Current File : //usr/share/systemtap/examples/memory/last_100_frees.stp
#!/usr/bin/stap
global bt%[100]
probe process("/lib*/libc.so.*").function("free") {
// we use @defined($mem) here because on 64 bit systems, the
// wildcard search takes us through both 64 bit and 32 bit
// libc (which doesn't have debuginfo), this means the probe
// point resolved from the 32 bit library has no context info
if (@defined($mem)) {
bt[execname(),tid(),$mem,sprint_ubacktrace()]
<<< local_clock_ns()
}
// Any monotonically increasing expression would do.
// With some arbitrary expression or constant instead,
// at worst we get the last 100ish results out of order.
}
probe end,error {
foreach ([e,t,p,b] in bt @max+) // iterate in increasing index order
printf("free #%d: %s[%d], pointer %p:\n%s\n\n",
@max(bt[e,t,p,b]), e, t, p, b)
}
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