Merge tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore updates from Kees Cook:
 "Improvements and fixes to pstore subsystem:

   - add additional checks for bad platform data

   - remove bounce buffer in console writer

   - protect read/unlink race with a mutex

   - correctly give up during dump locking failures

   - increase ftrace bandwidth by splitting ftrace buffers per CPU"

* tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  ramoops: add pdata NULL check to ramoops_probe
  pstore: Convert console write to use ->write_buf
  pstore: Protect unlink with read_mutex
  pstore: Use global ftrace filters for function trace filtering
  ftrace: Provide API to use global filtering for ftrace ops
  pstore: Clarify context field przs as dprzs
  pstore: improve error report for failed setup
  pstore: Merge per-CPU ftrace records into one
  pstore: Add ftrace timestamp counter
  ramoops: Split ftrace buffer space into per-CPU zones
  pstore: Make ramoops_init_przs generic for other prz arrays
  pstore: Allow prz to control need for locking
  pstore: Warn on PSTORE_TYPE_PMSG using deprecated function
  pstore: Make spinlock per zone instead of global
  pstore: Actually give up during locking failure

Documentation/devicetree/bindings/reserved-memory/ramoops.txt

@@ -46,3 +46,6 @@ Optional properties:
   (defaults to buffered mappings)
 
 - no-dump-oops: if present, only dump panics (defaults to panics and oops)
+
+- flags: if present, pass ramoops behavioral flags (defaults to 0,
+  see include/linux/pstore_ram.h RAMOOPS_FLAG_* for flag values).

fs/pstore/ftrace.c

@@ -27,6 +27,9 @@
 #include <asm/barrier.h>
 #include "internal.h"
 
+/* This doesn't need to be atomic: speed is chosen over correctness here. */
+static u64 pstore_ftrace_stamp;
+
 static void notrace pstore_ftrace_call(unsigned long ip,
 				       unsigned long parent_ip,
 				       struct ftrace_ops *op,
@@ -42,6 +45,7 @@ static void notrace pstore_ftrace_call(unsigned long ip,
 
 	rec.ip = ip;
 	rec.parent_ip = parent_ip;
+	pstore_ftrace_write_timestamp(&rec, pstore_ftrace_stamp++);
 	pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id());
 	psinfo->write_buf(PSTORE_TYPE_FTRACE, 0, NULL, 0, (void *)&rec,
 			  0, sizeof(rec), psinfo);
@@ -71,10 +75,13 @@ static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf,
 	if (!on ^ pstore_ftrace_enabled)
 		goto out;
 
-	if (on)
+	if (on) {
+		ftrace_ops_set_global_filter(&pstore_ftrace_ops);
 		ret = register_ftrace_function(&pstore_ftrace_ops);
-	else
+	} else {
 		ret = unregister_ftrace_function(&pstore_ftrace_ops);
+	}
+
 	if (ret) {
 		pr_err("%s: unable to %sregister ftrace ops: %zd\n",
 		       __func__, on ? "" : "un", ret);

fs/pstore/inode.c

@@ -107,9 +107,11 @@ static int pstore_ftrace_seq_show(struct seq_file *s, void *v)
 	struct pstore_ftrace_seq_data *data = v;
 	struct pstore_ftrace_record *rec = (void *)(ps->data + data->off);
 
-	seq_printf(s, "%d %08lx  %08lx  %pf <- %pF\n",
-		pstore_ftrace_decode_cpu(rec), rec->ip, rec->parent_ip,
-		(void *)rec->ip, (void *)rec->parent_ip);
+	seq_printf(s, "CPU:%d ts:%llu %08lx  %08lx  %pf <- %pF\n",
+		   pstore_ftrace_decode_cpu(rec),
+		   pstore_ftrace_read_timestamp(rec),
+		   rec->ip, rec->parent_ip, (void *)rec->ip,
+		   (void *)rec->parent_ip);
 
 	return 0;
 }
@@ -197,11 +199,14 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
 	if (err)
 		return err;
 
-	if (p->psi->erase)
+	if (p->psi->erase) {
+		mutex_lock(&p->psi->read_mutex);
 		p->psi->erase(p->type, p->id, p->count,
 			      d_inode(dentry)->i_ctime, p->psi);
-	else
+		mutex_unlock(&p->psi->read_mutex);
+	} else {
 		return -EPERM;
+	}
 
 	return simple_unlink(dir, dentry);
 }

fs/pstore/internal.h

@@ -5,40 +5,6 @@
 #include <linux/time.h>
 #include <linux/pstore.h>
 
-#if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)
-#define PSTORE_CPU_IN_IP 0x1
-#elif NR_CPUS <= 4 && defined(CONFIG_ARM)
-#define PSTORE_CPU_IN_IP 0x3
-#endif
-
-struct pstore_ftrace_record {
-	unsigned long ip;
-	unsigned long parent_ip;
-#ifndef PSTORE_CPU_IN_IP
-	unsigned int cpu;
-#endif
-};
-
-static inline void
-pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
-{
-#ifndef PSTORE_CPU_IN_IP
-	rec->cpu = cpu;
-#else
-	rec->ip |= cpu;
-#endif
-}
-
-static inline unsigned int
-pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
-{
-#ifndef PSTORE_CPU_IN_IP
-	return rec->cpu;
-#else
-	return rec->ip & PSTORE_CPU_IN_IP;
-#endif
-}
-
 #ifdef CONFIG_PSTORE_FTRACE
 extern void pstore_register_ftrace(void);
 extern void pstore_unregister_ftrace(void);

fs/pstore/platform.c

@@ -493,6 +493,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
 		if (!is_locked) {
 			pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
 				       , in_nmi() ? "NMI" : why);
+			return;
 		}
 	} else {
 		spin_lock_irqsave(&psinfo->buf_lock, flags);
@@ -584,8 +585,8 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c)
 		} else {
 			spin_lock_irqsave(&psinfo->buf_lock, flags);
 		}
-		memcpy(psinfo->buf, s, c);
-		psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, 0, c, psinfo);
+		psinfo->write_buf(PSTORE_TYPE_CONSOLE, 0, &id, 0,
+				  s, 0, c, psinfo);
 		spin_unlock_irqrestore(&psinfo->buf_lock, flags);
 		s += c;
 		c = e - s;

fs/pstore/ram_core.c

@@ -48,16 +48,15 @@ static inline size_t buffer_start(struct persistent_ram_zone *prz)
 	return atomic_read(&prz->buffer->start);
 }
 
-static DEFINE_RAW_SPINLOCK(buffer_lock);
-
 /* increase and wrap the start pointer, returning the old value */
 static size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
 {
 	int old;
 	int new;
-	unsigned long flags;
+	unsigned long flags = 0;
 
-	raw_spin_lock_irqsave(&buffer_lock, flags);
+	if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+		raw_spin_lock_irqsave(&prz->buffer_lock, flags);
 
 	old = atomic_read(&prz->buffer->start);
 	new = old + a;
@@ -65,7 +64,8 @@ static size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
 		new -= prz->buffer_size;
 	atomic_set(&prz->buffer->start, new);
 
-	raw_spin_unlock_irqrestore(&buffer_lock, flags);
+	if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+		raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
 
 	return old;
 }
@@ -75,9 +75,10 @@ static void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
 {
 	size_t old;
 	size_t new;
-	unsigned long flags;
+	unsigned long flags = 0;
 
-	raw_spin_lock_irqsave(&buffer_lock, flags);
+	if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+		raw_spin_lock_irqsave(&prz->buffer_lock, flags);
 
 	old = atomic_read(&prz->buffer->size);
 	if (old == prz->buffer_size)
@@ -89,7 +90,8 @@ static void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
 	atomic_set(&prz->buffer->size, new);
 
 exit:
-	raw_spin_unlock_irqrestore(&buffer_lock, flags);
+	if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+		raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
 }
 
 static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
@@ -465,7 +467,8 @@ static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
 }
 
 static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
-				    struct persistent_ram_ecc_info *ecc_info)
+				    struct persistent_ram_ecc_info *ecc_info,
+				    unsigned long flags)
 {
 	int ret;
 
@@ -493,6 +496,8 @@ static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
 
 	prz->buffer->sig = sig;
 	persistent_ram_zap(prz);
+	prz->buffer_lock = __RAW_SPIN_LOCK_UNLOCKED(buffer_lock);
+	prz->flags = flags;
 
 	return 0;
 }
@@ -517,7 +522,7 @@ void persistent_ram_free(struct persistent_ram_zone *prz)
 
 struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
 			u32 sig, struct persistent_ram_ecc_info *ecc_info,
-			unsigned int memtype)
+			unsigned int memtype, u32 flags)
 {
 	struct persistent_ram_zone *prz;
 	int ret = -ENOMEM;
@@ -532,7 +537,7 @@ struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
 	if (ret)
 		goto err;
 
-	ret = persistent_ram_post_init(prz, sig, ecc_info);
+	ret = persistent_ram_post_init(prz, sig, ecc_info, flags);
 	if (ret)
 		goto err;
 

include/linux/ftrace.h

@@ -398,6 +398,7 @@ int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
 void ftrace_free_filter(struct ftrace_ops *ops);
+void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
 
 int register_ftrace_command(struct ftrace_func_command *cmd);
 int unregister_ftrace_command(struct ftrace_func_command *cmd);
@@ -645,6 +646,7 @@ static inline unsigned long ftrace_location(unsigned long ip)
 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
 #define ftrace_free_filter(ops) do { } while (0)
+#define ftrace_ops_set_global_filter(ops) do { } while (0)
 
 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 			    size_t cnt, loff_t *ppos) { return -ENODEV; }

include/linux/pstore.h

@@ -89,4 +89,80 @@ extern int pstore_register(struct pstore_info *);
 extern void pstore_unregister(struct pstore_info *);
 extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);
 
+struct pstore_ftrace_record {
+	unsigned long ip;
+	unsigned long parent_ip;
+	u64 ts;
+};
+
+/*
+ * ftrace related stuff: Both backends and frontends need these so expose
+ * them here.
+ */
+
+#if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)
+#define PSTORE_CPU_IN_IP 0x1
+#elif NR_CPUS <= 4 && defined(CONFIG_ARM)
+#define PSTORE_CPU_IN_IP 0x3
+#endif
+
+#define TS_CPU_SHIFT 8
+#define TS_CPU_MASK (BIT(TS_CPU_SHIFT) - 1)
+
+/*
+ * If CPU number can be stored in IP, store it there, otherwise store it in
+ * the time stamp. This means more timestamp resolution is available when
+ * the CPU can be stored in the IP.
+ */
+#ifdef PSTORE_CPU_IN_IP
+static inline void
+pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
+{
+	rec->ip |= cpu;
+}
+
+static inline unsigned int
+pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
+{
+	return rec->ip & PSTORE_CPU_IN_IP;
+}
+
+static inline u64
+pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
+{
+	return rec->ts;
+}
+
+static inline void
+pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
+{
+	rec->ts = val;
+}
+#else
+static inline void
+pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
+{
+	rec->ts &= ~(TS_CPU_MASK);
+	rec->ts |= cpu;
+}
+
+static inline unsigned int
+pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
+{
+	return rec->ts & TS_CPU_MASK;
+}
+
+static inline u64
+pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
+{
+	return rec->ts >> TS_CPU_SHIFT;
+}
+
+static inline void
+pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
+{
+	rec->ts = (rec->ts & TS_CPU_MASK) | (val << TS_CPU_SHIFT);
+}
+#endif
+
 #endif /*_LINUX_PSTORE_H*/

include/linux/pstore_ram.h

@@ -24,6 +24,13 @@
 #include <linux/list.h>
 #include <linux/types.h>
 
+/*
+ * Choose whether access to the RAM zone requires locking or not.  If a zone
+ * can be written to from different CPUs like with ftrace for example, then
+ * PRZ_FLAG_NO_LOCK is used. For all other cases, locking is required.
+ */
+#define PRZ_FLAG_NO_LOCK	BIT(0)
+
 struct persistent_ram_buffer;
 struct rs_control;
 
@@ -40,6 +47,8 @@ struct persistent_ram_zone {
 	void *vaddr;
 	struct persistent_ram_buffer *buffer;
 	size_t buffer_size;
+	u32 flags;
+	raw_spinlock_t buffer_lock;
 
 	/* ECC correction */
 	char *par_buffer;
@@ -55,7 +64,7 @@ struct persistent_ram_zone {
 
 struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
 			u32 sig, struct persistent_ram_ecc_info *ecc_info,
-			unsigned int memtype);
+			unsigned int memtype, u32 flags);
 void persistent_ram_free(struct persistent_ram_zone *prz);
 void persistent_ram_zap(struct persistent_ram_zone *prz);
 
@@ -77,6 +86,8 @@ ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
  * @mem_address	physical memory address to contain ramoops
  */
 
+#define RAMOOPS_FLAG_FTRACE_PER_CPU	BIT(0)
+
 struct ramoops_platform_data {
 	unsigned long	mem_size;
 	phys_addr_t	mem_address;
@@ -86,6 +97,7 @@ struct ramoops_platform_data {
 	unsigned long	ftrace_size;
 	unsigned long	pmsg_size;
 	int		dump_oops;
+	u32		flags;
 	struct persistent_ram_ecc_info ecc_info;
 };
 

kernel/trace/ftrace.c

@@ -4258,6 +4258,23 @@ int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
 }
 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
 
+/**
+ * ftrace_ops_set_global_filter - setup ops to use global filters
+ * @ops - the ops which will use the global filters
+ *
+ * ftrace users who need global function trace filtering should call this.
+ * It can set the global filter only if ops were not initialized before.
+ */
+void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
+{
+	if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
+		return;
+
+	ftrace_ops_init(ops);
+	ops->func_hash = &global_ops.local_hash;
+}
+EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
+
 static int
 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
 		 int reset, int enable)