From: Josh Poimboeuf <jpoimboe@redhat.com>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Sami Tolvanen <samitolvanen@google.com>,
Sedat Dilek <sedat.dilek@gmail.com>,
Kees Cook <keescook@chromium.org>,
Nick Desaulniers <ndesaulniers@google.com>,
clang-built-linux@googlegroups.com,
Miroslav Benes <mbenes@suse.cz>, Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>
Subject: [PATCH v2 12/20] x86/xen: Support objtool validation in xen-asm.S
Date: Thu, 21 Jan 2021 15:29:28 -0600 [thread overview]
Message-ID: <8b042a09c69e8645f3b133ef6653ba28f896807d.1611263462.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1611263461.git.jpoimboe@redhat.com>
The OBJECT_FILES_NON_STANDARD annotation is used to tell objtool to
ignore a file. File-level ignores won't work when validating vmlinux.o.
Tweak the ELF metadata and unwind hints to allow objtool to follow the
code.
Cc: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
arch/x86/xen/Makefile | 1 -
arch/x86/xen/xen-asm.S | 29 +++++++++++++++++++----------
2 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index fc5c5ba4aacb..40b5779fce21 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
-OBJECT_FILES_NON_STANDARD_xen-asm.o := y
ifdef CONFIG_FUNCTION_TRACER
# Do not profile debug and lowlevel utilities
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 1cb0e84b9161..a05e80b552c0 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -14,6 +14,7 @@
#include <asm/thread_info.h>
#include <asm/asm.h>
#include <asm/frame.h>
+#include <asm/unwind_hints.h>
#include <xen/interface/xen.h>
@@ -146,6 +147,7 @@ SYM_FUNC_END(xen_read_cr2_direct);
.macro xen_pv_trap name
SYM_CODE_START(xen_\name)
+ UNWIND_HINT_EMPTY
pop %rcx
pop %r11
jmp \name
@@ -184,6 +186,7 @@ xen_pv_trap asm_exc_xen_hypervisor_callback
SYM_CODE_START(xen_early_idt_handler_array)
i = 0
.rept NUM_EXCEPTION_VECTORS
+ UNWIND_HINT_EMPTY
pop %rcx
pop %r11
jmp early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE
@@ -210,11 +213,13 @@ hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
* rsp->rax }
*/
SYM_CODE_START(xen_iret)
+ UNWIND_HINT_EMPTY
pushq $0
jmp hypercall_iret
SYM_CODE_END(xen_iret)
SYM_CODE_START(xen_sysret64)
+ UNWIND_HINT_EMPTY
/*
* We're already on the usermode stack at this point, but
* still with the kernel gs, so we can easily switch back.
@@ -250,7 +255,8 @@ SYM_CODE_END(xen_sysret64)
*/
/* Normal 64-bit system call target */
-SYM_FUNC_START(xen_syscall_target)
+SYM_CODE_START(xen_syscall_target)
+ UNWIND_HINT_EMPTY
popq %rcx
popq %r11
@@ -263,12 +269,13 @@ SYM_FUNC_START(xen_syscall_target)
movq $__USER_CS, 1*8(%rsp)
jmp entry_SYSCALL_64_after_hwframe
-SYM_FUNC_END(xen_syscall_target)
+SYM_CODE_END(xen_syscall_target)
#ifdef CONFIG_IA32_EMULATION
/* 32-bit compat syscall target */
-SYM_FUNC_START(xen_syscall32_target)
+SYM_CODE_START(xen_syscall32_target)
+ UNWIND_HINT_EMPTY
popq %rcx
popq %r11
@@ -281,10 +288,11 @@ SYM_FUNC_START(xen_syscall32_target)
movq $__USER32_CS, 1*8(%rsp)
jmp entry_SYSCALL_compat_after_hwframe
-SYM_FUNC_END(xen_syscall32_target)
+SYM_CODE_END(xen_syscall32_target)
/* 32-bit compat sysenter target */
-SYM_FUNC_START(xen_sysenter_target)
+SYM_CODE_START(xen_sysenter_target)
+ UNWIND_HINT_EMPTY
/*
* NB: Xen is polite and clears TF from EFLAGS for us. This means
* that we don't need to guard against single step exceptions here.
@@ -301,17 +309,18 @@ SYM_FUNC_START(xen_sysenter_target)
movq $__USER32_CS, 1*8(%rsp)
jmp entry_SYSENTER_compat_after_hwframe
-SYM_FUNC_END(xen_sysenter_target)
+SYM_CODE_END(xen_sysenter_target)
#else /* !CONFIG_IA32_EMULATION */
-SYM_FUNC_START_ALIAS(xen_syscall32_target)
-SYM_FUNC_START(xen_sysenter_target)
+SYM_CODE_START(xen_syscall32_target)
+SYM_CODE_START(xen_sysenter_target)
+ UNWIND_HINT_EMPTY
lea 16(%rsp), %rsp /* strip %rcx, %r11 */
mov $-ENOSYS, %rax
pushq $0
jmp hypercall_iret
-SYM_FUNC_END(xen_sysenter_target)
-SYM_FUNC_END_ALIAS(xen_syscall32_target)
+SYM_CODE_END(xen_sysenter_target)
+SYM_CODE_END(xen_syscall32_target)
#endif /* CONFIG_IA32_EMULATION */
--
2.29.2
next prev parent reply other threads:[~2021-01-21 21:38 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 21:29 [PATCH v2 00/20] objtool: vmlinux.o and CLANG LTO support Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 01/20] objtool: Fix error handling for STD/CLD warnings Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 02/20] objtool: Fix retpoline detection in asm code Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 03/20] objtool: Fix ".cold" section suffix check for newer versions of GCC Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 04/20] objtool: Support retpoline jump detection for vmlinux.o Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 05/20] x86/ftrace: Add UNWIND_HINT_FUNC annotation for ftrace_stub Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 06/20] objtool: Assume only ELF functions do sibling calls Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 07/20] objtool: Add asm version of STACK_FRAME_NON_STANDARD Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 08/20] objtool: Combine UNWIND_HINT_RET_OFFSET and UNWIND_HINT_FUNC Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 09/20] objtool: Add xen_start_kernel() to noreturn list Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 10/20] objtool: Move unsuffixed symbol conversion to a helper function Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 11/20] objtool: Add CONFIG_CFI_CLANG support Josh Poimboeuf
2021-01-21 21:29 ` Josh Poimboeuf [this message]
2021-01-21 21:29 ` [PATCH v2 13/20] x86/xen: Support objtool vmlinux.o validation in xen-head.S Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 14/20] x86/xen/pvh: Annotate indirect branch as safe Josh Poimboeuf
2021-01-22 5:17 ` Jürgen Groß
2021-01-21 21:29 ` [PATCH v2 15/20] x86/ftrace: Support objtool vmlinux.o validation in ftrace_64.S Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 16/20] x86/acpi: Annotate indirect branch as safe Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 17/20] x86/acpi: Support objtool validation in wakeup_64.S Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 18/20] x86/power: Annotate indirect branches as safe Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 19/20] x86/power: Move restore_registers() to top of the file Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 20/20] x86/power: Support objtool validation in hibernate_asm_64.S Josh Poimboeuf
2021-01-21 22:38 ` [PATCH v2 00/20] objtool: vmlinux.o and CLANG LTO support Sedat Dilek
2021-01-22 15:41 ` Josh Poimboeuf
2021-01-22 21:17 ` Sami Tolvanen
2021-01-23 1:32 ` Nick Desaulniers
2021-01-23 2:26 ` Josh Poimboeuf
2021-01-23 2:31 ` Sedat Dilek
2021-01-23 2:46 ` Josh Poimboeuf
2021-01-23 2:50 ` Sedat Dilek
2021-01-25 22:43 ` Sami Tolvanen
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