[v2 0/7] x86: enable User-Mode Instruction Prevention
This is v2 of my first submission done a while ago[1]. I apologize for the delay. User-Mode Instruction Prevention (UMIP) is a security feature present in new Intel Processors. If enabled, it prevents the execution of certain instructions if the Current Privilege Level (CPL) is greater than 0. If these instructions were executed while in CPL > 0, user space applications could have access to system-wide settings such as the global and local descriptor tables, the segment selectors to the current task state and the local descriptor table. These are the instructions covered by UMIP: * SGDT - Store Global Descriptor Table * SIDT - Store Interrupt Descriptor Table * SLDT - Store Local Descriptor Table * SMSW - Store Machine Status Word * STR - Store Task Register If any of these instructions is executed with CPL > 0, a general protection exception is issued when UMIP is enabled. There is a caveat, however. Certain applications rely on some of these instructions to function. An example of this are applications that use WineHQ[2]. For instance, these applications rely on sidt returning a non- accesible memory location[3]. During the discussions, it was proposed that the fault could be relied to the user-space and perform the emulation in user-mode. However, this would break existing applications until, for instance, they update to a new WineHQ version. However, this approach would require UMIP to be disabled by default. The concensus in this forum is to always enable it. This patchset initially treated tasks running in virtual-8086 mode as a special case. However, I received clarification that DOSEMU[4] does not support applications that use these instructions. It relies on WineHQ for this[4]. Furthermore, the applications for which the concern was raised run in protected mode [3]. This version keeps UMIP enabled at all times and by default. If a general protection fault caused by the instructions protected by UMIP is detected, such fault will be fixed-up by returning dummy values as follows: * SGDT and SIDT return a base address to a dummy location in kernel memory and a limit of 0. * STR, SLDT returns 0 as the segment selector. This seems OK since we are providing a dummy value as the base address of the global descriptor table. * SMSW returns 0. Lastly, I found very useful the code for Intel MPX (Memory Protection Extensions) used to parse opcodes and the memory locations contained in the general purpose registers when used as operands. I put some of this code in a separate file that both MPX and UMIP can access and avoid code duplication. While here, I fixed two small bugs that I found in the MPX implementation. The code that I used to test the emulated instructions can be found in [6]. [1]. https://lwn.net/Articles/705877/ [2]. https://www.winehq.org/ [3]. https://www.winehq.org/pipermail/wine-devel/2016-November/115320.html [4]. http://www.dosemu.org/ [5]. http://marc.info/?l=linux-kernel&m=147876798717927&w=2 [6]. https://github.com/01org/luv-yocto/tree/rneri/umip/meta-luv/recipes-core/umip/files Thanks and BR, Ricardo Cc: Andy Lutomirski Cc: Andrew Morton Cc: Borislav Petkov Cc: Brian Gerst Cc: Chen Yucong Cc: Chris Metcalf Cc: Dave Hansen Cc: Fenghua Yu Cc: Huang Rui Cc: Jiri Slaby Cc: Jonathan Corbet Cc: Michael S. Tsirkin Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Ravi V. Shankar Cc: Vlastimil Babka Cc: Shuah Khan Cc: Paolo Bonzini Cc: Liang Z Li Cc: x...@kernel.org Cc: linux-msdos@vger.kernel.org Changes since V1: * Virtual-8086 mode tasks are not treated in a special manner. All code for this purpose was removed. * Instead of attempting to disable UMIP during a context switch or when entering virtual-8086 mode, UMIP remains enabled all the time. General protection faults that occur are fixed-up by returning dummy values as detailed above. * Removed umip= kernel parameter in favor of using clearcpuid=514 to disable UMIP. * Removed selftests designed to detect the absence of SIGSEGV signals when running in virtual-8086 mode. * Reused code from MPX to decode instructions operands. For this purpose code was put in a common location. * Fixed two bugs in MPX code that decodes operands. Ricardo Neri (7): x86/mpx: Do not use SIB index if index points to R/ESP x86/mpx: Fail when implicit zero-displacement is used along with R/EBP x86/mpx, x86/insn: Relocate insn util functions to a new insn-utils x86/cpufeature: Add User-Mode Instruction Prevention definitions x86: Add emulation code for UMIP instructions x86/traps: Fixup general protection faults caused by UMIP x86: Enable User-Mode Instruction Prevention arch/x86/Kconfig| 10 ++ arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/disabled-features.h| 8 +- arch/x86/include/asm/insn.h | 6 + arch/x86/include/asm/umip.h | 16 +++ arch/x86/include/uapi/asm/processor-flags.h | 2 + arch/x86/ke
[v2 4/7] x86/cpufeature: Add User-Mode Instruction Prevention definitions
User-Mode Instruction Prevention is a security feature present in new Intel processors that, when set, prevents the execution of a subset of instructions if such instructions are executed in user mode (CPL > 0). Attempting to execute such instructions causes a general protection exception. The subset of instructions comprises: * SGDT - Store Global Descriptor Table * SIDT - Store Interrupt Descriptor Table * SLDT - Store Local Descriptor Table * SMSW - Store Machine Status Word * STR - Store Task Register This feature is also added to the list of disabled-features to allow a cleaner handling of build-time configuration. Cc: Andy Lutomirski Cc: Andrew Morton Cc: H. Peter Anvin Cc: Borislav Petkov Cc: Brian Gerst Cc: Chen Yucong Cc: Chris Metcalf Cc: Dave Hansen Cc: Fenghua Yu Cc: Huang Rui Cc: Jiri Slaby Cc: Jonathan Corbet Cc: Michael S. Tsirkin Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Ravi V. Shankar Cc: Shuah Khan Cc: Vlastimil Babka Cc: Tony Luck Cc: Paolo Bonzini Cc: Liang Z. Li Cc: Alexandre Julliard Cc: Stas Sergeev Cc: x...@kernel.org Cc: linux-msdos@vger.kernel.org Signed-off-by: Ricardo Neri --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/disabled-features.h| 8 +++- arch/x86/include/uapi/asm/processor-flags.h | 2 ++ 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index eafee31..be61bf9 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -286,6 +286,7 @@ /* Intel-defined CPU features, CPUID level 0x0007:0 (ecx), word 16 */ #define X86_FEATURE_AVX512VBMI (16*32+ 1) /* AVX512 Vector Bit Manipulation instructions*/ +#define X86_FEATURE_UMIP (16*32+ 2) /* User Mode Instruction Protection */ #define X86_FEATURE_PKU(16*32+ 3) /* Protection Keys for Userspace */ #define X86_FEATURE_OSPKE (16*32+ 4) /* OS Protection Keys Enable */ #define X86_FEATURE_RDPID (16*32+ 22) /* RDPID instruction */ diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index 85599ad..4707445 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -16,6 +16,12 @@ # define DISABLE_MPX (1<<(X86_FEATURE_MPX & 31)) #endif +#ifdef CONFIG_X86_INTEL_UMIP +# define DISABLE_UMIP 0 +#else +# define DISABLE_UMIP (1<<(X86_FEATURE_UMIP & 31)) +#endif + #ifdef CONFIG_X86_64 # define DISABLE_VME (1<<(X86_FEATURE_VME & 31)) # define DISABLE_K6_MTRR (1<<(X86_FEATURE_K6_MTRR & 31)) @@ -55,7 +61,7 @@ #define DISABLED_MASK130 #define DISABLED_MASK140 #define DISABLED_MASK150 -#define DISABLED_MASK16(DISABLE_PKU|DISABLE_OSPKE) +#define DISABLED_MASK16(DISABLE_PKU|DISABLE_OSPKE|DISABLE_UMIP) #define DISABLED_MASK170 #define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18) diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h index 567de50..d2c2af8 100644 --- a/arch/x86/include/uapi/asm/processor-flags.h +++ b/arch/x86/include/uapi/asm/processor-flags.h @@ -104,6 +104,8 @@ #define X86_CR4_OSFXSR _BITUL(X86_CR4_OSFXSR_BIT) #define X86_CR4_OSXMMEXCPT_BIT 10 /* enable unmasked SSE exceptions */ #define X86_CR4_OSXMMEXCPT _BITUL(X86_CR4_OSXMMEXCPT_BIT) +#define X86_CR4_UMIP_BIT 11 /* enable UMIP support */ +#define X86_CR4_UMIP _BITUL(X86_CR4_UMIP_BIT) #define X86_CR4_VMXE_BIT 13 /* enable VMX virtualization */ #define X86_CR4_VMXE _BITUL(X86_CR4_VMXE_BIT) #define X86_CR4_SMXE_BIT 14 /* enable safer mode (TXT) */ -- 2.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-msdos" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[v2 3/7] x86/mpx, x86/insn: Relocate insn util functions to a new insn-utils
Other kernel submodules can benefit from using the utility functions
defined in mpx.c to obtain the addresses and values of operands contained
in the general purpose registers. An instance of this is the emulation code
used for instructions protected by the Intel User-Mode Instruction
Prevention feature.
Thus, these functions are relocated to a new insn-utils.c file. The reason
to not relocate these utilities for insn.c is that the latter solely
analyses instructions given by a struct insn. The file insn-utils.c intends
to be used when, for instance, determining addresses from the contents
of the general purpose registers.
To avoid creating a new insn-utils.h, insn.h is used. One caveat, however,
is that several #include's were needed by the utility functions.
Functions are simply relocated. There are not functional or indentation
changes.
Cc: Dave Hansen
Cc: Adam Buchbinder
Cc: Colin Ian King
Cc: Lorenzo Stoakes
Cc: Qiaowei Ren
Cc: Arnaldo Carvalho de Melo
Cc: Masami Hiramatsu
Cc: Adrian Hunter
Cc: Kees Cook
Cc: Thomas Garnier
Cc: Peter Zijlstra
Cc: Borislav Petkov
Cc: Dmitry Vyukov
Cc: Ravi V. Shankar
Cc: x...@kernel.org
Signed-off-by: Ricardo Neri
---
arch/x86/include/asm/insn.h | 6 ++
arch/x86/lib/Makefile | 2 +-
arch/x86/lib/insn-utils.c | 148
arch/x86/mm/mpx.c | 136 +---
4 files changed, 156 insertions(+), 136 deletions(-)
create mode 100644 arch/x86/lib/insn-utils.c
diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index b3e32b0..9dc9d42 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -22,6 +22,10 @@
/* insn_attr_t is defined in inat.h */
#include
+#include
+#include
+#include
+#include
struct insn_field {
union {
@@ -106,6 +110,8 @@ extern void insn_get_sib(struct insn *insn);
extern void insn_get_displacement(struct insn *insn);
extern void insn_get_immediate(struct insn *insn);
extern void insn_get_length(struct insn *insn);
+extern void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs);
+extern int get_reg_offset_rm(struct insn *insn, struct pt_regs *regs);
/* Attribute will be determined after getting ModRM (for opcode groups) */
static inline void insn_get_attribute(struct insn *insn)
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 34a7413..0d01d82 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -23,7 +23,7 @@ lib-y := delay.o misc.o cmdline.o cpu.o
lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
-lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o
+lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-utils.o
lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o
diff --git a/arch/x86/lib/insn-utils.c b/arch/x86/lib/insn-utils.c
new file mode 100644
index 000..598bbd6
--- /dev/null
+++ b/arch/x86/lib/insn-utils.c
@@ -0,0 +1,148 @@
+/*
+ * Utility functions for x86 operand and address decoding
+ *
+ * Copyright (C) Intel Corporation 2016
+ */
+#include
+#include
+#include
+#include
+
+enum reg_type {
+ REG_TYPE_RM = 0,
+ REG_TYPE_INDEX,
+ REG_TYPE_BASE,
+};
+
+static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
+ enum reg_type type)
+{
+ int regno = 0;
+
+ static const int regoff[] = {
+ offsetof(struct pt_regs, ax),
+ offsetof(struct pt_regs, cx),
+ offsetof(struct pt_regs, dx),
+ offsetof(struct pt_regs, bx),
+ offsetof(struct pt_regs, sp),
+ offsetof(struct pt_regs, bp),
+ offsetof(struct pt_regs, si),
+ offsetof(struct pt_regs, di),
+#ifdef CONFIG_X86_64
+ offsetof(struct pt_regs, r8),
+ offsetof(struct pt_regs, r9),
+ offsetof(struct pt_regs, r10),
+ offsetof(struct pt_regs, r11),
+ offsetof(struct pt_regs, r12),
+ offsetof(struct pt_regs, r13),
+ offsetof(struct pt_regs, r14),
+ offsetof(struct pt_regs, r15),
+#endif
+ };
+ int nr_registers = ARRAY_SIZE(regoff);
+ /*
+* Don't possibly decode a 32-bit instructions as
+* reading a 64-bit-only register.
+*/
+ if (IS_ENABLED(CONFIG_X86_64) && !insn->x86_64)
+ nr_registers -= 8;
+
+ switch (type) {
+ case REG_TYPE_RM:
+ regno = X86_MODRM_RM(insn->modrm.value);
+ if (X86_REX_B(insn->rex_prefix.value))
+ regno += 8;
+ break;
+
+ case REG_TYPE_INDEX:
+ regno = X86_SIB_INDEX(insn->sib.value);
+ if (X86_REX_X(insn->rex_prefix.value))
+ regno += 8;
+ /*
+
[v2 5/7] x86: Add emulation code for UMIP instructions
The feature User-Mode Instruction Prevention present in recent Intel
processor prevents a group of instructions from being executed with
CPL > 0. Otherwise, a general protection fault is issued.
Rather than relaying this fault to the user space (in the form of a SIGSEGV
signal), the instructions protected by UMIP can be emulated to provide
dummy results. This allows to conserve the current kernel behavior and not
reveal the system resources that UMIP intends to protect (the global
descriptor and interrupt descriptor tables, the segment selectors of the
local descriptor table and the task state and the machine status word).
This emulation is needed because certain applications (e.g., WineHQ) rely
on this subset of instructions to function.
The instructions protected by UMIP can be split in two groups. Those who
return a kernel memory address (sgdt and sidt) and those who return a
value (sldt, str and smsw).
For the instructions that return a kernel memory address, the result is
emulated as the location of a dummy variable in the kernel memory space.
This is needed as applications such as WineHQ rely on the result being
located in the kernel memory space function. The limit for the GDT and the
IDT are set to zero.
The instructions sldt and str return a segment selector relative to the
base address of the global descriptor table. Since the actual address of
such table is not revealed, it makes sense to emulate the result as zero.
The instruction smsw is emulated to return zero.
Cc: Andy Lutomirski
Cc: Andrew Morton
Cc: H. Peter Anvin
Cc: Borislav Petkov
Cc: Brian Gerst
Cc: Chen Yucong
Cc: Chris Metcalf
Cc: Dave Hansen
Cc: Fenghua Yu
Cc: Huang Rui
Cc: Jiri Slaby
Cc: Jonathan Corbet
Cc: Michael S. Tsirkin
Cc: Paul Gortmaker
Cc: Peter Zijlstra
Cc: Ravi V. Shankar
Cc: Shuah Khan
Cc: Vlastimil Babka
Cc: Tony Luck
Cc: Paolo Bonzini
Cc: Liang Z. Li
Cc: Alexandre Julliard
Cc: Stas Sergeev
Cc: x...@kernel.org
Cc: linux-msdos@vger.kernel.org
Signed-off-by: Ricardo Neri
---
arch/x86/include/asm/umip.h | 16 +
arch/x86/kernel/Makefile| 1 +
arch/x86/kernel/umip.c | 170
3 files changed, 187 insertions(+)
create mode 100644 arch/x86/include/asm/umip.h
create mode 100644 arch/x86/kernel/umip.c
diff --git a/arch/x86/include/asm/umip.h b/arch/x86/include/asm/umip.h
new file mode 100644
index 000..7bcaca6
--- /dev/null
+++ b/arch/x86/include/asm/umip.h
@@ -0,0 +1,16 @@
+#ifndef _ASM_X86_UMIP_H
+#define _ASM_X86_UMIP_H
+
+#include
+#include
+#include
+
+#ifdef CONFIG_X86_INTEL_UMIP
+int fixup_umip_exception(struct pt_regs *regs);
+#else
+static inline int fixup_umip_exception(struct pt_regs *regs)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_X86_INTEL_UMIP */
+#endif /* _ASM_X86_UMIP_H */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 581386c..c4aec02 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -124,6 +124,7 @@ obj-$(CONFIG_EFI) += sysfb_efi.o
obj-$(CONFIG_PERF_EVENTS) += perf_regs.o
obj-$(CONFIG_TRACING) += tracepoint.o
obj-$(CONFIG_SCHED_MC_PRIO)+= itmt.o
+obj-$(CONFIG_X86_INTEL_UMIP) += umip.o
ifdef CONFIG_FRAME_POINTER
obj-y += unwind_frame.o
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
new file mode 100644
index 000..a104aea
--- /dev/null
+++ b/arch/x86/kernel/umip.c
@@ -0,0 +1,170 @@
+/*
+ * umip.c Emulation for instruction protected by the Intel User-Mode
+ * Instruction Prevention. The instructions are:
+ *sgdt
+ *sldt
+ *sidt
+ *str
+ *smsw
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ * Ricardo Neri
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+/*
+ * The address of this dummy values need to be readable by
+ * the user space
+ */
+
+static const long umip_dummy_gdt_base;
+static const long umip_dummy_idt_base;
+
+enum umip_insn {
+ UMIP_SGDT = 0, /* opcode 0f 01 ModR/M reg 0 */
+ UMIP_SIDT, /* opcode 0f 01 ModR/M reg 1 */
+ UMIP_SLDT, /* opcode 0f 00 ModR/M reg 0 */
+ UMIP_SMSW, /* opcode 0f 01 ModR/M reg 4 */
+ UMIP_STR, /* opcode 0f 00 ModR/M reg 1 */
+};
+
+static int __identify_insn(struct insn *insn)
+{
+ /* by getting modrm we also get the opcode */
+ insn_get_modrm(insn);
+ if (insn->opcode.bytes[0] != 0xf)
+ return -EINVAL;
+
+ if (insn->opcode.bytes[1] == 0x1) {
+ switch (X86_MODRM_REG(insn->modrm.value)) {
+ case 0:
+ return UMIP_SGDT;
+ case 1:
+ return UMIP_SIDT;
+ case 4:
+ return UMIP_SMSW;
+ default:
+ return -EINVAL;
+ }
+ } else if (insn->opcode.bytes[1] == 0x0) {
+
[v2 6/7] x86/traps: Fixup general protection faults caused by UMIP
If the User-Mode Instruction Prevention CPU feature is available and
enabled, a general protection fault will be issued if the instructions
sgdt, sldt, sidt, str or smsw are executed from user-mode context
(CPL > 0). If the fault was caused by any of the instructions protected
by UMIP, fixup_umip_exceptino will emulate dummy results for these
instructions.
Cc: Andy Lutomirski
Cc: Andrew Morton
Cc: H. Peter Anvin
Cc: Borislav Petkov
Cc: Brian Gerst
Cc: Chen Yucong
Cc: Chris Metcalf
Cc: Dave Hansen
Cc: Fenghua Yu
Cc: Huang Rui
Cc: Jiri Slaby
Cc: Jonathan Corbet
Cc: Michael S. Tsirkin
Cc: Paul Gortmaker
Cc: Peter Zijlstra
Cc: Ravi V. Shankar
Cc: Shuah Khan
Cc: Vlastimil Babka
Cc: Tony Luck
Cc: Paolo Bonzini
Cc: Liang Z. Li
Cc: Alexandre Julliard
Cc: Stas Sergeev
Cc: x...@kernel.org
Cc: linux-msdos@vger.kernel.org
Signed-off-by: Ricardo Neri
---
arch/x86/kernel/traps.c | 4
1 file changed, 4 insertions(+)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index bf0c6d0..5044fb3 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -64,6 +64,7 @@
#include
#include
#include
+#include
#ifdef CONFIG_X86_64
#include
@@ -491,6 +492,9 @@ do_general_protection(struct pt_regs *regs, long error_code)
RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
cond_local_irq_enable(regs);
+ if (user_mode(regs) && !fixup_umip_exception(regs))
+ return;
+
if (v8086_mode(regs)) {
local_irq_enable();
handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
--
2.9.3
--
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[v2 7/7] x86: Enable User-Mode Instruction Prevention
User_mode Instruction Prevention (UMIP) is enabled by setting/clearing a
bit in %cr4.
It makes sense to enable UMIP at some point while booting, before user
spaces come up. Like SMAP and SMEP, is not critical to have it enabled
very early during boot. This is because UMIP is relevant only when there is
a userspace to be protected from. Given the similarities in relevance, it
makes sense to enable UMIP along with SMAP and SMEP.
UMIP is enabled by default. It can be disabled by adding clearcpuid=514
to the kernel parameters.
Cc: Andy Lutomirski
Cc: Andrew Morton
Cc: H. Peter Anvin
Cc: Borislav Petkov
Cc: Brian Gerst
Cc: Chen Yucong
Cc: Chris Metcalf
Cc: Dave Hansen
Cc: Fenghua Yu
Cc: Huang Rui
Cc: Jiri Slaby
Cc: Jonathan Corbet
Cc: Michael S. Tsirkin
Cc: Paul Gortmaker
Cc: Peter Zijlstra
Cc: Ravi V. Shankar
Cc: Shuah Khan
Cc: Vlastimil Babka
Cc: Tony Luck
Cc: Paolo Bonzini
Cc: Liang Z. Li
Cc: Alexandre Julliard
Cc: Stas Sergeev
Cc: x...@kernel.org
Cc: linux-msdos@vger.kernel.org
Signed-off-by: Ricardo Neri
---
arch/x86/Kconfig | 10 ++
arch/x86/kernel/cpu/common.c | 16 +++-
2 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e487493..bae1a8f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1733,6 +1733,16 @@ config X86_SMAP
If unsure, say Y.
+config X86_INTEL_UMIP
+ def_bool y
+ depends on CPU_SUP_INTEL
+ prompt "User Mode Instruction Prevention" if EXPERT
+ ---help---
+ The User Mode Instruction Prevention (UMIP) is a security
+ feature in newer Intel processors. If enabled, a general
+ protection fault is issued if the instructions SGDT, SLDT,
+ SIDT, SMSW and STR are executed in user mode.
+
config X86_INTEL_MPX
prompt "Intel MPX (Memory Protection Extensions)"
def_bool n
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index dc1697c..b38a639 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -306,6 +306,19 @@ static __always_inline void setup_smap(struct cpuinfo_x86
*c)
}
}
+static __always_inline void setup_umip(struct cpuinfo_x86 *c)
+{
+ if (cpu_feature_enabled(X86_FEATURE_UMIP) &&
+ cpu_has(c, X86_FEATURE_UMIP))
+ cr4_set_bits(X86_CR4_UMIP);
+ else
+ /*
+* Make sure UMIP is disabled in case it was enabled in a
+* previous boot (e.g., via kexec).
+*/
+ cr4_clear_bits(X86_CR4_UMIP);
+}
+
/*
* Protection Keys are not available in 32-bit mode.
*/
@@ -1059,9 +1072,10 @@ static void identify_cpu(struct cpuinfo_x86 *c)
/* Disable the PN if appropriate */
squash_the_stupid_serial_number(c);
- /* Set up SMEP/SMAP */
+ /* Set up SMEP/SMAP/UMIP */
setup_smep(c);
setup_smap(c);
+ setup_umip(c);
/*
* The vendor-specific functions might have changed features.
--
2.9.3
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[v2 2/7] x86/mpx: Fail when implicit zero-displacement is used along with R/EBP
Section 2.2.1.2 of the Intel 64 and IA-32 Architectures Software
Developer's Manual volume 2A states that when memory addressing with no
explicit displacement (i.e, mod part of ModR/M is 0), a SIB byte is used
and the base of the SIB byte points to (R/EBP) (i.e., base = 5), an
explicit displacement of 0 must be used.
Make the address decoder to return -EINVAL in such a case.
Cc: Dave Hansen
Cc: Adam Buchbinder
Cc: Colin Ian King
Cc: Lorenzo Stoakes
Cc: Qiaowei Ren
Cc: Ravi V. Shankar
Cc: x...@kernel.org
Signed-off-by: Ricardo Neri
---
arch/x86/mm/mpx.c | 7 +++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 6a75a75..71681d0 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -120,6 +120,13 @@ static int get_reg_offset(struct insn *insn, struct
pt_regs *regs,
case REG_TYPE_BASE:
regno = X86_SIB_BASE(insn->sib.value);
+ if (regno == 5 && X86_MODRM_RM(insn->modrm.value) == 0) {
+ WARN_ONCE(1, "An explicit displacement is required when
%sBP used as SIB base.",
+ (IS_ENABLED(CONFIG_X86_64) && insn->x86_64) ?
+ "R13 or R" : "E");
+ return -EINVAL;
+ }
+
if (X86_REX_B(insn->rex_prefix.value))
regno += 8;
break;
--
2.9.3
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[v2 1/7] x86/mpx: Do not use SIB index if index points to R/ESP
Section 2.2.1.2 of the Intel 64 and IA-32 Architectures Software
Developer's Manual volume 2A states that when memory addressing is used
(i.e., mod part of ModR/M is not 3), a SIB byte is used and the index of
the SIB byte points to the R/ESP (i.e.,index = 4), the index should not be
used in the computation of the memory address.
An example of such instruction could be
insn -0x80(%rsp)
This is represented as:
[opcode] 4c 24 80
ModR/M: mod: 1, reg: 1: r/m: 4 (R/ESP)
SIB 24: sc: 0, index: 100 (R/ESP), base(R/ESP): 100
Displacement -0x80
The correct address is (base) + displacement; no index is used.
Care is taken to allow R12 to be used as index, which is a valid scenario.
Cc: Dave Hansen
Cc: Adam Buchbinder
Cc: Colin Ian King
Cc: Lorenzo Stoakes
Cc: Qiaowei Ren
Cc: Ravi V. Shankar
Cc: x...@kernel.org
Signed-off-by: Ricardo Neri
---
arch/x86/mm/mpx.c | 12 +++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 324e571..6a75a75 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -109,6 +109,13 @@ static int get_reg_offset(struct insn *insn, struct
pt_regs *regs,
regno = X86_SIB_INDEX(insn->sib.value);
if (X86_REX_X(insn->rex_prefix.value))
regno += 8;
+ /*
+* If mod !=3, SP is not used as index. Check is done after
+* looking at REX.X This is because R12 can be used as an
+* index.
+*/
+ if (regno == 4 && X86_MODRM_RM(insn->modrm.value) != 3)
+ return 0;
break;
case REG_TYPE_BASE:
@@ -161,7 +168,10 @@ static void __user *mpx_get_addr_ref(struct insn *insn,
struct pt_regs *regs)
goto out_err;
base = regs_get_register(regs, base_offset);
- indx = regs_get_register(regs, indx_offset);
+ if (indx_offset)
+ indx = regs_get_register(regs, indx_offset);
+ else
+ indx = 0;
addr = base + indx * (1 << X86_SIB_SCALE(sib));
} else {
addr_offset = get_reg_offset(insn, regs, REG_TYPE_RM);
--
2.9.3
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Re: [v2 2/7] x86/mpx: Fail when implicit zero-displacement is used along with R/EBP
On Fri, Dec 23, 2016 at 5:37 PM, Ricardo Neri
wrote:
> Section 2.2.1.2 of the Intel 64 and IA-32 Architectures Software
> Developer's Manual volume 2A states that when memory addressing with no
> explicit displacement (i.e, mod part of ModR/M is 0), a SIB byte is used
> and the base of the SIB byte points to (R/EBP) (i.e., base = 5), an
> explicit displacement of 0 must be used.
>
> Make the address decoder to return -EINVAL in such a case.
>
> Cc: Dave Hansen
> Cc: Adam Buchbinder
> Cc: Colin Ian King
> Cc: Lorenzo Stoakes
> Cc: Qiaowei Ren
> Cc: Ravi V. Shankar
> Cc: x...@kernel.org
> Signed-off-by: Ricardo Neri
> ---
> arch/x86/mm/mpx.c | 7 +++
> 1 file changed, 7 insertions(+)
>
> diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
> index 6a75a75..71681d0 100644
> --- a/arch/x86/mm/mpx.c
> +++ b/arch/x86/mm/mpx.c
> @@ -120,6 +120,13 @@ static int get_reg_offset(struct insn *insn, struct
> pt_regs *regs,
>
> case REG_TYPE_BASE:
> regno = X86_SIB_BASE(insn->sib.value);
> + if (regno == 5 && X86_MODRM_RM(insn->modrm.value) == 0) {
> + WARN_ONCE(1, "An explicit displacement is required
> when %sBP used as SIB base.",
> + (IS_ENABLED(CONFIG_X86_64) && insn->x86_64)
> ?
> + "R13 or R" : "E");
> + return -EINVAL;
> + }
> +
Now that I've read the cover letter, I see what's going on. This
should not warn -- user code can easily trigger this deliberately.
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Re: [v2 1/7] x86/mpx: Do not use SIB index if index points to R/ESP
On Fri, Dec 23, 2016 at 5:37 PM, Ricardo Neri wrote: > Section 2.2.1.2 of the Intel 64 and IA-32 Architectures Software > Developer's Manual volume 2A states that when memory addressing is used > (i.e., mod part of ModR/M is not 3), a SIB byte is used and the index of > the SIB byte points to the R/ESP (i.e.,index = 4), the index should not be > used in the computation of the memory address. > > An example of such instruction could be > > insn -0x80(%rsp) > > This is represented as: > > [opcode] 4c 24 80 > > ModR/M: mod: 1, reg: 1: r/m: 4 (R/ESP) > SIB 24: sc: 0, index: 100 (R/ESP), base(R/ESP): 100 > Displacement -0x80 > > The correct address is (base) + displacement; no index is used. > > Care is taken to allow R12 to be used as index, which is a valid scenario. Since I have no idea what this patch has to do with the rest of the series, I'll ask a question: Why isn't this code in the standard x86 instruction decoder? Is the decoder similarly buggy? -- To unsubscribe from this list: send the line "unsubscribe linux-msdos" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [v2 6/7] x86/traps: Fixup general protection faults caused by UMIP
On Fri, Dec 23, 2016 at 5:37 PM, Ricardo Neri wrote: > If the User-Mode Instruction Prevention CPU feature is available and > enabled, a general protection fault will be issued if the instructions > sgdt, sldt, sidt, str or smsw are executed from user-mode context > (CPL > 0). If the fault was caused by any of the instructions protected > by UMIP, fixup_umip_exceptino will emulate dummy results for these > instructions. > > Cc: Andy Lutomirski > Cc: Andrew Morton > Cc: H. Peter Anvin > Cc: Borislav Petkov > Cc: Brian Gerst > Cc: Chen Yucong > Cc: Chris Metcalf > Cc: Dave Hansen > Cc: Fenghua Yu > Cc: Huang Rui > Cc: Jiri Slaby > Cc: Jonathan Corbet > Cc: Michael S. Tsirkin > Cc: Paul Gortmaker > Cc: Peter Zijlstra > Cc: Ravi V. Shankar > Cc: Shuah Khan > Cc: Vlastimil Babka > Cc: Tony Luck > Cc: Paolo Bonzini > Cc: Liang Z. Li > Cc: Alexandre Julliard > Cc: Stas Sergeev > Cc: x...@kernel.org > Cc: linux-msdos@vger.kernel.org > Signed-off-by: Ricardo Neri > --- > arch/x86/kernel/traps.c | 4 > 1 file changed, 4 insertions(+) > > diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c > index bf0c6d0..5044fb3 100644 > --- a/arch/x86/kernel/traps.c > +++ b/arch/x86/kernel/traps.c > @@ -64,6 +64,7 @@ > #include > #include > #include > +#include > > #ifdef CONFIG_X86_64 > #include > @@ -491,6 +492,9 @@ do_general_protection(struct pt_regs *regs, long > error_code) > RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); > cond_local_irq_enable(regs); > > + if (user_mode(regs) && !fixup_umip_exception(regs)) > + return; > + I would do fixup_umip_exception(regs) == 0 to make it more obvious what's going on. Also, since you're allowing this in v8086 mode, I think this should have an explicit test in tools/testing/selftests/x86/entry_from_vm86.c. I *think* it will work fine, but the pt_regs handling in vm86 mode is quite scary and has been rewritten recently. -- To unsubscribe from this list: send the line "unsubscribe linux-msdos" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [v2 5/7] x86: Add emulation code for UMIP instructions
On Fri, Dec 23, 2016 at 5:37 PM, Ricardo Neri
wrote:
> The feature User-Mode Instruction Prevention present in recent Intel
> processor prevents a group of instructions from being executed with
> CPL > 0. Otherwise, a general protection fault is issued.
>
> Rather than relaying this fault to the user space (in the form of a SIGSEGV
> signal), the instructions protected by UMIP can be emulated to provide
> dummy results. This allows to conserve the current kernel behavior and not
> reveal the system resources that UMIP intends to protect (the global
> descriptor and interrupt descriptor tables, the segment selectors of the
> local descriptor table and the task state and the machine status word).
>
> This emulation is needed because certain applications (e.g., WineHQ) rely
> on this subset of instructions to function.
>
> The instructions protected by UMIP can be split in two groups. Those who
> return a kernel memory address (sgdt and sidt) and those who return a
> value (sldt, str and smsw).
>
> For the instructions that return a kernel memory address, the result is
> emulated as the location of a dummy variable in the kernel memory space.
> This is needed as applications such as WineHQ rely on the result being
> located in the kernel memory space function. The limit for the GDT and the
> IDT are set to zero.
Nak. This is a trivial KASLR bypass. Just give them hardcoded
values. For x86_64, I would suggest 0xfffe and
0x.
>
> The instructions sldt and str return a segment selector relative to the
> base address of the global descriptor table. Since the actual address of
> such table is not revealed, it makes sense to emulate the result as zero.
Hmm, now I wonder if anything uses SLDT to see if there is an LDT. If
so, we could emulate it better, but I doubt this matters.
>
> The instruction smsw is emulated to return zero.
If you're going to emulate it, please return something plausible. The
protected mode bit should be on, for example. 0x33 is probably
reasonable.
> +static int __emulate_umip_insn(struct insn *insn, enum umip_insn umip_inst,
> + unsigned char *data, int *data_size)
> +{
> + unsigned long const *dummy_base_addr;
> + unsigned short dummy_limit = 0;
> + unsigned short dummy_value = 0;
> +
> + switch (umip_inst) {
> + /*
> +* These two instructions return the base address and limit of the
> +* global and interrupt descriptor table. The base address can be
> +* 32-bit or 64-bit. Limit is always 16-bit.
> +*/
> + case UMIP_SGDT:
> + case UMIP_SIDT:
> + if (umip_inst == UMIP_SGDT)
> + dummy_base_addr = &umip_dummy_gdt_base;
> + else
> + dummy_base_addr = &umip_dummy_idt_base;
> + if (X86_MODRM_MOD(insn->modrm.value) == 3) {
> + WARN_ONCE(1, "SGDT cannot take register as
> argument!\n");
No warnings please.
> +int fixup_umip_exception(struct pt_regs *regs)
> +{
> + struct insn insn;
> + unsigned char buf[MAX_INSN_SIZE];
> + /* 10 bytes is the maximum size of the result of UMIP instructions */
> + unsigned char dummy_data[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
> + int x86_64 = !test_thread_flag(TIF_IA32);
user_64bit_mode(regs)
> + int not_copied, nr_copied, reg_offset, dummy_data_size;
> + void __user *uaddr;
> + unsigned long *reg_addr;
> + enum umip_insn umip_inst;
> +
> + not_copied = copy_from_user(buf, (void __user *)regs->ip,
> sizeof(buf));
This is slightly wrong due to PKRU. I doubt we care.
> + nr_copied = sizeof(buf) - not_copied;
> + /*
> +* The decoder _should_ fail nicely if we pass it a short buffer.
> +* But, let's not depend on that implementation detail. If we
> +* did not get anything, just error out now.
> +*/
> + if (!nr_copied)
> + return -EFAULT;
If the caller cares about EINVAL vs EFAULT, it cares because it is
considering changing the signal to a fake page fault. If so, then
this should be EINVAL -- failure to read the text should just prevent
emulation.
> + insn_init(&insn, buf, nr_copied, x86_64);
> + insn_get_length(&insn);
> + if (nr_copied < insn.length)
> + return -EFAULT;
Ditto.
> +
> + umip_inst = __identify_insn(&insn);
> + /* Check if we found an instruction protected by UMIP */
> + if (umip_inst < 0)
> + return -EINVAL;
> +
> + if (__emulate_umip_insn(&insn, umip_inst, dummy_data,
> &dummy_data_size))
> + return -EINVAL;
> +
> + /* If operand is a register, write directly to it */
> + if (X86_MODRM_MOD(insn.modrm.value) == 3) {
> + reg_offset = get_reg_offset_rm(&insn, regs);
> + reg_addr = (unsigned long *)((unsigned long)regs +
> reg_offset);
> +
Re: [v2 3/7] x86/mpx, x86/insn: Relocate insn util functions to a new insn-utils
Hi Ricardo, [auto build test WARNING on tip/auto-latest] [also build test WARNING on v4.9 next-20161223] [cannot apply to tip/x86/core] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Ricardo-Neri/x86-enable-User-Mode-Instruction-Prevention/20161224-094338 config: x86_64-randconfig-x008-201651 (attached as .config) compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901 reproduce: # save the attached .config to linux build tree make ARCH=x86_64 All warnings (new ones prefixed by >>): >> warning: objtool: x86 instruction decoder differs from kernel --- 0-DAY kernel test infrastructureOpen Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation .config.gz Description: application/gzip
Re: [v2 7/7] x86: Enable User-Mode Instruction Prevention
Hi Ricardo,
[auto build test WARNING on tip/auto-latest]
[also build test WARNING on next-20161223]
[cannot apply to tip/x86/core v4.9]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Ricardo-Neri/x86-enable-User-Mode-Instruction-Prevention/20161224-094338
config: x86_64-acpi-redef (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All warnings (new ones prefixed by >>):
arch/x86/kernel/umip.c: In function '__identify_insn':
>> arch/x86/kernel/umip.c:65:1: warning: control reaches end of non-void
>> function [-Wreturn-type]
}
^
vim +65 arch/x86/kernel/umip.c
78301541 Ricardo Neri 2016-12-23 49return UMIP_SGDT;
78301541 Ricardo Neri 2016-12-23 50case 1:
78301541 Ricardo Neri 2016-12-23 51return UMIP_SIDT;
78301541 Ricardo Neri 2016-12-23 52case 4:
78301541 Ricardo Neri 2016-12-23 53return UMIP_SMSW;
78301541 Ricardo Neri 2016-12-23 54default:
78301541 Ricardo Neri 2016-12-23 55return -EINVAL;
78301541 Ricardo Neri 2016-12-23 56}
78301541 Ricardo Neri 2016-12-23 57} else if (insn->opcode.bytes[1] ==
0x0) {
78301541 Ricardo Neri 2016-12-23 58if
(X86_MODRM_REG(insn->modrm.value) == 0)
78301541 Ricardo Neri 2016-12-23 59return UMIP_SLDT;
78301541 Ricardo Neri 2016-12-23 60else if
(X86_MODRM_REG(insn->modrm.value) == 1)
78301541 Ricardo Neri 2016-12-23 61return UMIP_STR;
78301541 Ricardo Neri 2016-12-23 62else
78301541 Ricardo Neri 2016-12-23 63return -EINVAL;
78301541 Ricardo Neri 2016-12-23 64}
78301541 Ricardo Neri 2016-12-23 @65 }
78301541 Ricardo Neri 2016-12-23 66
78301541 Ricardo Neri 2016-12-23 67 static int __emulate_umip_insn(struct
insn *insn, enum umip_insn umip_inst,
78301541 Ricardo Neri 2016-12-23 68 unsigned char
*data, int *data_size)
78301541 Ricardo Neri 2016-12-23 69 {
78301541 Ricardo Neri 2016-12-23 70unsigned long const *dummy_base_addr;
78301541 Ricardo Neri 2016-12-23 71unsigned short dummy_limit = 0;
78301541 Ricardo Neri 2016-12-23 72unsigned short dummy_value = 0;
78301541 Ricardo Neri 2016-12-23 73
:: The code at line 65 was first introduced by commit
:: 7830154191c35fde49ef59c2b9328f6b32203be4 x86: Add emulation code for
UMIP instructions
:: TO: Ricardo Neri
:: CC: 0day robot
---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
.config.gz
Description: application/gzip
Re: [v2 6/7] x86/traps: Fixup general protection faults caused by UMIP
Hi Ricardo,
[auto build test ERROR on tip/auto-latest]
[also build test ERROR on next-20161223]
[cannot apply to tip/x86/core v4.9]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Ricardo-Neri/x86-enable-User-Mode-Instruction-Prevention/20161224-094338
config: x86_64-rhel (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All errors (new ones prefixed by >>):
In file included from arch/x86/tools/test_get_len.c:27:0:
>> arch/x86/include/asm/insn.h:26:23: fatal error: linux/bug.h: No such file or
>> directory
#include
^
compilation terminated.
--
In file included from tools/include/linux/compiler.h:55:0,
from arch/x86/include/asm/insn.h:25,
from arch/x86/tools/insn_sanity.c:34:
>> tools/include/linux/types.h:28:18: error: conflicting types for 'u64'
typedef uint64_t u64;
^~~
In file included from /usr/include/asm-generic/types.h:6:0,
from /usr/include/x86_64-linux-gnu/asm/types.h:4,
from tools/include/linux/types.h:9,
from tools/include/linux/compiler.h:55,
from arch/x86/include/asm/insn.h:25,
from arch/x86/tools/insn_sanity.c:34:
include/asm-generic/int-ll64.h:25:28: note: previous declaration of 'u64'
was here
typedef unsigned long long u64;
^~~
In file included from tools/include/linux/compiler.h:55:0,
from arch/x86/include/asm/insn.h:25,
from arch/x86/tools/insn_sanity.c:34:
>> tools/include/linux/types.h:29:17: error: conflicting types for 's64'
typedef int64_t s64;
^~~
In file included from /usr/include/asm-generic/types.h:6:0,
from /usr/include/x86_64-linux-gnu/asm/types.h:4,
from tools/include/linux/types.h:9,
from tools/include/linux/compiler.h:55,
from arch/x86/include/asm/insn.h:25,
from arch/x86/tools/insn_sanity.c:34:
include/asm-generic/int-ll64.h:24:26: note: previous declaration of 's64'
was here
typedef signed long long s64;
^~~
In file included from tools/include/linux/types.h:4:0,
from tools/include/linux/compiler.h:55,
from arch/x86/include/asm/insn.h:25,
from arch/x86/tools/insn_sanity.c:34:
>> include/linux/stddef.h:10:2: error: expected identifier before numeric
>> constant
false = 0,
^
In file included from arch/x86/include/asm/ptrace.h:5:0,
from arch/x86/include/asm/insn.h:28,
from arch/x86/tools/insn_sanity.c:34:
>> arch/x86/include/asm/page_types.h:61:15: error: unknown type name
>> 'phys_addr_t'
static inline phys_addr_t get_max_mapped(void)
^~~
arch/x86/include/asm/page_types.h: In function 'get_max_mapped':
>> arch/x86/include/asm/page_types.h:63:10: error: 'phys_addr_t' undeclared
>> (first use in this function)
return (phys_addr_t)max_pfn_mapped << PAGE_SHIFT;
^~~
arch/x86/include/asm/page_types.h:63:10: note: each undeclared identifier is
reported only once for each function it appears in
>> arch/x86/include/asm/page_types.h:63:22: error: expected ';' before
>> 'max_pfn_mapped'
return (phys_addr_t)max_pfn_mapped << PAGE_SHIFT;
^~
In file included from arch/x86/include/asm/insn.h:28:0,
from arch/x86/tools/insn_sanity.c:34:
arch/x86/include/asm/ptrace.h: At top level:
>> arch/x86/include/asm/ptrace.h:33:8: error: redefinition of 'struct pt_regs'
struct pt_regs {
^~~
In file included from arch/x86/include/asm/insn.h:26:0,
from arch/x86/tools/insn_sanity.c:34:
include/linux/bug.h:13:8: note: originally defined here
struct pt_regs;
^~~
vim +33 arch/x86/include/asm/ptrace.h
92bc2056 include/asm-x86/ptrace.h Harvey Harrison 2008-02-08 27
unsigned long sp;
92bc2056 include/asm-x86/ptrace.h Harvey Harrison 2008-02-08 28
unsigned long ss;
65ea5b03 include/asm-x86/ptrace.h H. Peter Anvin 2008-01-30 29 };
8fc37f2c include/asm-x86/ptrace.h Thomas Gleixner 2007-10-23 30
8fc37f2c include/asm-x86/ptrace.h Thomas Gleixner 2007-10-23 31 #else /*
__i386__ */
8fc37f2c include/asm-x86/ptrace.h Thomas Gleixner 2007-10-23 32
65ea5b03 include/asm-x86/ptrace.h H. Peter Anvin 200
