Re: [PATCH v4 14/15] kprobes: remove dependency on CONFIG_MODULES

2024-04-17 Thread Masami Hiramatsu
static int trace_kprobe_module_callback(struct notifier_block *nb, > unsigned long val, void *data) > @@ -704,6 +712,7 @@ static struct notifier_block trace_kprobe_module_nb = { > .notifier_call = trace_kprobe_module_callback, > .priority = 1 /* Invoked after kprobe module callback */ > }; > +#endif > > static int count_symbols(void *data, unsigned long unused) > { > @@ -1933,8 +1942,10 @@ static __init int init_kprobe_trace_early(void) > if (ret) > return ret; > > +#ifdef CONFIG_MODULES > if (register_module_notifier(_kprobe_module_nb)) > return -EINVAL; > +#endif > > return 0; > } > -- > 2.43.0 > > -- Masami Hiramatsu

[PATCH for-next v2] tracing/kprobes: Add symbol counting check when module loads

2024-04-17 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Currently, kprobe event checks whether the target symbol name is unique or not, so that it does not put a probe on an unexpected place. But this skips the check if the target is on a module because the module may not be loaded. To fix this issue, this patch

[PATCH] bootconfig: Fix the kerneldoc of _xbc_exit()

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Fix the kerneldoc of _xbc_exit() which is updated to have an @early argument and the function name is changed. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202404150036.kpj3hefa-...@intel.com/ Signed-off-by: Masami Hiramatsu

[PATCH v9 36/36] fgraph: Skip recording calltime/rettime if it is not nneeded

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Skip recording calltime and rettime if the fgraph_ops does not need it. This is a kind of performance optimization for fprobe. Since the fprobe user does not use these entries, recording timestamp in fgraph is just a overhead (e.g. eBPF, ftrace). So introduce

[PATCH v9 35/36] Documentation: probes: Update fprobe on function-graph tracer

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Update fprobe documentation for the new fprobe on function-graph tracer. This includes some bahvior changes and pt_regs to ftrace_regs interface change. Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Update @fregs parameter explanation

[PATCH v9 34/36] selftests/ftrace: Add a test case for repeating register/unregister fprobe

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) This test case repeats define and undefine the fprobe dynamic event to ensure that the fprobe does not cause any issue with such operations. Signed-off-by: Masami Hiramatsu (Google) --- .../test.d/dynevent/add_remove_fprobe_repeat.tc| 19

[PATCH v9 33/36] selftests: ftrace: Remove obsolate maxactive syntax check

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Since the fprobe event does not support maxactive anymore, stop testing the maxactive syntax error checking. Signed-off-by: Masami Hiramatsu (Google) --- .../ftrace/test.d/dynevent/fprobe_syntax_errors.tc |4 +--- 1 file changed, 1 insertion(+), 3 deletions

[PATCH v9 32/36] tracing/fprobe: Remove nr_maxactive from fprobe

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Remove depercated fprobe::nr_maxactive. This involves fprobe events to rejects the maxactive number. Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Newly added. --- include/linux/fprobe.h |2 -- kernel/trace/trace_fprobe.c | 44

[PATCH v9 31/36] fprobe: Rewrite fprobe on function-graph tracer

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Rewrite fprobe implementation on function-graph tracer. Major API changes are: - 'nr_maxactive' field is deprecated. - This depends on CONFIG_DYNAMIC_FTRACE_WITH_ARGS or !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS, and CONFIG_HAVE_FUNCTION_GRAPH_FREGS. So

[PATCH v9 30/36] ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add CONFIG_HAVE_FTRACE_GRAPH_FUNC kconfig in addition to ftrace_graph_func macro check. This is for the other feature (e.g. FPROBE) which requires to access ftrace_regs from fgraph_ops::entryfunc() can avoid compiling if the fgraph can not pass the valid

[PATCH v9 29/36] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Enable kprobe_multi feature if CONFIG_FPROBE is enabled. The pt_regs is converted from ftrace_regs by ftrace_partial_regs(), thus some registers may always returns 0. But it should be enough for function entry (access arguments) and exit (access return value

[PATCH v9 28/36] tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS. With this change, fprobe events mostly use ftrace_regs instead of pt_regs. Note that if the arch doesn't enable HAVE_PT_REGS_COMPAT_FTRACE_REGS, fprobe events will not be able to be used from

[PATCH v9 27/36] tracing: Add ftrace_fill_perf_regs() for perf event

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add ftrace_fill_perf_regs() which should be compatible with the perf_fetch_caller_regs(). In other words, the pt_regs returned from the ftrace_fill_perf_regs() must satisfy 'user_mode(regs) == false' and can be used for stack tracing. Signed-off-by: Masami

[PATCH v9 26/36] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add ftrace_partial_regs() which converts the ftrace_regs to pt_regs. This is for the eBPF which needs this to keep the same pt_regs interface to access registers. Thus when replacing the pt_regs with ftrace_regs in fprobes (which is used by kprobe_multi eBPF event

[PATCH v9 25/36] fprobe: Use ftrace_regs in fprobe exit handler

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Change the fprobe exit handler to use ftrace_regs structure instead of pt_regs. This also introduce HAVE_PT_REGS_TO_FTRACE_REGS_CAST which means the ftrace_regs's memory layout is equal to the pt_regs so that those are able to cast. Fprobe introduces a new

[PATCH v9 24/36] fprobe: Use ftrace_regs in fprobe entry handler

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) This allows fprobes to be available with CONFIG_DYNAMIC_FTRACE_WITH_ARGS instead of CONFIG_DYNAMIC_FTRACE_WITH_REGS, then we can enable fprobe on arm64. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Florent Revest --- Changes in v6: - Keep using

[PATCH v9 23/36] function_graph: Pass ftrace_regs to retfunc

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Pass ftrace_regs to the fgraph_ops::retfunc(). If ftrace_regs is not available, it passes a NULL instead. User callback function can access some registers (including return address) via this ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) --- Changes

[PATCH v9 22/36] function_graph: Replace fgraph_ret_regs with ftrace_regs

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Use ftrace_regs instead of fgraph_ret_regs for tracing return value on function_graph tracer because of simplifying the callback interface. The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by CONFIG_HAVE_FUNCTION_GRAPH_FREGS. Signed-off-by: Masami

[PATCH v9 21/36] function_graph: Pass ftrace_regs to entryfunc

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Pass ftrace_regs to the fgraph_ops::entryfunc(). If ftrace_regs is not available, it passes a NULL instead. User callback function can access some registers (including return address) via this ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) --- Changes

[PATCH v9 20/36] ftrace: Add multiple fgraph storage selftest

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add a selftest for multiple function graph tracer with storage on a same function. In this case, the shadow stack entry will be shared among those fgraph with different data storage. So this will ensure the fgraph will not mixed those storage data. Signed-off

[PATCH v9 19/36] function_graph: Add selftest for passing local variables

2024-04-15 Thread Masami Hiramatsu (Google)
From: Steven Rostedt (VMware) Add boot up selftest that passes variables from a function entry to a function exit, and make sure that they do get passed around. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Add reserved size test

[PATCH v9 18/36] function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data()

2024-04-15 Thread Masami Hiramatsu (Google)
shadow ret_stack and this then can be retrieved by fgraph_retrieve_data() called by the corresponding retfunc(). Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v8: - Avoid using DIV_ROUND_UP() in the hot path. Changes in v3: - Store

[PATCH v9 17/36] function_graph: Move graph notrace bit to shadow stack global var

2024-04-15 Thread Masami Hiramatsu (Google)
are) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Make description lines shorter than 76 chars. --- include/linux/trace_recursion.h |7 --- kernel/trace/trace.h |9 + kernel/trace/trace_functions_graph.c | 10 ++ 3 files chan

[PATCH v9 16/36] function_graph: Move graph depth stored data to shadow stack global var

2024-04-15 Thread Masami Hiramatsu (Google)
are) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/trace_recursion.h | 29 - kernel/trace/trace.h| 34 -- 2 files changed, 32 insertions(+), 31 deletions(-) diff --git a/include/linux/trace_recursion.h b/incl

[PATCH v9 15/36] function_graph: Move set_graph_function tests to shadow stack global var

2024-04-15 Thread Masami Hiramatsu (Google)
are) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/trace_recursion.h |5 + kernel/trace/trace.h | 32 +--- kernel/trace/trace_functions_graph.c |6 +++--- kernel/trace/trace_irqsoff.c |4 ++-- kernel/tr

[PATCH v9 14/36] function_graph: Add "task variables" per task for fgraph_ops

2024-04-15 Thread Masami Hiramatsu (Google)
s on a per task basis having a way to maintain state for each task. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v3: - Move fgraph_ops::idx to previous patch in the series. Changes in v2: - Make description lines shorter than 76 chars. --

[PATCH v9 13/36] function_graph: Use a simple LRU for fgraph_array index number

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Since the fgraph_array index is used for the bitmap on the shadow stack, it may leave some entries after a function_graph instance is removed. Thus if another instance reuses the fgraph_array index soon after releasing it, the fgraph may confuse to call the newer

[PATCH v9 12/36] function_graph: Have the instances use their own ftrace_ops for filtering

2024-04-15 Thread Masami Hiramatsu (Google)
function_graph_enter_ops() instead of function_graph_enter() so that it avoid pushing on shadow stack multiple times on the same function. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v9: - Fix to clear fgraph_array correctly when ftrace_startup

[PATCH v9 11/36] ftrace: Allow ftrace startup flags exist without dynamic ftrace

2024-04-15 Thread Masami Hiramatsu (Google)
to compile because dynamic ftrace is disabled. This change is needed to move some of the logic of what is passed to ftrace_startup() out of the parameters of ftrace_startup(). Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/ftrace.h | 18

[PATCH v9 10/36] ftrace: Allow function_graph tracer to be enabled in instances

2024-04-15 Thread Masami Hiramatsu (Google)
-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Fix to remove set_graph_array() completely. --- include/linux/ftrace.h |1 + kernel/trace/ftrace.c|1 + kernel/trace/trace.h | 13 ++- kernel

[PATCH v9 09/36] ftrace/function_graph: Pass fgraph_ops to function graph callbacks

2024-04-15 Thread Masami Hiramatsu (Google)
to the function graph tracer. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - cleanup to set argument name on function prototype. --- include/linux/ftrace.h | 10 +++--- kernel/trace/fgraph.c| 16

[PATCH v9 08/36] function_graph: Remove logic around ftrace_graph_entry and return

2024-04-15 Thread Masami Hiramatsu (Google)
into the function_graph tracer. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Fix typo and make lines shorter than 76 chars in the description. - Remove unneeded return from return_run() function. --- kernel/trace/fgraph.c | 67

[PATCH v9 07/36] function_graph: Allow multiple users to attach to function graph

2024-04-15 Thread Masami Hiramatsu (Google)
are called is not completely handled yet, but that shouldn't be too hard to manage. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v7: - Fix max limitation check in ftrace_graph_push_return(). - Rewrite the shadow stack implementation using bitmap

[PATCH v9 06/36] function_graph: Add an array structure that will allow multiple callbacks

2024-04-15 Thread Masami Hiramatsu (Google)
on the shadow stack. We need to only save the index, because this will allow the fgraph_ops to be freed before the function returns (which may happen if the function call schedule for a long time). Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Remove

[PATCH v9 05/36] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long

2024-04-15 Thread Masami Hiramatsu (Google)
dt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v7: - Use DIV_ROUND_UP() to calculate FGRAPH_RET_INDEX --- kernel/trace/fgraph.c |9 ++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 30

[PATCH v9 04/36] function_graph: Convert ret_stack to a series of longs

2024-04-15 Thread Masami Hiramatsu (Google)
for the return side of the functions. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/sched.h |2 - kernel/trace/fgraph.c | 124 - 2 files changed, 71 insertions(+), 55 deletions(-) diff --git

[PATCH v9 03/36] x86: tracing: Add ftrace_regs definition in the header

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add ftrace_regs definition for x86_64 in the ftrace header to clarify what register will be accessible from ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) --- Changes in v3: - Add rip to be saved. Changes in v2: - Newly added. --- arch/x86/include

[PATCH v9 02/36] tracing: Rename ftrace_regs_return_value to ftrace_regs_get_return_value

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Rename ftrace_regs_return_value to ftrace_regs_get_return_value as same as other ftrace_regs_get/set_* APIs. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Mark Rutland --- Changes in v6: - Moved to top of the series. Changes in v3: - Newly added

[PATCH v9 01/36] tracing: Add a comment about ftrace_regs definition

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) To clarify what will be expected on ftrace_regs, add a comment to the architecture independent definition of the ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Mark Rutland --- Changes in v8: - Update that the saved registers depends

[PATCH v9 00/36] tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph

2024-04-15 Thread Masami Hiramatsu (Google)
it in the return callback. This series can be applied against the probes/for-next branch, which is based on v6.9-rc3. This series can also be found below branch. https://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git/log/?h=topic/fprobe-on-fgraph Thank you, --- Masami Hiramatsu (Google) (21

[PATCH for-next v2] tracing/kprobes: Add symbol counting check when module loads

2024-04-15 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Check the number of probe target symbols in the target module when the module is loaded. If the probe is not on the unique name symbols in the module, it will be rejected at that point. Note that the symbol which has a unique name in the target module

[PATCH] tracing: probes: Fix to zero initialize a local variable

2024-03-20 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Fix to initialize 'val' local variable with zero. Dan reported that Smatch static code checker reports an error that a local 'val' variable needs to be initialized. Actually, the 'val' is expected to be initialized by FETCH_OP_ARG in the same loop

[PATCH v2] kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address

2024-03-14 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Read from an unsafe address with copy_from_kernel_nofault() in arch_adjust_kprobe_addr() because this function is used before checking the address is in text or not. Syzcaller bot found a bug and reported the case if user specifies inaccessible data area

[PATCH] kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address

2024-03-14 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Read from an unsafe address with copy_from_kernel_nofault() in arch_adjust_kprobe_addr() because this function is used before checking the address is in text or not. Syzcaller bot found a bug and reported the case if user specifies inaccessible data area

[PATCH] fprobe: Fix to allocate entry_data_size buffer with rethook instances

2024-02-29 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Fix to allocate fprobe::entry_data_size buffer with rethook instances. If fprobe doesn't allocate entry_data_size buffer for each rethook instance, fprobe entry handler can cause a buffer overrun when storing entry data in entry handler. Reported-by: Jiri Olsa

[PATCH v8 35/35] Documentation: probes: Update fprobe on function-graph tracer

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Update fprobe documentation for the new fprobe on function-graph tracer. This includes some bahvior changes and pt_regs to ftrace_regs interface change. Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Update @fregs parameter explanation

[PATCH v8 34/35] selftests/ftrace: Add a test case for repeating register/unregister fprobe

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) This test case repeats define and undefine the fprobe dynamic event to ensure that the fprobe does not cause any issue with such operations. Signed-off-by: Masami Hiramatsu (Google) --- .../test.d/dynevent/add_remove_fprobe_repeat.tc| 19

[PATCH v8 33/35] selftests: ftrace: Remove obsolate maxactive syntax check

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Since the fprobe event does not support maxactive anymore, stop testing the maxactive syntax error checking. Signed-off-by: Masami Hiramatsu (Google) --- .../ftrace/test.d/dynevent/fprobe_syntax_errors.tc |4 +--- 1 file changed, 1 insertion(+), 3 deletions

[PATCH v8 32/35] tracing/fprobe: Remove nr_maxactive from fprobe

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Remove depercated fprobe::nr_maxactive. This involves fprobe events to rejects the maxactive number. Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Newly added. --- include/linux/fprobe.h |2 -- kernel/trace/trace_fprobe.c | 44

[PATCH v8 31/35] fprobe: Rewrite fprobe on function-graph tracer

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Rewrite fprobe implementation on function-graph tracer. Major API changes are: - 'nr_maxactive' field is deprecated. - This depends on CONFIG_DYNAMIC_FTRACE_WITH_ARGS or !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS, and CONFIG_HAVE_FUNCTION_GRAPH_FREGS. So

[PATCH v8 30/35] ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add CONFIG_HAVE_FTRACE_GRAPH_FUNC kconfig in addition to ftrace_graph_func macro check. This is for the other feature (e.g. FPROBE) which requires to access ftrace_regs from fgraph_ops::entryfunc() can avoid compiling if the fgraph can not pass the valid

[PATCH v8 29/35] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Enable kprobe_multi feature if CONFIG_FPROBE is enabled. The pt_regs is converted from ftrace_regs by ftrace_partial_regs(), thus some registers may always returns 0. But it should be enough for function entry (access arguments) and exit (access return value

[PATCH v8 28/35] tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS. With this change, fprobe events mostly use ftrace_regs instead of pt_regs. Note that if the arch doesn't enable HAVE_PT_REGS_COMPAT_FTRACE_REGS, fprobe events will not be able to be used from

[PATCH v8 27/35] tracing: Add ftrace_fill_perf_regs() for perf event

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add ftrace_fill_perf_regs() which should be compatible with the perf_fetch_caller_regs(). In other words, the pt_regs returned from the ftrace_fill_perf_regs() must satisfy 'user_mode(regs) == false' and can be used for stack tracing. Signed-off-by: Masami

[PATCH v8 26/35] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add ftrace_partial_regs() which converts the ftrace_regs to pt_regs. This is for the eBPF which needs this to keep the same pt_regs interface to access registers. Thus when replacing the pt_regs with ftrace_regs in fprobes (which is used by kprobe_multi eBPF event

[PATCH v8 25/35] fprobe: Use ftrace_regs in fprobe exit handler

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Change the fprobe exit handler to use ftrace_regs structure instead of pt_regs. This also introduce HAVE_PT_REGS_TO_FTRACE_REGS_CAST which means the ftrace_regs's memory layout is equal to the pt_regs so that those are able to cast. Fprobe introduces a new

[PATCH v8 24/35] fprobe: Use ftrace_regs in fprobe entry handler

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) This allows fprobes to be available with CONFIG_DYNAMIC_FTRACE_WITH_ARGS instead of CONFIG_DYNAMIC_FTRACE_WITH_REGS, then we can enable fprobe on arm64. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Florent Revest --- Changes in v6: - Keep using

[PATCH v8 23/35] function_graph: Pass ftrace_regs to retfunc

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Pass ftrace_regs to the fgraph_ops::retfunc(). If ftrace_regs is not available, it passes a NULL instead. User callback function can access some registers (including return address) via this ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) --- Changes

[PATCH v8 22/35] function_graph: Replace fgraph_ret_regs with ftrace_regs

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Use ftrace_regs instead of fgraph_ret_regs for tracing return value on function_graph tracer because of simplifying the callback interface. The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by CONFIG_HAVE_FUNCTION_GRAPH_FREGS. Signed-off-by: Masami

[PATCH v8 21/35] function_graph: Pass ftrace_regs to entryfunc

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Pass ftrace_regs to the fgraph_ops::entryfunc(). If ftrace_regs is not available, it passes a NULL instead. User callback function can access some registers (including return address) via this ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) --- Changes

[PATCH v8 20/35] ftrace: Add multiple fgraph storage selftest

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add a selftest for multiple function graph tracer with storage on a same function. In this case, the shadow stack entry will be shared among those fgraph with different data storage. So this will ensure the fgraph will not mixed those storage data. Signed-off

[PATCH v8 19/35] function_graph: Add selftest for passing local variables

2024-02-25 Thread Masami Hiramatsu (Google)
From: Steven Rostedt (VMware) Add boot up selftest that passes variables from a function entry to a function exit, and make sure that they do get passed around. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Add reserved size test

[PATCH v8 18/35] function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data()

2024-02-25 Thread Masami Hiramatsu (Google)
shadow ret_stack and this then can be retrieved by fgraph_retrieve_data() called by the corresponding retfunc(). Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v8: - Avoid using DIV_ROUND_UP() in the hot path. Changes in v3: - Store

[PATCH v8 17/35] function_graph: Move graph notrace bit to shadow stack global var

2024-02-25 Thread Masami Hiramatsu (Google)
are) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Make description lines shorter than 76 chars. --- include/linux/trace_recursion.h |7 --- kernel/trace/trace.h |9 + kernel/trace/trace_functions_graph.c | 10 ++ 3 files chan

[PATCH v8 16/35] function_graph: Move graph depth stored data to shadow stack global var

2024-02-25 Thread Masami Hiramatsu (Google)
are) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/trace_recursion.h | 29 - kernel/trace/trace.h| 34 -- 2 files changed, 32 insertions(+), 31 deletions(-) diff --git a/include/linux/trace_recursion.h b/incl

[PATCH v8 15/35] function_graph: Move set_graph_function tests to shadow stack global var

2024-02-25 Thread Masami Hiramatsu (Google)
are) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/trace_recursion.h |5 + kernel/trace/trace.h | 32 +--- kernel/trace/trace_functions_graph.c |6 +++--- kernel/trace/trace_irqsoff.c |4 ++-- kernel/tr

[PATCH v8 14/35] function_graph: Add "task variables" per task for fgraph_ops

2024-02-25 Thread Masami Hiramatsu (Google)
s on a per task basis having a way to maintain state for each task. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v3: - Move fgraph_ops::idx to previous patch in the series. Changes in v2: - Make description lines shorter than 76 chars. --

[PATCH v8 13/35] function_graph: Use a simple LRU for fgraph_array index number

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Since the fgraph_array index is used for the bitmap on the shadow stack, it may leave some entries after a function_graph instance is removed. Thus if another instance reuses the fgraph_array index soon after releasing it, the fgraph may confuse to call the newer

[PATCH v8 12/35] function_graph: Have the instances use their own ftrace_ops for filtering

2024-02-25 Thread Masami Hiramatsu (Google)
function_graph_enter_ops() instead of function_graph_enter() so that it avoid pushing on shadow stack multiple times on the same function. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v8: - Fix a compilation error in loongarch implementation

[PATCH v8 11/35] ftrace: Allow ftrace startup flags exist without dynamic ftrace

2024-02-25 Thread Masami Hiramatsu (Google)
to compile because dynamic ftrace is disabled. This change is needed to move some of the logic of what is passed to ftrace_startup() out of the parameters of ftrace_startup(). Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/ftrace.h | 18

[PATCH v8 10/35] ftrace: Allow function_graph tracer to be enabled in instances

2024-02-25 Thread Masami Hiramatsu (Google)
-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Fix to remove set_graph_array() completely. --- include/linux/ftrace.h |1 + kernel/trace/ftrace.c|1 + kernel/trace/trace.h | 13 ++- kernel

[PATCH v8 09/35] ftrace/function_graph: Pass fgraph_ops to function graph callbacks

2024-02-25 Thread Masami Hiramatsu (Google)
to the function graph tracer. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - cleanup to set argument name on function prototype. --- include/linux/ftrace.h | 10 +++--- kernel/trace/fgraph.c| 16

[PATCH v8 08/35] function_graph: Remove logic around ftrace_graph_entry and return

2024-02-25 Thread Masami Hiramatsu (Google)
into the function_graph tracer. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Fix typo and make lines shorter than 76 chars in the description. - Remove unneeded return from return_run() function. --- kernel/trace/fgraph.c | 67

[PATCH v8 07/35] function_graph: Allow multiple users to attach to function graph

2024-02-25 Thread Masami Hiramatsu (Google)
are called is not completely handled yet, but that shouldn't be too hard to manage. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v7: - Fix max limitation check in ftrace_graph_push_return(). - Rewrite the shadow stack implementation using bitmap

[PATCH v8 06/35] function_graph: Add an array structure that will allow multiple callbacks

2024-02-25 Thread Masami Hiramatsu (Google)
on the shadow stack. We need to only save the index, because this will allow the fgraph_ops to be freed before the function returns (which may happen if the function call schedule for a long time). Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Remove

[PATCH v8 05/35] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long

2024-02-25 Thread Masami Hiramatsu (Google)
dt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v7: - Use DIV_ROUND_UP() to calculate FGRAPH_RET_INDEX --- kernel/trace/fgraph.c |9 ++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 30

[PATCH v8 04/35] function_graph: Convert ret_stack to a series of longs

2024-02-25 Thread Masami Hiramatsu (Google)
for the return side of the functions. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/sched.h |2 - kernel/trace/fgraph.c | 124 - 2 files changed, 71 insertions(+), 55 deletions(-) diff --git

[PATCH v8 03/35] x86: tracing: Add ftrace_regs definition in the header

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add ftrace_regs definition for x86_64 in the ftrace header to clarify what register will be accessible from ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) --- Changes in v3: - Add rip to be saved. Changes in v2: - Newly added. --- arch/x86/include

[PATCH v8 02/35] tracing: Rename ftrace_regs_return_value to ftrace_regs_get_return_value

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Rename ftrace_regs_return_value to ftrace_regs_get_return_value as same as other ftrace_regs_get/set_* APIs. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Mark Rutland --- Changes in v6: - Moved to top of the series. Changes in v3: - Newly added

[PATCH v8 01/35] tracing: Add a comment about ftrace_regs definition

2024-02-25 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) To clarify what will be expected on ftrace_regs, add a comment to the architecture independent definition of the ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Mark Rutland --- Changes in v8: - Update that the saved registers depends

[PATCH v8 00/35] tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph

2024-02-25 Thread Masami Hiramatsu (Google)
. https://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git/log/?h=topic/fprobe-on-fgraph Thank you, --- Masami Hiramatsu (Google) (20): tracing: Add a comment about ftrace_regs definition tracing: Rename ftrace_regs_return_value to ftrace_regs_get_return_value x86

[PATCH RFC 5/5] tracing/probes: Support $argN in return probe (kprobe and fprobe)

2024-02-14 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Support accessing $argN in the return probe events. This will help users to record entry data in function return (exit) event for simplfing the function entry/exit information in one event, and record the result values (e.g. allocated object/initialized object

[PATCH RFC 4/5] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init

2024-02-14 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Instead of incrementing the trace_probe::nr_args, init it at trace_probe_init(). This is a cleanup, so the behavior is not changed. Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_eprobe.c |2 +- kernel/trace/trace_probe.c | 10

[PATCH RFC 3/5] tracing/probes: Cleanup probe argument parser

2024-02-14 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Cleanup traceprobe_parse_probe_arg_body() to split out the type parser and post-processing part of fetch_insn. This makes no functional change. Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_probe.c | 230

[PATCH RFC 2/5] tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event

2024-02-14 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Despite the fprobe event, "Kretprobe" was commented. So fix it. Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_fprobe.c |2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace_fprobe.c b/ke

[PATCH RFC 1/5] tracing/probes: Fix to search structure fields correctly

2024-02-14 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Fix to search a field from the structure which has anonymous union correctly. Since the reference `type` pointer was updated in the loop, the search loop suddenly aborted where it hits an anonymous union. Thus it can not find the field after the anonymous union

[PATCH RFC 0/5] tracing/probes: Support function parameter access from return probe

2024-02-14 Thread Masami Hiramatsu (Google)
nitialized at exit. TODO: - update README file - add/update ftracetest - update documents Thank you, --- Masami Hiramatsu (Google) (5): tracing/probes: Fix to search structure fields correctly tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event tracing/p

[PATCH v7 35/36] selftests/ftrace: Add a test case for repeating register/unregister fprobe

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) This test case repeats define and undefine the fprobe dynamic event to ensure that the fprobe does not cause any issue with such operations. Signed-off-by: Masami Hiramatsu (Google) --- .../test.d/dynevent/add_remove_fprobe_repeat.tc| 19

[PATCH v7 20/36] function_graph: Improve push operation for several interrupts

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Improve push and data reserve operation on the shadow stack for several sequencial interrupts. To push a ret_stack or data entry on the shadow stack, we need to prepare an index (offset) entry before updating the stack pointer (curr_ret_stack) so that unwinder

[PATCH v7 21/36] function_graph: Add selftest for passing local variables

2024-02-06 Thread Masami Hiramatsu (Google)
From: Steven Rostedt (VMware) Add boot up selftest that passes variables from a function entry to a function exit, and make sure that they do get passed around. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Add reserved size test

[PATCH v7 36/36] Documentation: probes: Update fprobe on function-graph tracer

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Update fprobe documentation for the new fprobe on function-graph tracer. This includes some bahvior changes and pt_regs to ftrace_regs interface change. Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Update @fregs parameter explanation

[PATCH v7 34/36] selftests: ftrace: Remove obsolate maxactive syntax check

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Since the fprobe event does not support maxactive anymore, stop testing the maxactive syntax error checking. Signed-off-by: Masami Hiramatsu (Google) --- .../ftrace/test.d/dynevent/fprobe_syntax_errors.tc |4 +--- 1 file changed, 1 insertion(+), 3 deletions

[PATCH v7 33/36] tracing/fprobe: Remove nr_maxactive from fprobe

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Remove depercated fprobe::nr_maxactive. This involves fprobe events to rejects the maxactive number. Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Newly added. --- include/linux/fprobe.h |2 -- kernel/trace/trace_fprobe.c | 44

[PATCH v7 32/36] fprobe: Rewrite fprobe on function-graph tracer

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Rewrite fprobe implementation on function-graph tracer. Major API changes are: - 'nr_maxactive' field is deprecated. - This depends on CONFIG_DYNAMIC_FTRACE_WITH_ARGS or !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS, and CONFIG_HAVE_FUNCTION_GRAPH_FREGS. So

[PATCH v7 13/36] function_graph: Have the instances use their own ftrace_ops for filtering

2024-02-06 Thread Masami Hiramatsu (Google)
function_graph_enter_ops() instead of function_graph_enter() so that it avoid pushing on shadow stack multiple times on the same function. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v7: - Move FGRAPH_TYPE_BITMAP type implementation to earlier patch

[PATCH v7 31/36] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Enable kprobe_multi feature if CONFIG_FPROBE is enabled. The pt_regs is converted from ftrace_regs by ftrace_partial_regs(), thus some registers may always returns 0. But it should be enough for function entry (access arguments) and exit (access return value

[PATCH v7 30/36] tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS. With this change, fprobe events mostly use ftrace_regs instead of pt_regs. Note that if the arch doesn't enable HAVE_PT_REGS_COMPAT_FTRACE_REGS, fprobe events will not be able to be used from

[PATCH v7 29/36] tracing: Add ftrace_fill_perf_regs() for perf event

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add ftrace_fill_perf_regs() which should be compatible with the perf_fetch_caller_regs(). In other words, the pt_regs returned from the ftrace_fill_perf_regs() must satisfy 'user_mode(regs) == false' and can be used for stack tracing. Signed-off-by: Masami

[PATCH v7 28/36] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Add ftrace_partial_regs() which converts the ftrace_regs to pt_regs. If the architecture defines its own ftrace_regs, this copies partial registers to pt_regs and returns it. If not, ftrace_regs is the same as pt_regs and ftrace_partial_regs() will return

[PATCH v7 27/36] fprobe: Use ftrace_regs in fprobe exit handler

2024-02-06 Thread Masami Hiramatsu (Google)
From: Masami Hiramatsu (Google) Change the fprobe exit handler to use ftrace_regs structure instead of pt_regs. This also introduce HAVE_PT_REGS_TO_FTRACE_REGS_CAST which means the ftrace_regs's memory layout is equal to the pt_regs so that those are able to cast. Fprobe introduces a new

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