diff options
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/dl-sysdep.h | |
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/dl-sysdep.h')
-rw-r--r-- | ldso/ldso/sparc/dl-sysdep.h | 51 |
1 files changed, 47 insertions, 4 deletions
diff --git a/ldso/ldso/sparc/dl-sysdep.h b/ldso/ldso/sparc/dl-sysdep.h index c6ac89e11..ddf74e21e 100644 --- a/ldso/ldso/sparc/dl-sysdep.h +++ b/ldso/ldso/sparc/dl-sysdep.h @@ -41,9 +41,51 @@ extern unsigned int _dl_linux_resolver(unsigned int reloc_entry, /* * Define this if you want a dynamic loader that works on Solaris. */ +#ifndef __linux__ #define SOLARIS_COMPATIBLE +#endif + +#ifndef COMPILE_ASM +/* Cheap modulo implementation, taken from arm/ld_sysdep.h. */ +static inline unsigned long +sparc_mod(unsigned long m, unsigned long p) +{ + unsigned long i, t, inc; + + i = p; + t = 0; + + while (!(i & (1 << 31))) { + i <<= 1; + t++; + } + + t--; + + for (inc = t; inc > 2; inc--) { + i = p << inc; -#define do_rem(result, n, base) result = (n % base) + if (i & (1 << 31)) + break; + + while (m >= i) { + m -= i; + i <<= 1; + if (i & (1 << 31)) + break; + if (i < p) + break; + } + } + + while (m >= p) + m -= p; + + return m; +} + +#define do_rem(result, n, base) result = sparc_mod(n, base); +#endif /* * dbx wants the binder to have a specific name. Mustn't disappoint it. @@ -53,9 +95,10 @@ extern unsigned int _dl_linux_resolver(unsigned int reloc_entry, #endif /* 4096 bytes alignment */ -#define PAGE_ALIGN 0xfffff000 -#define ADDR_ALIGN 0xfff -#define OFFS_ALIGN 0x7ffff000 +/* ...but 8192 is required for mmap() on sparc64 kernel */ +#define PAGE_ALIGN 0xffffe000 +#define ADDR_ALIGN 0x1fff +#define OFFS_ALIGN 0x7fffe000 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so PLT entries should not be allowed to define the value. |