Merge tag 'for-v3.7' of git://git.infradead.org/users/cbou/linux-pstore
Pull pstore changes from Anton Vorontsov:
1) We no longer ad-hoc to the function tracer "high level"
infrastructure and no longer use its debugfs knobs. The change
slightly touches kernel/trace directory, but it got the needed ack
from Steven Rostedt:
http://lkml.org/lkml/2012/8/21/688
2) Added maintainers entry;
3) A bunch of fixes, nothing special.
* tag 'for-v3.7' of git://git.infradead.org/users/cbou/linux-pstore:
pstore: Avoid recursive spinlocks in the oops_in_progress case
pstore/ftrace: Convert to its own enable/disable debugfs knob
pstore/ram: Add missing platform_device_unregister
MAINTAINERS: Add pstore maintainers
pstore/ram: Mark ramoops_pstore_write_buf() as notrace
pstore/ram: Fix printk format warning
pstore/ram: Fix possible NULL dereference
diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt
index 197ad59..69b3cac 100644
--- a/Documentation/ramoops.txt
+++ b/Documentation/ramoops.txt
@@ -102,9 +102,7 @@
file. Here is an example of usage:
# mount -t debugfs debugfs /sys/kernel/debug/
- # cd /sys/kernel/debug/tracing
- # echo function > current_tracer
- # echo 1 > options/func_pstore
+ # echo 1 > /sys/kernel/debug/pstore/record_ftrace
# reboot -f
[...]
# mount -t pstore pstore /mnt/
diff --git a/MAINTAINERS b/MAINTAINERS
index 42c2264a..4b58d54 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5550,6 +5550,18 @@
S: Maintained
F: drivers/block/ps3vram.c
+PSTORE FILESYSTEM
+M: Anton Vorontsov <cbouatmailru@gmail.com>
+M: Colin Cross <ccross@android.com>
+M: Kees Cook <keescook@chromium.org>
+M: Tony Luck <tony.luck@intel.com>
+S: Maintained
+T: git git://git.infradead.org/users/cbou/linux-pstore.git
+F: fs/pstore/
+F: include/linux/pstore*
+F: drivers/firmware/efivars.c
+F: drivers/acpi/apei/erst.c
+
PTP HARDWARE CLOCK SUPPORT
M: Richard Cochran <richardcochran@gmail.com>
S: Maintained
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index d39bb5c..ca71db6 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -23,6 +23,7 @@
bool "Persistent function tracer"
depends on PSTORE
depends on FUNCTION_TRACER
+ depends on DEBUG_FS
help
With this option kernel traces function calls into a persistent
ram buffer that can be decoded and dumped after reboot through
diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c
index a130d48..2d57e1a 100644
--- a/fs/pstore/ftrace.c
+++ b/fs/pstore/ftrace.c
@@ -17,19 +17,113 @@
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/atomic.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/ftrace.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/err.h>
+#include <linux/cache.h>
#include <asm/barrier.h>
#include "internal.h"
-void notrace pstore_ftrace_call(unsigned long ip, unsigned long parent_ip)
+static void notrace pstore_ftrace_call(unsigned long ip,
+ unsigned long parent_ip)
{
+ unsigned long flags;
struct pstore_ftrace_record rec = {};
if (unlikely(oops_in_progress))
return;
+ local_irq_save(flags);
+
rec.ip = ip;
rec.parent_ip = parent_ip;
pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id());
psinfo->write_buf(PSTORE_TYPE_FTRACE, 0, NULL, 0, (void *)&rec,
sizeof(rec), psinfo);
+
+ local_irq_restore(flags);
+}
+
+static struct ftrace_ops pstore_ftrace_ops __read_mostly = {
+ .func = pstore_ftrace_call,
+};
+
+static DEFINE_MUTEX(pstore_ftrace_lock);
+static bool pstore_ftrace_enabled;
+
+static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ u8 on;
+ ssize_t ret;
+
+ ret = kstrtou8_from_user(buf, count, 2, &on);
+ if (ret)
+ return ret;
+
+ mutex_lock(&pstore_ftrace_lock);
+
+ if (!on ^ pstore_ftrace_enabled)
+ goto out;
+
+ if (on)
+ ret = register_ftrace_function(&pstore_ftrace_ops);
+ else
+ ret = unregister_ftrace_function(&pstore_ftrace_ops);
+ if (ret) {
+ pr_err("%s: unable to %sregister ftrace ops: %zd\n",
+ __func__, on ? "" : "un", ret);
+ goto err;
+ }
+
+ pstore_ftrace_enabled = on;
+out:
+ ret = count;
+err:
+ mutex_unlock(&pstore_ftrace_lock);
+
+ return ret;
+}
+
+static ssize_t pstore_ftrace_knob_read(struct file *f, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char val[] = { '0' + pstore_ftrace_enabled, '\n' };
+
+ return simple_read_from_buffer(buf, count, ppos, val, sizeof(val));
+}
+
+static const struct file_operations pstore_knob_fops = {
+ .open = simple_open,
+ .read = pstore_ftrace_knob_read,
+ .write = pstore_ftrace_knob_write,
+};
+
+void pstore_register_ftrace(void)
+{
+ struct dentry *dir;
+ struct dentry *file;
+
+ if (!psinfo->write_buf)
+ return;
+
+ dir = debugfs_create_dir("pstore", NULL);
+ if (!dir) {
+ pr_err("%s: unable to create pstore directory\n", __func__);
+ return;
+ }
+
+ file = debugfs_create_file("record_ftrace", 0600, dir, NULL,
+ &pstore_knob_fops);
+ if (!file) {
+ pr_err("%s: unable to create record_ftrace file\n", __func__);
+ goto err_file;
+ }
+
+ return;
+err_file:
+ debugfs_remove(dir);
}
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index 0d0d3b7..4847f58 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -39,6 +39,12 @@
#endif
}
+#ifdef CONFIG_PSTORE_FTRACE
+extern void pstore_register_ftrace(void);
+#else
+static inline void pstore_register_ftrace(void) {}
+#endif
+
extern struct pstore_info *psinfo;
extern void pstore_set_kmsg_bytes(int);
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 29996e8..a40da07 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -164,7 +164,13 @@
if (c > psinfo->bufsize)
c = psinfo->bufsize;
- spin_lock_irqsave(&psinfo->buf_lock, flags);
+
+ if (oops_in_progress) {
+ if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
+ break;
+ } else {
+ spin_lock_irqsave(&psinfo->buf_lock, flags);
+ }
memcpy(psinfo->buf, s, c);
psinfo->write(PSTORE_TYPE_CONSOLE, 0, NULL, 0, c, psinfo);
spin_unlock_irqrestore(&psinfo->buf_lock, flags);
@@ -236,6 +242,7 @@
kmsg_dump_register(&pstore_dumper);
pstore_register_console();
+ pstore_register_ftrace();
if (pstore_update_ms >= 0) {
pstore_timer.expires = jiffies +
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 0b311bc..1a4f6da 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -32,6 +32,7 @@
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
+#include <linux/compiler.h>
#include <linux/pstore_ram.h>
#define RAMOOPS_KERNMSG_HDR "===="
@@ -181,12 +182,11 @@
return len;
}
-
-static int ramoops_pstore_write_buf(enum pstore_type_id type,
- enum kmsg_dump_reason reason,
- u64 *id, unsigned int part,
- const char *buf, size_t size,
- struct pstore_info *psi)
+static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
+ enum kmsg_dump_reason reason,
+ u64 *id, unsigned int part,
+ const char *buf, size_t size,
+ struct pstore_info *psi)
{
struct ramoops_context *cxt = psi->data;
struct persistent_ram_zone *prz = cxt->przs[cxt->dump_write_cnt];
@@ -406,7 +406,7 @@
goto fail_init_fprz;
if (!cxt->przs && !cxt->cprz && !cxt->fprz) {
- pr_err("memory size too small, minimum is %lu\n",
+ pr_err("memory size too small, minimum is %zu\n",
cxt->console_size + cxt->record_size +
cxt->ftrace_size);
goto fail_cnt;
@@ -414,13 +414,14 @@
cxt->pstore.data = cxt;
/*
- * Console can handle any buffer size, so prefer dumps buffer
- * size since usually it is smaller.
+ * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
+ * have to handle dumps, we must have at least record_size buffer. And
+ * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
+ * ZERO_SIZE_PTR).
*/
- if (cxt->przs)
- cxt->pstore.bufsize = cxt->przs[0]->buffer_size;
- else
- cxt->pstore.bufsize = cxt->cprz->buffer_size;
+ if (cxt->console_size)
+ cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
+ cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
spin_lock_init(&cxt->pstore.buf_lock);
if (!cxt->pstore.buf) {
@@ -537,6 +538,7 @@
static void __exit ramoops_exit(void)
{
platform_driver_unregister(&ramoops_driver);
+ platform_device_unregister(dummy);
kfree(dummy_data);
}
module_exit(ramoops_exit);
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index c892587..ee3034a 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -64,14 +64,6 @@
void *data;
};
-
-#ifdef CONFIG_PSTORE_FTRACE
-extern void pstore_ftrace_call(unsigned long ip, unsigned long parent_ip);
-#else
-static inline void pstore_ftrace_call(unsigned long ip, unsigned long parent_ip)
-{ }
-#endif
-
#ifdef CONFIG_PSTORE
extern int pstore_register(struct pstore_info *);
#else
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 483162a..507a7a9 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -13,7 +13,6 @@
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
-#include <linux/pstore.h>
#include <linux/fs.h>
#include "trace.h"
@@ -76,10 +75,9 @@
preempt_enable_notrace();
}
-/* Our two options */
+/* Our option */
enum {
TRACE_FUNC_OPT_STACK = 0x1,
- TRACE_FUNC_OPT_PSTORE = 0x2,
};
static struct tracer_flags func_flags;
@@ -109,12 +107,6 @@
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1)) {
- /*
- * So far tracing doesn't support multiple buffers, so
- * we make an explicit call for now.
- */
- if (unlikely(func_flags.val & TRACE_FUNC_OPT_PSTORE))
- pstore_ftrace_call(ip, parent_ip);
pc = preempt_count();
trace_function(tr, ip, parent_ip, flags, pc);
}
@@ -181,9 +173,6 @@
#ifdef CONFIG_STACKTRACE
{ TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
#endif
-#ifdef CONFIG_PSTORE_FTRACE
- { TRACER_OPT(func_pstore, TRACE_FUNC_OPT_PSTORE) },
-#endif
{ } /* Always set a last empty entry */
};
@@ -236,8 +225,6 @@
}
break;
- case TRACE_FUNC_OPT_PSTORE:
- break;
default:
return -EINVAL;
}
