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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2009-03-26 10:24:36 -0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2009-03-26 10:24:24 -0400
commit504665a91498f43d220b7d0942281067283a35f7 (patch)
tree5399477888501a58fe33f088fe335d342d46ade4 /arch/s390
parente13ed9b2704487e98d9241282765869fbd9a2dda (diff)
[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/s390')
-rw-r--r--arch/s390/kernel/module.c19
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,
310 info->plt_initialized = 1; 310 info->plt_initialized = 1;
311 } 311 }
312 if (r_type == R_390_PLTOFF16 || 312 if (r_type == R_390_PLTOFF16 ||
313 r_type == R_390_PLTOFF32 313 r_type == R_390_PLTOFF32 ||
314 || r_type == R_390_PLTOFF64 314 r_type == R_390_PLTOFF64)
315 )
316 val = me->arch.plt_offset - me->arch.got_offset + 315 val = me->arch.plt_offset - me->arch.got_offset +
317 info->plt_offset + rela->r_addend; 316 info->plt_offset + rela->r_addend;
318 else 317 else {
319 val = (Elf_Addr) me->module_core + 318 if (!((r_type == R_390_PLT16DBL &&
320 me->arch.plt_offset + info->plt_offset + 319 val - loc + 0xffffUL < 0x1ffffeUL) ||
321 rela->r_addend - loc; 320 (r_type == R_390_PLT32DBL &&
321 val - loc + 0xffffffffULL < 0x1fffffffeULL)))
322 val = (Elf_Addr) me->module_core +
323 me->arch.plt_offset +
324 info->plt_offset;
325 val += rela->r_addend - loc;
326 }
322 if (r_type == R_390_PLT16DBL) 327 if (r_type == R_390_PLT16DBL)
323 *(unsigned short *) loc = val >> 1; 328 *(unsigned short *) loc = val >> 1;
324 else if (r_type == R_390_PLTOFF16) 329 else if (r_type == R_390_PLTOFF16)