| Message ID | 20190816122403.14994-2-raphael.gault@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | objtool: Add support for arm64 | expand |
Hi Raphaël, On 16/08/19 13:23, Raphael Gault wrote: > The jump destination and relocation offset used previously are only > reliable on x86_64 architecture. We abstract these computations by calling > arch-dependent implementations. > > Signed-off-by: Raphael Gault <raphael.gault@arm.com> > --- > tools/objtool/arch.h | 6 ++++++ > tools/objtool/arch/x86/decode.c | 11 +++++++++++ > tools/objtool/check.c | 15 ++++++++++----- > 3 files changed, 27 insertions(+), 5 deletions(-) > > diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h > index ced3765c4f44..a9a50a25ca66 100644 > --- a/tools/objtool/arch.h > +++ b/tools/objtool/arch.h > @@ -66,6 +66,8 @@ struct stack_op { > struct op_src src; > }; > > +struct instruction; > + > void arch_initial_func_cfi_state(struct cfi_state *state); > > 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); > > +unsigned long arch_jump_destination(struct instruction *insn); > + > +unsigned long arch_dest_rela_offset(int addend); > + > #endif /* _ARCH_H */ > diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c > index 0567c47a91b1..fa33b3465722 100644 > --- a/tools/objtool/arch/x86/decode.c > +++ b/tools/objtool/arch/x86/decode.c > @@ -11,6 +11,7 @@ > #include "lib/inat.c" > #include "lib/insn.c" > > +#include "../../check.h" > #include "../../elf.h" > #include "../../arch.h" > #include "../../warn.h" > @@ -66,6 +67,11 @@ bool arch_callee_saved_reg(unsigned char reg) > } > } > > +unsigned long arch_dest_rela_offset(int addend) > +{ > + return addend + 4; > +} > + > int arch_decode_instruction(struct elf *elf, struct section *sec, > unsigned long offset, unsigned int maxlen, > unsigned int *len, enum insn_type *type, > @@ -497,3 +503,8 @@ void arch_initial_func_cfi_state(struct cfi_state *state) > state->regs[16].base = CFI_CFA; > state->regs[16].offset = -8; > } > + > +unsigned long arch_jump_destination(struct instruction *insn) > +{ > + return insn->offset + insn->len + insn->immediate; > +} > diff --git a/tools/objtool/check.c b/tools/objtool/check.c > index 176f2f084060..479fab46b656 100644 > --- a/tools/objtool/check.c > +++ b/tools/objtool/check.c > @@ -563,7 +563,7 @@ static int add_jump_destinations(struct objtool_file *file) > insn->len); > if (!rela) { > 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) { > dest_sec = rela->sym->sec; > dest_off = rela->addend + 4; > @@ -659,7 +659,7 @@ static int add_call_destinations(struct objtool_file *file) > rela = find_rela_by_dest_range(insn->sec, insn->offset, > insn->len); > if (!rela) { > - dest_off = insn->offset + insn->len + insn->immediate; > + dest_off = arch_jump_destination(insn); > insn->call_dest = find_symbol_by_offset(insn->sec, > dest_off); > > @@ -672,14 +672,19 @@ static int add_call_destinations(struct objtool_file *file) > } > > } else if (rela->sym->type == STT_SECTION) { > + /* > + * the original x86_64 code adds 4 to the rela->addend > + * which is not needed on arm64 architecture. > + */ I'm not sure this is worth mentioning in generic code. You might include it in the commit message to justify the change. > + dest_off = arch_dest_rela_offset(rela->addend); > insn->call_dest = find_symbol_by_offset(rela->sym->sec, > - rela->addend+4); > + dest_off); > if (!insn->call_dest || > insn->call_dest->type != STT_FUNC) { > - 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, > rela->sym->sec->name, > - rela->addend + 4); > + dest_off); > return -1; > } > } else > Otherwise, the change looks good to me. Thanks,
On Fri, Aug 16, 2019 at 01:23:46PM +0100, Raphael Gault wrote: > @@ -672,14 +672,19 @@ static int add_call_destinations(struct objtool_file *file) > } > > } else if (rela->sym->type == STT_SECTION) { > + /* > + * the original x86_64 code adds 4 to the rela->addend > + * which is not needed on arm64 architecture. > + */ > + dest_off = arch_dest_rela_offset(rela->addend); I agree with Julien that this comment isn't needed. The "arch_" prefix already implies there are arch-specific differences. Also, this patch should replace all the other "addend + 4" usages: $ git grep "addend + 4" tools/objtool tools/objtool/arch/x86/decode.c: return addend + 4; tools/objtool/check.c: dest_off = rela->addend + 4; tools/objtool/check.c: dest_off = rela->sym->sym.st_value + rela->addend + 4;
diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h index ced3765c4f44..a9a50a25ca66 100644 --- a/tools/objtool/arch.h +++ b/tools/objtool/arch.h @@ -66,6 +66,8 @@ struct stack_op { struct op_src src; }; +struct instruction; + void arch_initial_func_cfi_state(struct cfi_state *state); 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); +unsigned long arch_jump_destination(struct instruction *insn); + +unsigned long arch_dest_rela_offset(int addend); + #endif /* _ARCH_H */ diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 0567c47a91b1..fa33b3465722 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -11,6 +11,7 @@ #include "lib/inat.c" #include "lib/insn.c" +#include "../../check.h" #include "../../elf.h" #include "../../arch.h" #include "../../warn.h" @@ -66,6 +67,11 @@ bool arch_callee_saved_reg(unsigned char reg) } } +unsigned long arch_dest_rela_offset(int addend) +{ + return addend + 4; +} + int arch_decode_instruction(struct elf *elf, struct section *sec, unsigned long offset, unsigned int maxlen, unsigned int *len, enum insn_type *type, @@ -497,3 +503,8 @@ void arch_initial_func_cfi_state(struct cfi_state *state) state->regs[16].base = CFI_CFA; state->regs[16].offset = -8; } + +unsigned long arch_jump_destination(struct instruction *insn) +{ + return insn->offset + insn->len + insn->immediate; +} diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 176f2f084060..479fab46b656 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -563,7 +563,7 @@ static int add_jump_destinations(struct objtool_file *file) insn->len); if (!rela) { 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) { dest_sec = rela->sym->sec; dest_off = rela->addend + 4; @@ -659,7 +659,7 @@ static int add_call_destinations(struct objtool_file *file) rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); if (!rela) { - dest_off = insn->offset + insn->len + insn->immediate; + dest_off = arch_jump_destination(insn); insn->call_dest = find_symbol_by_offset(insn->sec, dest_off); @@ -672,14 +672,19 @@ static int add_call_destinations(struct objtool_file *file) } } else if (rela->sym->type == STT_SECTION) { + /* + * the original x86_64 code adds 4 to the rela->addend + * which is not needed on arm64 architecture. + */ + dest_off = arch_dest_rela_offset(rela->addend); insn->call_dest = find_symbol_by_offset(rela->sym->sec, - rela->addend+4); + dest_off); if (!insn->call_dest || insn->call_dest->type != STT_FUNC) { - 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, rela->sym->sec->name, - rela->addend + 4); + dest_off); return -1; } } else
The jump destination and relocation offset used previously are only reliable on x86_64 architecture. We abstract these computations by calling arch-dependent implementations. Signed-off-by: Raphael Gault <raphael.gault@arm.com> --- tools/objtool/arch.h | 6 ++++++ tools/objtool/arch/x86/decode.c | 11 +++++++++++ tools/objtool/check.c | 15 ++++++++++----- 3 files changed, 27 insertions(+), 5 deletions(-)