Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Lots of easy overlapping changes in the confict
resolutions here.

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -478,6 +478,7 @@ What:		/sys/devices/system/cpu/vulnerabilities
 		/sys/devices/system/cpu/vulnerabilities/meltdown
 		/sys/devices/system/cpu/vulnerabilities/spectre_v1
 		/sys/devices/system/cpu/vulnerabilities/spectre_v2
+		/sys/devices/system/cpu/vulnerabilities/spec_store_bypass
 Date:		January 2018
 Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
 Description:	Information about CPU vulnerabilities

Documentation/admin-guide/kernel-parameters.txt

@@ -2680,6 +2680,9 @@
 			allow data leaks with this option, which is equivalent
 			to spectre_v2=off.
 
+	nospec_store_bypass_disable
+			[HW] Disable all mitigations for the Speculative Store Bypass vulnerability
+
 	noxsave		[BUGS=X86] Disables x86 extended register state save
 			and restore using xsave. The kernel will fallback to
 			enabling legacy floating-point and sse state.
@@ -4025,6 +4028,48 @@
 			Not specifying this option is equivalent to
 			spectre_v2=auto.
 
+	spec_store_bypass_disable=
+			[HW] Control Speculative Store Bypass (SSB) Disable mitigation
+			(Speculative Store Bypass vulnerability)
+
+			Certain CPUs are vulnerable to an exploit against a
+			a common industry wide performance optimization known
+			as "Speculative Store Bypass" in which recent stores
+			to the same memory location may not be observed by
+			later loads during speculative execution. The idea
+			is that such stores are unlikely and that they can
+			be detected prior to instruction retirement at the
+			end of a particular speculation execution window.
+
+			In vulnerable processors, the speculatively forwarded
+			store can be used in a cache side channel attack, for
+			example to read memory to which the attacker does not
+			directly have access (e.g. inside sandboxed code).
+
+			This parameter controls whether the Speculative Store
+			Bypass optimization is used.
+
+			on      - Unconditionally disable Speculative Store Bypass
+			off     - Unconditionally enable Speculative Store Bypass
+			auto    - Kernel detects whether the CPU model contains an
+				  implementation of Speculative Store Bypass and
+				  picks the most appropriate mitigation. If the
+				  CPU is not vulnerable, "off" is selected. If the
+				  CPU is vulnerable the default mitigation is
+				  architecture and Kconfig dependent. See below.
+			prctl   - Control Speculative Store Bypass per thread
+				  via prctl. Speculative Store Bypass is enabled
+				  for a process by default. The state of the control
+				  is inherited on fork.
+			seccomp - Same as "prctl" above, but all seccomp threads
+				  will disable SSB unless they explicitly opt out.
+
+			Not specifying this option is equivalent to
+			spec_store_bypass_disable=auto.
+
+			Default mitigations:
+			X86:	If CONFIG_SECCOMP=y "seccomp", otherwise "prctl"
+
 	spia_io_base=	[HW,MTD]
 	spia_fio_base=
 	spia_pedr=

Documentation/networking/ppp_generic.txt

@@ -300,12 +300,6 @@ unattached instance are:
 The ioctl calls available on an instance of /dev/ppp attached to a
 channel are:
 
-* PPPIOCDETACH detaches the instance from the channel.  This ioctl is
-  deprecated since the same effect can be achieved by closing the
-  instance.  In order to prevent possible races this ioctl will fail
-  with an EINVAL error if more than one file descriptor refers to this
-  instance (i.e. as a result of dup(), dup2() or fork()).
-
 * PPPIOCCONNECT connects this channel to a PPP interface.  The
   argument should point to an int containing the interface unit
   number.  It will return an EINVAL error if the channel is already

Documentation/userspace-api/index.rst

@@ -19,6 +19,7 @@ place where this information is gathered.
    no_new_privs
    seccomp_filter
    unshare
+   spec_ctrl
 
 .. only::  subproject and html
 

Documentation/userspace-api/spec_ctrl.rst

+===================
+Speculation Control
+===================
+
+Quite some CPUs have speculation-related misfeatures which are in
+fact vulnerabilities causing data leaks in various forms even across
+privilege domains.
+
+The kernel provides mitigation for such vulnerabilities in various
+forms. Some of these mitigations are compile-time configurable and some
+can be supplied on the kernel command line.
+
+There is also a class of mitigations which are very expensive, but they can
+be restricted to a certain set of processes or tasks in controlled
+environments. The mechanism to control these mitigations is via
+:manpage:`prctl(2)`.
+
+There are two prctl options which are related to this:
+
+ * PR_GET_SPECULATION_CTRL
+
+ * PR_SET_SPECULATION_CTRL
+
+PR_GET_SPECULATION_CTRL
+-----------------------
+
+PR_GET_SPECULATION_CTRL returns the state of the speculation misfeature
+which is selected with arg2 of prctl(2). The return value uses bits 0-3 with
+the following meaning:
+
+==== ===================== ===================================================
+Bit  Define                Description
+==== ===================== ===================================================
+0    PR_SPEC_PRCTL         Mitigation can be controlled per task by
+                           PR_SET_SPECULATION_CTRL.
+1    PR_SPEC_ENABLE        The speculation feature is enabled, mitigation is
+                           disabled.
+2    PR_SPEC_DISABLE       The speculation feature is disabled, mitigation is
+                           enabled.
+3    PR_SPEC_FORCE_DISABLE Same as PR_SPEC_DISABLE, but cannot be undone. A
+                           subsequent prctl(..., PR_SPEC_ENABLE) will fail.
+==== ===================== ===================================================
+
+If all bits are 0 the CPU is not affected by the speculation misfeature.
+
+If PR_SPEC_PRCTL is set, then the per-task control of the mitigation is
+available. If not set, prctl(PR_SET_SPECULATION_CTRL) for the speculation
+misfeature will fail.
+
+PR_SET_SPECULATION_CTRL
+-----------------------
+
+PR_SET_SPECULATION_CTRL allows to control the speculation misfeature, which
+is selected by arg2 of :manpage:`prctl(2)` per task. arg3 is used to hand
+in the control value, i.e. either PR_SPEC_ENABLE or PR_SPEC_DISABLE or
+PR_SPEC_FORCE_DISABLE.
+
+Common error codes
+------------------
+======= =================================================================
+Value   Meaning
+======= =================================================================
+EINVAL  The prctl is not implemented by the architecture or unused
+        prctl(2) arguments are not 0.
+
+ENODEV  arg2 is selecting a not supported speculation misfeature.
+======= =================================================================
+
+PR_SET_SPECULATION_CTRL error codes
+-----------------------------------
+======= =================================================================
+Value   Meaning
+======= =================================================================
+0       Success
+
+ERANGE  arg3 is incorrect, i.e. it's neither PR_SPEC_ENABLE nor
+        PR_SPEC_DISABLE nor PR_SPEC_FORCE_DISABLE.
+
+ENXIO   Control of the selected speculation misfeature is not possible.
+        See PR_GET_SPECULATION_CTRL.
+
+EPERM   Speculation was disabled with PR_SPEC_FORCE_DISABLE and caller
+        tried to enable it again.
+======= =================================================================
+
+Speculation misfeature controls
+-------------------------------
+- PR_SPEC_STORE_BYPASS: Speculative Store Bypass
+
+  Invocations:
+   * prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, 0, 0, 0);
+   * 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);

MAINTAINERS

@@ -2332,7 +2332,7 @@ F:	drivers/gpio/gpio-ath79.c
 F:	Documentation/devicetree/bindings/gpio/gpio-ath79.txt
 
 ATHEROS ATH GENERIC UTILITIES
-M:	"Luis R. Rodriguez" <mcgrof@do-not-panic.com>
+M:	Kalle Valo <kvalo@codeaurora.org>
 L:	linux-wireless@vger.kernel.org
 S:	Supported
 F:	drivers/net/wireless/ath/*
@@ -2347,7 +2347,7 @@ S:	Maintained
 F:	drivers/net/wireless/ath/ath5k/
 
 ATHEROS ATH6KL WIRELESS DRIVER
-M:	Kalle Valo <kvalo@qca.qualcomm.com>
+M:	Kalle Valo <kvalo@codeaurora.org>
 L:	linux-wireless@vger.kernel.org
 W:	http://wireless.kernel.org/en/users/Drivers/ath6kl
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git
@@ -5386,7 +5386,6 @@ S:	Maintained
 F:	drivers/iommu/exynos-iommu.c
 
 EZchip NPS platform support
-M:	Elad Kanfi <eladkan@mellanox.com>
 M:	Vineet Gupta <vgupta@synopsys.com>
 S:	Supported
 F:	arch/arc/plat-eznps
@@ -6502,9 +6501,15 @@ F:	Documentation/networking/hinic.txt
 F:	drivers/net/ethernet/huawei/hinic/
 
 HUGETLB FILESYSTEM
-M:	Nadia Yvette Chambers <nyc@holomorphy.com>
+M:	Mike Kravetz <mike.kravetz@oracle.com>
+L:	linux-mm@kvack.org
 S:	Maintained
 F:	fs/hugetlbfs/
+F:	mm/hugetlb.c
+F:	include/linux/hugetlb.h
+F:	Documentation/admin-guide/mm/hugetlbpage.rst
+F:	Documentation/vm/hugetlbfs_reserv.rst
+F:	Documentation/ABI/testing/sysfs-kernel-mm-hugepages
 
 HVA ST MEDIA DRIVER
 M:	Jean-Christophe Trotin <jean-christophe.trotin@st.com>
@@ -9020,7 +9025,7 @@ Q:	http://patchwork.ozlabs.org/project/netdev/list/
 F:	drivers/net/ethernet/mellanox/mlx5/core/en_*
 
 MELLANOX ETHERNET INNOVA DRIVERS
-M:	Boris Pismenny <borisp@mellanox.com>
+R:	Boris Pismenny <borisp@mellanox.com>
 L:	netdev@vger.kernel.org
 S:	Supported
 W:	http://www.mellanox.com
@@ -9030,6 +9035,15 @@ F:	drivers/net/ethernet/mellanox/mlx5/core/accel/*
 F:	drivers/net/ethernet/mellanox/mlx5/core/fpga/*
 F:	include/linux/mlx5/mlx5_ifc_fpga.h
 
+MELLANOX ETHERNET INNOVA IPSEC DRIVER
+R:	Boris Pismenny <borisp@mellanox.com>
+L:	netdev@vger.kernel.org
+S:	Supported
+W:	http://www.mellanox.com
+Q:	http://patchwork.ozlabs.org/project/netdev/list/
+F:	drivers/net/ethernet/mellanox/mlx5/core/en_ipsec/*
+F:	drivers/net/ethernet/mellanox/mlx5/core/ipsec*
+
 MELLANOX ETHERNET SWITCH DRIVERS
 M:	Jiri Pirko <jiri@mellanox.com>
 M:	Ido Schimmel <idosch@mellanox.com>
@@ -9077,7 +9091,6 @@ F:	include/uapi/rdma/mlx4-abi.h
 
 MELLANOX MLX5 core VPI driver
 M:	Saeed Mahameed <saeedm@mellanox.com>
-M:	Matan Barak <matanb@mellanox.com>
 M:	Leon Romanovsky <leonro@mellanox.com>
 L:	netdev@vger.kernel.org
 L:	linux-rdma@vger.kernel.org
@@ -9088,7 +9101,6 @@ F:	drivers/net/ethernet/mellanox/mlx5/core/
 F:	include/linux/mlx5/
 
 MELLANOX MLX5 IB driver
-M:	Matan Barak <matanb@mellanox.com>
 M:	Leon Romanovsky <leonro@mellanox.com>
 L:	linux-rdma@vger.kernel.org
 W:	http://www.mellanox.com
@@ -11628,7 +11640,7 @@ S:	Maintained
 F:	drivers/media/tuners/qt1010*
 
 QUALCOMM ATHEROS ATH10K WIRELESS DRIVER
-M:	Kalle Valo <kvalo@qca.qualcomm.com>
+M:	Kalle Valo <kvalo@codeaurora.org>
 L:	ath10k@lists.infradead.org
 W:	http://wireless.kernel.org/en/users/Drivers/ath10k
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git
@@ -11679,7 +11691,7 @@ S:	Maintained
 F:	drivers/media/platform/qcom/venus/
 
 QUALCOMM WCN36XX WIRELESS DRIVER
-M:	Eugene Krasnikov <k.eugene.e@gmail.com>
+M:	Kalle Valo <kvalo@codeaurora.org>
 L:	wcn36xx@lists.infradead.org
 W:	http://wireless.kernel.org/en/users/Drivers/wcn36xx
 T:	git git://github.com/KrasnikovEugene/wcn36xx.git

arch/alpha/Kconfig

@@ -211,6 +211,7 @@ config ALPHA_EIGER
 config ALPHA_JENSEN
 	bool "Jensen"
 	depends on BROKEN
+	select DMA_DIRECT_OPS
 	help
 	  DEC PC 150 AXP (aka Jensen): This is a very old Digital system - one
 	  of the first-generation Alpha systems. A number of these systems

arch/alpha/include/asm/dma-mapping.h

@@ -2,11 +2,15 @@
 #ifndef _ALPHA_DMA_MAPPING_H
 #define _ALPHA_DMA_MAPPING_H
 
-extern const struct dma_map_ops *dma_ops;
+extern const struct dma_map_ops alpha_pci_ops;
 
 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	return dma_ops;
+#ifdef CONFIG_ALPHA_JENSEN
+	return &dma_direct_ops;
+#else
+	return &alpha_pci_ops;
+#endif
 }
 
 #endif	/* _ALPHA_DMA_MAPPING_H */

arch/alpha/kernel/io.c

@@ -37,20 +37,20 @@ unsigned int ioread32(void __iomem *addr)
 
 void iowrite8(u8 b, void __iomem *addr)
 {
-	IO_CONCAT(__IO_PREFIX,iowrite8)(b, addr);
 	mb();
+	IO_CONCAT(__IO_PREFIX,iowrite8)(b, addr);
 }
 
 void iowrite16(u16 b, void __iomem *addr)
 {
-	IO_CONCAT(__IO_PREFIX,iowrite16)(b, addr);
 	mb();
+	IO_CONCAT(__IO_PREFIX,iowrite16)(b, addr);
 }
 
 void iowrite32(u32 b, void __iomem *addr)
 {
-	IO_CONCAT(__IO_PREFIX,iowrite32)(b, addr);
 	mb();
+	IO_CONCAT(__IO_PREFIX,iowrite32)(b, addr);
 }
 
 EXPORT_SYMBOL(ioread8);
@@ -176,26 +176,26 @@ u64 readq(const volatile void __iomem *addr)
 
 void writeb(u8 b, volatile void __iomem *addr)
 {
-	__raw_writeb(b, addr);
 	mb();
+	__raw_writeb(b, addr);
 }
 
 void writew(u16 b, volatile void __iomem *addr)
 {
-	__raw_writew(b, addr);
 	mb();
+	__raw_writew(b, addr);
 }
 
 void writel(u32 b, volatile void __iomem *addr)
 {
-	__raw_writel(b, addr);
 	mb();
+	__raw_writel(b, addr);
 }
 
 void writeq(u64 b, volatile void __iomem *addr)
 {
-	__raw_writeq(b, addr);
 	mb();
+	__raw_writeq(b, addr);
 }
 
 EXPORT_SYMBOL(readb);

arch/alpha/kernel/pci-noop.c

@@ -102,36 +102,3 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
 	else
 		return -ENODEV;
 }
-
-static void *alpha_noop_alloc_coherent(struct device *dev, size_t size,
-				       dma_addr_t *dma_handle, gfp_t gfp,
-				       unsigned long attrs)
-{
-	void *ret;
-
-	if (!dev || *dev->dma_mask >= 0xffffffffUL)
-		gfp &= ~GFP_DMA;
-	ret = (void *)__get_free_pages(gfp, get_order(size));
-	if (ret) {
-		memset(ret, 0, size);
-		*dma_handle = virt_to_phys(ret);
-	}
-	return ret;
-}
-
-static int alpha_noop_supported(struct device *dev, u64 mask)
-{
-	return mask < 0x00ffffffUL ? 0 : 1;
-}
-
-const struct dma_map_ops alpha_noop_ops = {
-	.alloc			= alpha_noop_alloc_coherent,
-	.free			= dma_noop_free_coherent,
-	.map_page		= dma_noop_map_page,
-	.map_sg			= dma_noop_map_sg,
-	.mapping_error		= dma_noop_mapping_error,
-	.dma_supported		= alpha_noop_supported,
-};
-
-const struct dma_map_ops *dma_ops = &alpha_noop_ops;
-EXPORT_SYMBOL(dma_ops);

arch/alpha/kernel/pci_iommu.c

@@ -950,6 +950,4 @@ const struct dma_map_ops alpha_pci_ops = {
 	.mapping_error		= alpha_pci_mapping_error,
 	.dma_supported		= alpha_pci_supported,
 };
-
-const struct dma_map_ops *dma_ops = &alpha_pci_ops;
-EXPORT_SYMBOL(dma_ops);
+EXPORT_SYMBOL(alpha_pci_ops);

arch/arm/mm/dma-mapping.c

@@ -466,12 +466,6 @@ void __init dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
 void __init dma_contiguous_remap(void)
 {
 	int i;
-
-	if (!dma_mmu_remap_num)
-		return;
-
-	/* call flush_cache_all() since CMA area would be large enough */
-	flush_cache_all();
 	for (i = 0; i < dma_mmu_remap_num; i++) {
 		phys_addr_t start = dma_mmu_remap[i].base;
 		phys_addr_t end = start + dma_mmu_remap[i].size;
@@ -504,15 +498,7 @@ void __init dma_contiguous_remap(void)
 		flush_tlb_kernel_range(__phys_to_virt(start),
 				       __phys_to_virt(end));
 
-		/*
-		 * All the memory in CMA region will be on ZONE_MOVABLE.
-		 * If that zone is considered as highmem, the memory in CMA
-		 * region is also considered as highmem even if it's
-		 * physical address belong to lowmem. In this case,
-		 * re-mapping isn't required.
-		 */
-		if (!is_highmem_idx(ZONE_MOVABLE))
-			iotable_init(&map, 1);
+		iotable_init(&map, 1);
 	}
 }
 

arch/arm64/include/asm/atomic_lse.h

@@ -117,7 +117,7 @@ static inline void atomic_and(int i, atomic_t *v)
 	/* LSE atomics */
 	"	mvn	%w[i], %w[i]\n"
 	"	stclr	%w[i], %[v]")
-	: [i] "+r" (w0), [v] "+Q" (v->counter)
+	: [i] "+&r" (w0), [v] "+Q" (v->counter)
 	: "r" (x1)
 	: __LL_SC_CLOBBERS);
 }
@@ -135,7 +135,7 @@ static inline int atomic_fetch_and##name(int i, atomic_t *v)		\
 	/* LSE atomics */						\
 	"	mvn	%w[i], %w[i]\n"					\
 	"	ldclr" #mb "	%w[i], %w[i], %[v]")			\
-	: [i] "+r" (w0), [v] "+Q" (v->counter)				\
+	: [i] "+&r" (w0), [v] "+Q" (v->counter)				\
 	: "r" (x1)							\
 	: __LL_SC_CLOBBERS, ##cl);					\
 									\
@@ -161,7 +161,7 @@ static inline void atomic_sub(int i, atomic_t *v)
 	/* LSE atomics */
 	"	neg	%w[i], %w[i]\n"
 	"	stadd	%w[i], %[v]")
-	: [i] "+r" (w0), [v] "+Q" (v->counter)
+	: [i] "+&r" (w0), [v] "+Q" (v->counter)
 	: "r" (x1)
 	: __LL_SC_CLOBBERS);
 }
@@ -180,7 +180,7 @@ static inline int atomic_sub_return##name(int i, atomic_t *v)		\
 	"	neg	%w[i], %w[i]\n"					\
 	"	ldadd" #mb "	%w[i], w30, %[v]\n"			\
 	"	add	%w[i], %w[i], w30")				\
-	: [i] "+r" (w0), [v] "+Q" (v->counter)				\
+	: [i] "+&r" (w0), [v] "+Q" (v->counter)				\
 	: "r" (x1)							\
 	: __LL_SC_CLOBBERS , ##cl);					\
 									\
@@ -207,7 +207,7 @@ static inline int atomic_fetch_sub##name(int i, atomic_t *v)		\
 	/* LSE atomics */						\
 	"	neg	%w[i], %w[i]\n"					\
 	"	ldadd" #mb "	%w[i], %w[i], %[v]")			\
-	: [i] "+r" (w0), [v] "+Q" (v->counter)				\
+	: [i] "+&r" (w0), [v] "+Q" (v->counter)				\
 	: "r" (x1)							\
 	: __LL_SC_CLOBBERS, ##cl);					\
 									\
@@ -314,7 +314,7 @@ static inline void atomic64_and(long i, atomic64_t *v)
 	/* LSE atomics */
 	"	mvn	%[i], %[i]\n"
 	"	stclr	%[i], %[v]")
-	: [i] "+r" (x0), [v] "+Q" (v->counter)
+	: [i] "+&r" (x0), [v] "+Q" (v->counter)
 	: "r" (x1)
 	: __LL_SC_CLOBBERS);
 }
@@ -332,7 +332,7 @@ static inline long atomic64_fetch_and##name(long i, atomic64_t *v)	\
 	/* LSE atomics */						\
 	"	mvn	%[i], %[i]\n"					\
 	"	ldclr" #mb "	%[i], %[i], %[v]")			\
-	: [i] "+r" (x0), [v] "+Q" (v->counter)				\
+	: [i] "+&r" (x0), [v] "+Q" (v->counter)				\
 	: "r" (x1)							\
 	: __LL_SC_CLOBBERS, ##cl);					\
 									\
@@ -358,7 +358,7 @@ static inline void atomic64_sub(long i, atomic64_t *v)
 	/* LSE atomics */
 	"	neg	%[i], %[i]\n"
 	"	stadd	%[i], %[v]")
-	: [i] "+r" (x0), [v] "+Q" (v->counter)
+	: [i] "+&r" (x0), [v] "+Q" (v->counter)
 	: "r" (x1)
 	: __LL_SC_CLOBBERS);
 }
@@ -377,7 +377,7 @@ static inline long atomic64_sub_return##name(long i, atomic64_t *v)	\
 	"	neg	%[i], %[i]\n"					\
 	"	ldadd" #mb "	%[i], x30, %[v]\n"			\
 	"	add	%[i], %[i], x30")				\
-	: [i] "+r" (x0), [v] "+Q" (v->counter)				\
+	: [i] "+&r" (x0), [v] "+Q" (v->counter)				\
 	: "r" (x1)							\
 	: __LL_SC_CLOBBERS, ##cl);					\
 									\
@@ -404,7 +404,7 @@ static inline long atomic64_fetch_sub##name(long i, atomic64_t *v)	\
 	/* LSE atomics */						\
 	"	neg	%[i], %[i]\n"					\
 	"	ldadd" #mb "	%[i], %[i], %[v]")			\
-	: [i] "+r" (x0), [v] "+Q" (v->counter)				\
+	: [i] "+&r" (x0), [v] "+Q" (v->counter)				\
 	: "r" (x1)							\
 	: __LL_SC_CLOBBERS, ##cl);					\
 									\
@@ -435,7 +435,7 @@ static inline long atomic64_dec_if_positive(atomic64_t *v)
 	"	sub	x30, x30, %[ret]\n"
 	"	cbnz	x30, 1b\n"
 	"2:")
-	: [ret] "+r" (x0), [v] "+Q" (v->counter)
+	: [ret] "+&r" (x0), [v] "+Q" (v->counter)
 	:
 	: __LL_SC_CLOBBERS, "cc", "memory");
 
@@ -516,7 +516,7 @@ static inline long __cmpxchg_double##name(unsigned long old1,		\
 	"	eor	%[old1], %[old1], %[oldval1]\n"			\
 	"	eor	%[old2], %[old2], %[oldval2]\n"			\
 	"	orr	%[old1], %[old1], %[old2]")			\
-	: [old1] "+r" (x0), [old2] "+r" (x1),				\
+	: [old1] "+&r" (x0), [old2] "+&r" (x1),				\
 	  [v] "+Q" (*(unsigned long *)ptr)				\
 	: [new1] "r" (x2), [new2] "r" (x3), [ptr] "r" (x4),		\
 	  [oldval1] "r" (oldval1), [oldval2] "r" (oldval2)		\

arch/arm64/kernel/arm64ksyms.c

@@ -75,3 +75,11 @@ NOKPROBE_SYMBOL(_mcount);
 	/* arm-smccc */
 EXPORT_SYMBOL(__arm_smccc_smc);
 EXPORT_SYMBOL(__arm_smccc_hvc);
+
+	/* tishift.S */
+extern long long __ashlti3(long long a, int b);
+EXPORT_SYMBOL(__ashlti3);
+extern long long __ashrti3(long long a, int b);
+EXPORT_SYMBOL(__ashrti3);
+extern long long __lshrti3(long long a, int b);
+EXPORT_SYMBOL(__lshrti3);

arch/arm64/lib/tishift.S

-/*
- * Copyright (C) 2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  */
 
 #include <linux/linkage.h>

arch/arm64/mm/fault.c

@@ -293,6 +293,57 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr,
 static void __do_user_fault(struct siginfo *info, unsigned int esr)
 {
 	current->thread.fault_address = (unsigned long)info->si_addr;
+
+	/*
+	 * If the faulting address is in the kernel, we must sanitize the ESR.
+	 * From userspace's point of view, kernel-only mappings don't exist
+	 * at all, so we report them as level 0 translation faults.
+	 * (This is not quite the way that "no mapping there at all" behaves:
+	 * an alignment fault not caused by the memory type would take
+	 * precedence over translation fault for a real access to empty
+	 * space. Unfortunately we can't easily distinguish "alignment fault
+	 * not caused by memory type" from "alignment fault caused by memory
+	 * type", so we ignore this wrinkle and just return the translation
+	 * fault.)
+	 */
+	if (current->thread.fault_address >= TASK_SIZE) {
+		switch (ESR_ELx_EC(esr)) {
+		case ESR_ELx_EC_DABT_LOW:
+			/*
+			 * These bits provide only information about the
+			 * faulting instruction, which userspace knows already.
+			 * We explicitly clear bits which are architecturally
+			 * RES0 in case they are given meanings in future.
+			 * We always report the ESR as if the fault was taken
+			 * to EL1 and so ISV and the bits in ISS[23:14] are
+			 * clear. (In fact it always will be a fault to EL1.)
+			 */
+			esr &= ESR_ELx_EC_MASK | ESR_ELx_IL |
+				ESR_ELx_CM | ESR_ELx_WNR;
+			esr |= ESR_ELx_FSC_FAULT;
+			break;
+		case ESR_ELx_EC_IABT_LOW:
+			/*
+			 * Claim a level 0 translation fault.
+			 * All other bits are architecturally RES0 for faults
+			 * reported with that DFSC value, so we clear them.
+			 */
+			esr &= ESR_ELx_EC_MASK | ESR_ELx_IL;
+			esr |= ESR_ELx_FSC_FAULT;
+			break;
+		default:
+			/*
+			 * This should never happen (entry.S only brings us
+			 * into this code for insn and data aborts from a lower
+			 * exception level). Fail safe by not providing an ESR
+			 * context record at all.