tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
tracing/probes: Avoid setting TPARG_FL_FENTRY and TPARG_FL_RETURN
When parsing a kprobe event, the return probe always sets both
TPARG_FL_RETURN and TPARG_FL_FENTRY, but this is not useful because
some fetchargs are only for return probe and some others only for
function entry. Make it obviously mutual exclusive.
Link: https://lore.kernel.org/all/168507468731.913472.11354553441385410734.stgit@mhiramat.roam.corp.google.com/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
+6
-1
+1
-1
kernel/trace/trace_kprobe.c
+1
-1
kernel/trace/trace_kprobe.c
···
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if (is_return)
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flags |= TPARG_FL_RETURN;
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ret = kprobe_on_func_entry(NULL, symbol, offset);
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-
if (ret == 0)
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+
if (ret == 0 && !is_return)
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flags |= TPARG_FL_FENTRY;
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/* Defer the ENOENT case until register kprobe */
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if (ret == -EINVAL && is_return) {
+5
kernel/trace/trace_probe.h
+5
kernel/trace/trace_probe.h
···
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#define trace_probe_for_each_link_rcu(pos, tp) \
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list_for_each_entry_rcu(pos, &(tp)->event->files, list)
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+
/*
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+
* The flags used for parsing trace_probe arguments.
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* TPARG_FL_RETURN, TPARG_FL_FENTRY and TPARG_FL_TPOINT are mutually exclusive.
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* TPARG_FL_KERNEL and TPARG_FL_USER are also mutually exclusive.
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+
*/
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#define TPARG_FL_RETURN BIT(0)
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#define TPARG_FL_KERNEL BIT(1)
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#define TPARG_FL_FENTRY BIT(2)