Re: [PATCH v3 8/9] trace_uprobe/sdt: Document about reference counter
On Tue, 17 Apr 2018 10:02:43 +0530 Ravi Bangoriawrote: > From: Ravi Bangoria > > Reference counter gate the invocation of probe. If present, > by default reference count is 0. Kernel needs to increment > it before tracing the probe and decrement it when done. This > is identical to semaphore in Userspace Statically Defined > Tracepoints (USDT). > > Document usage of reference counter. > > Signed-off-by: Ravi Bangoria Looks good to me. Acked-by: Masami Hiramatsu Thanks! > --- > Documentation/trace/uprobetracer.txt | 16 +--- > kernel/trace/trace.c | 2 +- > 2 files changed, 14 insertions(+), 4 deletions(-) > > diff --git a/Documentation/trace/uprobetracer.txt > b/Documentation/trace/uprobetracer.txt > index bf526a7c..cb6751d 100644 > --- a/Documentation/trace/uprobetracer.txt > +++ b/Documentation/trace/uprobetracer.txt > @@ -19,15 +19,25 @@ user to calculate the offset of the probepoint in the > object. > > Synopsis of uprobe_tracer > - > - p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe > - r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe) > - -:[GRP/]EVENT : Clear uprobe or uretprobe event > + p[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] > + r[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] > + -:[GRP/]EVENT > + > + p : Set a uprobe > + r : Set a return uprobe (uretprobe) > + - : Clear uprobe or uretprobe event > >GRP : Group name. If omitted, "uprobes" is the default value. >EVENT : Event name. If omitted, the event name is generated based >on PATH+OFFSET. >PATH : Path to an executable or a library. >OFFSET: Offset where the probe is inserted. > + REF_CTR_OFFSET: Reference counter offset. Optional field. Reference count > + gate the invocation of probe. If present, by default > + reference count is 0. Kernel needs to increment it before > + tracing the probe and decrement it when done. This is > + identical to semaphore in Userspace Statically Defined > + Tracepoints (USDT). > >FETCHARGS : Arguments. Each probe can have up to 128 args. > %REG : Fetch register REG > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 300f4ea..d211937 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -4604,7 +4604,7 @@ static int tracing_trace_options_open(struct inode > *inode, struct file *file) >"place (kretprobe): [:][+]|\n" > #endif > #ifdef CONFIG_UPROBE_EVENTS > - "\tplace: :\n" > + " place (uprobe): :[(ref_ctr_offset)]\n" > #endif > "\t args: =fetcharg[:type]\n" > "\t fetcharg: %, @, @[+|-],\n" > -- > 1.8.3.1 > -- Masami Hiramatsu
Re: [PATCH v3 8/9] trace_uprobe/sdt: Document about reference counter
On Tue, 17 Apr 2018 10:02:43 +0530 Ravi Bangoria wrote: > From: Ravi Bangoria > > Reference counter gate the invocation of probe. If present, > by default reference count is 0. Kernel needs to increment > it before tracing the probe and decrement it when done. This > is identical to semaphore in Userspace Statically Defined > Tracepoints (USDT). > > Document usage of reference counter. > > Signed-off-by: Ravi Bangoria Looks good to me. Acked-by: Masami Hiramatsu Thanks! > --- > Documentation/trace/uprobetracer.txt | 16 +--- > kernel/trace/trace.c | 2 +- > 2 files changed, 14 insertions(+), 4 deletions(-) > > diff --git a/Documentation/trace/uprobetracer.txt > b/Documentation/trace/uprobetracer.txt > index bf526a7c..cb6751d 100644 > --- a/Documentation/trace/uprobetracer.txt > +++ b/Documentation/trace/uprobetracer.txt > @@ -19,15 +19,25 @@ user to calculate the offset of the probepoint in the > object. > > Synopsis of uprobe_tracer > - > - p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe > - r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe) > - -:[GRP/]EVENT : Clear uprobe or uretprobe event > + p[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] > + r[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] > + -:[GRP/]EVENT > + > + p : Set a uprobe > + r : Set a return uprobe (uretprobe) > + - : Clear uprobe or uretprobe event > >GRP : Group name. If omitted, "uprobes" is the default value. >EVENT : Event name. If omitted, the event name is generated based >on PATH+OFFSET. >PATH : Path to an executable or a library. >OFFSET: Offset where the probe is inserted. > + REF_CTR_OFFSET: Reference counter offset. Optional field. Reference count > + gate the invocation of probe. If present, by default > + reference count is 0. Kernel needs to increment it before > + tracing the probe and decrement it when done. This is > + identical to semaphore in Userspace Statically Defined > + Tracepoints (USDT). > >FETCHARGS : Arguments. Each probe can have up to 128 args. > %REG : Fetch register REG > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 300f4ea..d211937 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -4604,7 +4604,7 @@ static int tracing_trace_options_open(struct inode > *inode, struct file *file) >"place (kretprobe): [:][+]|\n" > #endif > #ifdef CONFIG_UPROBE_EVENTS > - "\tplace: :\n" > + " place (uprobe): :[(ref_ctr_offset)]\n" > #endif > "\t args: =fetcharg[:type]\n" > "\t fetcharg: %, @, @[+|-],\n" > -- > 1.8.3.1 > -- Masami Hiramatsu
[PATCH v3 8/9] trace_uprobe/sdt: Document about reference counter
From: Ravi BangoriaReference counter gate the invocation of probe. If present, by default reference count is 0. Kernel needs to increment it before tracing the probe and decrement it when done. This is identical to semaphore in Userspace Statically Defined Tracepoints (USDT). Document usage of reference counter. Signed-off-by: Ravi Bangoria --- Documentation/trace/uprobetracer.txt | 16 +--- kernel/trace/trace.c | 2 +- 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt index bf526a7c..cb6751d 100644 --- a/Documentation/trace/uprobetracer.txt +++ b/Documentation/trace/uprobetracer.txt @@ -19,15 +19,25 @@ user to calculate the offset of the probepoint in the object. Synopsis of uprobe_tracer - - p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe - r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe) - -:[GRP/]EVENT : Clear uprobe or uretprobe event + p[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] + r[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] + -:[GRP/]EVENT + + p : Set a uprobe + r : Set a return uprobe (uretprobe) + - : Clear uprobe or uretprobe event GRP : Group name. If omitted, "uprobes" is the default value. EVENT : Event name. If omitted, the event name is generated based on PATH+OFFSET. PATH : Path to an executable or a library. OFFSET: Offset where the probe is inserted. + REF_CTR_OFFSET: Reference counter offset. Optional field. Reference count + gate the invocation of probe. If present, by default + reference count is 0. Kernel needs to increment it before + tracing the probe and decrement it when done. This is + identical to semaphore in Userspace Statically Defined + Tracepoints (USDT). FETCHARGS : Arguments. Each probe can have up to 128 args. %REG : Fetch register REG diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 300f4ea..d211937 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4604,7 +4604,7 @@ static int tracing_trace_options_open(struct inode *inode, struct file *file) "place (kretprobe): [:][+]|\n" #endif #ifdef CONFIG_UPROBE_EVENTS - "\tplace: :\n" + " place (uprobe): :[(ref_ctr_offset)]\n" #endif "\t args: =fetcharg[:type]\n" "\t fetcharg: %, @, @[+|-],\n" -- 1.8.3.1
[PATCH v3 8/9] trace_uprobe/sdt: Document about reference counter
From: Ravi Bangoria Reference counter gate the invocation of probe. If present, by default reference count is 0. Kernel needs to increment it before tracing the probe and decrement it when done. This is identical to semaphore in Userspace Statically Defined Tracepoints (USDT). Document usage of reference counter. Signed-off-by: Ravi Bangoria --- Documentation/trace/uprobetracer.txt | 16 +--- kernel/trace/trace.c | 2 +- 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt index bf526a7c..cb6751d 100644 --- a/Documentation/trace/uprobetracer.txt +++ b/Documentation/trace/uprobetracer.txt @@ -19,15 +19,25 @@ user to calculate the offset of the probepoint in the object. Synopsis of uprobe_tracer - - p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe - r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe) - -:[GRP/]EVENT : Clear uprobe or uretprobe event + p[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] + r[:[GRP/]EVENT] PATH:OFFSET[(REF_CTR_OFFSET)] [FETCHARGS] + -:[GRP/]EVENT + + p : Set a uprobe + r : Set a return uprobe (uretprobe) + - : Clear uprobe or uretprobe event GRP : Group name. If omitted, "uprobes" is the default value. EVENT : Event name. If omitted, the event name is generated based on PATH+OFFSET. PATH : Path to an executable or a library. OFFSET: Offset where the probe is inserted. + REF_CTR_OFFSET: Reference counter offset. Optional field. Reference count + gate the invocation of probe. If present, by default + reference count is 0. Kernel needs to increment it before + tracing the probe and decrement it when done. This is + identical to semaphore in Userspace Statically Defined + Tracepoints (USDT). FETCHARGS : Arguments. Each probe can have up to 128 args. %REG : Fetch register REG diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 300f4ea..d211937 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4604,7 +4604,7 @@ static int tracing_trace_options_open(struct inode *inode, struct file *file) "place (kretprobe): [:][+]|\n" #endif #ifdef CONFIG_UPROBE_EVENTS - "\tplace: :\n" + " place (uprobe): :[(ref_ctr_offset)]\n" #endif "\t args: =fetcharg[:type]\n" "\t fetcharg: %, @, @[+|-],\n" -- 1.8.3.1