linux.git/lib/dynamic_debug.c, branch v5.15.185

dyndbg: fix old BUG_ON in >control parser

2024-05-17T09:51:04+00:00

commit 00e7d3bea2ce7dac7bee1cf501fb071fd0ea8f6c upstream.

Fix a BUG_ON from 2009.  Even if it looks "unreachable" (I didn't
really look), lets make sure by removing it, doing pr_err and return
-EINVAL instead.

Cc: stable 
Signed-off-by: Jim Cromie 
Link: https://lore.kernel.org/r/20240429193145.66543-2-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman

dyndbg: drop EXPORTed dynamic_debug_exec_queries

2022-10-26T10:35:08+00:00

[ Upstream commit e26ef3af964acfea311403126acee8c56c89e26b ]

This exported fn is unused, and will not be needed. Lets dump it.

The export was added to let drm control pr_debugs, as part of using
them to avoid drm_debug_enabled overheads.  But its better to just
implement the drm.debug bitmap interface, then its available for
everyone.

Fixes: a2d375eda771 ("dyndbg: refine export, rename to dynamic_debug_exec_queries()")
Fixes: 4c0d77828d4f ("dyndbg: export ddebug_exec_queries")
Acked-by: Jason Baron 
Acked-by: Daniel Vetter 
Signed-off-by: Jim Cromie 
Link: https://lore.kernel.org/r/20220904214134.408619-10-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

dyndbg: let query-modname override actual module name

2022-10-26T10:35:08+00:00

[ Upstream commit e75ef56f74965f426dd819a41336b640ffdd8fbc ]

dyndbg's control-parser: ddebug_parse_query(), requires that search
terms: module, func, file, lineno, are used only once in a query; a
thing cannot be named both foo and bar.

The cited commit added an overriding module modname, taken from the
module loader, which is authoritative.  So it set query.module 1st,
which disallowed its use in the query-string.

But now, its useful to allow a module-load to enable classes across a
whole (or part of) a subsystem at once.

  # enable (dynamic-debug in) drm only
  modprobe drm dyndbg="class DRM_UT_CORE +p"

  # get drm_helper too
  modprobe drm dyndbg="class DRM_UT_CORE module drm* +p"

  # get everything that knows DRM_UT_CORE
  modprobe drm dyndbg="class DRM_UT_CORE module * +p"

  # also for boot-args:
  drm.dyndbg="class DRM_UT_CORE module * +p"

So convert the override into a default, by filling it only when/after
the query-string omitted the module.

NB: the query class FOO handling is forthcoming.

Fixes: 8e59b5cfb9a6 dynamic_debug: add modname arg to exec_query callchain
Acked-by: Jason Baron 
Acked-by: Daniel Vetter 
Signed-off-by: Jim Cromie 
Link: https://lore.kernel.org/r/20220904214134.408619-8-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

dyndbg: fix static_branch manipulation

2022-10-26T10:35:08+00:00

[ Upstream commit ee879be38bc87f8cedc79ae2742958db6533ca59 ]

In https://lore.kernel.org/lkml/20211209150910.GA23668@axis.com/

Vincent's patch commented on, and worked around, a bug toggling
static_branch's, when a 2nd PRINTK-ish flag was added.  The bug
results in a premature static_branch_disable when the 1st of 2 flags
was disabled.

The cited commit computed newflags, but then in the JUMP_LABEL block,
failed to use that result, instead using just one of the terms in it.
Using newflags instead made the code work properly.

This is Vincents test-case, reduced.  It needs the 2nd flag to
demonstrate the bug, but it's explanatory here.

pt_test() {
    echo 5 > /sys/module/dynamic_debug/verbose

    site="module tcp" # just one callsite
    echo " $site =_ " > /proc/dynamic_debug/control # clear it

    # A B ~A ~B
    for flg in +T +p "-T #broke here" -p; do
	echo " $site $flg " > /proc/dynamic_debug/control
    done;

    # A B ~B ~A
    for flg in +T +p "-p #broke here" -T; do
	echo " $site $flg " > /proc/dynamic_debug/control
    done
}
pt_test

Fixes: 84da83a6ffc0 dyndbg: combine flags & mask into a struct, simplify with it
CC: vincent.whitchurch@axis.com
Acked-by: Jason Baron 
Acked-by: Daniel Vetter 
Signed-off-by: Jim Cromie 
Link: https://lore.kernel.org/r/20220904214134.408619-2-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

dyndbg: make dyndbg a known cli param

2021-11-18T18:16:52+00:00

[ Upstream commit 5ca173974888368fecfb17ae6fe455df5fd2a9d2 ]

Right now dyndbg shows up as an unknown parameter if used on boot:

    Unknown command line parameters: dyndbg=+p

That's because it is unknown, it doesn't sit in the __param
section, so the processing done to warn users supplying an unknown
parameter doesn't think it is legitimate.

Install a dummy handler to register it. dynamic debug needs to search
the whole command line for modules listed that are currently builtin,
so there's no real work to be done in this callback.

Fixes: 86d1919a4fb0 ("init: print out unknown kernel parameters")
Tested-by: Jim Cromie 
Signed-off-by: Andrew Halaney 
Signed-off-by: Jason Baron 
Link: https://lore.kernel.org/r/1634139622-20667-2-git-send-email-jbaron@akamai.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

lib: fix spelling mistakes

2021-07-08T18:48:20+00:00

Fix some spelling mistakes in comments:
permanentely ==> permanently
wont ==> won't
remaning ==> remaining
succed ==> succeed
shouldnt ==> shouldn't
alpha-numeric ==> alphanumeric
storeing ==> storing
funtion ==> function
documenation ==> documentation
Determin ==> Determine
intepreted ==> interpreted
ammount ==> amount
obious ==> obvious
interupts ==> interrupts
occured ==> occurred
asssociated ==> associated
taking into acount ==> taking into account
squence ==> sequence
stil ==> still
contiguos ==> contiguous
matchs ==> matches

Link: https://lkml.kernel.org/r/20210607072555.12416-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei 
Reviewed-by: Jacob Keller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dyndbg: display KiB of data memory used.

2021-05-27T12:41:57+00:00

If booted with verbose>=1, dyndbg prints the memory usage in bytes,
of builtin modules' prdebugs.  KiB reads better.

no functional changes.

Signed-off-by: Jim Cromie 
Link: https://lore.kernel.org/r/20210525033240.35260-1-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman

dyndbg: drop uninformative vpr_info

2021-05-13T18:50:23+00:00

Remove a vpr_info which I added in 2012, when I knew even less than now.
In 2020, a simpler pr_fmt stripped it of context, and any remaining value.

no functional change.

Signed-off-by: Jim Cromie 
Link: https://lore.kernel.org/r/20210504222235.1033685-3-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman

dyndbg: avoid calling dyndbg_emit_prefix when it has no work

2021-05-13T18:50:23+00:00

Wrap function in a static-inline one, which checks flags to avoid
calling the function unnecessarily.

And hoist its output-buffer initialization to the grand-caller, which
is already allocating the buffer on the stack, and can trivially
initialize it too.

Signed-off-by: Jim Cromie 
Link: https://lore.kernel.org/r/20210504222235.1033685-2-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman

dyndbg: fix parsing file query without a line-range suffix

2021-04-30T05:43:20+00:00

Query like 'file tcp_input.c line 1234 +p' was broken by
commit aaebe329bff0 ("dyndbg: accept 'file foo.c:func1' and 'file
foo.c:10-100'") because a file name without a ':' now makes the loop in
ddebug_parse_query() exits early before parsing the 'line 1234' part.
As a result, all pr_debug() in tcp_input.c will be enabled, instead of only
the one on line 1234.  Changing 'break' to 'continue' fixes this.

Fixes: aaebe329bff0 ("dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100'")
Cc: stable 
Reviewed-by: Eric Dumazet 
Signed-off-by: Shuo Chen 
Acked-by: Jason Baron 
Link: https://lore.kernel.org/r/20210414212400.2927281-1-giantchen@gmail.com
Signed-off-by: Greg Kroah-Hartman