From: Sami Tolvanen <samitolvanen@google.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
Jann Horn <jannh@google.com>,
the arch/x86 maintainers <x86@kernel.org>,
Masahiro Yamada <masahiroy@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Will Deacon <will@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
Kees Cook <keescook@chromium.org>,
Nick Desaulniers <ndesaulniers@google.com>,
clang-built-linux <clang-built-linux@googlegroups.com>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
linux-arch <linux-arch@vger.kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-kbuild <linux-kbuild@vger.kernel.org>,
kernel list <linux-kernel@vger.kernel.org>,
linux-pci@vger.kernel.org
Subject: Re: [PATCH v6 22/25] x86/asm: annotate indirect jumps
Date: Fri, 23 Oct 2020 10:36:17 -0700 [thread overview]
Message-ID: <20201023173617.GA3021099@google.com> (raw)
In-Reply-To: <CABCJKufL6=FiaeD8T0P+mK4JeR9J80hhjvJ6Z9S-m9UnCESxVA@mail.gmail.com>
On Wed, Oct 21, 2020 at 05:22:59PM -0700, Sami Tolvanen wrote:
> There are a couple of differences, like the first "undefined stack
> state" warning pointing to set_bringup_idt_handler.constprop.0()
> instead of __switch_to_asm(). I tried running this with --backtrace,
> but objtool segfaults at the first .entry.text warning:
Looks like it segfaults when calling BT_FUNC() for an instruction that
doesn't have a section (?). Applying this patch allows objtool to finish
with --backtrace:
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index c216dd4d662c..618b0c4f2890 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2604,7 +2604,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
ret = validate_branch(file, func,
insn->jump_dest, state);
if (ret) {
- if (backtrace)
+ if (backtrace && insn->sec)
BT_FUNC("(branch)", insn);
return ret;
}
Running objtool -barfld on an allyesconfig+LTO vmlinux.o prints out the
following, ignoring the crypto warnings for now:
__switch_to_asm()+0x0: undefined stack state
xen_hypercall_set_trap_table()+0x0: <=== (sym)
.entry.text+0xffd: sibling call from callable instruction with modified stack frame
.entry.text+0xfcb: (branch)
.entry.text+0xfb5: (alt)
.entry.text+0xfb0: (alt)
.entry.text+0xf78: (branch)
.entry.text+0x9c: (branch)
xen_syscall_target()+0x15: (branch)
xen_syscall_target()+0x0: <=== (sym)
.entry.text+0x1754: unsupported instruction in callable function
.entry.text+0x171d: (branch)
.entry.text+0x1707: (alt)
.entry.text+0x1701: (alt)
xen_syscall32_target()+0x15: (branch)
xen_syscall32_target()+0x0: <=== (sym)
.entry.text+0x1634: redundant CLD
do_suspend_lowlevel()+0x116: sibling call from callable instruction with modified stack frame
do_suspend_lowlevel()+0x9a: (branch)
do_suspend_lowlevel()+0x0: <=== (sym)
... [skipping crypto stack pointer alignment warnings] ...
__x86_retpoline_rdi()+0x10: return with modified stack frame
__x86_retpoline_rdi()+0x0: (branch)
.altinstr_replacement+0x13d: (branch)
.text+0xaf4c7: (alt)
.text+0xb03b0: (branch)
.text+0xaf482: (branch)
crc_pcl()+0x10: (branch)
crc_pcl()+0x0: <=== (sym)
__x86_retpoline_rdi()+0x0: stack state mismatch: cfa1=7+32 cfa2=7+8
.altinstr_replacement+0x20b: (branch)
__x86_indirect_thunk_rdi()+0x0: (alt)
__x86_indirect_thunk_rdi()+0x0: <=== (sym)
.head.text+0xfb: unsupported instruction in callable function
.head.text+0x207: (branch)
sev_es_play_dead()+0xff: (branch)
sev_es_play_dead()+0xd2: (branch)
sev_es_play_dead()+0xa8: (alt)
sev_es_play_dead()+0x144: (branch)
sev_es_play_dead()+0x10b: (branch)
sev_es_play_dead()+0x1f: (branch)
sev_es_play_dead()+0x0: <=== (sym)
__x86_retpoline_rdi()+0x0: stack state mismatch: cfa1=7+32 cfa2=-1+0
.altinstr_replacement+0x107: (branch)
.text+0x2885: (alt)
.text+0x2860: <=== (hint)
.entry.text+0x48: stack state mismatch: cfa1=7-8 cfa2=-1+0
.altinstr_replacement+0xffffffffffffffff: (branch)
.entry.text+0x21: (alt)
.entry.text+0x1c: (alt)
.entry.text+0x10: <=== (hint)
.entry.text+0x15fd: stack state mismatch: cfa1=7-8 cfa2=-1+0
.altinstr_replacement+0xffffffffffffffff: (branch)
.entry.text+0x15dc: (alt)
.entry.text+0x15d7: (alt)
.entry.text+0x15d0: <=== (hint)
.entry.text+0x168c: stack state mismatch: cfa1=7-8 cfa2=-1+0
.altinstr_replacement+0xffffffffffffffff: (branch)
.entry.text+0x166b: (alt)
.entry.text+0x1666: (alt)
.entry.text+0x1660: <=== (hint)
Sami
next prev parent reply other threads:[~2020-10-23 17:36 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-13 0:31 [PATCH v6 00/25] Add support for Clang LTO Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 01/25] kbuild: preprocess module linker script Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 02/25] objtool: Add a pass for generating __mcount_loc Sami Tolvanen
2020-10-14 16:50 ` Ingo Molnar
2020-10-14 18:21 ` Peter Zijlstra
2020-10-15 20:10 ` Josh Poimboeuf
2020-10-13 0:31 ` [PATCH v6 03/25] objtool: Don't autodetect vmlinux.o Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 04/25] tracing: move function tracer options to Kconfig Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 05/25] tracing: add support for objtool mcount Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 06/25] x86, build: use " Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 07/25] treewide: remove DISABLE_LTO Sami Tolvanen
2020-10-14 22:43 ` Kees Cook
2020-10-17 1:46 ` Masahiro Yamada
2020-10-13 0:31 ` [PATCH v6 08/25] kbuild: add support for Clang LTO Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 09/25] kbuild: lto: fix module versioning Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 10/25] objtool: Split noinstr validation from --vmlinux Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 11/25] kbuild: lto: postpone objtool Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 12/25] kbuild: lto: limit inlining Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 13/25] kbuild: lto: merge module sections Sami Tolvanen
2020-10-14 22:49 ` Kees Cook
2020-10-20 16:42 ` Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 14/25] kbuild: lto: remove duplicate dependencies from .mod files Sami Tolvanen
2020-10-14 22:50 ` Kees Cook
2020-12-03 17:59 ` Masahiro Yamada
2020-12-03 18:47 ` Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 15/25] init: lto: ensure initcall ordering Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 16/25] init: lto: fix PREL32 relocations Sami Tolvanen
2020-10-14 22:53 ` Kees Cook
2020-10-15 0:12 ` Jann Horn
2020-10-13 0:31 ` [PATCH v6 17/25] PCI: Fix PREL32 relocations for LTO Sami Tolvanen
2020-10-14 22:58 ` Kees Cook
2020-10-13 0:31 ` [PATCH v6 18/25] modpost: lto: strip .lto from module names Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 19/25] scripts/mod: disable LTO for empty.c Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 20/25] efi/libstub: disable LTO Sami Tolvanen
2020-10-13 0:31 ` [PATCH v6 21/25] drivers/misc/lkdtm: disable LTO for rodata.o Sami Tolvanen
2020-10-13 0:32 ` [PATCH v6 22/25] x86/asm: annotate indirect jumps Sami Tolvanen
2020-10-14 22:46 ` Kees Cook
2020-10-14 23:23 ` Jann Horn
2020-10-15 10:22 ` Peter Zijlstra
2020-10-15 20:39 ` Josh Poimboeuf
2020-10-20 16:45 ` Sami Tolvanen
2020-10-20 18:52 ` Josh Poimboeuf
2020-10-20 19:24 ` Sami Tolvanen
2020-10-21 8:56 ` Peter Zijlstra
2020-10-21 9:08 ` Peter Zijlstra
2020-10-21 9:32 ` Peter Zijlstra
2020-10-21 21:27 ` Josh Poimboeuf
2020-10-22 7:25 ` Peter Zijlstra
2020-10-23 17:48 ` Sami Tolvanen
2020-10-23 18:04 ` Nick Desaulniers
2020-10-21 15:01 ` Sami Tolvanen
2020-10-22 0:22 ` Sami Tolvanen
2020-10-23 17:36 ` Sami Tolvanen [this message]
2020-11-09 23:11 ` Sami Tolvanen
2020-11-10 2:29 ` Josh Poimboeuf
2020-11-10 3:18 ` Nick Desaulniers
2020-11-10 4:48 ` Sami Tolvanen
2020-11-10 16:11 ` Josh Poimboeuf
2020-11-10 17:46 ` Josh Poimboeuf
2020-11-10 18:59 ` Sami Tolvanen
2020-11-13 19:54 ` Josh Poimboeuf
2020-11-13 20:24 ` Sami Tolvanen
2020-11-13 20:52 ` Josh Poimboeuf
2020-11-13 22:34 ` Josh Poimboeuf
2020-11-13 22:54 ` Sami Tolvanen
2020-11-13 22:56 ` Josh Poimboeuf
2020-11-13 23:31 ` Sami Tolvanen
2020-11-14 0:49 ` Josh Poimboeuf
2020-10-21 9:51 ` Peter Zijlstra
2020-10-21 18:30 ` Josh Poimboeuf
2020-10-13 0:32 ` [PATCH v6 23/25] x86, vdso: disable LTO only for vDSO Sami Tolvanen
2020-10-13 0:32 ` [PATCH v6 24/25] x86, cpu: disable LTO for cpu.c Sami Tolvanen
2020-10-13 0:32 ` [PATCH v6 25/25] x86, build: allow LTO_CLANG and THINLTO to be selected Sami Tolvanen
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