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authorLinus Torvalds <torvalds@linux-foundation.org>2018-02-04 11:45:55 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-04 11:45:55 -0800
commit35277995e17919ab838beae765f440674e8576eb (patch)
treee35b60bb3c0c179f147e9acaad5444f1e5d9117e /arch
parent0a646e9c992e4846665dc995c86f30c599cda64c (diff)
parentb2ac58f90540e39324e7a29a7ad471407ae0bf48 (diff)
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull spectre/meltdown updates from Thomas Gleixner: "The next round of updates related to melted spectrum: - The initial set of spectre V1 mitigations: - Array index speculation blocker and its usage for syscall, fdtable and the n180211 driver. - Speculation barrier and its usage in user access functions - Make indirect calls in KVM speculation safe - Blacklisting of known to be broken microcodes so IPBP/IBSR are not touched. - The initial IBPB support and its usage in context switch - The exposure of the new speculation MSRs to KVM guests. - A fix for a regression in x86/32 related to the cpu entry area - Proper whitelisting for known to be safe CPUs from the mitigations. - objtool fixes to deal proper with retpolines and alternatives - Exclude __init functions from retpolines which speeds up the boot process. - Removal of the syscall64 fast path and related cleanups and simplifications - Removal of the unpatched paravirt mode which is yet another source of indirect unproteced calls. - A new and undisputed version of the module mismatch warning - A couple of cleanup and correctness fixes all over the place Yet another step towards full mitigation. There are a few things still missing like the RBS underflow mitigation for Skylake and other small details, but that's being worked on. That said, I'm taking a belated christmas vacation for a week and hope that everything is magically solved when I'm back on Feb 12th" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES KVM/x86: Add IBPB support KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALL x86/pti: Mark constant arrays as __initconst x86/spectre: Simplify spectre_v2 command line parsing x86/retpoline: Avoid retpolines for built-in __init functions x86/kvm: Update spectre-v1 mitigation KVM: VMX: make MSR bitmaps per-VCPU x86/paravirt: Remove 'noreplace-paravirt' cmdline option x86/speculation: Use Indirect Branch Prediction Barrier in context switch x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable" x86/spectre: Report get_user mitigation for spectre_v1 nl80211: Sanitize array index in parse_txq_params vfs, fdtable: Prevent bounds-check bypass via speculative execution x86/syscall: Sanitize syscall table de-references under speculation x86/get_user: Use pointer masking to limit speculation ...
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/entry/common.c9
-rw-r--r--arch/x86/entry/entry_64.S127
-rw-r--r--arch/x86/entry/syscall_64.c7
-rw-r--r--arch/x86/include/asm/barrier.h28
-rw-r--r--arch/x86/include/asm/fixmap.h6
-rw-r--r--arch/x86/include/asm/msr.h3
-rw-r--r--arch/x86/include/asm/nospec-branch.h2
-rw-r--r--arch/x86/include/asm/pgtable_32_types.h5
-rw-r--r--arch/x86/include/asm/processor.h2
-rw-r--r--arch/x86/include/asm/syscall.h6
-rw-r--r--arch/x86/include/asm/thread_info.h3
-rw-r--r--arch/x86/include/asm/tlbflush.h2
-rw-r--r--arch/x86/include/asm/uaccess.h15
-rw-r--r--arch/x86/include/asm/uaccess_32.h6
-rw-r--r--arch/x86/include/asm/uaccess_64.h12
-rw-r--r--arch/x86/kernel/alternative.c14
-rw-r--r--arch/x86/kernel/cpu/bugs.c96
-rw-r--r--arch/x86/kernel/cpu/common.c25
-rw-r--r--arch/x86/kernel/cpu/intel.c27
-rw-r--r--arch/x86/kernel/process_64.c4
-rw-r--r--arch/x86/kernel/ptrace.c2
-rw-r--r--arch/x86/kernel/signal.c2
-rw-r--r--arch/x86/kvm/cpuid.c22
-rw-r--r--arch/x86/kvm/cpuid.h1
-rw-r--r--arch/x86/kvm/svm.c116
-rw-r--r--arch/x86/kvm/vmx.c656
-rw-r--r--arch/x86/kvm/x86.c1
-rw-r--r--arch/x86/lib/getuser.S10
-rw-r--r--arch/x86/lib/usercopy_32.c8
-rw-r--r--arch/x86/mm/tlb.c33
30 files changed, 745 insertions, 505 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 1e3883e45687..74f6eee15179 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -21,6 +21,7 @@
#include <linux/export.h>
#include <linux/context_tracking.h>
#include <linux/user-return-notifier.h>
+#include <linux/nospec.h>
#include <linux/uprobes.h>
#include <linux/livepatch.h>
#include <linux/syscalls.h>
@@ -206,7 +207,7 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs)
* special case only applies after poking regs and before the
* very next return to user mode.
*/
- current->thread.status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
+ ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
#endif
user_enter_irqoff();
@@ -282,7 +283,8 @@ __visible void do_syscall_64(struct pt_regs *regs)
* regs->orig_ax, which changes the behavior of some syscalls.
*/
if (likely((nr & __SYSCALL_MASK) < NR_syscalls)) {
- regs->ax = sys_call_table[nr & __SYSCALL_MASK](
+ nr = array_index_nospec(nr & __SYSCALL_MASK, NR_syscalls);
+ regs->ax = sys_call_table[nr](
regs->di, regs->si, regs->dx,
regs->r10, regs->r8, regs->r9);
}
@@ -304,7 +306,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
unsigned int nr = (unsigned int)regs->orig_ax;
#ifdef CONFIG_IA32_EMULATION
- current->thread.status |= TS_COMPAT;
+ ti->status |= TS_COMPAT;
#endif
if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) {
@@ -318,6 +320,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
}
if (likely(nr < IA32_NR_syscalls)) {
+ nr = array_index_nospec(nr, IA32_NR_syscalls);
/*
* It's possible that a 32-bit syscall implementation
* takes a 64-bit parameter but nonetheless assumes that
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index a83570495162..c752abe89d80 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -236,91 +236,20 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
pushq %r9 /* pt_regs->r9 */
pushq %r10 /* pt_regs->r10 */
pushq %r11 /* pt_regs->r11 */
- sub $(6*8), %rsp /* pt_regs->bp, bx, r12-15 not saved */
- UNWIND_HINT_REGS extra=0
-
- TRACE_IRQS_OFF
-
- /*
- * If we need to do entry work or if we guess we'll need to do
- * exit work, go straight to the slow path.
- */
- movq PER_CPU_VAR(current_task), %r11
- testl $_TIF_WORK_SYSCALL_ENTRY|_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
- jnz entry_SYSCALL64_slow_path
-
-entry_SYSCALL_64_fastpath:
- /*
- * Easy case: enable interrupts and issue the syscall. If the syscall
- * needs pt_regs, we'll call a stub that disables interrupts again
- * and jumps to the slow path.
- */
- TRACE_IRQS_ON
- ENABLE_INTERRUPTS(CLBR_NONE)
-#if __SYSCALL_MASK == ~0
- cmpq $__NR_syscall_max, %rax
-#else
- andl $__SYSCALL_MASK, %eax
- cmpl $__NR_syscall_max, %eax
-#endif
- ja 1f /* return -ENOSYS (already in pt_regs->ax) */
- movq %r10, %rcx
-
- /*
- * This call instruction is handled specially in stub_ptregs_64.
- * It might end up jumping to the slow path. If it jumps, RAX
- * and all argument registers are clobbered.
- */
-#ifdef CONFIG_RETPOLINE
- movq sys_call_table(, %rax, 8), %rax
- call __x86_indirect_thunk_rax
-#else
- call *sys_call_table(, %rax, 8)
-#endif
-.Lentry_SYSCALL_64_after_fastpath_call:
-
- movq %rax, RAX(%rsp)
-1:
+ pushq %rbx /* pt_regs->rbx */
+ pushq %rbp /* pt_regs->rbp */
+ pushq %r12 /* pt_regs->r12 */
+ pushq %r13 /* pt_regs->r13 */
+ pushq %r14 /* pt_regs->r14 */
+ pushq %r15 /* pt_regs->r15 */
+ UNWIND_HINT_REGS
- /*
- * If we get here, then we know that pt_regs is clean for SYSRET64.
- * If we see that no exit work is required (which we are required
- * to check with IRQs off), then we can go straight to SYSRET64.
- */
- DISABLE_INTERRUPTS(CLBR_ANY)
TRACE_IRQS_OFF
- movq PER_CPU_VAR(current_task), %r11
- testl $_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
- jnz 1f
-
- LOCKDEP_SYS_EXIT
- TRACE_IRQS_ON /* user mode is traced as IRQs on */
- movq RIP(%rsp), %rcx
- movq EFLAGS(%rsp), %r11
- addq $6*8, %rsp /* skip extra regs -- they were preserved */
- UNWIND_HINT_EMPTY
- jmp .Lpop_c_regs_except_rcx_r11_and_sysret
-1:
- /*
- * The fast path looked good when we started, but something changed
- * along the way and we need to switch to the slow path. Calling
- * raise(3) will trigger this, for example. IRQs are off.
- */
- TRACE_IRQS_ON
- ENABLE_INTERRUPTS(CLBR_ANY)
- SAVE_EXTRA_REGS
- movq %rsp, %rdi
- call syscall_return_slowpath /* returns with IRQs disabled */
- jmp return_from_SYSCALL_64
-
-entry_SYSCALL64_slow_path:
/* IRQs are off. */
- SAVE_EXTRA_REGS
movq %rsp, %rdi
call do_syscall_64 /* returns with IRQs disabled */
-return_from_SYSCALL_64:
TRACE_IRQS_IRETQ /* we're about to change IF */
/*
@@ -393,7 +322,6 @@ syscall_return_via_sysret:
/* rcx and r11 are already restored (see code above) */
UNWIND_HINT_EMPTY
POP_EXTRA_REGS
-.Lpop_c_regs_except_rcx_r11_and_sysret:
popq %rsi /* skip r11 */
popq %r10
popq %r9
@@ -424,47 +352,6 @@ syscall_return_via_sysret:
USERGS_SYSRET64
END(entry_SYSCALL_64)
-ENTRY(stub_ptregs_64)
- /*
- * Syscalls marked as needing ptregs land here.
- * If we are on the fast path, we need to save the extra regs,
- * which we achieve by trying again on the slow path. If we are on
- * the slow path, the extra regs are already saved.
- *
- * RAX stores a pointer to the C function implementing the syscall.
- * IRQs are on.
- */
- cmpq $.Lentry_SYSCALL_64_after_fastpath_call, (%rsp)
- jne 1f
-
- /*
- * Called from fast path -- disable IRQs again, pop return address
- * and jump to slow path
- */
- DISABLE_INTERRUPTS(CLBR_ANY)
- TRACE_IRQS_OFF
- popq %rax
- UNWIND_HINT_REGS extra=0
- jmp entry_SYSCALL64_slow_path
-
-1:
- JMP_NOSPEC %rax /* Called from C */
-END(stub_ptregs_64)
-
-.macro ptregs_stub func
-ENTRY(ptregs_\func)
- UNWIND_HINT_FUNC
- leaq \func(%rip), %rax
- jmp stub_ptregs_64
-END(ptregs_\func)
-.endm
-
-/* Instantiate ptregs_stub for each ptregs-using syscall */
-#define __SYSCALL_64_QUAL_(sym)
-#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_stub sym
-#define __SYSCALL_64(nr, sym, qual) __SYSCALL_64_QUAL_##qual(sym)
-#include <asm/syscalls_64.h>
-
/*
* %rdi: prev task
* %rsi: next task
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 9c09775e589d..c176d2fab1da 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -7,14 +7,11 @@
#include <asm/asm-offsets.h>
#include <asm/syscall.h>
-#define __SYSCALL_64_QUAL_(sym) sym
-#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_##sym
-
-#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long __SYSCALL_64_QUAL_##qual(sym)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
#include <asm/syscalls_64.h>
#undef __SYSCALL_64
-#define __SYSCALL_64(nr, sym, qual) [nr] = __SYSCALL_64_QUAL_##qual(sym),
+#define __SYSCALL_64(nr, sym, qual) [nr] = sym,
extern long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index 7fb336210e1b..30d406146016 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -24,6 +24,34 @@
#define wmb() asm volatile("sfence" ::: "memory")
#endif
+/**
+ * array_index_mask_nospec() - generate a mask that is ~0UL when the
+ * bounds check succeeds and 0 otherwise
+ * @index: array element index
+ * @size: number of elements in array
+ *
+ * Returns:
+ * 0 - (index < size)
+ */
+static inline unsigned long array_index_mask_nospec(unsigned long index,
+ unsigned long size)
+{
+ unsigned long mask;
+
+ asm ("cmp %1,%2; sbb %0,%0;"
+ :"=r" (mask)
+ :"r"(size),"r" (index)
+ :"cc");
+ return mask;
+}
+
+/* Override the default implementation from linux/nospec.h. */
+#define array_index_mask_nospec array_index_mask_nospec
+
+/* Prevent speculative execution past this barrier. */
+#define barrier_nospec() alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, \
+ "lfence", X86_FEATURE_LFENCE_RDTSC)
+
#ifdef CONFIG_X86_PPRO_FENCE
#define dma_rmb() rmb()
#else
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index 64c4a30e0d39..e203169931c7 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -137,8 +137,10 @@ enum fixed_addresses {
extern void reserve_top_address(unsigned long reserve);
-#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
-#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
+#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
+#define FIXADDR_TOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_TOT_START (FIXADDR_TOP - FIXADDR_TOT_SIZE)
extern int fixmaps_set;
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 07962f5f6fba..30df295f6d94 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -214,8 +214,7 @@ static __always_inline unsigned long long rdtsc_ordered(void)
* that some other imaginary CPU is updating continuously with a
* time stamp.
*/
- alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC,
- "lfence", X86_FEATURE_LFENCE_RDTSC);
+ barrier_nospec();
return rdtsc();
}
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index d15d471348b8..4d57894635f2 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -150,7 +150,7 @@ extern char __indirect_thunk_end[];
* On VMEXIT we must ensure that no RSB predictions learned in the guest
* can be followed in the host, by overwriting the RSB completely. Both
* retpoline and IBRS mitigations for Spectre v2 need this; only on future
- * CPUs with IBRS_ATT *might* it be avoided.
+ * CPUs with IBRS_ALL *might* it be avoided.
*/
static inline void vmexit_fill_RSB(void)
{
diff --git a/arch/x86/include/asm/pgtable_32_types.h b/arch/x86/include/asm/pgtable_32_types.h
index ce245b0cdfca..0777e18a1d23 100644
--- a/arch/x86/include/asm/pgtable_32_types.h
+++ b/arch/x86/include/asm/pgtable_32_types.h
@@ -44,8 +44,9 @@ extern bool __vmalloc_start_set; /* set once high_memory is set */
*/
#define CPU_ENTRY_AREA_PAGES (NR_CPUS * 40)
-#define CPU_ENTRY_AREA_BASE \
- ((FIXADDR_START - PAGE_SIZE * (CPU_ENTRY_AREA_PAGES + 1)) & PMD_MASK)
+#define CPU_ENTRY_AREA_BASE \
+ ((FIXADDR_TOT_START - PAGE_SIZE * (CPU_ENTRY_AREA_PAGES + 1)) \
+ & PMD_MASK)
#define PKMAP_BASE \
((CPU_ENTRY_AREA_BASE - PAGE_SIZE) & PMD_MASK)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 6207f2f740b6..793bae7e7ce3 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -460,8 +460,6 @@ struct thread_struct {
unsigned short gsindex;
#endif
- u32 status; /* thread synchronous flags */
-
#ifdef CONFIG_X86_64
unsigned long fsbase;
unsigned long gsbase;
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index e3c95e8e61c5..03eedc21246d 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -60,7 +60,7 @@ static inline long syscall_get_error(struct task_struct *task,
* TS_COMPAT is set for 32-bit syscall entries and then
* remains set until we return to user mode.
*/
- if (task->thread.status & (TS_COMPAT|TS_I386_REGS_POKED))
+ if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED))
/*
* Sign-extend the value so (int)-EFOO becomes (long)-EFOO
* and will match correctly in comparisons.
@@ -116,7 +116,7 @@ static inline void syscall_get_arguments(struct task_struct *task,
unsigned long *args)
{
# ifdef CONFIG_IA32_EMULATION
- if (task->thread.status & TS_COMPAT)
+ if (task->thread_info.status & TS_COMPAT)
switch (i) {
case 0:
if (!n--) break;
@@ -177,7 +177,7 @@ static inline void syscall_set_arguments(struct task_struct *task,
const unsigned long *args)
{
# ifdef CONFIG_IA32_EMULATION
- if (task->thread.status & TS_COMPAT)
+ if (task->thread_info.status & TS_COMPAT)
switch (i) {
case 0:
if (!n--) break;
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index d25a638a2720..a5d9521bb2cb 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -55,6 +55,7 @@ struct task_struct;
struct thread_info {
unsigned long flags; /* low level flags */
+ u32 status; /* thread synchronous flags */
};
#define INIT_THREAD_INFO(tsk) \
@@ -219,7 +220,7 @@ static inline int arch_within_stack_frames(const void * const stack,
#define in_ia32_syscall() true
#else
#define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \
- current->thread.status & TS_COMPAT)
+ current_thread_info()->status & TS_COMPAT)
#endif
/*
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index d33e4a26dc7e..2b8f18ca5874 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -174,6 +174,8 @@ struct tlb_state {
struct mm_struct *loaded_mm;
u16 loaded_mm_asid;
u16 next_asid;
+ /* last user mm's ctx id */
+ u64 last_ctx_id;
/*
* We can be in one of several states:
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 574dff4d2913..aae77eb8491c 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -124,6 +124,11 @@ extern int __get_user_bad(void);
#define __uaccess_begin() stac()
#define __uaccess_end() clac()
+#define __uaccess_begin_nospec() \
+({ \
+ stac(); \
+ barrier_nospec(); \
+})
/*
* This is a type: either unsigned long, if the argument fits into
@@ -445,7 +450,7 @@ do { \
({ \
int __gu_err; \
__inttype(*(ptr)) __gu_val; \
- __uaccess_begin(); \
+ __uaccess_begin_nospec(); \
__get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \
__uaccess_end(); \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
@@ -487,6 +492,10 @@ struct __large_struct { unsigned long buf[100]; };
__uaccess_begin(); \
barrier();
+#define uaccess_try_nospec do { \
+ current->thread.uaccess_err = 0; \
+ __uaccess_begin_nospec(); \
+
#define uaccess_catch(err) \
__uaccess_end(); \
(err) |= (current->thread.uaccess_err ? -EFAULT : 0); \
@@ -548,7 +557,7 @@ struct __large_struct { unsigned long buf[100]; };
* get_user_ex(...);
* } get_user_catch(err)
*/
-#define get_user_try uaccess_try
+#define get_user_try uaccess_try_nospec
#define get_user_catch(err) uaccess_catch(err)
#define get_user_ex(x, ptr) do { \
@@ -582,7 +591,7 @@ extern void __cmpxchg_wrong_size(void)
__typeof__(ptr) __uval = (uval); \
__typeof__(*(ptr)) __old = (old); \
__typeof__(*(ptr)) __new = (new); \
- __uaccess_begin(); \
+ __uaccess_begin_nospec(); \
switch (size) { \
case 1: \
{ \
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 72950401b223..ba2dc1930630 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -29,21 +29,21 @@ raw_copy_from_user(void *to, const void __user *from, unsigned long n)
switch (n) {
case 1:
ret = 0;
- __uaccess_begin();
+ __uaccess_begin_nospec();
__get_user_asm_nozero(*(u8 *)to, from, ret,
"b", "b", "=q", 1);
__uaccess_end();
return ret;
case 2:
ret = 0;
- __uaccess_begin();
+ __uaccess_begin_nospec();
__get_user_asm_nozero(*(u16 *)to, from, ret,
"w", "w", "=r", 2);
__uaccess_end();
return ret;
case 4:
ret = 0;
- __uaccess_begin();
+ __uaccess_begin_nospec();
__get_user_asm_nozero(*(u32 *)to, from, ret,
"l", "k", "=r", 4);
__uaccess_end();
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index f07ef3c575db..62546b3a398e 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -55,31 +55,31 @@ raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
return copy_user_generic(dst, (__force void *)src, size);
switch (size) {
case 1:
- __uaccess_begin();
+ __uaccess_begin_nospec();
__get_user_asm_nozero(*(u8 *)dst, (u8 __user *)src,
ret, "b", "b", "=q", 1);
__uaccess_end();
return ret;
case 2:
- __uaccess_begin();
+ __uaccess_begin_nospec();
__get_user_asm_nozero(*(u16 *)dst, (u16 __user *)src,
ret, "w", "w", "=r", 2);
__uaccess_end();
return ret;
case 4:
- __uaccess_begin();
+ __uaccess_begin_nospec();
__get_user_asm_nozero(*(u32 *)dst, (u32 __user *)src,
ret, "l", "k", "=r", 4);
__uaccess_end();
return ret;
case 8:
- __uaccess_begin();
+ __uaccess_begin_nospec();
__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
ret, "q", "", "=r", 8);
__uaccess_end();
return ret;
case 10:
- __uaccess_begin();
+ __uaccess_begin_nospec();
__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
ret, "q", "", "=r", 10);
if (likely(!ret))
@@ -89,7 +89,7 @@ raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
__uaccess_end();
return ret;
case 16:
- __uaccess_begin();
+ __uaccess_begin_nospec();
__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
ret, "q", "", "=r", 16);
if (likely(!ret))
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 30571fdaaf6f..a481763a3776 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -46,17 +46,6 @@ static int __init setup_noreplace_smp(char *str)
}
__setup("noreplace-smp", setup_noreplace_smp);
-#ifdef CONFIG_PARAVIRT
-static int __initdata_or_module noreplace_paravirt = 0;
-
-static int __init setup_noreplace_paravirt(char *str)
-{
- noreplace_paravirt = 1;
- return 1;
-}
-__setup("noreplace-paravirt", setup_noreplace_paravirt);
-#endif
-
#define DPRINTK(fmt, args...) \
do { \
if (debug_alternative) \
@@ -599,9 +588,6 @@ void __init_or_module apply_paravirt(struct paravirt_patch_site *start,
struct paravirt_patch_site *p;
char insnbuf[MAX_PATCH_LEN];
- if (noreplace_paravirt)
- return;
-
for (p = start; p < end; p++) {
unsigned int used;
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 3bfb2b23d79c..71949bf2de5a 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -103,7 +103,7 @@ bool retpoline_module_ok(bool has_retpoline)
if (spectre_v2_enabled == SPECTRE_V2_NONE || has_retpoline)
return true;
- pr_err("System may be vunerable to spectre v2\n");
+ pr_err("System may be vulnerable to spectre v2\n");
spectre_v2_bad_module = true;
return false;
}
@@ -119,13 +119,13 @@ static inline const char *spectre_v2_module_string(void) { return ""; }
static void __init spec2_print_if_insecure(const char *reason)
{
if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
- pr_info("%s\n", reason);
+ pr_info("%s selected on command line.\n", reason);
}
static void __init spec2_print_if_secure(const char *reason)
{
if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
- pr_info("%s\n", reason);
+ pr_info("%s selected on command line.\n", reason);
}
static inline bool retp_compiler(void)
@@ -140,42 +140,68 @@ static inline bool match_option(const char *arg, int arglen, const char *opt)
return len == arglen && !strncmp(arg, opt, len);
}
+static const struct {
+ const char *option;
+ enum spectre_v2_mitigation_cmd cmd;
+ bool secure;
+} mitigation_options[] = {
+ { "off", SPECTRE_V2_CMD_NONE, false },
+ { "on", SPECTRE_V2_CMD_FORCE, true },
+ { "retpoline", SPECTRE_V2_CMD_RETPOLINE, false },
+ { "retpoline,amd", SPECTRE_V2_CMD_RETPOLINE_AMD, false },
+ { "retpoline,generic", SPECTRE_V2_CMD_RETPOLINE_GENERIC, false },
+ { "auto", SPECTRE_V2_CMD_AUTO, false },
+};
+
static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
{
char arg[20];
- int ret;
-
- ret = cmdline_find_option(boot_command_line, "spectre_v2", arg,
- sizeof(arg));
- if (ret > 0) {
- if (match_option(arg, ret, "off")) {
- goto disable;
- } else if (match_option(arg, ret, "on")) {
- spec2_print_if_secure("force enabled on command line.");
- return SPECTRE_V2_CMD_FORCE;
- } else if (match_option(arg, ret, "retpoline")) {
- spec2_print_if_insecure("retpoline selected on command line.");
- return SPECTRE_V2_CMD_RETPOLINE;
- } else if (match_option(arg, ret, "retpoline,amd")) {
- if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
- pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n");
- return SPECTRE_V2_CMD_AUTO;
- }
- spec2_print_if_insecure("AMD retpoline selected on command line.");
- return SPECTRE_V2_CMD_RETPOLINE_AMD;
- } else if (match_option(arg, ret, "retpoline,generic")) {
- spec2_print_if_insecure("generic retpoline selected on command line.");
- return SPECTRE_V2_CMD_RETPOLINE_GENERIC;
- } else if (match_option(arg, ret, "auto")) {
+ int ret, i;
+ enum spectre_v2_mitigation_cmd cmd = SPECTRE_V2_CMD_AUTO;
+
+ if (cmdline_find_option_bool(boot_command_line, "nospectre_v2"))
+ return SPECTRE_V2_CMD_NONE;
+ else {
+ ret = cmdline_find_option(boot_command_line, "spectre_v2", arg,
+ sizeof(arg));
+ if (ret < 0)
return SPECTRE_V2_CMD_AUTO;
+
+ for (i = 0; i < ARRAY_SIZE(mitigation_options); i++) {
+ if (!match_option(arg, ret, mitigation_options[i].option))
+ continue;
+ cmd = mitigation_options[i].cmd;
+ break;
}
+
+ if (i >= ARRAY_SIZE(mitigation_options)) {
+ pr_err("unknown option (%s). Switching to AUTO select\n",
+ mitigation_options[i].option);
+ return SPECTRE_V2_CMD_AUTO;
+ }
+ }
+
+ if ((cmd == SPECTRE_V2_CMD_RETPOLINE ||
+ cmd == SPECTRE_V2_CMD_RETPOLINE_AMD ||
+ cmd == SPECTRE_V2_CMD_RETPOLINE_GENERIC) &&
+ !IS_ENABLED(CONFIG_RETPOLINE)) {
+ pr_err("%s selected but not compiled in. Switching to AUTO select\n",
+ mitigation_options[i].option);
+ return SPECTRE_V2_CMD_AUTO;
}
- if (!cmdline_find_option_bool(boot_command_line, "nospectre_v2"))
+ if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
+ pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n");
return SPECTRE_V2_CMD_AUTO;
-disable:
- spec2_print_if_insecure("disabled on command line.");
- return SPECTRE_V2_CMD_NONE;
+ }
+
+ if (mitigation_options[i].secure)
+ spec2_print_if_secure(mitigation_options[i].option);
+ else
+ spec2_print_if_insecure(mitigation_options[i].option);
+
+ return cmd;
}
/* Check for Skylake-like CPUs (for RSB handling) */
@@ -213,10 +239,10 @@ static void __init spectre_v2_select_mitigation(void)
return;
case SPECTRE_V2_CMD_FORCE:
- /* FALLTRHU */
case SPECTRE_V2_CMD_AUTO:
- goto retpoline_auto;
-
+ if (IS_ENABLED(CONFIG_RETPOLINE))
+ goto retpoline_auto;
+ break;
case SPECTRE_V2_CMD_RETPOLINE_AMD:
if (IS_ENABLED(CONFIG_RETPOLINE))
goto retpoline_amd;
@@ -297,7 +323,7 @@ ssize_t cpu_show_spectre_v1(struct device *dev,
{
if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1))
return sprintf(buf, "Not affected\n");
- return sprintf(buf, "Vulnerable\n");
+ return sprintf(buf, "Mitigation: __user pointer sanitization\n");
}
ssize_t cpu_show_spectre_v2(struct device *dev,
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index c7c996a692fd..d63f4b5706e4 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -750,6 +750,26 @@ static void apply_forced_caps(struct cpuinfo_x86 *c)
}
}
+static void init_speculation_control(struct cpuinfo_x86 *c)
+{
+ /*
+ * The Intel SPEC_CTRL CPUID bit implies IBRS and IBPB support,
+ * and they also have a different bit for STIBP support. Also,
+ * a hypervisor might have set the individual AMD bits even on
+ * Intel CPUs, for finer-grained selection of what's available.
+ *
+ * We use the AMD bits in 0x8000_0008 EBX as the generic hardware
+ * features, which are visible in /proc/cpuinfo and used by the
+ * kernel. So set those accordingly from the Intel bits.
+ */
+ if (cpu_has(c, X86_FEATURE_SPEC_CTRL)) {
+ set_cpu_cap(c, X86_FEATURE_IBRS);
+ set_cpu_cap(c, X86_FEATURE_IBPB);
+ }
+ if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
+ set_cpu_cap(c, X86_FEATURE_STIBP);
+}
+