This is the 4.19.7 stable release

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Merge 4.19.7 into android-4.19

Changes in 4.19.7
	mm/huge_memory: rename freeze_page() to unmap_page()
	mm/huge_memory: splitting set mapping+index before unfreeze
	mm/huge_memory: fix lockdep complaint on 32-bit i_size_read()
	mm/khugepaged: collapse_shmem() stop if punched or truncated
	mm/khugepaged: fix crashes due to misaccounted holes
	mm/khugepaged: collapse_shmem() remember to clear holes
	mm/khugepaged: minor reorderings in collapse_shmem()
	mm/khugepaged: collapse_shmem() without freezing new_page
	mm/khugepaged: collapse_shmem() do not crash on Compound
	lan743x: Enable driver to work with LAN7431
	lan743x: fix return value for lan743x_tx_napi_poll
	net: don't keep lonely packets forever in the gro hash
	net: gemini: Fix copy/paste error
	net: thunderx: set tso_hdrs pointer to NULL in nicvf_free_snd_queue
	packet: copy user buffers before orphan or clone
	rapidio/rionet: do not free skb before reading its length
	s390/qeth: fix length check in SNMP processing
	usbnet: ipheth: fix potential recvmsg bug and recvmsg bug 2
	net: thunderx: set xdp_prog to NULL if bpf_prog_add fails
	net: skb_scrub_packet(): Scrub offload_fwd_mark
	virtio-net: disable guest csum during XDP set
	virtio-net: fail XDP set if guest csum is negotiated
	net/dim: Update DIM start sample after each DIM iteration
	tcp: defer SACK compression after DupThresh
	net: phy: add workaround for issue where PHY driver doesn't bind to the device
	tipc: fix lockdep warning during node delete
	x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation
	x86/speculation: Apply IBPB more strictly to avoid cross-process data leak
	x86/speculation: Propagate information about RSB filling mitigation to sysfs
	x86/speculation: Add RETPOLINE_AMD support to the inline asm CALL_NOSPEC variant
	x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support
	x86/retpoline: Remove minimal retpoline support
	x86/speculation: Update the TIF_SSBD comment
	x86/speculation: Clean up spectre_v2_parse_cmdline()
	x86/speculation: Remove unnecessary ret variable in cpu_show_common()
	x86/speculation: Move STIPB/IBPB string conditionals out of cpu_show_common()
	x86/speculation: Disable STIBP when enhanced IBRS is in use
	x86/speculation: Rename SSBD update functions
	x86/speculation: Reorganize speculation control MSRs update
	sched/smt: Make sched_smt_present track topology
	x86/Kconfig: Select SCHED_SMT if SMP enabled
	sched/smt: Expose sched_smt_present static key
	x86/speculation: Rework SMT state change
	x86/l1tf: Show actual SMT state
	x86/speculation: Reorder the spec_v2 code
	x86/speculation: Mark string arrays const correctly
	x86/speculataion: Mark command line parser data __initdata
	x86/speculation: Unify conditional spectre v2 print functions
	x86/speculation: Add command line control for indirect branch speculation
	x86/speculation: Prepare for per task indirect branch speculation control
	x86/process: Consolidate and simplify switch_to_xtra() code
	x86/speculation: Avoid __switch_to_xtra() calls
	x86/speculation: Prepare for conditional IBPB in switch_mm()
	ptrace: Remove unused ptrace_may_access_sched() and MODE_IBRS
	x86/speculation: Split out TIF update
	x86/speculation: Prevent stale SPEC_CTRL msr content
	x86/speculation: Prepare arch_smt_update() for PRCTL mode
	x86/speculation: Add prctl() control for indirect branch speculation
	x86/speculation: Enable prctl mode for spectre_v2_user
	x86/speculation: Add seccomp Spectre v2 user space protection mode
	x86/speculation: Provide IBPB always command line options
	userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmas
	kvm: mmu: Fix race in emulated page table writes
	kvm: svm: Ensure an IBPB on all affected CPUs when freeing a vmcb
	KVM: nVMX/nSVM: Fix bug which sets vcpu->arch.tsc_offset to L1 tsc_offset
	KVM: x86: Fix kernel info-leak in KVM_HC_CLOCK_PAIRING hypercall
	KVM: LAPIC: Fix pv ipis use-before-initialization
	KVM: X86: Fix scan ioapic use-before-initialization
	KVM: VMX: re-add ple_gap module parameter
	xtensa: enable coprocessors that are being flushed
	xtensa: fix coprocessor context offset definitions
	xtensa: fix coprocessor part of ptrace_{get,set}xregs
	udf: Allow mounting volumes with incorrect identification strings
	btrfs: Always try all copies when reading extent buffers
	Btrfs: ensure path name is null terminated at btrfs_control_ioctl
	Btrfs: fix rare chances for data loss when doing a fast fsync
	Btrfs: fix race between enabling quotas and subvolume creation
	btrfs: relocation: set trans to be NULL after ending transaction
	PCI: layerscape: Fix wrong invocation of outbound window disable accessor
	PCI: dwc: Fix MSI-X EP framework address calculation bug
	PCI: Fix incorrect value returned from pcie_get_speed_cap()
	arm64: dts: rockchip: Fix PCIe reset polarity for rk3399-puma-haikou.
	x86/MCE/AMD: Fix the thresholding machinery initialization order
	x86/fpu: Disable bottom halves while loading FPU registers
	perf/x86/intel: Move branch tracing setup to the Intel-specific source file
	perf/x86/intel: Add generic branch tracing check to intel_pmu_has_bts()
	perf/x86/intel: Disallow precise_ip on BTS events
	fs: fix lost error code in dio_complete
	ALSA: wss: Fix invalid snd_free_pages() at error path
	ALSA: ac97: Fix incorrect bit shift at AC97-SPSA control write
	ALSA: control: Fix race between adding and removing a user element
	ALSA: sparc: Fix invalid snd_free_pages() at error path
	ALSA: hda: Add ASRock N68C-S UCC the power_save blacklist
	ALSA: hda/realtek - Support ALC300
	ALSA: hda/realtek - fix headset mic detection for MSI MS-B171
	ALSA: hda/realtek - fix the pop noise on headphone for lenovo laptops
	ALSA: hda/realtek - Add auto-mute quirk for HP Spectre x360 laptop
	function_graph: Create function_graph_enter() to consolidate architecture code
	ARM: function_graph: Simplify with function_graph_enter()
	microblaze: function_graph: Simplify with function_graph_enter()
	x86/function_graph: Simplify with function_graph_enter()
	nds32: function_graph: Simplify with function_graph_enter()
	powerpc/function_graph: Simplify with function_graph_enter()
	sh/function_graph: Simplify with function_graph_enter()
	sparc/function_graph: Simplify with function_graph_enter()
	parisc: function_graph: Simplify with function_graph_enter()
	riscv/function_graph: Simplify with function_graph_enter()
	s390/function_graph: Simplify with function_graph_enter()
	arm64: function_graph: Simplify with function_graph_enter()
	MIPS: function_graph: Simplify with function_graph_enter()
	function_graph: Make ftrace_push_return_trace() static
	function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack
	function_graph: Have profiler use curr_ret_stack and not depth
	function_graph: Move return callback before update of curr_ret_stack
	function_graph: Reverse the order of pushing the ret_stack and the callback
	binder: fix race that allows malicious free of live buffer
	ext2: initialize opts.s_mount_opt as zero before using it
	ext2: fix potential use after free
	ASoC: intel: cht_bsw_max98090_ti: Add quirk for boards using pmc_plt_clk_0
	ASoC: pcm186x: Fix device reset-registers trigger value
	ARM: dts: rockchip: Remove @0 from the veyron memory node
	dmaengine: at_hdmac: fix memory leak in at_dma_xlate()
	dmaengine: at_hdmac: fix module unloading
	staging: most: use format specifier "%s" in snprintf
	staging: vchiq_arm: fix compat VCHIQ_IOC_AWAIT_COMPLETION
	staging: mt7621-dma: fix potentially dereferencing uninitialized 'tx_desc'
	staging: mt7621-pinctrl: fix uninitialized variable ngroups
	staging: rtl8723bs: Fix incorrect sense of ether_addr_equal
	staging: rtl8723bs: Add missing return for cfg80211_rtw_get_station
	USB: usb-storage: Add new IDs to ums-realtek
	usb: core: quirks: add RESET_RESUME quirk for Cherry G230 Stream series
	Revert "usb: dwc3: gadget: skip Set/Clear Halt when invalid"
	iio/hid-sensors: Fix IIO_CHAN_INFO_RAW returning wrong values for signed numbers
	iio:st_magn: Fix enable device after trigger
	lib/test_kmod.c: fix rmmod double free
	mm: cleancache: fix corruption on missed inode invalidation
	mm: use swp_offset as key in shmem_replace_page()
	Drivers: hv: vmbus: check the creation_status in vmbus_establish_gpadl()
	misc: mic/scif: fix copy-paste error in scif_create_remote_lookup
	Linux 4.19.7

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

Documentation/admin-guide/kernel-parameters.txt

@@ -4169,9 +4169,13 @@
 
 	spectre_v2=	[X86] Control mitigation of Spectre variant 2
 			(indirect branch speculation) vulnerability.
+			The default operation protects the kernel from
+			user space attacks.
 
-			on   - unconditionally enable
-			off  - unconditionally disable
+			on   - unconditionally enable, implies
+			       spectre_v2_user=on
+			off  - unconditionally disable, implies
+			       spectre_v2_user=off
 			auto - kernel detects whether your CPU model is
 			       vulnerable
 
@@ -4181,6 +4185,12 @@
 			CONFIG_RETPOLINE configuration option, and the
 			compiler with which the kernel was built.
 
+			Selecting 'on' will also enable the mitigation
+			against user space to user space task attacks.
+
+			Selecting 'off' will disable both the kernel and
+			the user space protections.
+
 			Specific mitigations can also be selected manually:
 
 			retpoline	  - replace indirect branches
@@ -4190,6 +4200,48 @@
 			Not specifying this option is equivalent to
 			spectre_v2=auto.
 
+	spectre_v2_user=
+			[X86] Control mitigation of Spectre variant 2
+		        (indirect branch speculation) vulnerability between
+		        user space tasks
+
+			on	- Unconditionally enable mitigations. Is
+				  enforced by spectre_v2=on
+
+			off     - Unconditionally disable mitigations. Is
+				  enforced by spectre_v2=off
+
+			prctl   - Indirect branch speculation is enabled,
+				  but mitigation can be enabled via prctl
+				  per thread.  The mitigation control state
+				  is inherited on fork.
+
+			prctl,ibpb
+				- Like "prctl" above, but only STIBP is
+				  controlled per thread. IBPB is issued
+				  always when switching between different user
+				  space processes.
+
+			seccomp
+				- Same as "prctl" above, but all seccomp
+				  threads will enable the mitigation unless
+				  they explicitly opt out.
+
+			seccomp,ibpb
+				- Like "seccomp" above, but only STIBP is
+				  controlled per thread. IBPB is issued
+				  always when switching between different
+				  user space processes.
+
+			auto    - Kernel selects the mitigation depending on
+				  the available CPU features and vulnerability.
+
+			Default mitigation:
+			If CONFIG_SECCOMP=y then "seccomp", otherwise "prctl"
+
+			Not specifying this option is equivalent to
+			spectre_v2_user=auto.
+
 	spec_store_bypass_disable=
 			[HW] Control Speculative Store Bypass (SSB) Disable mitigation
 			(Speculative Store Bypass vulnerability)

Documentation/userspace-api/spec_ctrl.rst

@@ -92,3 +92,12 @@ Speculation misfeature controls
    * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_ENABLE, 0, 0);
    * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_DISABLE, 0, 0);
    * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_FORCE_DISABLE, 0, 0);
+
+- PR_SPEC_INDIR_BRANCH: Indirect Branch Speculation in User Processes
+                        (Mitigate Spectre V2 style attacks against user processes)
+
+  Invocations:
+   * prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, 0, 0, 0);
+   * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_ENABLE, 0, 0);
+   * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_DISABLE, 0, 0);
+   * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_FORCE_DISABLE, 0, 0);

Makefile

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 4
 PATCHLEVEL = 19
-SUBLEVEL = 6
+SUBLEVEL = 7
 EXTRAVERSION =
 NAME = "People's Front"
 

arch/arm/boot/dts/rk3288-veyron.dtsi

@@ -10,7 +10,11 @@
 #include "rk3288.dtsi"
 
 / {
-	memory@0 {
+	/*
+	 * The default coreboot on veyron devices ignores memory@0 nodes
+	 * and would instead create another memory node.
+	 */
+	memory {
 		device_type = "memory";
 		reg = <0x0 0x0 0x0 0x80000000>;
 	};

arch/arm/kernel/ftrace.c

@@ -227,9 +227,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 			   unsigned long frame_pointer)
 {
 	unsigned long return_hooker = (unsigned long) &return_to_handler;
-	struct ftrace_graph_ent trace;
 	unsigned long old;
-	int err;
 
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return;
@@ -237,21 +235,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 	old = *parent;
 	*parent = return_hooker;
 
-	trace.func = self_addr;
-	trace.depth = current->curr_ret_stack + 1;
-
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace)) {
+	if (function_graph_enter(old, self_addr, frame_pointer, NULL))
 		*parent = old;
-		return;
-	}
-
-	err = ftrace_push_return_trace(old, self_addr, &trace.depth,
-				       frame_pointer, NULL);
-	if (err == -EBUSY) {
-		*parent = old;
-		return;
-	}
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE

arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts

@@ -153,7 +153,7 @@
 };
 
 &pcie0 {
-	ep-gpios = <&gpio4 RK_PC6 GPIO_ACTIVE_LOW>;
+	ep-gpios = <&gpio4 RK_PC6 GPIO_ACTIVE_HIGH>;
 	num-lanes = <4>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pcie_clkreqn_cpm>;

arch/arm64/kernel/ftrace.c

@@ -216,8 +216,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 {
 	unsigned long return_hooker = (unsigned long)&return_to_handler;
 	unsigned long old;
-	struct ftrace_graph_ent trace;
-	int err;
 
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return;
@@ -229,18 +227,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 	 */
 	old = *parent;
 
-	trace.func = self_addr;
-	trace.depth = current->curr_ret_stack + 1;
-
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace))
-		return;
-
-	err = ftrace_push_return_trace(old, self_addr, &trace.depth,
-				       frame_pointer, NULL);
-	if (err == -EBUSY)
-		return;
-	else
+	if (!function_graph_enter(old, self_addr, frame_pointer, NULL))
 		*parent = return_hooker;
 }
 

arch/microblaze/kernel/ftrace.c

@@ -22,8 +22,7 @@
 void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 {
 	unsigned long old;
-	int faulted, err;
-	struct ftrace_graph_ent trace;
+	int faulted;
 	unsigned long return_hooker = (unsigned long)
 				&return_to_handler;
 
@@ -63,18 +62,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 		return;
 	}
 
-	err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0, NULL);
-	if (err == -EBUSY) {
+	if (function_graph_enter(old, self_addr, 0, NULL))
 		*parent = old;
-		return;
-	}
-
-	trace.func = self_addr;
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace)) {
-		current->curr_ret_stack--;
-		*parent = old;
-	}
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 

arch/mips/kernel/ftrace.c

@@ -322,7 +322,6 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
 			   unsigned long fp)
 {
 	unsigned long old_parent_ra;
-	struct ftrace_graph_ent trace;
 	unsigned long return_hooker = (unsigned long)
 	    &return_to_handler;
 	int faulted, insns;
@@ -369,12 +368,6 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
 	if (unlikely(faulted))
 		goto out;
 
-	if (ftrace_push_return_trace(old_parent_ra, self_ra, &trace.depth, fp,
-				     NULL) == -EBUSY) {
-		*parent_ra_addr = old_parent_ra;
-		return;
-	}
-
 	/*
 	 * Get the recorded ip of the current mcount calling site in the
 	 * __mcount_loc section, which will be used to filter the function
@@ -382,13 +375,10 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
 	 */
 
 	insns = core_kernel_text(self_ra) ? 2 : MCOUNT_OFFSET_INSNS + 1;
-	trace.func = self_ra - (MCOUNT_INSN_SIZE * insns);
+	self_ra -= (MCOUNT_INSN_SIZE * insns);
 
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace)) {
-		current->curr_ret_stack--;
+	if (function_graph_enter(old_parent_ra, self_ra, fp, NULL))
 		*parent_ra_addr = old_parent_ra;
-	}
 	return;
 out:
 	ftrace_graph_stop();

arch/nds32/kernel/ftrace.c

@@ -211,29 +211,15 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 			   unsigned long frame_pointer)
 {
 	unsigned long return_hooker = (unsigned long)&return_to_handler;
-	struct ftrace_graph_ent trace;
 	unsigned long old;
-	int err;
 
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return;
 
 	old = *parent;
 
-	trace.func = self_addr;
-	trace.depth = current->curr_ret_stack + 1;
-
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace))
-		return;
-
-	err = ftrace_push_return_trace(old, self_addr, &trace.depth,
-				       frame_pointer, NULL);
-
-	if (err == -EBUSY)
-		return;
-
-	*parent = return_hooker;
+	if (!function_graph_enter(old, self_addr, frame_pointer, NULL))
+		*parent = return_hooker;
 }
 
 noinline void ftrace_graph_caller(void)

arch/parisc/kernel/ftrace.c

@@ -30,7 +30,6 @@ static void __hot prepare_ftrace_return(unsigned long *parent,
 					unsigned long self_addr)
 {
 	unsigned long old;
-	struct ftrace_graph_ent trace;
 	extern int parisc_return_to_handler;
 
 	if (unlikely(ftrace_graph_is_dead()))
@@ -41,19 +40,9 @@ static void __hot prepare_ftrace_return(unsigned long *parent,
 
 	old = *parent;
 
-	trace.func = self_addr;
-	trace.depth = current->curr_ret_stack + 1;
-
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace))
-		return;
-
-        if (ftrace_push_return_trace(old, self_addr, &trace.depth,
-				     0, NULL) == -EBUSY)
-                return;
-
-	/* activate parisc_return_to_handler() as return point */
-	*parent = (unsigned long) &parisc_return_to_handler;
+	if (!function_graph_enter(old, self_addr, 0, NULL))
+		/* activate parisc_return_to_handler() as return point */
+		*parent = (unsigned long) &parisc_return_to_handler;
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 

arch/powerpc/kernel/trace/ftrace.c

@@ -697,7 +697,6 @@ int ftrace_disable_ftrace_graph_caller(void)
  */
 unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
 {
-	struct ftrace_graph_ent trace;
 	unsigned long return_hooker;
 
 	if (unlikely(ftrace_graph_is_dead()))
@@ -708,18 +707,8 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
 
 	return_hooker = ppc_function_entry(return_to_handler);
 
-	trace.func = ip;
-	trace.depth = current->curr_ret_stack + 1;
-
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace))
-		goto out;
-
-	if (ftrace_push_return_trace(parent, ip, &trace.depth, 0,
-				     NULL) == -EBUSY)
-		goto out;
-
-	parent = return_hooker;
+	if (!function_graph_enter(parent, ip, 0, NULL))
+		parent = return_hooker;
 out:
 	return parent;
 }

arch/riscv/kernel/ftrace.c

@@ -132,7 +132,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 {
 	unsigned long return_hooker = (unsigned long)&return_to_handler;
 	unsigned long old;
-	struct ftrace_graph_ent trace;
 	int err;
 
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
@@ -144,17 +143,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 	 */
 	old = *parent;
 
-	trace.func = self_addr;
-	trace.depth = current->curr_ret_stack + 1;
-
-	if (!ftrace_graph_entry(&trace))
-		return;
-
-	err = ftrace_push_return_trace(old, self_addr, &trace.depth,
-				       frame_pointer, parent);
-	if (err == -EBUSY)
-		return;
-	*parent = return_hooker;
+	if (function_graph_enter(old, self_addr, frame_pointer, parent))
+		*parent = return_hooker;
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE

arch/s390/kernel/ftrace.c

@@ -203,22 +203,13 @@ device_initcall(ftrace_plt_init);
  */
 unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
 {
-	struct ftrace_graph_ent trace;
-
 	if (unlikely(ftrace_graph_is_dead()))
 		goto out;
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		goto out;
 	ip -= MCOUNT_INSN_SIZE;
-	trace.func = ip;
-	trace.depth = current->curr_ret_stack + 1;
-	/* Only trace if the calling function expects to. */
-	if (!ftrace_graph_entry(&trace))
-		goto out;
-	if (ftrace_push_return_trace(parent, ip, &trace.depth, 0,
-				     NULL) == -EBUSY)
-		goto out;
-	parent = (unsigned long) return_to_handler;
+	if (!function_graph_enter(parent, ip, 0, NULL))
+		parent = (unsigned long) return_to_handler;
 out:
 	return parent;
 }

arch/sh/kernel/ftrace.c

@@ -321,8 +321,7 @@ int ftrace_disable_ftrace_graph_caller(void)
 void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 {
 	unsigned long old;
-	int faulted, err;
-	struct ftrace_graph_ent trace;
+	int faulted;
 	unsigned long return_hooker = (unsigned long)&return_to_handler;
 
 	if (unlikely(ftrace_graph_is_dead()))
@@ -365,18 +364,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 		return;
 	}
 
-	err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0, NULL);
-	if (err == -EBUSY) {
+	if (function_graph_enter(old, self_addr, 0, NULL))
 		__raw_writel(old, parent);
-		return;
-	}
-
-	trace.func = self_addr;
-
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace)) {
-		current->curr_ret_stack--;
-		__raw_writel(old, parent);
-	}
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */

arch/sparc/kernel/ftrace.c

@@ -126,20 +126,11 @@ unsigned long prepare_ftrace_return(unsigned long parent,
 				    unsigned long frame_pointer)
 {
 	unsigned long return_hooker = (unsigned long) &return_to_handler;
-	struct ftrace_graph_ent trace;
 
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return parent + 8UL;
 
-	trace.func = self_addr;
-	trace.depth = current->curr_ret_stack + 1;
-
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace))
-		return parent + 8UL;
-
-	if (ftrace_push_return_trace(parent, self_addr, &trace.depth,
-				     frame_pointer, NULL) == -EBUSY)
+	if (function_graph_enter(parent, self_addr, frame_pointer, NULL))
 		return parent + 8UL;
 
 	return return_hooker;

arch/x86/Kconfig

@@ -441,10 +441,6 @@ config RETPOLINE
 	  branches. Requires a compiler with -mindirect-branch=thunk-extern
 	  support for full protection. The kernel may run slower.
 
-	  Without compiler support, at least indirect branches in assembler
-	  code are eliminated. Since this includes the syscall entry path,
-	  it is not entirely pointless.
-
 config INTEL_RDT
 	bool "Intel Resource Director Technology support"
 	default n
@@ -1005,13 +1001,7 @@ config NR_CPUS
 	  to the kernel image.
 
 config SCHED_SMT
-	bool "SMT (Hyperthreading) scheduler support"
-	depends on SMP
-	---help---
-	  SMT scheduler support improves the CPU scheduler's decision making
-	  when dealing with Intel Pentium 4 chips with HyperThreading at a
-	  cost of slightly increased overhead in some places. If unsure say
-	  N here.
+	def_bool y if SMP
 
 config SCHED_MC
 	def_bool y

arch/x86/Makefile

@@ -223,9 +223,10 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 
 # Avoid indirect branches in kernel to deal with Spectre
 ifdef CONFIG_RETPOLINE
-ifneq ($(RETPOLINE_CFLAGS),)
-  KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE
+ifeq ($(RETPOLINE_CFLAGS),)
+  $(error You are building kernel with non-retpoline compiler, please update your compiler.)
 endif
+  KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
 endif
 
 archscripts: scripts_basic

arch/x86/events/core.c

@@ -438,26 +438,6 @@ int x86_setup_perfctr(struct perf_event *event)
 	if (config == -1LL)
 		return -EINVAL;
 
-	/*
-	 * Branch tracing:
-	 */
-	if (attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS &&
-	    !attr->freq && hwc->sample_period == 1) {
-		/* BTS is not supported by this architecture. */
-		if (!x86_pmu.bts_active)
-			return -EOPNOTSUPP;
-
-		/* BTS is currently only allowed for user-mode. */
-		if (!attr->exclude_kernel)
-			return -EOPNOTSUPP;
-
-		/* disallow bts if conflicting events are present */
-		if (x86_add_exclusive(x86_lbr_exclusive_lbr))
-			return -EBUSY;
-
-		event->destroy = hw_perf_lbr_event_destroy;
-	}
-
 	hwc->config |= config;
 
 	return 0;

arch/x86/events/intel/core.c

@@ -2358,16 +2358,7 @@ done:
 static struct event_constraint *
 intel_bts_constraints(struct perf_event *event)
 {
-	struct hw_perf_event *hwc = &event->hw;
-	unsigned int hw_event, bts_event;
-
-	if (event->attr.freq)
-		return NULL;
-
-	hw_event = hwc->config & INTEL_ARCH_EVENT_MASK;
-	bts_event = x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS);
-
-	if (unlikely(hw_event == bts_event && hwc->sample_period == 1))
+	if (unlikely(intel_pmu_has_bts(event)))
 		return &bts_constraint;
 
 	return NULL;
@@ -2986,10 +2977,51 @@ static unsigned long intel_pmu_large_pebs_flags(struct perf_event *event)
 	return flags;
 }
 
+static int intel_pmu_bts_config(struct perf_event *event)
+{
+	struct perf_event_attr *attr = &event->attr;
+
+	if (unlikely(intel_pmu_has_bts(event))) {
+		/* BTS is not supported by this architecture. */
+		if (!x86_pmu.bts_active)
+			return -EOPNOTSUPP;
+
+		/* BTS is currently only allowed for user-mode. */
+		if (!attr->exclude_kernel)
+			return -EOPNOTSUPP;
+
+		/* BTS is not allowed for precise events. */
+		if (attr->precise_ip)
+			return -EOPNOTSUPP;
+
+		/* disallow bts if conflicting events are present */
+		if (x86_add_exclusive(x86_lbr_exclusive_lbr))
+			return -EBUSY;
+
+		event->destroy = hw_perf_lbr_event_destroy;
+	}
+
+	return 0;
+}
+
+static int core_pmu_hw_config(struct perf_event *event)
+{
+	int ret = x86_pmu_hw_config(event);
+
+	if (ret)
+		return ret;
+
+	return intel_pmu_bts_config(event);
+}
+
 static int intel_pmu_hw_config(struct perf_event *event)
 {
 	int ret = x86_pmu_hw_config(event);
 
+	if (ret)
+		return ret;
+
+	ret = intel_pmu_bts_config(event);
 	if (ret)
 		return ret;
 
@@ -3015,7 +3047,7 @@ static int intel_pmu_hw_config(struct perf_event *event)
 		/*
 		 * BTS is set up earlier in this path, so don't account twice
 		 */
-		if (!intel_pmu_has_bts(event)) {
+		if (!unlikely(intel_pmu_has_bts(event))) {
 			/* disallow lbr if conflicting events are present */
 			if (x86_add_exclusive(x86_lbr_exclusive_lbr))
 				return -EBUSY;
@@ -3478,7 +3510,7 @@ static __initconst const struct x86_pmu core_pmu = {
 	.enable_all		= core_pmu_enable_all,
 	.enable			= core_pmu_enable_event,
 	.disable		= x86_pmu_disable_event,
-	.hw_config		= x86_pmu_hw_config,
+	.hw_config		= core_pmu_hw_config,
 	.schedule_events	= x86_schedule_events,
 	.eventsel		= MSR_ARCH_PERFMON_EVENTSEL0,
 	.perfctr		= MSR_ARCH_PERFMON_PERFCTR0,