driver core: Add device probe log helper dev_warn_probe()

Some drivers can still provide their functionality to a certain extent
even when some of their resource acquisitions eventually fail. In su

driver core: Add device probe log helper dev_warn_probe()

Some drivers can still provide their functionality to a certain extent
even when some of their resource acquisitions eventually fail. In such
cases, emitting errors isn't the desired action, but warnings should be
emitted instead.

To solve this, introduce dev_warn_probe() as a new device probe log helper,
which behaves identically as the already existing dev_err_probe(), while it
produces warnings instead of errors. The intended use is with the resources
that are actually optional for a particular driver.

While there, copyedit the kerneldoc for dev_err_probe() a bit, to simplify
its wording a bit, and reuse it as the kerneldoc for dev_warn_probe(), with
the necessary wording adjustments, of course.

Signed-off-by: Dragan Simic <[email protected]>
Tested-by: Hélène Vulquin <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Link: https://patch.msgid.link/2be0a28538bb2a3d1bcc91e2ca1f2d0dc09146d9.1727601608.git.dsimic@manjaro.org
Signed-off-by: Mark Brown <[email protected]>

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dev_printk: add new dev_err_probe() helpers

This is similar to dev_err_probe() but for cases where an ERR_PTR() or
ERR_CAST() is to be returned simplifying patterns like:

dev_err_probe(dev, ret, .

dev_printk: add new dev_err_probe() helpers

This is similar to dev_err_probe() but for cases where an ERR_PTR() or
ERR_CAST() is to be returned simplifying patterns like:

dev_err_probe(dev, ret, ...);
return ERR_PTR(ret)
or
dev_err_probe(dev, PTR_ERR(ptr), ...);
return ERR_CAST(ptr)

Signed-off-by: Nuno Sa <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jonathan Cameron <[email protected]>

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dev_printk: Add and use dev_no_printk()

When printk-indexing is enabled, each dev_printk() invocation emits a
pi_entry structure. This is even true when the dev_printk() is
protected by an always-f

dev_printk: Add and use dev_no_printk()

When printk-indexing is enabled, each dev_printk() invocation emits a
pi_entry structure. This is even true when the dev_printk() is
protected by an always-false check, as is typically the case for debug
messages: while the actual code to print the message is optimized out by
the compiler, the pi_entry structure is still emitted.

Avoid emitting pi_entry structures for unavailable dev_printk() kernel
messages by:
1. Introducing a dev_no_printk() helper, mimicked after the existing
no_printk() helper, which calls _dev_printk() instead of
dev_printk(),
2. Replacing all "if (0) dev_printk(...)" constructs by calls to the
new helper.

This reduces the size of an arm64 defconfig kernel with
CONFIG_PRINTK_INDEX=y by 957 KiB.

Fixes: ad7d61f159db7397 ("printk: index: Add indexing support to dev_printk")
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Xiubo Li <[email protected]>
Reviewed-by: Chris Down <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/8583d54f1687c801c6cda8edddf2cf0344c6e883.1709127473.git.geert+renesas@glider.be
Signed-off-by: Petr Mladek <[email protected]>

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driver core: Move dev_err_probe() to where it belogs

dev_err_probe() belongs to the printing API, hence
move the definition from device.h to dev_printk.h.

There is no change to the callers at all,

driver core: Move dev_err_probe() to where it belogs

dev_err_probe() belongs to the printing API, hence
move the definition from device.h to dev_printk.h.

There is no change to the callers at all, since:
1) implementation is located in the same core.c;
2) dev_printk.h is guaranteed to be included by device.h.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Andi Shyti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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printk: index: Add indexing support to dev_printk

While for most kinds of issues we have counters, tracepoints, or metrics
with a stable interface which can reliably be used to indicate issues,
in o

printk: index: Add indexing support to dev_printk

While for most kinds of issues we have counters, tracepoints, or metrics
with a stable interface which can reliably be used to indicate issues,
in order to react to production issues quickly we sometimes need to work
with the interface which most kernel developers naturally use when
developing: printk, and printk-esques like dev_printk.

dev_printk is by far the most likely custom subsystem printk to benefit
from the printk indexing infrastructure, since niche device issues
brought about by production changes, firmware upgrades, and the like are
one of the most common things that we need printk infrastructure's
assistance to monitor.

Often these errors were never expected to practically manifest in
reality, and exhibit in code without extensive (or any) metrics present.
As such, there are typically very few options for issue detection
available to those with large fleets at the time the incident happens,
and we thus benefit strongly from monitoring netconsole in these
instances.

As such, add the infrastructure for dev_printk to be indexed in the
printk index. Even on a minimal kernel config, the coverage of the base
kernel's printk index is significantly improved:

Before:

[root@ktst ~]# wc -l /sys/kernel/debug/printk/index/vmlinux
4497 /sys/kernel/debug/printk/index/vmlinux

After:

[root@ktst ~]# wc -l /sys/kernel/debug/printk/index/vmlinux
5573 /sys/kernel/debug/printk/index/vmlinux

In terms of implementation, in order to trivially disambiguate them,
dev_printk is now a macro which wraps _dev_printk.

Signed-off-by: Chris Down <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Tested-by: Petr Mladek <[email protected]>
Acked-by: Andy Shevchenko <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/959c7aed1017cb2c9de922e0a820d397e29c6a5a.1623775748.git.chris@chrisdown.name

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printk: Remove trailing semicolon in macros

Macros should not use a trailing semicolon.

Signed-off-by: Huilong Deng <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Signed-off-b

printk: Remove trailing semicolon in macros

Macros should not use a trailing semicolon.

Signed-off-by: Huilong Deng <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>

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printk: move dictionary keys to dev_printk_info

Dictionaries are only used for SUBSYSTEM and DEVICE properties. The
current implementation stores the property names each time they are
used. This req

printk: move dictionary keys to dev_printk_info

Dictionaries are only used for SUBSYSTEM and DEVICE properties. The
current implementation stores the property names each time they are
used. This requires more space than otherwise necessary. Also,
because the dictionary entries are currently considered optional,
it cannot be relied upon that they are always available, even if the
writer wanted to store them. These issues will increase should new
dictionary properties be introduced.

Rather than storing the subsystem and device properties in the
dict ring, introduce a struct dev_printk_info with separate fields
to store only the property values. Embed this struct within the
struct printk_info to provide guaranteed availability.

Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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dynamic_debug: add an option to enable dynamic debug for modules only

Instead of enabling dynamic debug globally with CONFIG_DYNAMIC_DEBUG,
CONFIG_DYNAMIC_DEBUG_CORE will only enable core function o

dynamic_debug: add an option to enable dynamic debug for modules only

Instead of enabling dynamic debug globally with CONFIG_DYNAMIC_DEBUG,
CONFIG_DYNAMIC_DEBUG_CORE will only enable core function of dynamic
debug. With the DYNAMIC_DEBUG_MODULE defined for any modules, dynamic
debug will be tied to them.

This is useful for people who only want to enable dynamic debug for
kernel modules without worrying about kernel image size and memory
consumption is increasing too much.

[[email protected]: v2]
Link: http://lkml.kernel.org/r/[email protected]

Signed-off-by: Orson Zhai <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Petr Mladek <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Jason Baron <[email protected]>
Cc: Randy Dunlap <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

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device.h: move dev_printk()-like functions to dev_printk.h

device.h has everything and the kitchen sink when it comes to struct
device things, so split out the printk-specific things to a separate .

device.h: move dev_printk()-like functions to dev_printk.h

device.h has everything and the kitchen sink when it comes to struct
device things, so split out the printk-specific things to a separate .h
file to make things easier to maintain and manage over time.

Cc: Suzuki K Poulose <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Saravana Kannan <[email protected]>
Cc: Heikki Krogerus <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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