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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /tools/testing/selftests/arm64/bti
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to '')
-rw-r--r--tools/testing/selftests/arm64/bti/.gitignore2
-rw-r--r--tools/testing/selftests/arm64/bti/Makefile61
-rw-r--r--tools/testing/selftests/arm64/bti/assembler.h80
-rw-r--r--tools/testing/selftests/arm64/bti/btitest.h23
-rw-r--r--tools/testing/selftests/arm64/bti/compiler.h21
-rw-r--r--tools/testing/selftests/arm64/bti/gen/.gitignore2
-rw-r--r--tools/testing/selftests/arm64/bti/signal.c37
-rw-r--r--tools/testing/selftests/arm64/bti/signal.h21
-rw-r--r--tools/testing/selftests/arm64/bti/start.S14
-rw-r--r--tools/testing/selftests/arm64/bti/syscall.S23
-rw-r--r--tools/testing/selftests/arm64/bti/system.c22
-rw-r--r--tools/testing/selftests/arm64/bti/system.h28
-rw-r--r--tools/testing/selftests/arm64/bti/test.c230
-rw-r--r--tools/testing/selftests/arm64/bti/teststubs.S39
-rw-r--r--tools/testing/selftests/arm64/bti/trampoline.S29
15 files changed, 632 insertions, 0 deletions
diff --git a/tools/testing/selftests/arm64/bti/.gitignore b/tools/testing/selftests/arm64/bti/.gitignore
new file mode 100644
index 000000000..73869faba
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/.gitignore
@@ -0,0 +1,2 @@
+btitest
+nobtitest
diff --git a/tools/testing/selftests/arm64/bti/Makefile b/tools/testing/selftests/arm64/bti/Makefile
new file mode 100644
index 000000000..ccdac414a
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/Makefile
@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: GPL-2.0
+
+TEST_GEN_PROGS := btitest nobtitest
+
+PROGS := $(patsubst %,gen/%,$(TEST_GEN_PROGS))
+
+# These tests are built as freestanding binaries since otherwise BTI
+# support in ld.so is required which is not currently widespread; when
+# it is available it will still be useful to test this separately as the
+# cases for statically linked and dynamically lined binaries are
+# slightly different.
+
+CFLAGS_NOBTI = -mbranch-protection=none -DBTI=0
+CFLAGS_BTI = -mbranch-protection=standard -DBTI=1
+
+CFLAGS_COMMON = -ffreestanding -Wall -Wextra $(CFLAGS)
+
+BTI_CC_COMMAND = $(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -c -o $@ $<
+NOBTI_CC_COMMAND = $(CC) $(CFLAGS_NOBTI) $(CFLAGS_COMMON) -c -o $@ $<
+
+%-bti.o: %.c
+ $(BTI_CC_COMMAND)
+
+%-bti.o: %.S
+ $(BTI_CC_COMMAND)
+
+%-nobti.o: %.c
+ $(NOBTI_CC_COMMAND)
+
+%-nobti.o: %.S
+ $(NOBTI_CC_COMMAND)
+
+BTI_OBJS = \
+ test-bti.o \
+ signal-bti.o \
+ start-bti.o \
+ syscall-bti.o \
+ system-bti.o \
+ teststubs-bti.o \
+ trampoline-bti.o
+gen/btitest: $(BTI_OBJS)
+ $(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -nostdlib -static -o $@ $^
+
+NOBTI_OBJS = \
+ test-nobti.o \
+ signal-nobti.o \
+ start-nobti.o \
+ syscall-nobti.o \
+ system-nobti.o \
+ teststubs-nobti.o \
+ trampoline-nobti.o
+gen/nobtitest: $(NOBTI_OBJS)
+ $(CC) $(CFLAGS_BTI) $(CFLAGS_COMMON) -nostdlib -static -o $@ $^
+
+# Including KSFT lib.mk here will also mangle the TEST_GEN_PROGS list
+# to account for any OUTPUT target-dirs optionally provided by
+# the toplevel makefile
+include ../../lib.mk
+
+$(TEST_GEN_PROGS): $(PROGS)
+ cp $(PROGS) $(OUTPUT)/
diff --git a/tools/testing/selftests/arm64/bti/assembler.h b/tools/testing/selftests/arm64/bti/assembler.h
new file mode 100644
index 000000000..04e7b7288
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/assembler.h
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef ASSEMBLER_H
+#define ASSEMBLER_H
+
+#define NT_GNU_PROPERTY_TYPE_0 5
+#define GNU_PROPERTY_AARCH64_FEATURE_1_AND 0xc0000000
+
+/* Bits for GNU_PROPERTY_AARCH64_FEATURE_1_BTI */
+#define GNU_PROPERTY_AARCH64_FEATURE_1_BTI (1U << 0)
+#define GNU_PROPERTY_AARCH64_FEATURE_1_PAC (1U << 1)
+
+
+.macro startfn name:req
+ .globl \name
+\name:
+ .macro endfn
+ .size \name, . - \name
+ .type \name, @function
+ .purgem endfn
+ .endm
+.endm
+
+.macro emit_aarch64_feature_1_and
+ .pushsection .note.gnu.property, "a"
+ .align 3
+ .long 2f - 1f
+ .long 6f - 3f
+ .long NT_GNU_PROPERTY_TYPE_0
+1: .string "GNU"
+2:
+ .align 3
+3: .long GNU_PROPERTY_AARCH64_FEATURE_1_AND
+ .long 5f - 4f
+4:
+#if BTI
+ .long GNU_PROPERTY_AARCH64_FEATURE_1_PAC | \
+ GNU_PROPERTY_AARCH64_FEATURE_1_BTI
+#else
+ .long 0
+#endif
+5:
+ .align 3
+6:
+ .popsection
+.endm
+
+.macro paciasp
+ hint 0x19
+.endm
+
+.macro autiasp
+ hint 0x1d
+.endm
+
+.macro __bti_
+ hint 0x20
+.endm
+
+.macro __bti_c
+ hint 0x22
+.endm
+
+.macro __bti_j
+ hint 0x24
+.endm
+
+.macro __bti_jc
+ hint 0x26
+.endm
+
+.macro bti what=
+ __bti_\what
+.endm
+
+#endif /* ! ASSEMBLER_H */
diff --git a/tools/testing/selftests/arm64/bti/btitest.h b/tools/testing/selftests/arm64/bti/btitest.h
new file mode 100644
index 000000000..2aff9b103
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/btitest.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef BTITEST_H
+#define BTITEST_H
+
+/* Trampolines for calling the test stubs: */
+void call_using_br_x0(void (*)(void));
+void call_using_br_x16(void (*)(void));
+void call_using_blr(void (*)(void));
+
+/* Test stubs: */
+void nohint_func(void);
+void bti_none_func(void);
+void bti_c_func(void);
+void bti_j_func(void);
+void bti_jc_func(void);
+void paciasp_func(void);
+
+#endif /* !BTITEST_H */
diff --git a/tools/testing/selftests/arm64/bti/compiler.h b/tools/testing/selftests/arm64/bti/compiler.h
new file mode 100644
index 000000000..ebb6204f4
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/compiler.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef COMPILER_H
+#define COMPILER_H
+
+#define __always_unused __attribute__((__unused__))
+#define __noreturn __attribute__((__noreturn__))
+#define __unreachable() __builtin_unreachable()
+
+/* curse(e) has value e, but the compiler cannot assume so */
+#define curse(e) ({ \
+ __typeof__(e) __curse_e = (e); \
+ asm ("" : "+r" (__curse_e)); \
+ __curse_e; \
+})
+
+#endif /* ! COMPILER_H */
diff --git a/tools/testing/selftests/arm64/bti/gen/.gitignore b/tools/testing/selftests/arm64/bti/gen/.gitignore
new file mode 100644
index 000000000..73869faba
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/gen/.gitignore
@@ -0,0 +1,2 @@
+btitest
+nobtitest
diff --git a/tools/testing/selftests/arm64/bti/signal.c b/tools/testing/selftests/arm64/bti/signal.c
new file mode 100644
index 000000000..f3fd29b91
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/signal.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "system.h"
+#include "signal.h"
+
+int sigemptyset(sigset_t *s)
+{
+ unsigned int i;
+
+ for (i = 0; i < _NSIG_WORDS; ++i)
+ s->sig[i] = 0;
+
+ return 0;
+}
+
+int sigaddset(sigset_t *s, int n)
+{
+ if (n < 1 || n > _NSIG)
+ return -EINVAL;
+
+ s->sig[(n - 1) / _NSIG_BPW] |= 1UL << (n - 1) % _NSIG_BPW;
+ return 0;
+}
+
+int sigaction(int n, struct sigaction *sa, const struct sigaction *old)
+{
+ return syscall(__NR_rt_sigaction, n, sa, old, sizeof(sa->sa_mask));
+}
+
+int sigprocmask(int how, const sigset_t *mask, sigset_t *old)
+{
+ return syscall(__NR_rt_sigprocmask, how, mask, old, sizeof(*mask));
+}
diff --git a/tools/testing/selftests/arm64/bti/signal.h b/tools/testing/selftests/arm64/bti/signal.h
new file mode 100644
index 000000000..103457dc8
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/signal.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef SIGNAL_H
+#define SIGNAL_H
+
+#include <linux/signal.h>
+
+#include "system.h"
+
+typedef __sighandler_t sighandler_t;
+
+int sigemptyset(sigset_t *s);
+int sigaddset(sigset_t *s, int n);
+int sigaction(int n, struct sigaction *sa, const struct sigaction *old);
+int sigprocmask(int how, const sigset_t *mask, sigset_t *old);
+
+#endif /* ! SIGNAL_H */
diff --git a/tools/testing/selftests/arm64/bti/start.S b/tools/testing/selftests/arm64/bti/start.S
new file mode 100644
index 000000000..831f952e0
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/start.S
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "assembler.h"
+
+startfn _start
+ mov x0, sp
+ b start
+endfn
+
+emit_aarch64_feature_1_and
diff --git a/tools/testing/selftests/arm64/bti/syscall.S b/tools/testing/selftests/arm64/bti/syscall.S
new file mode 100644
index 000000000..8dde8b6f3
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/syscall.S
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "assembler.h"
+
+startfn syscall
+ bti c
+ mov w8, w0
+ mov x0, x1
+ mov x1, x2
+ mov x2, x3
+ mov x3, x4
+ mov x4, x5
+ mov x5, x6
+ mov x6, x7
+ svc #0
+ ret
+endfn
+
+emit_aarch64_feature_1_and
diff --git a/tools/testing/selftests/arm64/bti/system.c b/tools/testing/selftests/arm64/bti/system.c
new file mode 100644
index 000000000..6385d8d49
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/system.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "system.h"
+
+#include <asm/unistd.h>
+
+#include "compiler.h"
+
+void __noreturn exit(int n)
+{
+ syscall(__NR_exit, n);
+ __unreachable();
+}
+
+ssize_t write(int fd, const void *buf, size_t size)
+{
+ return syscall(__NR_write, fd, buf, size);
+}
diff --git a/tools/testing/selftests/arm64/bti/system.h b/tools/testing/selftests/arm64/bti/system.h
new file mode 100644
index 000000000..aca118589
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/system.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#ifndef SYSTEM_H
+#define SYSTEM_H
+
+#include <linux/types.h>
+#include <linux/stddef.h>
+
+typedef __kernel_size_t size_t;
+typedef __kernel_ssize_t ssize_t;
+
+#include <linux/errno.h>
+#include <asm/hwcap.h>
+#include <asm/ptrace.h>
+#include <asm/unistd.h>
+
+#include "compiler.h"
+
+long syscall(int nr, ...);
+
+void __noreturn exit(int n);
+ssize_t write(int fd, const void *buf, size_t size);
+
+#endif /* ! SYSTEM_H */
diff --git a/tools/testing/selftests/arm64/bti/test.c b/tools/testing/selftests/arm64/bti/test.c
new file mode 100644
index 000000000..2cd8dcee5
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/test.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019,2021 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "system.h"
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <linux/errno.h>
+#include <linux/auxvec.h>
+#include <linux/signal.h>
+#include <asm/sigcontext.h>
+#include <asm/ucontext.h>
+
+typedef struct ucontext ucontext_t;
+
+#include "btitest.h"
+#include "compiler.h"
+#include "signal.h"
+
+#define EXPECTED_TESTS 18
+
+static volatile unsigned int test_num = 1;
+static unsigned int test_passed;
+static unsigned int test_failed;
+static unsigned int test_skipped;
+
+static void fdputs(int fd, const char *str)
+{
+ size_t len = 0;
+ const char *p = str;
+
+ while (*p++)
+ ++len;
+
+ write(fd, str, len);
+}
+
+static void putstr(const char *str)
+{
+ fdputs(1, str);
+}
+
+static void putnum(unsigned int num)
+{
+ char c;
+
+ if (num / 10)
+ putnum(num / 10);
+
+ c = '0' + (num % 10);
+ write(1, &c, 1);
+}
+
+#define puttestname(test_name, trampoline_name) do { \
+ putstr(test_name); \
+ putstr("/"); \
+ putstr(trampoline_name); \
+} while (0)
+
+void print_summary(void)
+{
+ putstr("# Totals: pass:");
+ putnum(test_passed);
+ putstr(" fail:");
+ putnum(test_failed);
+ putstr(" xfail:0 xpass:0 skip:");
+ putnum(test_skipped);
+ putstr(" error:0\n");
+}
+
+static const char *volatile current_test_name;
+static const char *volatile current_trampoline_name;
+static volatile int sigill_expected, sigill_received;
+
+static void handler(int n, siginfo_t *si __always_unused,
+ void *uc_ __always_unused)
+{
+ ucontext_t *uc = uc_;
+
+ putstr("# \t[SIGILL in ");
+ puttestname(current_test_name, current_trampoline_name);
+ putstr(", BTYPE=");
+ write(1, &"00011011"[((uc->uc_mcontext.pstate & PSR_BTYPE_MASK)
+ >> PSR_BTYPE_SHIFT) * 2], 2);
+ if (!sigill_expected) {
+ putstr("]\n");
+ putstr("not ok ");
+ putnum(test_num);
+ putstr(" ");
+ puttestname(current_test_name, current_trampoline_name);
+ putstr("(unexpected SIGILL)\n");
+ print_summary();
+ exit(128 + n);
+ }
+
+ putstr(" (expected)]\n");
+ sigill_received = 1;
+ /* zap BTYPE so that resuming the faulting code will work */
+ uc->uc_mcontext.pstate &= ~PSR_BTYPE_MASK;
+}
+
+/* Does the system have BTI? */
+static bool have_bti;
+
+static void __do_test(void (*trampoline)(void (*)(void)),
+ void (*fn)(void),
+ const char *trampoline_name,
+ const char *name,
+ int expect_sigill)
+{
+ /*
+ * Branch Target exceptions should only happen for BTI
+ * binaries running on a system with BTI:
+ */
+ if (!BTI || !have_bti)
+ expect_sigill = 0;
+
+ sigill_expected = expect_sigill;
+ sigill_received = 0;
+ current_test_name = name;
+ current_trampoline_name = trampoline_name;
+
+ trampoline(fn);
+
+ if (expect_sigill && !sigill_received) {
+ putstr("not ok ");
+ test_failed++;
+ } else {
+ putstr("ok ");
+ test_passed++;
+ }
+ putnum(test_num++);
+ putstr(" ");
+ puttestname(name, trampoline_name);
+ putstr("\n");
+}
+
+#define do_test(expect_sigill_br_x0, \
+ expect_sigill_br_x16, \
+ expect_sigill_blr, \
+ name) \
+do { \
+ __do_test(call_using_br_x0, name, "call_using_br_x0", #name, \
+ expect_sigill_br_x0); \
+ __do_test(call_using_br_x16, name, "call_using_br_x16", #name, \
+ expect_sigill_br_x16); \
+ __do_test(call_using_blr, name, "call_using_blr", #name, \
+ expect_sigill_blr); \
+} while (0)
+
+void start(int *argcp)
+{
+ struct sigaction sa;
+ void *const *p;
+ const struct auxv_entry {
+ unsigned long type;
+ unsigned long val;
+ } *auxv;
+ unsigned long hwcap = 0, hwcap2 = 0;
+
+ putstr("TAP version 13\n");
+ putstr("1..");
+ putnum(EXPECTED_TESTS);
+ putstr("\n");
+
+ /* Gross hack for finding AT_HWCAP2 from the initial process stack: */
+ p = (void *const *)argcp + 1 + *argcp + 1; /* start of environment */
+ /* step over environment */
+ while (*p++)
+ ;
+ for (auxv = (const struct auxv_entry *)p; auxv->type != AT_NULL; ++auxv) {
+ switch (auxv->type) {
+ case AT_HWCAP:
+ hwcap = auxv->val;
+ break;
+ case AT_HWCAP2:
+ hwcap2 = auxv->val;
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (hwcap & HWCAP_PACA)
+ putstr("# HWCAP_PACA present\n");
+ else
+ putstr("# HWCAP_PACA not present\n");
+
+ if (hwcap2 & HWCAP2_BTI) {
+ putstr("# HWCAP2_BTI present\n");
+ if (!(hwcap & HWCAP_PACA))
+ putstr("# Bad hardware? Expect problems.\n");
+ have_bti = true;
+ } else {
+ putstr("# HWCAP2_BTI not present\n");
+ have_bti = false;
+ }
+
+ putstr("# Test binary");
+ if (!BTI)
+ putstr(" not");
+ putstr(" built for BTI\n");
+
+ sa.sa_handler = (sighandler_t)(void *)handler;
+ sa.sa_flags = SA_SIGINFO;
+ sigemptyset(&sa.sa_mask);
+ sigaction(SIGILL, &sa, NULL);
+ sigaddset(&sa.sa_mask, SIGILL);
+ sigprocmask(SIG_UNBLOCK, &sa.sa_mask, NULL);
+
+ do_test(1, 1, 1, nohint_func);
+ do_test(1, 1, 1, bti_none_func);
+ do_test(1, 0, 0, bti_c_func);
+ do_test(0, 0, 1, bti_j_func);
+ do_test(0, 0, 0, bti_jc_func);
+ do_test(1, 0, 0, paciasp_func);
+
+ print_summary();
+
+ if (test_num - 1 != EXPECTED_TESTS)
+ putstr("# WARNING - EXPECTED TEST COUNT WRONG\n");
+
+ if (test_failed)
+ exit(1);
+ else
+ exit(0);
+}
diff --git a/tools/testing/selftests/arm64/bti/teststubs.S b/tools/testing/selftests/arm64/bti/teststubs.S
new file mode 100644
index 000000000..b62c8c35f
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/teststubs.S
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "assembler.h"
+
+startfn bti_none_func
+ bti
+ ret
+endfn
+
+startfn bti_c_func
+ bti c
+ ret
+endfn
+
+startfn bti_j_func
+ bti j
+ ret
+endfn
+
+startfn bti_jc_func
+ bti jc
+ ret
+endfn
+
+startfn paciasp_func
+ paciasp
+ autiasp
+ ret
+endfn
+
+startfn nohint_func
+ ret
+endfn
+
+emit_aarch64_feature_1_and
diff --git a/tools/testing/selftests/arm64/bti/trampoline.S b/tools/testing/selftests/arm64/bti/trampoline.S
new file mode 100644
index 000000000..09beb3f36
--- /dev/null
+++ b/tools/testing/selftests/arm64/bti/trampoline.S
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Arm Limited
+ * Original author: Dave Martin <Dave.Martin@arm.com>
+ */
+
+#include "assembler.h"
+
+startfn call_using_br_x0
+ bti c
+ br x0
+endfn
+
+startfn call_using_br_x16
+ bti c
+ mov x16, x0
+ br x16
+endfn
+
+startfn call_using_blr
+ paciasp
+ stp x29, x30, [sp, #-16]!
+ blr x0
+ ldp x29, x30, [sp], #16
+ autiasp
+ ret
+endfn
+
+emit_aarch64_feature_1_and