objtool: Add abstraction for destination offsets

The jump and call destination relocation offsets are x86-specific.
Abstract them by calling arch-specific implementations.

[ jthierry: Remove superfluous comment; replace other addend offsets
      	    with arch_dest_rela_offset() ]

Signed-off-by: Raphael Gault <raphael.gault@arm.com>
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Raphael Gault 2020-03-27 15:28:45 +00:00 committed by Ingo Molnar
parent aff5e16918
commit bfb08f2203
3 changed files with 27 additions and 8 deletions

View File

@ -66,6 +66,8 @@ struct stack_op {
struct op_src src; struct op_src src;
}; };
struct instruction;
void arch_initial_func_cfi_state(struct cfi_state *state); void arch_initial_func_cfi_state(struct cfi_state *state);
int arch_decode_instruction(struct elf *elf, struct section *sec, int arch_decode_instruction(struct elf *elf, struct section *sec,
@ -75,4 +77,8 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
bool arch_callee_saved_reg(unsigned char reg); bool arch_callee_saved_reg(unsigned char reg);
unsigned long arch_jump_destination(struct instruction *insn);
unsigned long arch_dest_rela_offset(int addend);
#endif /* _ARCH_H */ #endif /* _ARCH_H */

View File

@ -11,6 +11,7 @@
#include "../../../arch/x86/lib/inat.c" #include "../../../arch/x86/lib/inat.c"
#include "../../../arch/x86/lib/insn.c" #include "../../../arch/x86/lib/insn.c"
#include "../../check.h"
#include "../../elf.h" #include "../../elf.h"
#include "../../arch.h" #include "../../arch.h"
#include "../../warn.h" #include "../../warn.h"
@ -66,6 +67,16 @@ bool arch_callee_saved_reg(unsigned char reg)
} }
} }
unsigned long arch_dest_rela_offset(int addend)
{
return addend + 4;
}
unsigned long arch_jump_destination(struct instruction *insn)
{
return insn->offset + insn->len + insn->immediate;
}
int arch_decode_instruction(struct elf *elf, struct section *sec, int arch_decode_instruction(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int maxlen, unsigned long offset, unsigned int maxlen,
unsigned int *len, enum insn_type *type, unsigned int *len, enum insn_type *type,

View File

@ -574,13 +574,14 @@ static int add_jump_destinations(struct objtool_file *file)
insn->offset, insn->len); insn->offset, insn->len);
if (!rela) { if (!rela) {
dest_sec = insn->sec; dest_sec = insn->sec;
dest_off = insn->offset + insn->len + insn->immediate; dest_off = arch_jump_destination(insn);
} else if (rela->sym->type == STT_SECTION) { } else if (rela->sym->type == STT_SECTION) {
dest_sec = rela->sym->sec; dest_sec = rela->sym->sec;
dest_off = rela->addend + 4; dest_off = arch_dest_rela_offset(rela->addend);
} else if (rela->sym->sec->idx) { } else if (rela->sym->sec->idx) {
dest_sec = rela->sym->sec; dest_sec = rela->sym->sec;
dest_off = rela->sym->sym.st_value + rela->addend + 4; dest_off = rela->sym->sym.st_value +
arch_dest_rela_offset(rela->addend);
} else if (strstr(rela->sym->name, "_indirect_thunk_")) { } else if (strstr(rela->sym->name, "_indirect_thunk_")) {
/* /*
* Retpoline jumps are really dynamic jumps in * Retpoline jumps are really dynamic jumps in
@ -670,7 +671,7 @@ static int add_call_destinations(struct objtool_file *file)
rela = find_rela_by_dest_range(file->elf, insn->sec, rela = find_rela_by_dest_range(file->elf, insn->sec,
insn->offset, insn->len); insn->offset, insn->len);
if (!rela) { if (!rela) {
dest_off = insn->offset + insn->len + insn->immediate; dest_off = arch_jump_destination(insn);
insn->call_dest = find_func_by_offset(insn->sec, dest_off); insn->call_dest = find_func_by_offset(insn->sec, dest_off);
if (!insn->call_dest) if (!insn->call_dest)
insn->call_dest = find_symbol_by_offset(insn->sec, dest_off); insn->call_dest = find_symbol_by_offset(insn->sec, dest_off);
@ -693,13 +694,14 @@ static int add_call_destinations(struct objtool_file *file)
} }
} else if (rela->sym->type == STT_SECTION) { } else if (rela->sym->type == STT_SECTION) {
dest_off = arch_dest_rela_offset(rela->addend);
insn->call_dest = find_func_by_offset(rela->sym->sec, insn->call_dest = find_func_by_offset(rela->sym->sec,
rela->addend+4); dest_off);
if (!insn->call_dest) { if (!insn->call_dest) {
WARN_FUNC("can't find call dest symbol at %s+0x%x", WARN_FUNC("can't find call dest symbol at %s+0x%lx",
insn->sec, insn->offset, insn->sec, insn->offset,
rela->sym->sec->name, rela->sym->sec->name,
rela->addend + 4); dest_off);
return -1; return -1;
} }
} else } else
@ -810,7 +812,7 @@ static int handle_group_alt(struct objtool_file *file,
if (!insn->immediate) if (!insn->immediate)
continue; continue;
dest_off = insn->offset + insn->len + insn->immediate; dest_off = arch_jump_destination(insn);
if (dest_off == special_alt->new_off + special_alt->new_len) { if (dest_off == special_alt->new_off + special_alt->new_len) {
if (!fake_jump) { if (!fake_jump) {
WARN("%s: alternative jump to end of section", WARN("%s: alternative jump to end of section",