[RFC PATCH 02/10] objtool, x86: add several functions and files to the objtool whitelist

From: Josh Poimboeuf <jpoimboe@redhat.com>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, live-patching@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andy Lutomirski <luto@kernel.org>, Jiri Slaby <jslaby@suse.cz>,
	Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [RFC PATCH 02/10] objtool, x86: add several functions and files to the objtool whitelist
Date: Thu,  1 Jun 2017 00:44:08 -0500	[thread overview]
Message-ID: <1c982a42e4d2b9b3a4aa76bf0a0437842bbdf718.1496293620.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1496293620.git.jpoimboe@redhat.com>

In preparation for an objtool rewrite which will have broader checks,
whitelist functions and files which cause problems because they do
unusual things with the stack.

These whitelists serve as a TODO list for which functions and files
don't yet have undwarf unwinder coverage.  Eventually most of the
whitelists can be removed in favor of manual CFI hint annotations or
objtool improvements.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 arch/x86/crypto/Makefile           | 2 ++
 arch/x86/crypto/sha1-mb/Makefile   | 2 ++
 arch/x86/crypto/sha256-mb/Makefile | 2 ++
 arch/x86/kernel/Makefile           | 1 +
 arch/x86/kernel/acpi/Makefile      | 2 ++
 arch/x86/kernel/kprobes/opt.c      | 9 ++++++++-
 arch/x86/kernel/reboot.c           | 2 ++
 arch/x86/kvm/svm.c                 | 2 ++
 arch/x86/kvm/vmx.c                 | 3 +++
 arch/x86/lib/msr-reg.S             | 8 ++++----
 arch/x86/net/Makefile              | 2 ++
 arch/x86/platform/efi/Makefile     | 1 +
 arch/x86/power/Makefile            | 2 ++
 arch/x86/xen/Makefile              | 3 +++
 kernel/kexec_core.c                | 4 +++-
 15 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/arch/x86/crypto/Makefile b/arch/x86/crypto/Makefile
index 34b3fa2..9e32d40 100644
--- a/arch/x86/crypto/Makefile
+++ b/arch/x86/crypto/Makefile
@@ -2,6 +2,8 @@
 # Arch-specific CryptoAPI modules.
 #
 
+OBJECT_FILES_NON_STANDARD := y
+
 avx_supported := $(call as-instr,vpxor %xmm0$(comma)%xmm0$(comma)%xmm0,yes,no)
 avx2_supported := $(call as-instr,vpgatherdd %ymm0$(comma)(%eax$(comma)%ymm1\
 				$(comma)4)$(comma)%ymm2,yes,no)
diff --git a/arch/x86/crypto/sha1-mb/Makefile b/arch/x86/crypto/sha1-mb/Makefile
index 2f87563..2e14acc 100644
--- a/arch/x86/crypto/sha1-mb/Makefile
+++ b/arch/x86/crypto/sha1-mb/Makefile
@@ -2,6 +2,8 @@
 # Arch-specific CryptoAPI modules.
 #
 
+OBJECT_FILES_NON_STANDARD := y
+
 avx2_supported := $(call as-instr,vpgatherdd %ymm0$(comma)(%eax$(comma)%ymm1\
                                 $(comma)4)$(comma)%ymm2,yes,no)
 ifeq ($(avx2_supported),yes)
diff --git a/arch/x86/crypto/sha256-mb/Makefile b/arch/x86/crypto/sha256-mb/Makefile
index 41089e7..45b4fca 100644
--- a/arch/x86/crypto/sha256-mb/Makefile
+++ b/arch/x86/crypto/sha256-mb/Makefile
@@ -2,6 +2,8 @@
 # Arch-specific CryptoAPI modules.
 #
 
+OBJECT_FILES_NON_STANDARD := y
+
 avx2_supported := $(call as-instr,vpgatherdd %ymm0$(comma)(%eax$(comma)%ymm1\
                                 $(comma)4)$(comma)%ymm2,yes,no)
 ifeq ($(avx2_supported),yes)
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 4b99423..3c7c419 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -29,6 +29,7 @@ OBJECT_FILES_NON_STANDARD_head_$(BITS).o		:= y
 OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o	:= y
 OBJECT_FILES_NON_STANDARD_ftrace_$(BITS).o		:= y
 OBJECT_FILES_NON_STANDARD_test_nx.o			:= y
+OBJECT_FILES_NON_STANDARD_paravirt_patch_$(BITS).o	:= y
 
 # If instrumentation of this dir is enabled, boot hangs during first second.
 # Probably could be more selective here, but note that files related to irqs,
diff --git a/arch/x86/kernel/acpi/Makefile b/arch/x86/kernel/acpi/Makefile
index 26b78d8..85a9e17 100644
--- a/arch/x86/kernel/acpi/Makefile
+++ b/arch/x86/kernel/acpi/Makefile
@@ -1,3 +1,5 @@
+OBJECT_FILES_NON_STANDARD_wakeup_$(BITS).o := y
+
 obj-$(CONFIG_ACPI)		+= boot.o
 obj-$(CONFIG_ACPI_SLEEP)	+= sleep.o wakeup_$(BITS).o
 obj-$(CONFIG_ACPI_APEI)		+= apei.o
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 901c640..69ea0bc 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -28,6 +28,7 @@
 #include <linux/kdebug.h>
 #include <linux/kallsyms.h>
 #include <linux/ftrace.h>
+#include <linux/frame.h>
 
 #include <asm/text-patching.h>
 #include <asm/cacheflush.h>
@@ -94,6 +95,7 @@ static void synthesize_set_arg1(kprobe_opcode_t *addr, unsigned long val)
 }
 
 asm (
+			"optprobe_template_func:\n"
 			".global optprobe_template_entry\n"
 			"optprobe_template_entry:\n"
 #ifdef CONFIG_X86_64
@@ -131,7 +133,12 @@ asm (
 			"	popf\n"
 #endif
 			".global optprobe_template_end\n"
-			"optprobe_template_end:\n");
+			"optprobe_template_end:\n"
+			".type optprobe_template_func, @function\n"
+			".size optprobe_template_func, .-optprobe_template_func\n");
+
+void optprobe_template_func(void);
+STACK_FRAME_NON_STANDARD(optprobe_template_func);
 
 #define TMPL_MOVE_IDX \
 	((long)&optprobe_template_val - (long)&optprobe_template_entry)
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 2544700..67393fc 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -9,6 +9,7 @@
 #include <linux/sched.h>
 #include <linux/tboot.h>
 #include <linux/delay.h>
+#include <linux/frame.h>
 #include <acpi/reboot.h>
 #include <asm/io.h>
 #include <asm/apic.h>
@@ -123,6 +124,7 @@ void __noreturn machine_real_restart(unsigned int type)
 #ifdef CONFIG_APM_MODULE
 EXPORT_SYMBOL(machine_real_restart);
 #endif
+STACK_FRAME_NON_STANDARD(machine_real_restart);
 
 /*
  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 183ddb2..bb7a502 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -36,6 +36,7 @@
 #include <linux/slab.h>
 #include <linux/amd-iommu.h>
 #include <linux/hashtable.h>
+#include <linux/frame.h>
 
 #include <asm/apic.h>
 #include <asm/perf_event.h>
@@ -4908,6 +4909,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
 
 	mark_all_clean(svm->vmcb);
 }
+STACK_FRAME_NON_STANDARD(svm_vcpu_run);
 
 static void svm_set_cr3(struct kvm_vcpu *vcpu, unsigned long root)
 {
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 72f7839..bc8b933 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -33,6 +33,7 @@
 #include <linux/slab.h>
 #include <linux/tboot.h>
 #include <linux/hrtimer.h>
+#include <linux/frame.h>
 #include "kvm_cache_regs.h"
 #include "x86.h"
 
@@ -8675,6 +8676,7 @@ static void vmx_handle_external_intr(struct kvm_vcpu *vcpu)
 			);
 	}
 }
+STACK_FRAME_NON_STANDARD(vmx_handle_external_intr);
 
 static bool vmx_has_high_real_mode_segbase(void)
 {
@@ -9051,6 +9053,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	vmx_recover_nmi_blocking(vmx);
 	vmx_complete_interrupts(vmx);
 }
+STACK_FRAME_NON_STANDARD(vmx_vcpu_run);
 
 static void vmx_switch_vmcs(struct kvm_vcpu *vcpu, struct loaded_vmcs *vmcs)
 {
diff --git a/arch/x86/lib/msr-reg.S b/arch/x86/lib/msr-reg.S
index c815564..10ffa7e 100644
--- a/arch/x86/lib/msr-reg.S
+++ b/arch/x86/lib/msr-reg.S
@@ -13,14 +13,14 @@
 .macro op_safe_regs op
 ENTRY(\op\()_safe_regs)
 	pushq %rbx
-	pushq %rbp
+	pushq %r12
 	movq	%rdi, %r10	/* Save pointer */
 	xorl	%r11d, %r11d	/* Return value */
 	movl    (%rdi), %eax
 	movl    4(%rdi), %ecx
 	movl    8(%rdi), %edx
 	movl    12(%rdi), %ebx
-	movl    20(%rdi), %ebp
+	movl    20(%rdi), %r12d
 	movl    24(%rdi), %esi
 	movl    28(%rdi), %edi
 1:	\op
@@ -29,10 +29,10 @@ ENTRY(\op\()_safe_regs)
 	movl    %ecx, 4(%r10)
 	movl    %edx, 8(%r10)
 	movl    %ebx, 12(%r10)
-	movl    %ebp, 20(%r10)
+	movl    %r12d, 20(%r10)
 	movl    %esi, 24(%r10)
 	movl    %edi, 28(%r10)
-	popq %rbp
+	popq %r12
 	popq %rbx
 	ret
 3:
diff --git a/arch/x86/net/Makefile b/arch/x86/net/Makefile
index 90568c3..fefb4b6 100644
--- a/arch/x86/net/Makefile
+++ b/arch/x86/net/Makefile
@@ -1,4 +1,6 @@
 #
 # Arch-specific network modules
 #
+OBJECT_FILES_NON_STANDARD_bpf_jit.o += y
+
 obj-$(CONFIG_BPF_JIT) += bpf_jit.o bpf_jit_comp.o
diff --git a/arch/x86/platform/efi/Makefile b/arch/x86/platform/efi/Makefile
index f1d83b3..2f56e1e 100644
--- a/arch/x86/platform/efi/Makefile
+++ b/arch/x86/platform/efi/Makefile
@@ -1,4 +1,5 @@
 OBJECT_FILES_NON_STANDARD_efi_thunk_$(BITS).o := y
+OBJECT_FILES_NON_STANDARD_efi_stub_$(BITS).o := y
 
 obj-$(CONFIG_EFI) 		+= quirks.o efi.o efi_$(BITS).o efi_stub_$(BITS).o
 obj-$(CONFIG_EARLY_PRINTK_EFI)	+= early_printk.o
diff --git a/arch/x86/power/Makefile b/arch/x86/power/Makefile
index a6a198c..0504187 100644
--- a/arch/x86/power/Makefile
+++ b/arch/x86/power/Makefile
@@ -1,3 +1,5 @@
+OBJECT_FILES_NON_STANDARD_hibernate_asm_$(BITS).o := y
+
 # __restore_processor_state() restores %gs after S3 resume and so should not
 # itself be stack-protected
 nostackp := $(call cc-option, -fno-stack-protector)
diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index fffb0a1..bced7a3 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -1,3 +1,6 @@
+OBJECT_FILES_NON_STANDARD_xen-asm_$(BITS).o := y
+OBJECT_FILES_NON_STANDARD_xen-pvh.o := y
+
 ifdef CONFIG_FUNCTION_TRACER
 # Do not profile debug and lowlevel utilities
 CFLAGS_REMOVE_spinlock.o = -pg
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index ae1a3ba..154ffb4 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -38,6 +38,7 @@
 #include <linux/syscore_ops.h>
 #include <linux/compiler.h>
 #include <linux/hugetlb.h>
+#include <linux/frame.h>
 
 #include <asm/page.h>
 #include <asm/sections.h>
@@ -874,7 +875,7 @@ int kexec_load_disabled;
  * only when panic_cpu holds the current CPU number; this is the only CPU
  * which processes crash_kexec routines.
  */
-void __crash_kexec(struct pt_regs *regs)
+void __noclone __crash_kexec(struct pt_regs *regs)
 {
 	/* Take the kexec_mutex here to prevent sys_kexec_load
 	 * running on one cpu from replacing the crash kernel
@@ -896,6 +897,7 @@ void __crash_kexec(struct pt_regs *regs)
 		mutex_unlock(&kexec_mutex);
 	}
 }
+STACK_FRAME_NON_STANDARD(__crash_kexec);
 
 void crash_kexec(struct pt_regs *regs)
 {
-- 
2.7.4
