[GIT PULL] x86 fixes

Ingo Molnar
2016-05-25T22:01:47Z

Linus,

Please pull the latest x86-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

# HEAD: dc4fac84f8e66b147921ebdc385e767d5def7422 x86/mm: Switch from TASK_SIZE to TASK_SIZE_MAX in the page fault code

Misc fixes: EFI, entry code, pkeys and MPX fixes, TASK_SIZE cleanups and a tsc
frequency table fix.

Thanks,

Ingo

------------------>
Andy Lutomirski (2):
x86/fsgsbase/64: Use TASK_SIZE_MAX for FSBASE/GSBASE upper limits
x86/mm: Switch from TASK_SIZE to TASK_SIZE_MAX in the page fault code

Dave Hansen (2):
x86/cpufeature, x86/mm/pkeys: Fix broken compile-time disabling of pkeys
x86/mm/mpx: Work around MPX erratum SKD046

Jeremy Compostella (1):
x86/tsc: Add missing Cherrytrail frequency to the table

Josh Poimboeuf (1):
x86/entry/64: Fix stack return address retrieval in thunk

Linus Torvalds (1):
x86/efi: Fix 7-parameter efi_call()s

arch/x86/entry/thunk_64.S | 11 +++++-----
arch/x86/include/asm/bugs.h | 8 +++++++
arch/x86/include/asm/cpufeature.h | 12 +++++------
arch/x86/include/asm/disabled-features.h | 6 +++---
arch/x86/kernel/cpu/common.c | 7 ++++++
arch/x86/kernel/cpu/intel.c | 37 ++++++++++++++++++++++++++++++++
arch/x86/kernel/process_64.c | 4 ++--
arch/x86/kernel/ptrace.c | 4 ++--
arch/x86/kernel/tsc_msr.c | 3 +++
arch/x86/mm/fault.c | 11 +++++++---
arch/x86/platform/efi/efi_stub_64.S | 9 ++++----
11 files changed, 85 insertions(+), 27 deletions(-)

diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S
index 98df1fa8825c..027aec4a74df 100644
--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk_64.S
@@ -8,16 +8,15 @@
#include <linux/linkage.h>
#include "calling.h"
#include <asm/asm.h>
-#include <asm/frame.h>

/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
.macro THUNK name, func, put_ret_addr_in_rdi=0
.globl \name
.type \name, @function
\name:
- FRAME_BEGIN
+ pushq %rbp
+ movq %rsp, %rbp

- /* this one pushes 9 elems, the next one would be %rIP */
pushq %rdi
pushq %rsi
pushq %rdx
@@ -29,8 +28,8 @@
pushq %r11

.if \put_ret_addr_in_rdi
- /* 9*8(%rsp) is return addr on stack */
- movq 9*8(%rsp), %rdi
+ /* 8(%rbp) is return addr on stack */
+ movq 8(%rbp), %rdi
.endif

call \func
@@ -65,7 +64,7 @@
popq %rdx
popq %rsi
popq %rdi
- FRAME_END
+ popq %rbp
ret
_ASM_NOKPROBE(restore)
#endif
diff --git a/arch/x86/include/asm/bugs.h b/arch/x86/include/asm/bugs.h
index 08abf639075f..5490bbaf71d5 100644
--- a/arch/x86/include/asm/bugs.h
+++ b/arch/x86/include/asm/bugs.h
@@ -1,8 +1,16 @@
#ifndef _ASM_X86_BUGS_H
#define _ASM_X86_BUGS_H

+#include <asm/processor.h>
+
extern void check_bugs(void);

+#if defined(CONFIG_CPU_SUP_INTEL)
+void check_mpx_erratum(struct cpuinfo_x86 *c);
+#else
+static inline void check_mpx_erratum(struct cpuinfo_x86 *c) {}
+#endif
+
#if defined(CONFIG_CPU_SUP_INTEL) && defined(CONFIG_X86_32)
int ppro_with_ram_bug(void);
#else
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 25ebb54905e0..483fb547e3c0 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -64,9 +64,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
(((bit)>>5)==11 && (1UL<<((bit)&31) & REQUIRED_MASK11)) || \
(((bit)>>5)==12 && (1UL<<((bit)&31) & REQUIRED_MASK12)) || \
(((bit)>>5)==13 && (1UL<<((bit)&31) & REQUIRED_MASK13)) || \
- (((bit)>>5)==13 && (1UL<<((bit)&31) & REQUIRED_MASK14)) || \
- (((bit)>>5)==13 && (1UL<<((bit)&31) & REQUIRED_MASK15)) || \
- (((bit)>>5)==14 && (1UL<<((bit)&31) & REQUIRED_MASK16)) )
+ (((bit)>>5)==14 && (1UL<<((bit)&31) & REQUIRED_MASK14)) || \
+ (((bit)>>5)==15 && (1UL<<((bit)&31) & REQUIRED_MASK15)) || \
+ (((bit)>>5)==16 && (1UL<<((bit)&31) & REQUIRED_MASK16)) )

#define DISABLED_MASK_BIT_SET(bit) \
( (((bit)>>5)==0 && (1UL<<((bit)&31) & DISABLED_MASK0 )) || \
@@ -83,9 +83,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
(((bit)>>5)==11 && (1UL<<((bit)&31) & DISABLED_MASK11)) || \
(((bit)>>5)==12 && (1UL<<((bit)&31) & DISABLED_MASK12)) || \
(((bit)>>5)==13 && (1UL<<((bit)&31) & DISABLED_MASK13)) || \
- (((bit)>>5)==13 && (1UL<<((bit)&31) & DISABLED_MASK14)) || \
- (((bit)>>5)==13 && (1UL<<((bit)&31) & DISABLED_MASK15)) || \
- (((bit)>>5)==14 && (1UL<<((bit)&31) & DISABLED_MASK16)) )
+ (((bit)>>5)==14 && (1UL<<((bit)&31) & DISABLED_MASK14)) || \
+ (((bit)>>5)==15 && (1UL<<((bit)&31) & DISABLED_MASK15)) || \
+ (((bit)>>5)==16 && (1UL<<((bit)&31) & DISABLED_MASK16)) )

#define cpu_has(c, bit) \
(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 39343be7d4f4..911e9358ceb1 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -29,11 +29,11 @@
#endif /* CONFIG_X86_64 */

#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
-# define DISABLE_PKU (1<<(X86_FEATURE_PKU))
-# define DISABLE_OSPKE (1<<(X86_FEATURE_OSPKE))
-#else
# define DISABLE_PKU 0
# define DISABLE_OSPKE 0
+#else
+# define DISABLE_PKU (1<<(X86_FEATURE_PKU & 31))
+# define DISABLE_OSPKE (1<<(X86_FEATURE_OSPKE & 31))
#endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */

/*
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 6ef6ed9ccca6..0fe6953f421c 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -37,6 +37,7 @@
#include <asm/mtrr.h>
#include <linux/numa.h>
#include <asm/asm.h>
+#include <asm/bugs.h>
#include <asm/cpu.h>
#include <asm/mce.h>
#include <asm/msr.h>
@@ -270,6 +271,8 @@ static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
static __init int setup_disable_smep(char *arg)
{
setup_clear_cpu_cap(X86_FEATURE_SMEP);
+ /* Check for things that depend on SMEP being enabled: */
+ check_mpx_erratum(&boot_cpu_data);
return 1;
}
__setup("nosmep", setup_disable_smep);
@@ -310,6 +313,10 @@ static bool pku_disabled;

static __always_inline void setup_pku(struct cpuinfo_x86 *c)
{
+ /* check the boot processor, plus compile options for PKU: */
+ if (!cpu_feature_enabled(X86_FEATURE_PKU))
+ return;
+ /* checks the actual processor's cpuid bits: */
if (!cpu_has(c, X86_FEATURE_PKU))
return;
if (pku_disabled)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 8dae51fd3db1..6e2ffbebbcdb 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -25,6 +25,41 @@
#include <asm/apic.h>
#endif

+/*
+ * Just in case our CPU detection goes bad, or you have a weird system,
+ * allow a way to override the automatic disabling of MPX.
+ */
+static int forcempx;
+
+static int __init forcempx_setup(char *__unused)
+{
+ forcempx = 1;
+
+ return 1;
+}
+__setup("intel-skd-046-workaround=disable", forcempx_setup);
+
+void check_mpx_erratum(struct cpuinfo_x86 *c)
+{
+ if (forcempx)
+ return;
+ /*
+ * Turn off the MPX feature on CPUs where SMEP is not
+ * available or disabled.
+ *
+ * Works around Intel Erratum SKD046: "Branch Instructions
+ * May Initialize MPX Bound Registers Incorrectly".
+ *
+ * This might falsely disable MPX on systems without
+ * SMEP, like Atom processors without SMEP. But there
+ * is no such hardware known at the moment.
+ */
+ if (cpu_has(c, X86_FEATURE_MPX) && !cpu_has(c, X86_FEATURE_SMEP)) {
+ setup_clear_cpu_cap(X86_FEATURE_MPX);
+ pr_warn("x86/mpx: Disabling MPX since SMEP not present\n");
+ }
+}
+
static void early_init_intel(struct cpuinfo_x86 *c)
{
u64 misc_enable;
@@ -173,6 +208,8 @@ static void early_init_intel(struct cpuinfo_x86 *c)
if (edx & (1U << 28))
c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff);
}
+
+ check_mpx_erratum(c);
}

#ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 6b16c36f0939..6e789ca1f841 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -532,7 +532,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)

switch (code) {
case ARCH_SET_GS:
- if (addr >= TASK_SIZE_OF(task))
+ if (addr >= TASK_SIZE_MAX)
return -EPERM;
cpu = get_cpu();
task->thread.gsindex = 0;
@@ -546,7 +546,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
case ARCH_SET_FS:
/* Not strictly needed for fs, but do it for symmetry
with gs */
- if (addr >= TASK_SIZE_OF(task))
+ if (addr >= TASK_SIZE_MAX)
return -EPERM;
cpu = get_cpu();
task->thread.fsindex = 0;
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index e60ef918f53d..600edd225e81 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -392,7 +392,7 @@ static int putreg(struct task_struct *child,

#ifdef CONFIG_X86_64
case offsetof(struct user_regs_struct,fs_base):
- if (value >= TASK_SIZE_OF(child))
+ if (value >= TASK_SIZE_MAX)
return -EIO;
/*
* When changing the segment base, use do_arch_prctl
@@ -406,7 +406,7 @@ static int putreg(struct task_struct *child,
/*
* Exactly the same here as the %fs handling above.
*/
- if (value >= TASK_SIZE_OF(child))
+ if (value >= TASK_SIZE_MAX)
return -EIO;
if (child->thread.gsbase != value)
return do_arch_prctl(child, ARCH_SET_GS, value);
diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c
index 6aa0f4d9eea6..9911a0620f9a 100644
--- a/arch/x86/kernel/tsc_msr.c
+++ b/arch/x86/kernel/tsc_msr.c
@@ -23,6 +23,7 @@
#include <asm/param.h>

/* CPU reference clock frequency: in KHz */
+#define FREQ_80 80000
#define FREQ_83 83200
#define FREQ_100 99840
#define FREQ_133 133200
@@ -56,6 +57,8 @@ static struct freq_desc freq_desc_tables[] = {
{ 6, 0x37, 1, { FREQ_83, FREQ_100, FREQ_133, FREQ_166, 0, 0, 0, 0 } },
/* ANN */
{ 6, 0x5a, 1, { FREQ_83, FREQ_100, FREQ_133, FREQ_100, 0, 0, 0, 0 } },
+ /* AIRMONT */
+ { 6, 0x4c, 1, { FREQ_83, FREQ_100, FREQ_133, FREQ_166, FREQ_80, 0, 0, 0 } },
};

static int match_cpu(u8 family, u8 model)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 5ce1ed02f7e8..7d1fa7cd2374 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -292,7 +292,7 @@ void vmalloc_sync_all(void)
return;

for (address = VMALLOC_START & PMD_MASK;
- address >= TASK_SIZE && address < FIXADDR_TOP;
+ address >= TASK_SIZE_MAX && address < FIXADDR_TOP;
address += PMD_SIZE) {
struct page *page;

@@ -854,8 +854,13 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
return;
}
#endif
- /* Kernel addresses are always protection faults: */
- if (address >= TASK_SIZE)
+
+ /*
+ * To avoid leaking information about the kernel page table
+ * layout, pretend that user-mode accesses to kernel addresses
+ * are always protection faults.
+ */
+ if (address >= TASK_SIZE_MAX)
error_code |= PF_PROT;

if (likely(show_unhandled_signals))
diff --git a/arch/x86/platform/efi/efi_stub_64.S b/arch/x86/platform/efi/efi_stub_64.S
index 92723aeae0f9..cd95075944ab 100644
--- a/arch/x86/platform/efi/efi_stub_64.S
+++ b/arch/x86/platform/efi/efi_stub_64.S
@@ -11,7 +11,6 @@
#include <asm/msr.h>
#include <asm/processor-flags.h>
#include <asm/page_types.h>
-#include <asm/frame.h>

#define SAVE_XMM \
mov %rsp, %rax; \
@@ -40,10 +39,10 @@
mov (%rsp), %rsp

ENTRY(efi_call)
- FRAME_BEGIN
+ pushq %rbp
+ movq %rsp, %rbp
SAVE_XMM
- mov (%rsp), %rax
- mov 8(%rax), %rax
+ mov 16(%rbp), %rax
subq $48, %rsp
mov %r9, 32(%rsp)
mov %rax, 40(%rsp)
@@ -53,6 +52,6 @@ ENTRY(efi_call)
call *%rdi
addq $48, %rsp
RESTORE_XMM
- FRAME_END
+ popq %rbp
ret
ENDPROC(efi_call)