* [PATCH v2] dynamic_debug: Restore dev_dbg functionality, optimize stack
[not found] <1343334310.17538.32.camel@joe2Laptop>
@ 2012-07-28 7:55 ` Joe Perches
2012-07-31 21:55 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Joe Perches @ 2012-07-28 7:55 UTC (permalink / raw)
To: Andrew Morton, Greg Kroah-Hartman, David S. Miller, Jason Baron
Cc: Jim Cromie, Kay Sievers, linux-kernel, netdev
commit c4e00daaa9 ("driver-core: extend dev_printk() to pass structured data")
changed __dev_printk and broke dynamic-debug's ability to control the
dynamic prefix of dev_dbg(dev,..).
dynamic_emit_prefix() adds "[tid] module:func:line:" to the output and
those additions got lost.
In addition, the current dynamic debug code uses up to 3 recursion
levels via %pV. This can consume quite a bit of stack. Directly
call printk_emit to reduce the recursion depth.
These changes include:
o Remove KERN_DEBUG from dynamic_emit_prefix
o Create and use function create_syslog_header to format the syslog
header for printk_emit uses.
o Call create_syslog_header and neaten __dev_printk
o Call create_syslog_header and printk_emit from dynamic_dev_dbg
o Call create_syslog_header and printk_emit from dynamic_netdev_dbg
o Make __dev_printk and __netdev_printk static not global
o Remove include header declarations of __dev_printk and __netdev_printk
o Remove now unused EXPORT_SYMBOL()s of __dev_printk and __netdev_printk
o Whitespace neatening
Changes in v2:
o Fix dynamic_emit_prefix to always initialize output
o Call create_syslog_header and emit_printk from__netdev_printk and
eliminate call to dev_printk to remove another recursion via %pV
Signed-off-by: Joe Perches <joe@perches.com>
---
drivers/base/core.c | 57 +++++++++++++++++++++++----------------
include/linux/device.h | 11 +++-----
include/linux/netdevice.h | 3 --
lib/dynamic_debug.c | 65 ++++++++++++++++++++++++++++++++++++---------
net/core/dev.c | 24 ++++++++++++-----
5 files changed, 106 insertions(+), 54 deletions(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index f338037..d46b635 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1861,25 +1861,19 @@ void device_shutdown(void)
*/
#ifdef CONFIG_PRINTK
-int __dev_printk(const char *level, const struct device *dev,
- struct va_format *vaf)
+int create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
{
- char dict[128];
- size_t dictlen = 0;
const char *subsys;
-
- if (!dev)
- return printk("%s(NULL device *): %pV", level, vaf);
+ size_t pos = 0;
if (dev->class)
subsys = dev->class->name;
else if (dev->bus)
subsys = dev->bus->name;
else
- goto skip;
+ return 0;
- dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen,
- "SUBSYSTEM=%s", subsys);
+ pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
/*
* Add device identifier DEVICE=:
@@ -1895,28 +1889,41 @@ int __dev_printk(const char *level, const struct device *dev,
c = 'b';
else
c = 'c';
- dictlen++;
- dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen,
- "DEVICE=%c%u:%u",
- c, MAJOR(dev->devt), MINOR(dev->devt));
+ pos++;
+ pos += snprintf(hdr + pos, hdrlen - pos,
+ "DEVICE=%c%u:%u",
+ c, MAJOR(dev->devt), MINOR(dev->devt));
} else if (strcmp(subsys, "net") == 0) {
struct net_device *net = to_net_dev(dev);
- dictlen++;
- dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen,
- "DEVICE=n%u", net->ifindex);
+ pos++;
+ pos += snprintf(hdr + pos, hdrlen - pos,
+ "DEVICE=n%u", net->ifindex);
} else {
- dictlen++;
- dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen,
- "DEVICE=+%s:%s", subsys, dev_name(dev));
+ pos++;
+ pos += snprintf(hdr + pos, hdrlen - pos,
+ "DEVICE=+%s:%s", subsys, dev_name(dev));
}
-skip:
- return printk_emit(0, level[1] - '0',
- dictlen ? dict : NULL, dictlen,
+
+ return pos;
+}
+EXPORT_SYMBOL(create_syslog_header);
+
+static int __dev_printk(const char *level, const struct device *dev,
+ struct va_format *vaf)
+{
+ char hdr[128];
+ size_t hdrlen;
+
+ if (!dev)
+ return printk("%s(NULL device *): %pV", level, vaf);
+
+ hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
+
+ return printk_emit(0, level[1] - '0', hdrlen ? hdr : NULL, hdrlen,
"%s %s: %pV",
dev_driver_string(dev), dev_name(dev), vaf);
}
-EXPORT_SYMBOL(__dev_printk);
int dev_printk(const char *level, const struct device *dev,
const char *fmt, ...)
@@ -1931,6 +1938,7 @@ int dev_printk(const char *level, const struct device *dev,
vaf.va = &args;
r = __dev_printk(level, dev, &vaf);
+
va_end(args);
return r;
@@ -1950,6 +1958,7 @@ int func(const struct device *dev, const char *fmt, ...) \
vaf.va = &args; \
\
r = __dev_printk(kern_level, dev, &vaf); \
+ \
va_end(args); \
\
return r; \
diff --git a/include/linux/device.h b/include/linux/device.h
index 52a5f15..89b246c 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -891,12 +891,12 @@ extern const char *dev_driver_string(const struct device *dev);
#ifdef CONFIG_PRINTK
-extern int __dev_printk(const char *level, const struct device *dev,
- struct va_format *vaf);
+extern int create_syslog_header(const struct device *dev,
+ char *hdr, size_t hdrlen);
+
extern __printf(3, 4)
int dev_printk(const char *level, const struct device *dev,
- const char *fmt, ...)
- ;
+ const char *fmt, ...);
extern __printf(2, 3)
int dev_emerg(const struct device *dev, const char *fmt, ...);
extern __printf(2, 3)
@@ -914,9 +914,6 @@ int _dev_info(const struct device *dev, const char *fmt, ...);
#else
-static inline int __dev_printk(const char *level, const struct device *dev,
- struct va_format *vaf)
-{ return 0; }
static inline __printf(3, 4)
int dev_printk(const char *level, const struct device *dev,
const char *fmt, ...)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index eb06e58..291e0ee 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2715,9 +2715,6 @@ static inline const char *netdev_name(const struct net_device *dev)
return dev->name;
}
-extern int __netdev_printk(const char *level, const struct net_device *dev,
- struct va_format *vaf);
-
extern __printf(3, 4)
int netdev_printk(const char *level, const struct net_device *dev,
const char *format, ...);
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 7ca29a0..6b3ebab 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -521,25 +521,25 @@ static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
int pos_after_tid;
int pos = 0;
- pos += snprintf(buf + pos, remaining(pos), "%s", KERN_DEBUG);
+ *buf = '\0';
+
if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
if (in_interrupt())
- pos += snprintf(buf + pos, remaining(pos), "%s ",
- "<intr>");
+ pos += snprintf(buf + pos, remaining(pos), "<intr> ");
else
pos += snprintf(buf + pos, remaining(pos), "[%d] ",
- task_pid_vnr(current));
+ task_pid_vnr(current));
}
pos_after_tid = pos;
if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
pos += snprintf(buf + pos, remaining(pos), "%s:",
- desc->modname);
+ desc->modname);
if (desc->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
pos += snprintf(buf + pos, remaining(pos), "%s:",
- desc->function);
+ desc->function);
if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
pos += snprintf(buf + pos, remaining(pos), "%d:",
- desc->lineno);
+ desc->lineno);
if (pos - pos_after_tid)
pos += snprintf(buf + pos, remaining(pos), " ");
if (pos >= PREFIX_SIZE)
@@ -559,9 +559,13 @@ int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
BUG_ON(!fmt);
va_start(args, fmt);
+
vaf.fmt = fmt;
vaf.va = &args;
- res = printk("%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
+
+ res = printk(KERN_DEBUG "%s%pV",
+ dynamic_emit_prefix(descriptor, buf), &vaf);
+
va_end(args);
return res;
@@ -574,15 +578,30 @@ int __dynamic_dev_dbg(struct _ddebug *descriptor,
struct va_format vaf;
va_list args;
int res;
- char buf[PREFIX_SIZE];
BUG_ON(!descriptor);
BUG_ON(!fmt);
va_start(args, fmt);
+
vaf.fmt = fmt;
vaf.va = &args;
- res = __dev_printk(dynamic_emit_prefix(descriptor, buf), dev, &vaf);
+
+ if (!dev) {
+ res = printk(KERN_DEBUG "(NULL device *): %pV", &vaf);
+ } else {
+ char buf[PREFIX_SIZE];
+ char dict[128];
+ size_t dictlen;
+
+ dictlen = create_syslog_header(dev, dict, sizeof(dict));
+
+ res = printk_emit(0, 7, dictlen ? dict : NULL, dictlen,
+ "%s%s %s: %pV",
+ dynamic_emit_prefix(descriptor, buf),
+ dev_driver_string(dev), dev_name(dev), &vaf);
+ }
+
va_end(args);
return res;
@@ -592,20 +611,40 @@ EXPORT_SYMBOL(__dynamic_dev_dbg);
#ifdef CONFIG_NET
int __dynamic_netdev_dbg(struct _ddebug *descriptor,
- const struct net_device *dev, const char *fmt, ...)
+ const struct net_device *dev, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
int res;
- char buf[PREFIX_SIZE];
BUG_ON(!descriptor);
BUG_ON(!fmt);
va_start(args, fmt);
+
vaf.fmt = fmt;
vaf.va = &args;
- res = __netdev_printk(dynamic_emit_prefix(descriptor, buf), dev, &vaf);
+
+ if (dev && dev->dev.parent) {
+ char buf[PREFIX_SIZE];
+ char dict[128];
+ size_t dictlen;
+
+ dictlen = create_syslog_header(dev->dev.parent,
+ dict, sizeof(dict));
+
+ res = printk_emit(0, 7, dictlen ? dict : NULL, dictlen,
+ "%s%s %s %s: %pV",
+ dynamic_emit_prefix(descriptor, buf),
+ dev_driver_string(dev->dev.parent),
+ dev_name(dev->dev.parent),
+ netdev_name(dev), &vaf);
+ } else if (dev) {
+ res = printk(KERN_DEBUG "%s: %pV", netdev_name(dev), &vaf);
+ } else {
+ res = printk(KERN_DEBUG "(NULL net_device): %pV", &vaf);
+ }
+
va_end(args);
return res;
diff --git a/net/core/dev.c b/net/core/dev.c
index 0ebaea1..c7bcea4 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6358,22 +6358,30 @@ const char *netdev_drivername(const struct net_device *dev)
return empty;
}
-int __netdev_printk(const char *level, const struct net_device *dev,
+static int __netdev_printk(const char *level, const struct net_device *dev,
struct va_format *vaf)
{
int r;
- if (dev && dev->dev.parent)
- r = dev_printk(level, dev->dev.parent, "%s: %pV",
- netdev_name(dev), vaf);
- else if (dev)
+ if (dev && dev->dev.parent) {
+ char dict[128];
+ size_t dictlen = create_syslog_header(dev->dev.parent,
+ dict, sizeof(dict));
+
+ r = printk_emit(0, level[1] - '0',
+ dictlen ? dict : NULL, dictlen,
+ "%s %s %s: %pV",
+ dev_driver_string(dev->dev.parent),
+ dev_name(dev->dev.parent),
+ netdev_name(dev), &vaf);
+ } else if (dev) {
r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
- else
+ } else {
r = printk("%s(NULL net_device): %pV", level, vaf);
+ }
return r;
}
-EXPORT_SYMBOL(__netdev_printk);
int netdev_printk(const char *level, const struct net_device *dev,
const char *format, ...)
@@ -6388,6 +6396,7 @@ int netdev_printk(const char *level, const struct net_device *dev,
vaf.va = &args;
r = __netdev_printk(level, dev, &vaf);
+
va_end(args);
return r;
@@ -6407,6 +6416,7 @@ int func(const struct net_device *dev, const char *fmt, ...) \
vaf.va = &args; \
\
r = __netdev_printk(level, dev, &vaf); \
+ \
va_end(args); \
\
return r; \
--
1.7.8.111.gad25c.dirty
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