From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> commit 7bd2a600f3e9d27286bbf23c83d599e9cc7cf245 upstream. Track the reloc of instructions in the new instruction->reloc field to avoid having to look them up again later. ( Technically x86 instructions can have two relocations, but not jumps and calls, for which we're using this. ) Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Reviewed-by: Miroslav Benes <mbenes@xxxxxxx> Link: https://lkml.kernel.org/r/20210326151300.195441549@xxxxxxxxxxxxx Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/objtool/check.c | 28 ++++++++++++++++++++++------ tools/objtool/check.h | 1 + 2 files changed, 23 insertions(+), 6 deletions(-) --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -754,6 +754,25 @@ __weak bool arch_is_retpoline(struct sym return false; } +#define NEGATIVE_RELOC ((void *)-1L) + +static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn) +{ + if (insn->reloc == NEGATIVE_RELOC) + return NULL; + + if (!insn->reloc) { + insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec, + insn->offset, insn->len); + if (!insn->reloc) { + insn->reloc = NEGATIVE_RELOC; + return NULL; + } + } + + return insn->reloc; +} + /* * Find the destination instructions for all jumps. */ @@ -768,8 +787,7 @@ static int add_jump_destinations(struct if (!is_static_jump(insn)) continue; - reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); + reloc = insn_reloc(file, insn); if (!reloc) { dest_sec = insn->sec; dest_off = arch_jump_destination(insn); @@ -901,8 +919,7 @@ static int add_call_destinations(struct if (insn->type != INSN_CALL) continue; - reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); + reloc = insn_reloc(file, insn); if (!reloc) { dest_off = arch_jump_destination(insn); insn->call_dest = find_call_destination(insn->sec, dest_off); @@ -1085,8 +1102,7 @@ static int handle_group_alt(struct objto * alternatives code can adjust the relative offsets * accordingly. */ - alt_reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); + alt_reloc = insn_reloc(file, insn); if (alt_reloc && !arch_support_alt_relocation(special_alt, insn, alt_reloc)) { --- a/tools/objtool/check.h +++ b/tools/objtool/check.h @@ -55,6 +55,7 @@ struct instruction { struct instruction *jump_dest; struct instruction *first_jump_src; struct reloc *jump_table; + struct reloc *reloc; struct list_head alts; struct symbol *func; struct list_head stack_ops;
