[PATCH v2] dynamic_debug: Restore dev_dbg functionality, optimize stack
From: Joe Perches <joe@perches.com>
Date: 2012-07-28 07:55:16
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