In commit HEAD~1, pr_debug temporarily issued a printk:console event. Replace that use with 2 new events:
bash-5.1# ls events/dyndbg/ devdbg enable filter prdbg
..called from pr_debug(), dev_dbg() respectively for dyndbg builds.
This links the old pr_debug API to tracefs, via dyndbg, allowing pr_debug()s etc to add just a little more user-context to the trace-logs, and then at users option, less syslog.
The 2 trace_* calls accept their caller's args respectively, keeping the available info w/o alteration; ISTM this is the best basis to add filtering later.
1- struct _ddebug *descriptor, giving tracefs all of dyndbg's info. 2- struct device *dev, for trace_devdbg(), if !!dev
To pass the descriptor into the trace_*() calls, the callchain up to __dynamic_{pr_debug,{dev,netdev,ibdev}_dbg} are altered to provide it.
The 2nd event also gets the struct device *dev if !!dev, otherwise a trace_prdbg() is issued, since we have an event for that, and don't need to waste the trace-buffer space.
Signed-off-by: Jim Cromie jim.cromie@gmail.com --- include/trace/events/dyndbg.h | 67 +++++++++++++++++++++++++++++++++++ lib/dynamic_debug.c | 53 ++++++++++++++------------- 2 files changed, 96 insertions(+), 24 deletions(-) create mode 100644 include/trace/events/dyndbg.h
diff --git a/include/trace/events/dyndbg.h b/include/trace/events/dyndbg.h new file mode 100644 index 000000000000..82620b10e968 --- /dev/null +++ b/include/trace/events/dyndbg.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM dyndbg + +#if !defined(_TRACE_DYNDBG_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_DYNDBG_H + +#include <linux/tracepoint.h> + +/* capture pr_debug() callsite descriptor and message */ +TRACE_EVENT(prdbg, + TP_PROTO(const struct _ddebug *desc, const char *text, size_t len), + + TP_ARGS(desc, text, len), + + TP_STRUCT__entry( + __dynamic_array(char, msg, len + 1) + ), + + TP_fast_assign( + /* + * Each trace entry is printed in a new line. + * If the msg finishes with '\n', cut it off + * to avoid blank lines in the trace. + */ + if ((len > 0) && (text[len-1] == '\n')) + len -= 1; + + memcpy(__get_str(msg), text, len); + __get_str(msg)[len] = 0; + ), + + TP_printk("%s", __get_str(msg)) + +); + +/* capture dev_dbg() callsite descriptor, device, and message */ +TRACE_EVENT(devdbg, + TP_PROTO(const struct _ddebug *desc, const struct device *dev, + const char *text, size_t len), + + TP_ARGS(desc, dev, text, len), + + TP_STRUCT__entry( + __dynamic_array(char, msg, len + 1) + ), + + TP_fast_assign( + /* + * Each trace entry is printed in a new line. + * If the msg finishes with '\n', cut it off + * to avoid blank lines in the trace. + */ + if ((len > 0) && (text[len-1] == '\n')) + len -= 1; + + memcpy(__get_str(msg), text, len); + __get_str(msg)[len] = 0; + ), + + TP_printk("%s", __get_str(msg)) +); + +#endif /* _TRACE_DYNDBG_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 3fd035cd4653..2efdc4f1553f 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -36,7 +36,9 @@ #include <linux/sched.h> #include <linux/device.h> #include <linux/netdevice.h> -#include <trace/events/printk.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/dyndbg.h>
#include <rdma/ib_verbs.h>
@@ -648,7 +650,8 @@ struct dynamic_trace_bufs { static DEFINE_PER_CPU(struct dynamic_trace_bufs, dynamic_trace_bufs); static DEFINE_PER_CPU(int, dynamic_trace_reserve);
-static void dynamic_trace(const char *fmt, va_list args) +static void dynamic_trace(struct _ddebug *desc, const struct device *dev, + const char *fmt, va_list args) { struct dynamic_trace_buf *buf; int bufidx; @@ -667,7 +670,11 @@ static void dynamic_trace(const char *fmt, va_list args) buf = this_cpu_ptr(dynamic_trace_bufs.bufs) + bufidx;
len = vscnprintf(buf->buf, sizeof(buf->buf), fmt, args); - trace_console(buf->buf, len); + + if (dev == NULL) + trace_prdbg(desc, buf->buf, len); + else + trace_devdbg(desc, dev, buf->buf, len);
out: /* As above. */ @@ -676,9 +683,9 @@ static void dynamic_trace(const char *fmt, va_list args) preempt_enable_notrace(); }
-static void dynamic_printk(unsigned int flags, const char *fmt, ...) +static void dynamic_printk(struct _ddebug *desc, const char *fmt, ...) { - if (flags & _DPRINTK_FLAGS_TRACE) { + if (desc->flags & _DPRINTK_FLAGS_TRACE) { va_list args;
va_start(args, fmt); @@ -686,11 +693,11 @@ static void dynamic_printk(unsigned int flags, const char *fmt, ...) * All callers include the KERN_DEBUG prefix to keep the * vprintk case simple; strip it out for tracing. */ - dynamic_trace(fmt + strlen(KERN_DEBUG), args); + dynamic_trace(desc, NULL, fmt + strlen(KERN_DEBUG), args); va_end(args); }
- if (flags & _DPRINTK_FLAGS_PRINTK) { + if (desc->flags & _DPRINTK_FLAGS_PRINTK) { va_list args;
va_start(args, fmt); @@ -699,19 +706,19 @@ static void dynamic_printk(unsigned int flags, const char *fmt, ...) } }
-static void dynamic_dev_printk(unsigned int flags, const struct device *dev, +static void dynamic_dev_printk(struct _ddebug *desc, const struct device *dev, const char *fmt, ...) {
- if (flags & _DPRINTK_FLAGS_TRACE) { + if (desc->flags & _DPRINTK_FLAGS_TRACE) { va_list args;
va_start(args, fmt); - dynamic_trace(fmt, args); + dynamic_trace(desc, dev, fmt, args); va_end(args); }
- if (flags & _DPRINTK_FLAGS_PRINTK) { + if (desc->flags & _DPRINTK_FLAGS_PRINTK) { va_list args;
va_start(args, fmt); @@ -734,7 +741,7 @@ void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...) vaf.fmt = fmt; vaf.va = &args;
- dynamic_printk(descriptor->flags, KERN_DEBUG "%s%pV", + dynamic_printk(descriptor, KERN_DEBUG "%s%pV", dynamic_emit_prefix(descriptor, buf), &vaf);
va_end(args); @@ -745,7 +752,6 @@ void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev, const char *fmt, ...) { struct va_format vaf; - unsigned int flags; va_list args;
BUG_ON(!descriptor); @@ -755,15 +761,14 @@ void __dynamic_dev_dbg(struct _ddebug *descriptor,
vaf.fmt = fmt; vaf.va = &args; - flags = descriptor->flags;
if (!dev) { - dynamic_printk(flags, KERN_DEBUG "(NULL device *): %pV", + dynamic_printk(descriptor, KERN_DEBUG "(NULL device *): %pV", &vaf); } else { char buf[PREFIX_SIZE] = "";
- dynamic_dev_printk(flags, dev, "%s%s %s: %pV", + dynamic_dev_printk(descriptor, dev, "%s%s %s: %pV", dynamic_emit_prefix(descriptor, buf), dev_driver_string(dev), dev_name(dev), &vaf); @@ -794,7 +799,7 @@ void __dynamic_netdev_dbg(struct _ddebug *descriptor, if (dev && dev->dev.parent) { char buf[PREFIX_SIZE] = "";
- dynamic_dev_printk(flags, dev->dev.parent, + dynamic_dev_printk(descriptor, dev->dev.parent, "%s%s %s %s%s: %pV", dynamic_emit_prefix(descriptor, buf), dev_driver_string(dev->dev.parent), @@ -802,10 +807,10 @@ void __dynamic_netdev_dbg(struct _ddebug *descriptor, netdev_name(dev), netdev_reg_state(dev), &vaf); } else if (dev) { - dynamic_printk(flags, KERN_DEBUG "%s%s: %pV", - netdev_name(dev), netdev_reg_state(dev), &vaf); + dynamic_dev_printk(descriptor, &dev->dev, KERN_DEBUG "%s%s: %pV", + netdev_name(dev), netdev_reg_state(dev), &vaf); } else { - dynamic_printk(flags, KERN_DEBUG "(NULL net_device): %pV", + dynamic_printk(descriptor, KERN_DEBUG "(NULL net_device): %pV", &vaf); }
@@ -833,7 +838,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor, if (ibdev && ibdev->dev.parent) { char buf[PREFIX_SIZE] = "";
- dynamic_dev_printk(flags, ibdev->dev.parent, + dynamic_dev_printk(descriptor, ibdev->dev.parent, "%s%s %s %s: %pV", dynamic_emit_prefix(descriptor, buf), dev_driver_string(ibdev->dev.parent), @@ -841,10 +846,10 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor, dev_name(&ibdev->dev), &vaf); } else if (ibdev) { - dynamic_printk(flags, KERN_DEBUG "%s%s: %pV", - dev_name(&ibdev->dev), &vaf); + dynamic_dev_printk(descriptor, &ibdev->dev, KERN_DEBUG "%s%s: %pV", + dev_name(&ibdev->dev), &vaf); } else { - dynamic_printk(flags, KERN_DEBUG "(NULL ip_device): %pV", + dynamic_printk(descriptor, KERN_DEBUG "(NULL ip_device): %pV", &vaf); }