From: Josh Poimboeuf jpoimboe@redhat.com
[ Upstream commit 1f9a1b74942485a0a29e7c4a9a9f2fe8aea17766 ]
The JMP_NOSPEC macro branches to __x86_retpoline_*() rather than the __x86_indirect_thunk_*() wrappers used by C code. Detect jumps to __x86_retpoline_*() as retpoline dynamic jumps.
Presumably this doesn't trigger a user-visible bug. I only found it when testing vmlinux.o validation.
Fixes: 39b735332cb8 ("objtool: Detect jumps to retpoline thunks") Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Link: https://lore.kernel.org/r/31f5833e2e4f01e3d755889ac77e3661e906c09f.161126346... Signed-off-by: Sasha Levin sashal@kernel.org --- tools/objtool/arch/x86/special.c | 2 +- tools/objtool/check.c | 3 ++- tools/objtool/check.h | 11 +++++++++++ 3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c index fd4af88c0ea52..151b13d0a2676 100644 --- a/tools/objtool/arch/x86/special.c +++ b/tools/objtool/arch/x86/special.c @@ -48,7 +48,7 @@ bool arch_support_alt_relocation(struct special_alt *special_alt, * replacement group. */ return insn->offset == special_alt->new_off && - (insn->type == INSN_CALL || is_static_jump(insn)); + (insn->type == INSN_CALL || is_jump(insn)); }
/* diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 2e154f00ccec2..48e22e3c6f186 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -789,7 +789,8 @@ static int add_jump_destinations(struct objtool_file *file) dest_sec = reloc->sym->sec; dest_off = reloc->sym->sym.st_value + arch_dest_reloc_offset(reloc->addend); - } else if (strstr(reloc->sym->name, "_indirect_thunk_")) { + } else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) || + !strncmp(reloc->sym->name, "__x86_retpoline_", 16)) { /* * Retpoline jumps are really dynamic jumps in * disguise, so convert them accordingly. diff --git a/tools/objtool/check.h b/tools/objtool/check.h index 5ec00a4b891b6..2804848e628e3 100644 --- a/tools/objtool/check.h +++ b/tools/objtool/check.h @@ -54,6 +54,17 @@ static inline bool is_static_jump(struct instruction *insn) insn->type == INSN_JUMP_UNCONDITIONAL; }
+static inline bool is_dynamic_jump(struct instruction *insn) +{ + return insn->type == INSN_JUMP_DYNAMIC || + insn->type == INSN_JUMP_DYNAMIC_CONDITIONAL; +} + +static inline bool is_jump(struct instruction *insn) +{ + return is_static_jump(insn) || is_dynamic_jump(insn); +} + struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset);