| Message ID | 20220107052942.1349447-2-jim.cromie@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | dyndbg & drm.debug to tracefs | expand |
On Fri, Jan 07, 2022 at 06:29:24AM +0100, Jim Cromie wrote: > #ifdef CONFIG_JUMP_LABEL > - if (dp->flags & _DPRINTK_FLAGS_PRINT) { > - if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT)) > + if (dp->flags & _DPRINTK_FLAGS_ENABLED) { > + if (!(modifiers->flags & _DPRINTK_FLAGS_ENABLED)) > static_branch_disable(&dp->key.dd_key_true); > - } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT) > + } else if (modifiers->flags & _DPRINTK_FLAGS_ENABLED) > static_branch_enable(&dp->key.dd_key_true); > #endif > dp->flags = newflags; > -- > 2.33.1 > I haven't tested it so I could be mistaken, but when _DPRINTK_FLAGS_ENABLED gets two flags in the next patch, it looks like this code still has the problem which I mentioned in https://lore.kernel.org/lkml/20211209150910.GA23668@axis.com/? | I noticed a bug inside the CONFIG_JUMP_LABEL handling (also present | in the last version I posted) which should be fixed as part of the | diff below (I've added a comment). | [...] | #ifdef CONFIG_JUMP_LABEL | - if (dp->flags & _DPRINTK_FLAGS_PRINT) { | - if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT)) | + if (dp->flags & _DPRINTK_FLAGS_ENABLE) { | + /* | + * The newflags check is to ensure that the | + * static branch doesn't get disabled in step | + * 3: | + * | + * (1) +pf | + * (2) +x | + * (3) -pf | + */ | + if (!(modifiers->flags & _DPRINTK_FLAGS_ENABLE) && | + !(newflags & _DPRINTK_FLAGS_ENABLE)) { | static_branch_disable(&dp->key.dd_key_true); | - } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT) | + } | + } else if (modifiers->flags & _DPRINTK_FLAGS_ENABLE) { | static_branch_enable(&dp->key.dd_key_true); | + } | #endif
On Fri, Jan 14, 2022 at 4:57 AM Vincent Whitchurch <vincent.whitchurch@axis.com> wrote: > > On Fri, Jan 07, 2022 at 06:29:24AM +0100, Jim Cromie wrote: > > #ifdef CONFIG_JUMP_LABEL > > - if (dp->flags & _DPRINTK_FLAGS_PRINT) { > > - if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT)) > > + if (dp->flags & _DPRINTK_FLAGS_ENABLED) { > > + if (!(modifiers->flags & _DPRINTK_FLAGS_ENABLED)) > > static_branch_disable(&dp->key.dd_key_true); > > - } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT) > > + } else if (modifiers->flags & _DPRINTK_FLAGS_ENABLED) > > static_branch_enable(&dp->key.dd_key_true); > > #endif > > dp->flags = newflags; > > -- > > 2.33.1 > > > > I haven't tested it so I could be mistaken, but when > _DPRINTK_FLAGS_ENABLED gets two flags in the next patch, it looks like > this code still has the problem which I mentioned in > https://lore.kernel.org/lkml/20211209150910.GA23668@axis.com/? > Yes, thanks for noticing. I missed that detail. Apriori, I dont know why bit-and of bit-or'd flags doesnt cover it, but I will take a careful look. > | I noticed a bug inside the CONFIG_JUMP_LABEL handling (also present > | in the last version I posted) which should be fixed as part of the > | diff below (I've added a comment). > | [...] > | #ifdef CONFIG_JUMP_LABEL > | - if (dp->flags & _DPRINTK_FLAGS_PRINT) { > | - if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT)) > | + if (dp->flags & _DPRINTK_FLAGS_ENABLE) { > | + /* > | + * The newflags check is to ensure that the > | + * static branch doesn't get disabled in step > | + * 3: > | + * > | + * (1) +pf > | + * (2) +x > | + * (3) -pf > | + */ > | + if (!(modifiers->flags & _DPRINTK_FLAGS_ENABLE) && > | + !(newflags & _DPRINTK_FLAGS_ENABLE)) { > | static_branch_disable(&dp->key.dd_key_true); > | - } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT) > | + } > | + } else if (modifiers->flags & _DPRINTK_FLAGS_ENABLE) { > | static_branch_enable(&dp->key.dd_key_true); > | + } > | #endif
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index dce631e678dd..257a7bcbbe36 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -27,7 +27,7 @@ struct _ddebug { * writes commands to <debugfs>/dynamic_debug/control */ #define _DPRINTK_FLAGS_NONE 0 -#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */ +#define _DPRINTK_FLAGS_PRINTK (1<<0) /* printk() a message using the format */ #define _DPRINTK_FLAGS_INCL_MODNAME (1<<1) #define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2) #define _DPRINTK_FLAGS_INCL_LINENO (1<<3) @@ -37,8 +37,10 @@ struct _ddebug { (_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\ _DPRINTK_FLAGS_INCL_LINENO | _DPRINTK_FLAGS_INCL_TID) +#define _DPRINTK_FLAGS_ENABLED _DPRINTK_FLAGS_PRINTK + #if defined DEBUG -#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT +#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINTK #else #define _DPRINTK_FLAGS_DEFAULT 0 #endif @@ -120,10 +122,10 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor, #ifdef DEBUG #define DYNAMIC_DEBUG_BRANCH(descriptor) \ - likely(descriptor.flags & _DPRINTK_FLAGS_PRINT) + likely(descriptor.flags & _DPRINTK_FLAGS_ENABLED) #else #define DYNAMIC_DEBUG_BRANCH(descriptor) \ - unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) + unlikely(descriptor.flags & _DPRINTK_FLAGS_ENABLED) #endif #endif /* CONFIG_JUMP_LABEL */ diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index dd7f56af9aed..78a2912976c1 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -86,7 +86,7 @@ static inline const char *trim_prefix(const char *path) } static struct { unsigned flag:8; char opt_char; } opt_array[] = { - { _DPRINTK_FLAGS_PRINT, 'p' }, + { _DPRINTK_FLAGS_PRINTK, 'p' }, { _DPRINTK_FLAGS_INCL_MODNAME, 'm' }, { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' }, { _DPRINTK_FLAGS_INCL_LINENO, 'l' }, @@ -210,10 +210,10 @@ static int ddebug_change(const struct ddebug_query *query, if (newflags == dp->flags) continue; #ifdef CONFIG_JUMP_LABEL - if (dp->flags & _DPRINTK_FLAGS_PRINT) { - if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT)) + if (dp->flags & _DPRINTK_FLAGS_ENABLED) { + if (!(modifiers->flags & _DPRINTK_FLAGS_ENABLED)) static_branch_disable(&dp->key.dd_key_true); - } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT) + } else if (modifiers->flags & _DPRINTK_FLAGS_ENABLED) static_branch_enable(&dp->key.dd_key_true); #endif dp->flags = newflags;
Distinguish the condition: _DPRINTK_FLAGS_ENABLED from the bit: _DPRINTK_FLAGS_PRINT, in preparation to add _DPRINTK_FLAGS_TRACE next. Also add a 'K' to get _DPRINTK_FLAGS_PRINTK, to insure is not used elsewhere with a stale meaning. CC: vincent.whitchurch@axis.com Signed-off-by: Jim Cromie <jim.cromie@gmail.com> --- include/linux/dynamic_debug.h | 10 ++++++---- lib/dynamic_debug.c | 8 ++++---- 2 files changed, 10 insertions(+), 8 deletions(-)