Merge 4.4.144 into android-4.4

Changes in 4.4.144
	KVM/Eventfd: Avoid crash when assign and deassign specific eventfd in parallel.
	x86/MCE: Remove min interval polling limitation
	fat: fix memory allocation failure handling of match_strdup()
	ALSA: rawmidi: Change resized buffers atomically
	ARC: Fix CONFIG_SWAP
	ARC: mm: allow mprotect to make stack mappings executable
	mm: memcg: fix use after free in mem_cgroup_iter()
	ipv4: Return EINVAL when ping_group_range sysctl doesn't map to user ns
	ipv6: fix useless rol32 call on hash
	lib/rhashtable: consider param->min_size when setting initial table size
	net/ipv4: Set oif in fib_compute_spec_dst
	net: phy: fix flag masking in __set_phy_supported
	ptp: fix missing break in switch
	tg3: Add higher cpu clock for 5762.
	net: Don't copy pfmemalloc flag in __copy_skb_header()
	skbuff: Unconditionally copy pfmemalloc in __skb_clone()
	xhci: Fix perceived dead host due to runtime suspend race with event handler
	x86/paravirt: Make native_save_fl() extern inline
	x86/cpufeatures: Add CPUID_7_EDX CPUID leaf
	x86/cpufeatures: Add Intel feature bits for Speculation Control
	x86/cpufeatures: Add AMD feature bits for Speculation Control
	x86/msr: Add definitions for new speculation control MSRs
	x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown
	x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes
	x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support
	x86/cpufeatures: Clean up Spectre v2 related CPUID flags
	x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel
	x86/pti: Mark constant arrays as __initconst
	x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs
	x86/entry/64/compat: Clear registers for compat syscalls, to reduce speculation attack surface
	x86/speculation: Update Speculation Control microcode blacklist
	x86/speculation: Correct Speculation Control microcode blacklist again
	x86/speculation: Clean up various Spectre related details
	x86/speculation: Fix up array_index_nospec_mask() asm constraint
	x86/speculation: Add <asm/msr-index.h> dependency
	x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
	x86/mm: Factor out LDT init from context init
	x86/mm: Give each mm TLB flush generation a unique ID
	x86/speculation: Use Indirect Branch Prediction Barrier in context switch
	x86/spectre_v2: Don't check microcode versions when running under hypervisors
	x86/speculation: Use IBRS if available before calling into firmware
	x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP
	x86/speculation: Remove Skylake C2 from Speculation Control microcode blacklist
	selftest/seccomp: Fix the flag name SECCOMP_FILTER_FLAG_TSYNC
	selftest/seccomp: Fix the seccomp(2) signature
	xen: set cpu capabilities from xen_start_kernel()
	x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen
	x86/nospec: Simplify alternative_msr_write()
	x86/bugs: Concentrate bug detection into a separate function
	x86/bugs: Concentrate bug reporting into a separate function
	x86/bugs: Read SPEC_CTRL MSR during boot and re-use reserved bits
	x86/bugs, KVM: Support the combination of guest and host IBRS
	x86/cpu: Rename Merrifield2 to Moorefield
	x86/cpu/intel: Add Knights Mill to Intel family
	x86/bugs: Expose /sys/../spec_store_bypass
	x86/cpufeatures: Add X86_FEATURE_RDS
	x86/bugs: Provide boot parameters for the spec_store_bypass_disable mitigation
	x86/bugs/intel: Set proper CPU features and setup RDS
	x86/bugs: Whitelist allowed SPEC_CTRL MSR values
	x86/bugs/AMD: Add support to disable RDS on Fam[15, 16, 17]h if requested
	x86/speculation: Create spec-ctrl.h to avoid include hell
	prctl: Add speculation control prctls
	x86/process: Optimize TIF checks in __switch_to_xtra()
	x86/process: Correct and optimize TIF_BLOCKSTEP switch
	x86/process: Optimize TIF_NOTSC switch
	x86/process: Allow runtime control of Speculative Store Bypass
	x86/speculation: Add prctl for Speculative Store Bypass mitigation
	nospec: Allow getting/setting on non-current task
	proc: Provide details on speculation flaw mitigations
	seccomp: Enable speculation flaw mitigations
	prctl: Add force disable speculation
	seccomp: Use PR_SPEC_FORCE_DISABLE
	seccomp: Add filter flag to opt-out of SSB mitigation
	seccomp: Move speculation migitation control to arch code
	x86/speculation: Make "seccomp" the default mode for Speculative Store Bypass
	x86/bugs: Rename _RDS to _SSBD
	proc: Use underscores for SSBD in 'status'
	Documentation/spec_ctrl: Do some minor cleanups
	x86/bugs: Fix __ssb_select_mitigation() return type
	x86/bugs: Make cpu_show_common() static
	x86/bugs: Fix the parameters alignment and missing void
	x86/cpu: Make alternative_msr_write work for 32-bit code
	x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
	x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS
	x86/cpufeatures: Disentangle SSBD enumeration
	x86/cpu/AMD: Fix erratum 1076 (CPB bit)
	x86/cpufeatures: Add FEATURE_ZEN
	x86/speculation: Handle HT correctly on AMD
	x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
	x86/speculation: Add virtualized speculative store bypass disable support
	x86/speculation: Rework speculative_store_bypass_update()
	x86/bugs: Unify x86_spec_ctrl_{set_guest, restore_host}
	x86/bugs: Expose x86_spec_ctrl_base directly
	x86/bugs: Remove x86_spec_ctrl_set()
	x86/bugs: Rework spec_ctrl base and mask logic
	x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG
	x86/bugs: Rename SSBD_NO to SSB_NO
	x86/xen: Add call of speculative_store_bypass_ht_init() to PV paths
	x86/cpu: Re-apply forced caps every time CPU caps are re-read
	block: do not use interruptible wait anywhere
	clk: tegra: Fix PLL_U post divider and initial rate on Tegra30
	ubi: Introduce vol_ignored()
	ubi: Rework Fastmap attach base code
	ubi: Be more paranoid while seaching for the most recent Fastmap
	ubi: Fix races around ubi_refill_pools()
	ubi: Fix Fastmap's update_vol()
	ubi: fastmap: Erase outdated anchor PEBs during attach
	Linux 4.4.144

Change-Id: Ia3e9b2b7bc653cba68b76878d34f8fcbbc007a13
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

2 files changed, 35 insertions, 6 deletions

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index efd384f3f852..9a9203b15cde 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -16,6 +16,8 @@
 #include <linux/atomic.h>
 #include <linux/audit.h>
 #include <linux/compat.h>
+#include <linux/nospec.h>
+#include <linux/prctl.h>
 #include <linux/sched.h>
 #include <linux/seccomp.h>
 #include <linux/slab.h>
@@ -214,8 +216,11 @@ static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
 	return true;
 }
 
+void __weak arch_seccomp_spec_mitigate(struct task_struct *task) { }
+
 static inline void seccomp_assign_mode(struct task_struct *task,
-				       unsigned long seccomp_mode)
+				       unsigned long seccomp_mode,
+				       unsigned long flags)
 {
 	assert_spin_locked(&task->sighand->siglock);
 
@@ -225,6 +230,9 @@ static inline void seccomp_assign_mode(struct task_struct *task,
 	 * filter) is set.
 	 */
 	smp_mb__before_atomic();
+	/* Assume default seccomp processes want spec flaw mitigation. */
+	if ((flags & SECCOMP_FILTER_FLAG_SPEC_ALLOW) == 0)
+		arch_seccomp_spec_mitigate(task);
 	set_tsk_thread_flag(task, TIF_SECCOMP);
 }
 
@@ -292,7 +300,7 @@ static inline pid_t seccomp_can_sync_threads(void)
  * without dropping the locks.
  *
  */
-static inline void seccomp_sync_threads(void)
+static inline void seccomp_sync_threads(unsigned long flags)
 {
 	struct task_struct *thread, *caller;
 
@@ -333,7 +341,8 @@ static inline void seccomp_sync_threads(void)
 		 * allow one thread to transition the other.
 		 */
 		if (thread->seccomp.mode == SECCOMP_MODE_DISABLED)
-			seccomp_assign_mode(thread, SECCOMP_MODE_FILTER);
+			seccomp_assign_mode(thread, SECCOMP_MODE_FILTER,
+					    flags);
 	}
 }
 
@@ -452,7 +461,7 @@ static long seccomp_attach_filter(unsigned int flags,
 
 	/* Now that the new filter is in place, synchronize to all threads. */
 	if (flags & SECCOMP_FILTER_FLAG_TSYNC)
-		seccomp_sync_threads();
+		seccomp_sync_threads(flags);
 
 	return 0;
 }
@@ -747,7 +756,7 @@ static long seccomp_set_mode_strict(void)
 #ifdef TIF_NOTSC
 	disable_TSC();
 #endif
-	seccomp_assign_mode(current, seccomp_mode);
+	seccomp_assign_mode(current, seccomp_mode, 0);
 	ret = 0;
 
 out:
@@ -805,7 +814,7 @@ static long seccomp_set_mode_filter(unsigned int flags,
 	/* Do not free the successfully attached filter. */
 	prepared = NULL;
 
-	seccomp_assign_mode(current, seccomp_mode);
+	seccomp_assign_mode(current, seccomp_mode, flags);
 out:
 	spin_unlock_irq(&current->sighand->siglock);
 	if (flags & SECCOMP_FILTER_FLAG_TSYNC)
diff --git a/kernel/sys.c b/kernel/sys.c
index cf40663a54c2..3195435462a6 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2224,6 +2224,17 @@ static int prctl_set_vma(unsigned long opt, unsigned long start,
 }
 #endif
 
+int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
+{
+	return -EINVAL;
+}
+
+int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
+				    unsigned long ctrl)
+{
+	return -EINVAL;
+}
+
 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		unsigned long, arg4, unsigned long, arg5)
 {
@@ -2444,6 +2455,15 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		break;
 	case PR_SET_VMA:
 		error = prctl_set_vma(arg2, arg3, arg4, arg5);
+	case PR_GET_SPECULATION_CTRL:
+		if (arg3 || arg4 || arg5)
+			return -EINVAL;
+		error = arch_prctl_spec_ctrl_get(me, arg2);
+		break;
+	case PR_SET_SPECULATION_CTRL:
+		if (arg4 || arg5)
+			return -EINVAL;
+		error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
 		break;
 	default:
 		error = -EINVAL;