kernel_optimize_test/tools/perf/util/syscalltbl.h
Arnaldo Carvalho de Melo 30a910d7d3 perf trace: Preallocate the syscall table
We'll continue reading its details from tracefs as we need it, but
preallocate the whole thing otherwise we may realloc and end up with
pointers to the previous buffer.

I.e. in an upcoming algorithm we'll look for syscalls that have function
signatures that are similar to a given syscall to see if we can reuse
its BPF augmenter, so we may be at syscall 42, having a 'struct syscall'
pointing to that slot in trace->syscalls.table[] and try to read the
slot for an yet unread syscall, which would realloc that table to read
the info for syscall 43, say, which would trigger a realoc of
trace->syscalls.table[], and then the pointer we had for syscall 42
would be pointing to the previous block of memory. b00m.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-m3cjzzifibs13imafhkk77a0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-07-29 18:34:42 -03:00

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C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PERF_SYSCALLTBL_H
#define __PERF_SYSCALLTBL_H
struct syscalltbl {
union {
int audit_machine;
struct {
int max_id;
int nr_entries;
void *entries;
} syscalls;
};
};
struct syscalltbl *syscalltbl__new(void);
void syscalltbl__delete(struct syscalltbl *tbl);
const char *syscalltbl__name(const struct syscalltbl *tbl, int id);
int syscalltbl__id(struct syscalltbl *tbl, const char *name);
int syscalltbl__strglobmatch_first(struct syscalltbl *tbl, const char *syscall_glob, int *idx);
int syscalltbl__strglobmatch_next(struct syscalltbl *tbl, const char *syscall_glob, int *idx);
#endif /* __PERF_SYSCALLTBL_H */