Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

5 files changed, 415 insertions, 0 deletions

diff --git a/drivers/firmware/smccc/Kconfig b/drivers/firmware/smccc/Kconfig
new file mode 100644
index 000000000..15e746617
--- /dev/null
+++ b/drivers/firmware/smccc/Kconfig
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config HAVE_ARM_SMCCC
+	bool
+	help
+	  Include support for the Secure Monitor Call (SMC) and Hypervisor
+	  Call (HVC) instructions on Armv7 and above architectures.
+
+config HAVE_ARM_SMCCC_DISCOVERY
+	bool
+	depends on ARM_PSCI_FW
+	default y
+	help
+	 SMCCC v1.0 lacked discoverability and hence PSCI v1.0 was updated
+	 to add SMCCC discovery mechanism though the PSCI firmware
+	 implementation of PSCI_FEATURES(SMCCC_VERSION) which returns
+	 success on firmware compliant to SMCCC v1.1 and above.
+
+config ARM_SMCCC_SOC_ID
+	bool "SoC bus device for the ARM SMCCC SOC_ID"
+	depends on HAVE_ARM_SMCCC_DISCOVERY
+	default y
+	select SOC_BUS
+	help
+	  Include support for the SoC bus on the ARM SMCCC firmware based
+	  platforms providing some sysfs information about the SoC variant.
diff --git a/drivers/firmware/smccc/Makefile b/drivers/firmware/smccc/Makefile
new file mode 100644
index 000000000..40d19144a
--- /dev/null
+++ b/drivers/firmware/smccc/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY)	+= smccc.o kvm_guest.o
+obj-$(CONFIG_ARM_SMCCC_SOC_ID)	+= soc_id.o
diff --git a/drivers/firmware/smccc/kvm_guest.c b/drivers/firmware/smccc/kvm_guest.c
new file mode 100644
index 000000000..49e1de83d
--- /dev/null
+++ b/drivers/firmware/smccc/kvm_guest.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "smccc: KVM: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/bitmap.h>
+#include <linux/cache.h>
+#include <linux/kernel.h>
+#include <linux/memblock.h>
+#include <linux/string.h>
+
+#include <uapi/linux/psci.h>
+
+#include <asm/hypervisor.h>
+
+static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };
+
+void __init kvm_init_hyp_services(void)
+{
+	uuid_t kvm_uuid = ARM_SMCCC_VENDOR_HYP_UID_KVM;
+	struct arm_smccc_res res;
+	u32 val[4];
+
+	if (!arm_smccc_hypervisor_has_uuid(&kvm_uuid))
+		return;
+
+	memset(&res, 0, sizeof(res));
+	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, &res);
+
+	val[0] = lower_32_bits(res.a0);
+	val[1] = lower_32_bits(res.a1);
+	val[2] = lower_32_bits(res.a2);
+	val[3] = lower_32_bits(res.a3);
+
+	bitmap_from_arr32(__kvm_arm_hyp_services, val, ARM_SMCCC_KVM_NUM_FUNCS);
+
+	pr_info("hypervisor services detected (0x%08lx 0x%08lx 0x%08lx 0x%08lx)\n",
+		 res.a3, res.a2, res.a1, res.a0);
+
+	kvm_arch_init_hyp_services();
+}
+
+bool kvm_arm_hyp_service_available(u32 func_id)
+{
+	if (func_id >= ARM_SMCCC_KVM_NUM_FUNCS)
+		return false;
+
+	return test_bit(func_id, __kvm_arm_hyp_services);
+}
+EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);
+
+#ifdef CONFIG_ARM64
+void  __init kvm_arm_target_impl_cpu_init(void)
+{
+	int i;
+	u32 ver;
+	u64 max_cpus;
+	struct arm_smccc_res res;
+	struct target_impl_cpu *target;
+
+	if (!kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_VER) ||
+	    !kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_CPUS))
+		return;
+
+	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_VER_FUNC_ID,
+			     0, &res);
+	if (res.a0 != SMCCC_RET_SUCCESS)
+		return;
+
+	/* Version info is in lower 32 bits and is in SMMCCC_VERSION format */
+	ver = lower_32_bits(res.a1);
+	if (PSCI_VERSION_MAJOR(ver) != 1) {
+		pr_warn("Unsupported target CPU implementation version v%d.%d\n",
+			PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
+		return;
+	}
+
+	if (!res.a2) {
+		pr_warn("No target implementation CPUs specified\n");
+		return;
+	}
+
+	max_cpus = res.a2;
+	target = memblock_alloc(sizeof(*target) * max_cpus,  __alignof__(*target));
+	if (!target) {
+		pr_warn("Not enough memory for struct target_impl_cpu\n");
+		return;
+	}
+
+	for (i = 0; i < max_cpus; i++) {
+		arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID,
+				     i, 0, 0, &res);
+		if (res.a0 != SMCCC_RET_SUCCESS) {
+			pr_warn("Discovering target implementation CPUs failed\n");
+			goto mem_free;
+		}
+		target[i].midr = res.a1;
+		target[i].revidr = res.a2;
+		target[i].aidr = res.a3;
+	}
+
+	if (!cpu_errata_set_target_impl(max_cpus, target)) {
+		pr_warn("Failed to set target implementation CPUs\n");
+		goto mem_free;
+	}
+
+	pr_info("Number of target implementation CPUs is %lld\n", max_cpus);
+	return;
+
+mem_free:
+	memblock_free(target, sizeof(*target) * max_cpus);
+}
+#endif
diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c
new file mode 100644
index 000000000..bdee057db
--- /dev/null
+++ b/drivers/firmware/smccc/smccc.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Arm Limited
+ */
+
+#define pr_fmt(fmt) "smccc: " fmt
+
+#include <linux/cache.h>
+#include <linux/init.h>
+#include <linux/arm-smccc.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <asm/archrandom.h>
+
+static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
+static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
+
+bool __ro_after_init smccc_trng_available = false;
+s32 __ro_after_init smccc_soc_id_version = SMCCC_RET_NOT_SUPPORTED;
+s32 __ro_after_init smccc_soc_id_revision = SMCCC_RET_NOT_SUPPORTED;
+
+void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
+{
+	struct arm_smccc_res res;
+
+	smccc_version = version;
+	smccc_conduit = conduit;
+
+	smccc_trng_available = smccc_probe_trng();
+
+	if ((smccc_version >= ARM_SMCCC_VERSION_1_2) &&
+	    (smccc_conduit != SMCCC_CONDUIT_NONE)) {
+		arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+				     ARM_SMCCC_ARCH_SOC_ID, &res);
+		if ((s32)res.a0 >= 0) {
+			arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res);
+			smccc_soc_id_version = (s32)res.a0;
+			arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res);
+			smccc_soc_id_revision = (s32)res.a0;
+		}
+	}
+}
+
+enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)
+{
+	if (smccc_version < ARM_SMCCC_VERSION_1_1)
+		return SMCCC_CONDUIT_NONE;
+
+	return smccc_conduit;
+}
+EXPORT_SYMBOL_GPL(arm_smccc_1_1_get_conduit);
+
+u32 arm_smccc_get_version(void)
+{
+	return smccc_version;
+}
+EXPORT_SYMBOL_GPL(arm_smccc_get_version);
+
+s32 arm_smccc_get_soc_id_version(void)
+{
+	return smccc_soc_id_version;
+}
+
+s32 arm_smccc_get_soc_id_revision(void)
+{
+	return smccc_soc_id_revision;
+}
+EXPORT_SYMBOL_GPL(arm_smccc_get_soc_id_revision);
+
+bool arm_smccc_hypervisor_has_uuid(const uuid_t *hyp_uuid)
+{
+	struct arm_smccc_res res = {};
+	uuid_t uuid;
+
+	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
+	if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+		return false;
+
+	uuid = smccc_res_to_uuid(res.a0, res.a1, res.a2, res.a3);
+	return uuid_equal(&uuid, hyp_uuid);
+}
+EXPORT_SYMBOL_GPL(arm_smccc_hypervisor_has_uuid);
+
+static int __init smccc_devices_init(void)
+{
+	struct platform_device *pdev;
+
+	if (smccc_trng_available) {
+		pdev = platform_device_register_simple("smccc_trng", -1,
+						       NULL, 0);
+		if (IS_ERR(pdev))
+			pr_err("smccc_trng: could not register device: %ld\n",
+			       PTR_ERR(pdev));
+	}
+
+	return 0;
+}
+device_initcall(smccc_devices_init);
diff --git a/drivers/firmware/smccc/soc_id.c b/drivers/firmware/smccc/soc_id.c
new file mode 100644
index 000000000..a909d5e6d
--- /dev/null
+++ b/drivers/firmware/smccc/soc_id.c
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Arm Limited
+ */
+
+#define pr_fmt(fmt) "SMCCC: SOC_ID: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#define SMCCC_SOC_ID_JEP106_BANK_IDX_MASK	GENMASK(30, 24)
+/*
+ * As per the SMC Calling Convention specification v1.2 (ARM DEN 0028C)
+ * Section 7.4 SMCCC_ARCH_SOC_ID bits[23:16] are JEP-106 identification
+ * code with parity bit for the SiP. We can drop the parity bit.
+ */
+#define SMCCC_SOC_ID_JEP106_ID_CODE_MASK	GENMASK(22, 16)
+#define SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK	GENMASK(15, 0)
+
+#define JEP106_BANK_CONT_CODE(x)	\
+	(u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_BANK_IDX_MASK, (x)))
+#define JEP106_ID_CODE(x)	\
+	(u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_ID_CODE_MASK, (x)))
+#define IMP_DEF_SOC_ID(x)	\
+	(u16)(FIELD_GET(SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK, (x)))
+
+static struct soc_device *soc_dev;
+static struct soc_device_attribute *soc_dev_attr;
+
+#ifdef CONFIG_ARM64
+
+static char __ro_after_init smccc_soc_id_name[136] = "";
+
+static inline void str_fragment_from_reg(char *dst, unsigned long reg)
+{
+	dst[0] = (reg >> 0)  & 0xff;
+	dst[1] = (reg >> 8)  & 0xff;
+	dst[2] = (reg >> 16) & 0xff;
+	dst[3] = (reg >> 24) & 0xff;
+	dst[4] = (reg >> 32) & 0xff;
+	dst[5] = (reg >> 40) & 0xff;
+	dst[6] = (reg >> 48) & 0xff;
+	dst[7] = (reg >> 56) & 0xff;
+}
+
+static char __init *smccc_soc_name_init(void)
+{
+	struct arm_smccc_1_2_regs args;
+	struct arm_smccc_1_2_regs res;
+	size_t len;
+
+	/*
+	 * Issue Number 1.6 of the Arm SMC Calling Convention
+	 * specification introduces an optional "name" string
+	 * to the ARM_SMCCC_ARCH_SOC_ID function.  Fetch it if
+	 * available.
+	 */
+	args.a0 = ARM_SMCCC_ARCH_SOC_ID64;
+	args.a1 = 2;    /* SOC_ID name */
+	arm_smccc_1_2_invoke(&args, &res);
+
+	if ((u32)res.a0 == 0) {
+		/*
+		 * Copy res.a1..res.a17 to the smccc_soc_id_name string
+		 * 8 bytes at a time.  As per Issue 1.6 of the Arm SMC
+		 * Calling Convention, the string will be NUL terminated
+		 * and padded, from the end of the string to the end of the
+		 * 136 byte buffer, with NULs.
+		 */
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 0, res.a1);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 1, res.a2);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 2, res.a3);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 3, res.a4);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 4, res.a5);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 5, res.a6);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 6, res.a7);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 7, res.a8);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 8, res.a9);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 9, res.a10);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 10, res.a11);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 11, res.a12);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 12, res.a13);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 13, res.a14);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 14, res.a15);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 15, res.a16);
+		str_fragment_from_reg(smccc_soc_id_name + 8 * 16, res.a17);
+
+		len = strnlen(smccc_soc_id_name, sizeof(smccc_soc_id_name));
+		if (len) {
+			if (len == sizeof(smccc_soc_id_name))
+				pr_warn(FW_BUG "Ignoring improperly formatted name\n");
+			else
+				return smccc_soc_id_name;
+		}
+	}
+
+	return NULL;
+}
+
+#else
+
+static char __init *smccc_soc_name_init(void)
+{
+	return NULL;
+}
+
+#endif
+
+static int __init smccc_soc_init(void)
+{
+	int soc_id_rev, soc_id_version;
+	static char soc_id_str[20], soc_id_rev_str[12];
+	static char soc_id_jep106_id_str[12];
+
+	if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
+		return 0;
+
+	soc_id_version = arm_smccc_get_soc_id_version();
+	if (soc_id_version == SMCCC_RET_NOT_SUPPORTED) {
+		pr_info("ARCH_SOC_ID not implemented, skipping ....\n");
+		return 0;
+	}
+
+	if (soc_id_version < 0) {
+		pr_err("Invalid SoC Version: %x\n", soc_id_version);
+		return -EINVAL;
+	}
+
+	soc_id_rev = arm_smccc_get_soc_id_revision();
+	if (soc_id_rev < 0) {
+		pr_err("Invalid SoC Revision: %x\n", soc_id_rev);
+		return -EINVAL;
+	}
+
+	soc_dev_attr = kzalloc_obj(*soc_dev_attr);
+	if (!soc_dev_attr)
+		return -ENOMEM;
+
+	sprintf(soc_id_rev_str, "0x%08x", soc_id_rev);
+	sprintf(soc_id_jep106_id_str, "jep106:%02x%02x",
+		JEP106_BANK_CONT_CODE(soc_id_version),
+		JEP106_ID_CODE(soc_id_version));
+	sprintf(soc_id_str, "%s:%04x", soc_id_jep106_id_str,
+		IMP_DEF_SOC_ID(soc_id_version));
+
+	soc_dev_attr->soc_id = soc_id_str;
+	soc_dev_attr->revision = soc_id_rev_str;
+	soc_dev_attr->family = soc_id_jep106_id_str;
+	soc_dev_attr->machine = smccc_soc_name_init();
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+		kfree(soc_dev_attr);
+		return PTR_ERR(soc_dev);
+	}
+
+	pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id,
+		soc_dev_attr->revision);
+
+	return 0;
+}
+module_init(smccc_soc_init);
+
+static void __exit smccc_soc_exit(void)
+{
+	if (soc_dev)
+		soc_device_unregister(soc_dev);
+	kfree(soc_dev_attr);
+}
+module_exit(smccc_soc_exit);