes (this changes
wouldn't be needed if _dl_simple_ltoa() were fixed to not use
division on sparc).
- "#define SOLARIS_COMPATIBLE" in ld_sysdep.h broke ldso on Linux
because of redefining _dl_linux_resolve only in some places (it was
still referenced in INIT_GOT before redefinition). So
_dl_linux_resolve redefinition should be moved before INIT_GOT
definition or removed.
- sparc64 kernel requires mmap() addresses to be aligned to 8192, not
4096, otherwise mmap() call failed
- reloc_entry must be shifted by 10, not 12 (I found similar operation
in glibc sources)
Aside of sparc-specific fixes:
- I moved some _dl_dprintf()s inside if(_dl_debug_*) conditions (to avoid
debugging messages when LD_DEBUG is not defined)
- it seems that there was possible off-by-one in ltoa and ltoahex?
they are called with char[22] as 1st argument, and then '\0' is stored
in local[22] (_before_ p decrementation)... or am I missing something?
If not, fix is included in patch.
Diffstat (limited to 'ldso/ldso/sparc/elfinterp.c')
-rw-r--r-- | ldso/ldso/sparc/elfinterp.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/ldso/ldso/sparc/elfinterp.c b/ldso/ldso/sparc/elfinterp.c index 41bde4fa8..98435cbd4 100644 --- a/ldso/ldso/sparc/elfinterp.c +++ b/ldso/ldso/sparc/elfinterp.c @@ -72,7 +72,7 @@ unsigned int _dl_linux_resolver(unsigned int reloc_entry, unsigned int * plt) /* * Generate the correct relocation index into the .rela.plt section. */ - reloc_entry = (reloc_entry >> 12) - 0xc; + reloc_entry = (reloc_entry >> 10) - 0xc; this_reloc = (Elf32_Rela *) ((char *) rel_addr + reloc_entry); @@ -82,10 +82,14 @@ unsigned int _dl_linux_resolver(unsigned int reloc_entry, unsigned int * plt) symtab = (Elf32_Sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr); strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr); +#ifdef __SUPPORT_LD_DEBUG__ + if (_dl_debug_symbols) { _dl_dprintf(2, "tpnt = %x\n", tpnt); _dl_dprintf(2, "reloc = %x\n", this_reloc); _dl_dprintf(2, "symtab = %x\n", symtab); _dl_dprintf(2, "strtab = %x\n", strtab); + } +#endif if (unlikely(reloc_type != R_SPARC_JMP_SLOT)) { @@ -98,10 +102,10 @@ unsigned int _dl_linux_resolver(unsigned int reloc_entry, unsigned int * plt) instr_addr = ((int)this_reloc->r_offset + (int)tpnt->loadaddr); got_addr = (char **) instr_addr; - _dl_dprintf(2, "symtab_index %d\n", symtab_index); - #ifdef __SUPPORT_LD_DEBUG__ if (_dl_debug_symbols) { + _dl_dprintf(2, "symtab_index %x\n", symtab_index); + _dl_dprintf(2, "Resolving symbol %s\n", strtab + symtab[symtab_index].st_name); } |