[PATCH 15/16] dyndbg: allow inverted-flag-chars in modflags

[PATCH 15/16] dyndbg: allow inverted-flag-chars in modflags

[Jim Cromie]

Extend flags modifications to allow [PFMLT_XYZ] inverted flags.
This allows control-queries like:

  #> Q () { echo file inode.c $* > control } # to type less
  #> Q -P	# same as +p
  #> Q +X	# same as -x
  #> Q xyz-P	# same as xyz+p

This allows flags in a callsite to be simultaneously set and cleared,
while still starting with the current flagstate (with +- ops).
Generally, you chose -p or +p 1st, then set or clear flags
accordingly.

  # enable print on callsites with 'xy'; and re-mark with just 'z'
  #> Q xy+pXYz

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 Documentation/admin-guide/dynamic-debug-howto.rst | 8 +++++---
 lib/dynamic_debug.c                               | 6 ++++--
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 5404e23eeac8..493e74a14bdd 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -250,9 +250,11 @@ only callsites with x&y cleared.
 
 Flagsets cannot contain ``xX`` etc, a flag cannot be true and false.
 
-modflags containing upper-case flags is reserved/undefined for now.
-inverted-flags are currently ignored, usage gets trickier if given
-``-pXy``, it should leave x set.
+modflags may contain upper-case flags also, using these lets you
+invert the flag setting implied by the OP; '-pX' means disable
+printing, and mark that callsite with usr-x flag to create a group,
+for optional further manipulation.  Generally, '+p' and '-p' is your
+main choice, and use of inverted flags in modflags is rare.
 
 Notes::
 
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index b2630df0c3a5..82daf95b8f64 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -488,15 +488,17 @@ static int ddebug_parse_flags(const char *str,
 
 	/* calculate final mods: flags, mask based upon op */
 	switch (op) {
+		unsigned int tmp;
 	case '=':
 		mods->mask = 0;
 		break;
 	case '+':
-		mods->mask = ~0U;
+		mods->mask = ~mods->mask;
 		break;
 	case '-':
+		tmp = mods->mask;
 		mods->mask = ~mods->flags;
-		mods->flags = 0;
+		mods->flags = tmp;
 		break;
 	}
 
-- 
2.23.0

[PATCH v3 00/18] dynamic-debug cleanups, 2 new features

[Jim Cromie]

changes from v2:
  only claim one user flag, dont really need more
  fix patchset grooming err Reported-by: kbuild test robot <lkp@intel.com>
  quoting tweaks in Docs (unvalidated as better, but likely)
  rename to lib/dyndbg.c, update docs accordingly
  
changes from v1:
  dont drop trim_prefix yet, its harmless, and better supports old compilers.
  dont move externs to header, despite checkpatch

v1: https://lkml.org/lkml/2019/10/29/989
v2: https://lkml.org/lkml/2019/11/27/547

New Features (review):

accept new query input:
  file inode.c:100-200		# & line-range
  file inode.c:start_*		# & function

add 'u' user flag, allowing user to compose an arbitrary set of
callsites by marking them with 'u', without altering current
print-modifying flags.

extend flags-spec to allow filter-flags, which select callsites for
modification based upon their current flags.  This lets user activate
the set of callsites composed previously (u+p).

add negating flags to filter on absence of flags, or to negate a modification.

Jim Cromie (17):
  dyndbg-docs: eschew file /full/path query in docs
  dyndbg: drop obsolete comment on ddebug_proc_open
  dyndbg: raise verbosity needed to enable ddebug_proc_* logging
  dyndbg: rename __verbose section to __dyndbg
  dyndbg: fix overcounting of ram used by dyndbg
  dyndbg: fix a BUG_ON in ddebug_describe_flags
  dyndbg: refactor parse_linerange out of ddebug_parse_query
  dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100'
  dyndbg: refactor ddebug_read_flags out of ddebug_parse_flags
  dyndbg: combine flags & mask into a struct, use that
  dyndbg: add filter parameter to ddebug_parse_flags
  dyndbg: extend ddebug_parse_flags to accept optional filter-flags
  dyndbg: prefer declarative init in caller, to memset in callee
  dyndbg: add user-flag, negating-flags, and filtering on flags
  dyndbg: allow negating flag-chars in modflags
  dyndbg: make ddebug_tables list LIFO for add/remove_module
  dyndbg: rename lib/dynamic_debug.c to lib/dyndbg.c
  dyndbg-docs: normalize comments in examples

 Documentation/admin-guide/dynamic-debug-howto.rst | 176 ++++++++++++++++-----------
 include/asm-generic/vmlinux.lds.h                 |   6 +-
 include/linux/dynamic_debug.h                     |   5 +-
 kernel/module.c                                   |   2 +-
 lib/Makefile                                      |   4 +-
 lib/{dynamic_debug.c => dyndbg.c}                 | 285 ++++++++++++++++++++++++++------------------
 6 files changed, 285 insertions(+), 193 deletions(-)

-- 
2.23.0

[PATCH 15/16] dyndbg: allow inverted-flag-chars in modflags

[Jim Cromie]

Extend flags modifications to allow [PFMLT_XYZ] inverted flags.
This allows control-queries like:

  #> Q () { echo file inode.c $* > control } # to type less
  #> Q -P	# same as +p
  #> Q +X	# same as -x
  #> Q xyz-P	# same as xyz+p

This allows flags in a callsite to be simultaneously set and cleared,
while still starting with the current flagstate (with +- ops).
Generally, you chose -p or +p 1st, then set or clear flags
accordingly.

  # enable print on callsites with 'xy'; and re-mark with just 'z'
  #> Q xy+pXYz

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 Documentation/admin-guide/dynamic-debug-howto.rst | 8 +++++---
 lib/dynamic_debug.c                               | 6 ++++--
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 5404e23eeac8..493e74a14bdd 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -250,9 +250,11 @@ only callsites with x&y cleared.
 
 Flagsets cannot contain ``xX`` etc, a flag cannot be true and false.
 
-modflags containing upper-case flags is reserved/undefined for now.
-inverted-flags are currently ignored, usage gets trickier if given
-``-pXy``, it should leave x set.
+modflags may contain upper-case flags also, using these lets you
+invert the flag setting implied by the OP; '-pX' means disable
+printing, and mark that callsite with usr-x flag to create a group,
+for optional further manipulation.  Generally, '+p' and '-p' is your
+main choice, and use of inverted flags in modflags is rare.
 
 Notes::
 
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index b2630df0c3a5..82daf95b8f64 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -488,15 +488,17 @@ static int ddebug_parse_flags(const char *str,
 
 	/* calculate final mods: flags, mask based upon op */
 	switch (op) {
+		unsigned int tmp;
 	case '=':
 		mods->mask = 0;
 		break;
 	case '+':
-		mods->mask = ~0U;
+		mods->mask = ~mods->mask;
 		break;
 	case '-':
+		tmp = mods->mask;
 		mods->mask = ~mods->flags;
-		mods->flags = 0;
+		mods->flags = tmp;
 		break;
 	}
 
-- 
2.23.0