From 504665a91498f43d220b7d0942281067283a35f7 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 26 Mar 2009 15:24:36 +0100 Subject: [PATCH] [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 --- arch/s390/kernel/module.c | 19 ++++++++++++------- 1 file 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) -- 2.30.2