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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2009-03-26 15:24:36 +0100 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2009-03-26 15:24:24 +0100 |
commit | 504665a91498f43d220b7d0942281067283a35f7 (patch) | |
tree | 5399477888501a58fe33f088fe335d342d46ade4 /arch | |
parent | e13ed9b2704487e98d9241282765869fbd9a2dda (diff) | |
download | linux-504665a91498f43d220b7d0942281067283a35f7.tar.bz2 |
[S390] module function call optimization
Avoid the detour over the PLT if the branch target of a function call
in a module is in the range of the bras (16-bit) or brasl (32-bit)
instruction. The PLT is still generated but it is unused.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/s390/kernel/module.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c index 59b4e796680a..eed4a00cb676 100644 --- a/arch/s390/kernel/module.c +++ b/arch/s390/kernel/module.c @@ -310,15 +310,20 @@ apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab, info->plt_initialized = 1; } if (r_type == R_390_PLTOFF16 || - r_type == R_390_PLTOFF32 - || r_type == R_390_PLTOFF64 - ) + r_type == R_390_PLTOFF32 || + r_type == R_390_PLTOFF64) val = me->arch.plt_offset - me->arch.got_offset + info->plt_offset + rela->r_addend; - else - val = (Elf_Addr) me->module_core + - me->arch.plt_offset + info->plt_offset + - rela->r_addend - loc; + else { + if (!((r_type == R_390_PLT16DBL && + val - loc + 0xffffUL < 0x1ffffeUL) || + (r_type == R_390_PLT32DBL && + val - loc + 0xffffffffULL < 0x1fffffffeULL))) + val = (Elf_Addr) me->module_core + + me->arch.plt_offset + + info->plt_offset; + val += rela->r_addend - loc; + } if (r_type == R_390_PLT16DBL) *(unsigned short *) loc = val >> 1; else if (r_type == R_390_PLTOFF16) |