diff --git a/kpatch-build/create-diff-object.c b/kpatch-build/create-diff-object.c index 49d0aa9..2af7454 100644 --- a/kpatch-build/create-diff-object.c +++ b/kpatch-build/create-diff-object.c @@ -245,6 +245,7 @@ static int rela_equal(struct rela *rela1, struct rela *rela2) #ifdef __powerpc__ struct section *toc_relasec1, *toc_relasec2; struct rela *r_toc_relasec1, *r_toc_relasec2; + unsigned long toc_data1, toc_data2; #endif if (rela1->type != rela2->type || @@ -288,16 +289,59 @@ static int rela_equal(struct rela *rela1, struct rela *rela2) ERROR("cannot find .rela.toc"); r_toc_relasec1 = find_rela_by_offset(toc_relasec1, rela1->addend); - if (!r_toc_relasec1) - ERROR(".toc entry not found %s + %x", rela1->sym->name, rela1->addend); + if (!r_toc_relasec1) { + /* + * .toc section entries are mostly place holder for relocation entries, specified + * in .rela.toc section. Sometimes, .toc section may have constants as entries. + * These constants are not reference to any symbols, but plain instructions mostly + * due to some arithmetics in the functions referring them. + * + * They are referred by the functions like normal .toc entries, these entries can + * not be resolved to any symbols. + * + * Disassembly of section .toc: + * + * 0000000000000000 <.toc>: + * ... + * 148: R_PPC64_ADDR64 .data.capacity_margin + * 150: 0b d7 a3 70 andi. r3,r5,55051 + * 154: 3d 0a d7 a3 lhz r30,2621(r23) + * 158: R_PPC64_ADDR64 sched_max_numa_distance + * + * Relocation section '.rela.toc' at offset 0xadac0 contains 160 entries: + * Offset Info Type Symbol's Value Symbol's Name + Addend + * ... + * 0000000000000148 0000009100000026 R_PPC64_ADDR64 0000000000000000 .data.capacity_margin + 0 + * 0000000000000158 000001a500000026 R_PPC64_ADDR64 0000000000000000 sched_max_numa_distance + 0 + * + * Relocation section '.rela.text.select_task_rq_fair' at offset 0x90e98 contains 37 entries: + * Offset Info Type Symbol's Value Symbol's Name + Addend + * ... + * 0000000000000498 000000c90000000a R_PPC64_REL24 0000000000000000 __update_load_avg_blocked_se.isra.0 + 0 + * 00000000000004a0 0000008800000032 R_PPC64_TOC16_HA 0000000000000000 .toc + 148 + * 00000000000004ac 0000008800000040 R_PPC64_TOC16_LO_DS 0000000000000000 .toc + 148 + * 0000000000000514 0000008800000032 R_PPC64_TOC16_HA 0000000000000000 .toc + 150 + * 000000000000051c 0000008800000040 R_PPC64_TOC16_LO_DS 0000000000000000 .toc + 150 + * 00000000000005e0 000001870000000a R_PPC64_REL24 0000000000000000 __bitmap_intersects + 0 + */ + memcpy(&toc_data1, rela1->sym->sec->data->d_buf + rela1->addend, sizeof(toc_data1)); + if (!toc_data1) + ERROR(".toc entry not found %s + %x", rela1->sym->name, rela1->addend); + } toc_relasec2 = rela2->sym->sec->rela; if (!toc_relasec2) ERROR("cannot find .rela.toc"); r_toc_relasec2 = find_rela_by_offset(toc_relasec2, rela2->addend); - if (!r_toc_relasec2) - ERROR(".toc entry not found %s + %x", rela2->sym->name, rela2->addend); + if (!r_toc_relasec2) { + memcpy(&toc_data2, rela2->sym->sec->data->d_buf + rela2->addend, sizeof(toc_data2)); + if (!toc_data2) + ERROR(".toc entry not found %s + %x", rela2->sym->name, rela2->addend); + } + + if (!r_toc_relasec1 && !r_toc_relasec2) + return toc_data1 == toc_data2; if (r_toc_relasec1->string) return r_toc_relasec2->string &&