diff options
| author | Josh Poimboeuf <jpoimboe@kernel.org> | 2025-04-08 00:02:13 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-20 10:15:06 +0200 |
| commit | 1b7685256db2faa07b75ecd137d172cc45b11c74 (patch) | |
| tree | 3ac5ec844b09ed84664e9d9d368b72048949ccaf | |
| parent | ee2b0301d6bfe16b35d57947687c664ecb815775 (diff) | |
objtool: Fix INSN_CONTEXT_SWITCH handling in validate_unret()
[ Upstream commit a8df7d0ef92eca28c610206c6748daf537ac0586 ]
The !CONFIG_IA32_EMULATION version of xen_entry_SYSCALL_compat() ends
with a SYSCALL instruction which is classified by objtool as
INSN_CONTEXT_SWITCH.
Unlike validate_branch(), validate_unret() doesn't consider
INSN_CONTEXT_SWITCH in a non-function to be a dead end, so it keeps
going past the end of xen_entry_SYSCALL_compat(), resulting in the
following warning:
vmlinux.o: warning: objtool: xen_reschedule_interrupt+0x2a: RET before UNTRAIN
Fix that by adding INSN_CONTEXT_SWITCH handling to validate_unret() to
match what validate_branch() is already doing.
Fixes: a09a6e2399ba ("objtool: Add entry UNRET validation")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/f5eda46fd09f15b1f5cde3d9ae3b92b958342add.1744095216.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | tools/objtool/check.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 286a2c0af02a..127862fa05c6 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3990,6 +3990,11 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) WARN_INSN(insn, "RET before UNTRAIN"); return 1; + case INSN_CONTEXT_SWITCH: + if (insn_func(insn)) + break; + return 0; + case INSN_NOP: if (insn->retpoline_safe) return 0; |